PIC18F6627-E/PT [MICROCHIP]
64/80-Pin, 1-Mbit, Enhanced Flash Microcontrollers with 10-Bit A/D and nanoWatt Technology; 八十〇分之六十四引脚， 1 - Mbit的，增强型闪存微控制器与10位A / D和纳瓦技术
| 型号： | PIC18F6627-E/PT |
| 厂家： | 
MICROCHIP |
| 描述： | 64/80-Pin, 1-Mbit, Enhanced Flash Microcontrollers with 10-Bit A/D and nanoWatt Technology |
| 文件： | 总446页 (文件大小：7372K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
PIC18F8722 Family
Data Sheet
64/80-Pin, 1-Mbit,
Enhanced Flash Microcontrollers
with 10-Bit A/D and nanoWatt Technology
© 2008 Microchip Technology Inc.
DS39646C
Note the following details of the code protection feature on Microchip devices:
•
Microchip products meet the specification contained in their particular Microchip Data Sheet.
•
Microchip believes that its family of products is one of the most secure families of its kind on the market today, when used in the
intended manner and under normal conditions.
•
There are dishonest and possibly illegal methods used to breach the code protection feature. All of these methods, to our
knowledge, require using the Microchip products in a manner outside the operating specifications contained in Microchip’s Data
Sheets. Most likely, the person doing so is engaged in theft of intellectual property.
•
•
Microchip is willing to work with the customer who is concerned about the integrity of their code.
Neither Microchip nor any other semiconductor manufacturer can guarantee the security of their code. Code protection does not
mean that we are guaranteeing the product as “unbreakable.”
Code protection is constantly evolving. We at Microchip are committed to continuously improving the code protection features of our
products. Attempts to break Microchip’s code protection feature may be a violation of the Digital Millennium Copyright Act. If such acts
allow unauthorized access to your software or other copyrighted work, you may have a right to sue for relief under that Act.
Information contained in this publication regarding device
applications and the like is provided only for your convenience
and may be superseded by updates. It is your responsibility to
ensure that your application meets with your specifications.
MICROCHIP MAKES NO REPRESENTATIONS OR
WARRANTIES OF ANY KIND WHETHER EXPRESS OR
IMPLIED, WRITTEN OR ORAL, STATUTORY OR
OTHERWISE, RELATED TO THE INFORMATION,
INCLUDING BUT NOT LIMITED TO ITS CONDITION,
QUALITY, PERFORMANCE, MERCHANTABILITY OR
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conveyed, implicitly or otherwise, under any Microchip
intellectual property rights.
Trademarks
The Microchip name and logo, the Microchip logo, Accuron,
dsPIC, KEELOQ, KEELOQ logo, MPLAB, PIC, PICmicro,
PICSTART, rfPIC, SmartShunt and UNI/O are registered
trademarks of Microchip Technology Incorporated in the
U.S.A. and other countries.
FilterLab, Linear Active Thermistor, MXDEV, MXLAB,
SEEVAL, SmartSensor and The Embedded Control Solutions
Company are registered trademarks of Microchip Technology
Incorporated in the U.S.A.
Analog-for-the-Digital Age, Application Maestro, CodeGuard,
dsPICDEM, dsPICDEM.net, dsPICworks, dsSPEAK, ECAN,
ECONOMONITOR, FanSense, In-Circuit Serial
Programming, ICSP, ICEPIC, Mindi, MiWi, MPASM, MPLAB
Certified logo, MPLIB, MPLINK, mTouch, PICkit, PICDEM,
32
PICDEM.net, PICtail, PIC logo, PowerCal, PowerInfo,
PowerMate, PowerTool, REAL ICE, rfLAB, Select Mode, Total
Endurance, WiperLock and ZENA are trademarks of
Microchip Technology Incorporated in the U.S.A. and other
countries.
SQTP is a service mark of Microchip Technology Incorporated
in the U.S.A.
All other trademarks mentioned herein are property of their
respective companies.
© 2008, Microchip Technology Incorporated, Printed in the
U.S.A., All Rights Reserved.
Printed on recycled paper.
Microchip received ISO/TS-16949:2002 certification for its worldwide
headquarters, design and wafer fabrication facilities in Chandler and
Tempe, Arizona; Gresham, Oregon and design centers in California
and India. The Company’s quality system processes and procedures
are for its PIC® MCUs and dsPIC® DSCs, KEELOQ® code hopping
devices, Serial EEPROMs, microperipherals, nonvolatile memory and
analog products. In addition, Microchip’s quality system for the design
and manufacture of development systems is ISO 9001:2000 certified.
DS39646C-page ii
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
64/80-Pin, 1-Mbit, Enhanced Flash Microcontrollers with
10-Bit A/D and nanoWatt Technology
Power Management Features:
Peripheral Highlights (Continued):
• Run: CPU On, Peripherals On
• Idle: CPU Off, Peripherals On
• Sleep: CPU Off, Peripherals Off
• Ultra Low 50 nA Input Leakage
• Run mode Currents Down to 25 μA Typical
• Idle mode Currents Down to 6.8 μA Typical
• Sleep mode Current Down to 120 nA Typical
• Timer1 Oscillator: 900 nA, 32 kHz, 2V
• Watchdog Timer: 1.6 μA, 2V Typical
• Two-Speed Oscillator Start-up
• Up to 2 Capture/Compare/PWM (CCP) modules,
one with Auto-Shutdown (28-pin devices)
• Master Synchronous Serial Port (MSSP) module
Supporting 3-Wire SPI (all 4 modes) and I2C™
Master and Slave modes
• Enhanced Addressable USART module:
- Supports RS-485, RS-232 and LIN/J2602
- RS-232 operation using internal oscillator
block (no external crystal required)
• 10-Bit, up to 13-Channel Analog-to-Digital (A/D)
Converter module:
Flexible Oscillator Structure:
- Conversion available during Sleep
• Dual Analog Comparators with Input Multiplexing
• Programmable 16-Level High/Low-Voltage
Detection (HLVD) module
• Four Crystal modes, up to 40 MHz
• 4x Phase Lock Loop (PLL) – Available for Crystal
and Internal Oscillators
• Internal Oscillator Block:
Special Microcontroller Features:
- Fast wake from Sleep and Idle, 1 μs typical
- Provides a complete range of clock speeds
from 31 kHz to 32 MHz when used with PLL
- User-tunable to compensate for frequency drift
• Secondary oscillator using Timer1 @ 32 kHz
• Fail-Safe Clock Monitor:
• C Compiler Optimized Architecture
• 100,000 Erase/Write Cycle Enhanced Flash
Program Memory Typical
• 1,000,000 Erase/Write Cycle Data EEPROM
Memory Typical
• Flash/Data EEPROM Retention: 100 Years Typical
• Self-Programmable under Software Control
• Priority Levels for Interrupts
• 8 x 8 Single-Cycle Hardware Multiplier
• Extended Watchdog Timer (WDT):
- Allows for safe shutdown if peripheral clock stops
Peripheral Highlights:
• High-Current Sink/Source 25 mA/25 mA
• Three Programmable External Interrupts
• Four Input Change Interrupts
- Programmable period from 4 ms to 131s
• Single-Supply 5V In-Circuit Serial Programming™
(ICSP™) via Two Pins
• Enhanced Capture/Compare/PWM (ECCP)
module (40/44-pin devices only):
• In-Circuit Debug (ICD) via Two Pins
• Wide Operating Voltage Range: 2.0V to 5.5V
• Programmable Brown-out Reset (BOR) with
Software Enable Option
- One, two or four PWM outputs
- Programmable dead time
- Auto-shutdown and auto-restart
Program Memory
Data Memory
MSSP
10-Bit CCP/
Device
I/O
A/D ECCP
(ch) (PWM)
Flash # Single-Word SRAM EEPROM
(bytes) Instructions (bytes) (bytes)
Master
I C™
SPI
2
PIC18F6527 48K
PIC18F6622 64K
PIC18F6627 96K
PIC18F6722 128K
PIC18F8527 48K
PIC18F8622 64K
PIC18F8627 96K
PIC18F8722 128K
24576
32768
49152
65536
24576
32768
49152
65536
3936
3936
3936
3936
3936
3936
3936
3936
1024
1024
1024
1024
1024
1024
1024
1024
54
54
54
54
70
70
70
70
12
12
12
12
16
16
16
16
2/3
2/3
2/3
2/3
2/3
2/3
2/3
2/3
2
2
2
2
2
2
2
2
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2/3
2/3
2/3
2/3
2/3
2/3
2/3
2/3
N
N
N
N
Y
Y
Y
Y
© 2008 Microchip Technology Inc.
DS39646C-page 1
PIC18F8722 FAMILY
Pin Diagrams
64-Pin TQFP
64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49
RB0/INT0
RE1/WR/P2C
RE0/RD/P2D
RG0/ECCP3/P3A
RG1/TX2/CK2
RG2/RX2/DT2
RG3/CCP4/P3D
RG5/MCLR/VPP
RG4/CCP5/P1D
VSS
1
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
RB1/INT1
2
RB2/INT2
3
RB3/INT3
4
RB4/KBI0
5
RB5/KBI1/PGM
RB6/KBI2/PGC
VSS
6
7
PIC18F6527
PIC18F6622
PIC18F6627
PIC18F6722
8
OSC2/CLKO/RA6
OSC1/CLKI/RA7
VDD
9
VDD
10
11
12
13
14
15
16
RF7/SS1
RF6/AN11
RB7/KBI3/PGD
RC5/SDO1
RF5/AN10/CVREF
RF4/AN9
RC4/SDI1/SDA1
RC3/SCK1/SCL1
RC2/ECCP1/P1A
RF3/AN8
RF2/AN7/C1OUT
17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32
Note 1: The ECCP2/P2A pin placement is determined by the CCP2MX Configuration bit.
DS39646C-page 2
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
Pin Diagrams (Continued)
80-Pin TQFP
80 79 78 77 76 75 74 73 72 71 70 69 68 67 66 65 64 63 62 61
RH2/A18
RH3/A19
RJ2/WRL
60
1
2
RJ3/WRH
59
RB0/INT0
58
RE1/AD9/WR/P2C
RE0/AD8/RD/P2D
RG0/ECCP3/P3A
RG1/TX2/CK2
RG2/RX2/DT2
RG3/CCP4/P3D
RG5/MCLR/VPP
RG4/CCP5/P1D
VSS
3
RB1/INT1
57
4
RB2/INT2
56
55
54
53
52
51
50
49
48
47
46
45
44
43
42
41
5
RB3/INT3/ECCP2(1)/P2A(1)
6
RB4/KBI0
7
RB5/KBI1/PGM
RB6/KBI2/PGC
VSS
8
9
PIC18F8527
PIC18F8622
PIC18F8627
PIC18F8722
10
11
12
13
14
15
16
17
18
19
20
OSC2/CLKO/RA6
OSC1/CLKI/RA7
VDD
VDD
RF7/SS1
RB7/KBI3/PGD
RC5/SDO1
RF6/AN11
RF5/AN10/CVREF
RF4/AN9
RC4/SDI1/SDA1
RC3/SCK1/SCL1
RC2/ECCP1/P1A
RJ7/UB
RF3/AN8
RF2/AN7/C1OUT
RH7/AN15/P1B(2)
RH6/AN14/P1C(2)
RJ6/LB
40
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39
Note 1: The ECCP2/P2A pin placement is determined by the CCP2MX Configuration bit and Processor mode settings.
2: P1B, P1C, P3B and P3C pin placement is determined by the ECCPMX Configuration bit.
© 2008 Microchip Technology Inc.
DS39646C-page 3
PIC18F8722 FAMILY
Table of Contents
1.0 Device Overview .......................................................................................................................................................................... 7
2.0 Oscillator Configurations ............................................................................................................................................................ 31
3.0 Power-Managed Modes ............................................................................................................................................................. 41
4.0 Reset.......................................................................................................................................................................................... 49
5.0 Memory Organization................................................................................................................................................................. 63
6.0 Flash Program Memory.............................................................................................................................................................. 87
7.0 External Memory Bus................................................................................................................................................................. 97
8.0 Data EEPROM Memory ........................................................................................................................................................... 111
9.0 8 x 8 Hardware Multiplier.......................................................................................................................................................... 117
10.0 Interrupts .................................................................................................................................................................................. 119
11.0 I/O Ports ................................................................................................................................................................................... 135
12.0 Timer0 Module ......................................................................................................................................................................... 161
13.0 Timer1 Module ......................................................................................................................................................................... 165
14.0 Timer2 Module ......................................................................................................................................................................... 171
15.0 Timer3 Module ......................................................................................................................................................................... 173
16.0 Timer4 Module ......................................................................................................................................................................... 177
17.0 Capture/Compare/PWM (CCP) Modules ................................................................................................................................. 179
18.0 Enhanced Capture/Compare/PWM (ECCP) Module................................................................................................................ 187
19.0 Master Synchronous Serial Port (MSSP) Module .................................................................................................................... 205
20.0 Enhanced Universal Synchronous Receiver Transmitter (EUSART)....................................................................................... 247
21.0 10-Bit Analog-to-Digital Converter (A/D) Module ..................................................................................................................... 271
22.0 Comparator Module.................................................................................................................................................................. 281
23.0 Comparator Voltage Reference Module................................................................................................................................... 287
24.0 High/Low-Voltage Detect (HLVD)............................................................................................................................................. 291
25.0 Special Features of the CPU.................................................................................................................................................... 297
26.0 Instruction Set Summary.......................................................................................................................................................... 321
27.0 Development Support............................................................................................................................................................... 371
28.0 Electrical Characteristics .......................................................................................................................................................... 375
29.0 Packaging Information.............................................................................................................................................................. 419
Appendix A: Revision History............................................................................................................................................................. 425
Appendix B: Device Differences......................................................................................................................................................... 425
Appendix C: Conversion Considerations ........................................................................................................................................... 426
Appendix D: Migration From Baseline to Enhanced Devices............................................................................................................. 426
Appendix E: Migration From Mid-Range to Enhanced Devices......................................................................................................... 427
Appendix F: Migration From High-End to Enhanced Devices............................................................................................................ 427
Index .................................................................................................................................................................................................. 429
The Microchip Web Site..................................................................................................................................................................... 441
Customer Change Notification Service .............................................................................................................................................. 441
Customer Support.............................................................................................................................................................................. 441
Reader Response .............................................................................................................................................................................. 442
PIC18F8722 Family Product Identification System............................................................................................................................ 443
DS39646C-page 4
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
TO OUR VALUED CUSTOMERS
It is our intention to provide our valued customers with the best documentation possible to ensure successful use of your Microchip
products. To this end, we will continue to improve our publications to better suit your needs. Our publications will be refined and
enhanced as new volumes and updates are introduced.
If you have any questions or comments regarding this publication, please contact the Marketing Communications Department via
E-mail at docerrors@.microchip.com or fax the Reader Response Form in the back of this data sheet to (480) 792-4150. We
welcome your feedback.
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The last character of the literature number is the version number, (e.g., DS30000A is version A of document DS30000).
Errata
An errata sheet, describing minor operational differences from the data sheet and recommended workarounds, may exist for current
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To determine if an errata sheet exists for a particular device, please check with one of the following:
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© 2008 Microchip Technology Inc.
DS39646C-page 5
PIC18F8722 FAMILY
NOTES:
DS39646C-page 6
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
1.1.2
EXPANDED MEMORY
1.0
DEVICE OVERVIEW
The PIC18F8722 family provides ample room for
application code and includes members with 48, 64,
96 or 128 Kbytes of code space.
This document contains device specific information for
the following devices:
• PIC18F6527
• PIC18F6622
• PIC18F6627
• PIC18F6722
• PIC18F8527
• PIC18F8622
• PIC18F8627
• PIC18F8722
• PIC18LF6527
• PIC18LF6622
• PIC18LF6627
• PIC18LF6722
• PIC18LF8527
• PIC18LF8622
• PIC18LF8627
• PIC18LF8722
• Data RAM and Data EEPROM: The PIC18F8722
family also provides plenty of room for application
data. The devices have 3936 bytes of data RAM,
as well as 1024 bytes of data EEPROM, for long
term retention of nonvolatile data.
• Memory Endurance: The Enhanced Flash cells
for both program memory and data EEPROM are
rated to last for many thousands of erase/write
cycles, up to 100,000 for program memory and
1,000,000 for EEPROM. Data retention without
refresh is conservatively estimated to be greater
than 40 years.
This family offers the advantages of all PIC18 micro-
controllers – namely, high computational performance at
an economical price – with the addition of high-
endurance, Enhanced Flash program memory. On top of
these features, the PIC18F8722 family introduces
design enhancements that make these microcontrollers
a logical choice for many high-performance, power
sensitive applications.
1.1.3
MULTIPLE OSCILLATOR OPTIONS
AND FEATURES
All of the devices in the PIC18F8722 family offer ten
different oscillator options, allowing users a wide range
of choices in developing application hardware. These
include:
1.1
New Core Features
• Four Crystal modes, using crystals or ceramic
resonators
• Two External Clock modes, offering the option of
using two pins (oscillator input and a divide-by-4
clock output) or one pin (oscillator input, with the
second pin reassigned as general I/O)
1.1.1
nanoWatt TECHNOLOGY
All of the devices in the PIC18F8722 family incorporate
a range of features that can significantly reduce power
consumption during operation. Key items include:
• Alternate Run Modes: By clocking the controller
from the Timer1 source or the internal oscillator
block, power consumption during code execution
can be significantly reduced.
• Multiple Idle Modes: The controller can also run
with its CPU core disabled but the peripherals still
active. In these states, power consumption can be
reduced even further.
• On-the-fly Mode Switching: The power-
managed modes are invoked by user code during
operation, allowing the user to incorporate power-
saving ideas into their application’s software
design.
• Low Consumption in Key Modules: The
power requirements for both Timer1 and the
Watchdog Timer are minimized. See
Section 28.0 “Electrical Characteristics”
for values.
• Two External RC Oscillator modes with the same
pin options as the External Clock modes
• An internal oscillator block which provides an
8 MHz clock and an INTRC source (approxi-
mately 31 kHz), as well as a range of 6 user
selectable clock frequencies, between 125 kHz to
4 MHz, for a total of 8 clock frequencies. This
option frees the two oscillator pins for use as
additional general purpose I/O.
• A Phase Lock Loop (PLL) frequency multiplier,
available to both the high-speed crystal and inter-
nal oscillator modes, which allows clock speeds of
up to 40 MHz. Used with the internal oscillator, the
PLL gives users a complete selection of clock
speeds, from 31 kHz to 32 MHz – all without using
an external crystal or clock circuit.
© 2008 Microchip Technology Inc.
DS39646C-page 7
PIC18F8722 FAMILY
Besides its availability as a clock source, the internal
oscillator block provides a stable reference source that
gives the family additional features for robust operation:
1.2
Other Special Features
• Communications: The PIC18F8722 family
incorporates a range of serial communication
peripherals, including 2 independent Enhanced
USARTs and 2 Master SSP modules capable of
both SPI and I2C (Master and Slave) modes of
operation. Also, one of the general purpose I/O
ports can be reconfigured as an 8-bit Parallel
Slave Port for direct processor-to-processor
communications.
• CCP Modules: All devices in the family
incorporate two Capture/Compare/PWM (CCP)
modules and three Enhanced CCP (ECCP)
modules to maximize flexibility in control
applications. Up to four different time bases may
be used to perform several different operations at
once. Each of the three ECCP modules offer up to
four PWM outputs, allowing for a total of
12 PWMs. The ECCPs also offer many beneficial
features, including polarity selection,
• Fail-Safe Clock Monitor: This option constantly
monitors the main clock source against a reference
signal provided by the internal oscillator. If a clock
failure occurs, the controller is switched to the
internal oscillator block, allowing for continued
low-speed operation or a safe application shutdown.
• Two-Speed Start-up: This option allows the
internal oscillator to serve as the clock source
from Power-on Reset, or wake-up from Sleep
mode, until the primary clock source is available.
1.1.4
EXTERNAL MEMORY INTERFACE
In the unlikely event that 128 Kbytes of program
memory is inadequate for an application, the
PIC18F8527/8622/8627/8722 members of the family
also implement an external memory interface. This
allows the controller’s internal program counter to
address
a memory space of up to 2 Mbytes,
Programmable Dead-Time, Auto-Shutdown and
Restart and Half-Bridge and Full-Bridge
Output modes.
permitting a level of data access that few 8-bit devices
can claim.
• Self-Programmability: These devices can write
to their own program memory spaces under
internal software control. By using a bootloader
routine located in the protected boot block at the
top of program memory, it becomes possible to
create an application that can update itself in the
field.
• Extended Instruction Set: The PIC18F8722
family introduces an optional extension to the
PIC18 instruction set, which adds 8 new instruc-
tions and an Indexed Addressing mode. This
extension, enabled as a device configuration
option, has been specifically designed to optimize
re-entrant application code originally developed in
high-level languages, such as C.
• 10-bit A/D Converter: This module incorporates
programmable acquisition time, allowing for a
channel to be selected and a conversion to be
initiated without waiting for a sampling period and
thus, reduce code overhead.
• Extended Watchdog Timer (WDT): This
enhanced version incorporates a 16-bit prescaler,
allowing an extended time-out range that is stable
across operating voltage and temperature. See
Section 28.0 “Electrical Characteristics” for
time-out periods.
With the addition of new operating modes, the external
memory interface offers many new options, including:
• Operating the microcontroller entirely from
external memory
• Using combinations of on-chip and external
memory, up to the 2-Mbyte limit
• Using external Flash memory for reprogrammable
application code or large data tables
• Using external RAM devices for storing large
amounts of variable data
1.1.5
EASY MIGRATION
Regardless of the memory size, all devices share the
same rich set of peripherals, allowing for a smooth
migration path as applications grow and evolve.
The consistent pinout scheme used throughout the
entire family also aids in migrating to the next larger
device. This is true when moving between the 64-pin
members, between the 80-pin members, or even
jumping from 64-pin to 80-pin devices.
DS39646C-page 8
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
All other features for devices in this family are identical.
These are summarized in Table 1-2 and Table 1-2.
1.3
Details on Individual Family
Members
The pinouts for all devices are listed in Table 1-3 and
Table 1-4.
Devices in the PIC18F8722 family are available in
64-pin and 80-pin packages. Block diagrams for the
two groups are shown in Figure 1-1 and Figure 1-2.
Like all Microchip PIC18 devices, members of the
PIC18F8722 family are available as both standard and
low-voltage devices. Standard devices with Enhanced
Flash memory, designated with an “F” in the part
number (such as PIC18F6627), accommodate an
operating VDD range of 4.2V to 5.5V. Low-voltage
parts, designated by “LF” (such as PIC18LF6627),
function over an extended VDD range of 2.0V to 5.5V.
The devices are differentiated from each other in five
ways:
1. Flash program memory (48 Kbytes for
PIC18F6527/8527 devices, 64 Kbytes for
PIC18F6622/8622 devices, 96 Kbytes for
PIC18F6627/8627 devices and 128 Kbytes for
PIC18F6722/8722).
2. A/D channels (12 for 64-pin devices, 16 for
80-pin devices).
3. I/O ports (7 bidirectional ports on 64-pin devices,
9 bidirectional ports on 80-pin devices).
4. External Memory Bus, configurable for 8 and
16-bit operation, is available on PIC18F8527/
8622/8627/8722 devices.
TABLE 1-1:
DEVICE FEATURES (PIC18F6527/6622/6627/6722)
Features
PIC18F6527
PIC18F6622
PIC18F6627
PIC18F6722
Operating Frequency
Program Memory (Bytes)
Program Memory (Instructions)
Data Memory (Bytes)
Data EEPROM Memory (Bytes)
Interrupt Sources
DC – 40 MHz
48K
DC – 40 MHz
64K
DC – 40 MHz
96K
DC – 40 MHz
128K
24576
3936
32768
3936
49152
3936
65536
3936
1024
1024
1024
1024
28
28
28
28
I/O Ports
Ports A, B, C, D, E, F, G Ports A, B, C, D, E, F, G Ports A, B, C, D, E, F, G Ports A, B, C, D, E, F, G
Timers
5
2
5
2
5
2
5
2
Capture/Compare/PWM
Modules
Enhanced Capture/Compare/
PWM Modules
3
3
3
3
Enhanced USART
2
2
2
2
Serial Communications
MSSP,
MSSP,
MSSP,
MSSP,
Enhanced USART
Enhanced USART
Enhanced USART
Enhanced USART
Parallel Communications (PSP)
10-bit Analog-to-Digital Module
Resets (and Delays)
Yes
Yes
Yes
Yes
12 Input Channels
12 Input Channels
12 Input Channels
12 Input Channels
POR, BOR,
POR, BOR,
POR, BOR,
POR, BOR,
RESETInstruction,
Stack Full, Stack
RESETInstruction,
Stack Full, Stack
RESETInstruction,
Stack Full, Stack
RESETInstruction,
Stack Full, Stack
Underflow (PWRT, OST), Underflow (PWRT, OST), Underflow (PWRT, OST), Underflow (PWRT, OST),
MCLR (optional), WDT MCLR (optional), WDT MCLR (optional), WDT MCLR (optional), WDT
Programmable
Yes
Yes
Yes
Yes
High/Low-Voltage Detect
Programmable Brown-out
Reset
Yes
Yes
Yes
Yes
Instruction Set
75 Instructions;
75 Instructions;
75 Instructions;
75 Instructions;
83 with Extended
83 with Extended
83 with Extended
83 with Extended
Instruction Set enabled Instruction Set enabled Instruction Set enabled Instruction Set enabled
Packages
64-pin TQFP
64-pin TQFP
64-pin TQFP
64-pin TQFP
© 2008 Microchip Technology Inc.
DS39646C-page 9
PIC18F8722 FAMILY
TABLE 1-2:
DEVICE FEATURES (PIC18F8527/8622/8627/8722)
Features
PIC18F8527
PIC18F8622
PIC18F8627
PIC18F8722
Operating Frequency
Program Memory (Bytes)
Program Memory (Instructions)
Data Memory (Bytes)
Data EEPROM Memory (Bytes)
Interrupt Sources
DC – 40 MHz
48K
DC – 40 MHz
64K
DC – 40 MHz
96K
DC – 40 MHz
128K
24576
3936
32768
3936
49152
3936
65536
3936
1024
1024
1024
1024
29
29
29
29
I/O Ports
Ports A, B, C, D, E,
F, G, H, J
Ports A, B, C, D, E,
F, G, H, J
Ports A, B, C, D, E,
F, G, H, J
Ports A, B, C, D, E,
F, G, H, J
Timers
5
2
5
2
5
2
5
2
Capture/Compare/PWM
Modules
Enhanced Capture/Compare/
PWM Modules
3
2
3
2
3
2
3
2
Enhanced USART
Serial Communications
MSSP,
MSSP,
MSSP,
MSSP,
Enhanced USART
Enhanced USART
Enhanced USART
Enhanced USART
Parallel Communications
(PSP)
Yes
Yes
Yes
Yes
10-bit Analog-to-Digital Module
Resets (and Delays)
16 Input Channels
16 Input Channels
16 Input Channels
16 Input Channels
POR, BOR,
RESETInstruction,
Stack Full, Stack
POR, BOR,
RESETInstruction,
Stack Full, Stack
POR, BOR,
RESETInstruction,
Stack Full, Stack
POR, BOR,
RESETInstruction,
Stack Full, Stack
Underflow (PWRT, OST), Underflow (PWRT, OST), Underflow (PWRT, OST), Underflow (PWRT, OST),
MCLR (optional), WDT MCLR (optional), WDT MCLR (optional), WDT MCLR (optional), WDT
Programmable
Yes
Yes
Yes
Yes
High/Low-Voltage Detect
Programmable Brown-out
Reset
Yes
Yes
Yes
Yes
Instruction Set
75 Instructions;
75 Instructions;
75 Instructions;
75 Instructions;
83 with Extended
83 with Extended
83 with Extended
83 with Extended
Instruction Set enabled Instruction Set enabled Instruction Set enabled Instruction Set enabled
Packages
80-pin TQFP 80-pin TQFP 80-pin TQFP 80-pin TQFP
DS39646C-page 10
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
FIGURE 1-1:
PIC18F6527/6622/6627/6722 (64-PIN) BLOCK DIAGRAM
Data Bus<8>
Table Pointer<21>
inc/dec logic
21
PORTA
Data Latch
8
RA0:RA7(1)
8
Data Memory
(3.9 Kbytes)
PCLATU PCLATH
Address Latch
20
PCU PCH PCL
Program Counter
12
PORTB
Data Address<12>
RB0:RB7(1)
31-Level Stack
STKPTR
4
BSR
12
FSR0
FSR1
FSR2
4
Address Latch
Access
Bank
Program Memory
(48/64/96/128
Kbytes)
12
PORTC
Data Latch
RC0:RC7(1)
inc/dec
logic
8
Table Latch
Address
Decode
ROM Latch
IR
Instruction Bus <16>
PORTD
RD0:RD7(1)
8
State Machine
Control Signals
Instruction
Decode and
Control
PRODH PRODL
8 x 8 Multiply
PORTE
RE0:RE7(1)
3
8
OSC1(3)
Internal
Oscillator
Block
Power-up
Timer
BITOP
8
W
8
8
OSC2(3)
T1OSI
Oscillator
Start-up Timer
INTRC
Oscillator
PORTF
8
8
Power-on
Reset
RF0:RF7(1)
8 MHz
Oscillator
ALU<8>
8
Watchdog
Timer
T1OSO
Precision
Band Gap
Reference
Brown-out
Reset
MCLR(2)
VDD, VSS
Single-Supply
Programming
Fail-Safe
Clock Monitor
PORTG
In-Circuit
Debugger
RG0:RG5(1)
ADC
10-bit
BOR
Timer0
ECCP3
Timer1
Timer2
CCP5
Timer3
Comparators
Timer4
HLVD
ECCP1
ECCP2
CCP4
MSSP1
MSSP2
EUSART1
EUSART2
Note 1: See Table 1-3 for I/O port pin descriptions.
2: RG5 is only available when MCLR functionality is disabled.
3: OSC1/CLKI and OSC2/CLKO are only available in select oscillator modes and when these pins are not being used as
digital I/O. Refer to Section 2.0 “Oscillator Configurations” for additional information.
© 2008 Microchip Technology Inc.
DS39646C-page 11
PIC18F8722 FAMILY
FIGURE 1-2:
PIC18F8527/8622/8627/8722 (80-PIN) BLOCK DIAGRAM
Data Bus<8>
PORTA
Data Latch
Table Pointer<21>
inc/dec logic
8
RA0:RA7(1)
8
Data Memory
(3.9 Kbytes)
PCLATH
PCLATU
Address Latch
21
20
PORTB
PCU PCH PCL
Program Counter
RB0:RB7(1)
12
Data Address<12>
31-Level Stack
STKPTR
4
BSR
12
FSR0
FSR1
FSR2
4
Address Latch
PORTC
Access
Bank
Program Memory
(48/64/96/128
Kbytes)
RC0:RC7(1)
12
Data Latch
inc/dec
logic
8
PORTD
Table Latch
ROM Latch
RD0:RD7(1)
Address
Decode
Instruction Bus <16>
PORTE
IR
RE0:RE7(1)
AD15:AD0, A19:A16
(Multiplexed with PORTD,
PORTE and PORTH)
8
PORTF
PRODH PRODL
8 x 8 Multiply
Instruction
Decode &
Control
State Machine
Control Signals
RF0:RF7(1)
3
8
W
BITOP
8
PORTG
8
8
RG0:RG5(1)
OSC1(3)
OSC2(3)
Internal
Oscillator
Block
Power-up
Timer
8
8
Oscillator
Start-up Timer
ALU<8>
8
INTRC
Oscillator
PORTH
Power-on
Reset
T1OSI
RH0:RH7(1)
8 MHz
Oscillator
Watchdog
Timer
T1OSO
Precision
Band Gap
Reference
Brown-out
Reset
Fail-Safe
MCLR(2)
VDD, VSS
Single-Supply
Programming
PORTJ
RJ0:RJ7(1)
In-Circuit
Debugger
Clock Monitor
ADC
10-bit
BOR
Timer0
ECCP3
Timer1
Timer2
CCP5
Timer3
Comparators
Timer4
HLVD
CCP4
MSSP1
MSSP2
ECCP1
ECCP2
EUSART1
EUSART2
Note 1: See Table 1-4 for I/O port pin descriptions.
2: RG5 is only available when MCLR functionality is disabled.
3: OSC1/CLKI and OSC2/CLKO are only available in select oscillator modes and when these pins are not being used as
digital I/O. Refer to Section 2.0 “Oscillator Configurations” for additional information.
DS39646C-page 12
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
TABLE 1-3:
PIC18F6527/6622/6627/6722 PINOUT I/O DESCRIPTIONS
Pin Number
Pin
Type
Buffer
Type
Pin Name
Description
TQFP
RG5/MCLR/VPP
RG5
7
Master Clear (input) or programming voltage (input).
Digital input.
I
I
ST
ST
MCLR
Master Clear (Reset) input. This pin is an active-low
Reset to the device.
VPP
P
I
Programming voltage input.
OSC1/CLKI/RA7
OSC1
39
Oscillator crystal or external clock input.
Oscillator crystal input or external clock source input.
ST buffer when configured in RC mode, CMOS
otherwise.
ST
CMOS
TTL
CLKI
I
External clock source input. Always associated
with pin function OSC1. (See related OSC1/CLKI,
OSC2/CLKO pins.)
RA7
I/O
General purpose I/O pin.
OSC2/CLKO/RA6
OSC2
40
Oscillator crystal or clock output.
O
O
—
—
Oscillator crystal output. Connects to crystal or
resonator in Crystal Oscillator mode.
In RC mode, OSC2 pin outputs CLKO, which has
1/4 the frequency of OSC1 and denotes the
instruction cycle rate.
CLKO
RA6
I/O
TTL
General purpose I/O pin.
Legend: TTL = TTL compatible input CMOS
= CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels Analog= Analog input
I
P
= Input
= Power
O
= Output
I2C™
= I2C/SMBus input buffer
Note 1: Default assignment for ECCP2 when Configuration bit, CCP2MX, is set.
2: Alternate assignment for ECCP2 when Configuration bit, CCP2MX, is cleared.
© 2008 Microchip Technology Inc.
DS39646C-page 13
PIC18F8722 FAMILY
TABLE 1-3:
Pin Name
PIC18F6527/6622/6627/6722 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Number
TQFP
Pin
Type
Buffer
Type
Description
PORTA is a bidirectional I/O port.
RA0/AN0
RA0
24
23
22
I/O
I
TTL
Analog
Digital I/O.
Analog input 0.
AN0
RA1/AN1
RA1
I/O
I
TTL
Analog
Digital I/O.
Analog input 1.
AN1
RA2/AN2/VREF-
RA2
I/O
TTL
Digital I/O.
AN2
VREF-
I
I
Analog
Analog
Analog input 2.
A/D reference voltage (low) input.
RA3/AN3/VREF+
RA3
21
I/O
TTL
Digital I/O.
AN3
VREF+
I
I
Analog
Analog
Analog input 3.
A/D reference voltage (high) input.
RA4/T0CKI
RA4
28
27
I/O
I
ST
ST
Digital I/O.
Timer0 external clock input.
T0CKI
RA5/AN4/HLVDIN
RA5
I/O
TTL
Digital I/O.
AN4
HLVDIN
I
I
Analog
Analog
Analog input 4.
High/Low-Voltage Detect input.
RA6
RA7
See the OSC2/CLKO/RA6 pin.
See the OSC1/CLKI/RA7 pin.
Legend: TTL = TTL compatible input CMOS
= CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels Analog= Analog input
I
P
= Input
= Power
O
= Output
I2C™
= I2C/SMBus input buffer
Note 1: Default assignment for ECCP2 when Configuration bit, CCP2MX, is set.
2: Alternate assignment for ECCP2 when Configuration bit, CCP2MX, is cleared.
DS39646C-page 14
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
TABLE 1-3:
PIC18F6527/6622/6627/6722 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Number
TQFP
Pin
Type
Buffer
Type
Pin Name
Description
PORTB is a bidirectional I/O port. PORTB can be software
programmed for internal weak pull-ups on all inputs.
RB0/INT0/FLT0
RB0
48
I/O
I
I
TTL
ST
ST
Digital I/O.
External interrupt 0.
PWM Fault input for ECCPx.
INT0
FLT0
RB1/INT1
RB1
47
46
45
44
43
I/O
I
TTL
ST
Digital I/O.
External interrupt 1.
INT1
RB2/INT2
RB2
I/O
I
TTL
ST
Digital I/O.
External interrupt 2.
INT2
RB3/INT3
RB3
I/O
I
TTL
ST
Digital I/O.
External interrupt 3.
INT3
RB4/KBI0
RB4
I/O
I
TTL
TTL
Digital I/O.
Interrupt-on-change pin.
KBI0
RB5/KBI1/PGM
RB5
I/O
I
I/O
TTL
TTL
ST
Digital I/O.
Interrupt-on-change pin.
Low-Voltage ICSP™ Programming enable pin.
KBI1
PGM
RB6/KBI2/PGC
RB6
42
37
I/O
I
I/O
TTL
TTL
ST
Digital I/O.
Interrupt-on-change pin.
In-Circuit Debugger and ICSP programming clock pin.
KBI2
PGC
RB7/KBI3/PGD
RB7
I/O
I
I/O
TTL
TTL
ST
Digital I/O.
Interrupt-on-change pin.
In-Circuit Debugger and ICSP programming data pin.
KBI3
PGD
Legend: TTL = TTL compatible input CMOS
= CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels Analog= Analog input
I
P
= Input
= Power
O
= Output
I2C™
= I2C/SMBus input buffer
Note 1: Default assignment for ECCP2 when Configuration bit, CCP2MX, is set.
2: Alternate assignment for ECCP2 when Configuration bit, CCP2MX, is cleared.
© 2008 Microchip Technology Inc.
DS39646C-page 15
PIC18F8722 FAMILY
TABLE 1-3:
Pin Name
PIC18F6527/6622/6627/6722 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Number
TQFP
Pin
Type
Buffer
Type
Description
PORTC is a bidirectional I/O port.
RC0/T1OSO/T13CKI
RC0
30
29
I/O
O
I
ST
—
ST
Digital I/O.
Timer1 oscillator output.
Timer1/Timer3 external clock input.
T1OSO
T13CKI
RC1/T1OSI/ECCP2/P2A
RC1
I/O
I
I/O
ST
CMOS
ST
Digital I/O.
T1OSI
Timer1 oscillator input.
Enhanced Capture 2 input/Compare 2 output/
PWM 2 output.
ECCP2(1)
P2A(1)
O
—
ECCP2 PWM output A.
RC2/ECCP1/P1A
RC2
33
I/O
I/O
ST
ST
Digital I/O.
ECCP1
Enhanced Capture 1 input/Compare 1 output/
PWM 1 output.
P1A
O
—
ECCP1 PWM output A.
RC3/SCK1/SCL1
RC3
34
35
I/O
I/O
I/O
ST
ST
ST
Digital I/O.
SCK1
SCL1
Synchronous serial clock input/output for SPI mode.
Synchronous serial clock input/output for I2C™ mode.
RC4/SDI1/SDA1
RC4
I/O
I
I/O
ST
ST
ST
Digital I/O.
SDI1
SDA1
SPI data in.
I2C data I/O.
RC5/SDO1
RC5
36
31
I/O
O
ST
—
Digital I/O.
SPI data out.
SDO1
RC6/TX1/CK1
RC6
I/O
O
I/O
ST
—
ST
Digital I/O.
TX1
CK1
EUSART1 asynchronous transmit.
EUSART1 synchronous clock (see related RX1/DT1).
RC7/RX1/DT1
RC7
32
I/O
I
I/O
ST
ST
ST
Digital I/O.
RX1
DT1
EUSART1 asynchronous receive.
EUSART1 synchronous data (see related TX1/CK1).
Legend: TTL = TTL compatible input CMOS
= CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels Analog= Analog input
I
P
= Input
= Power
O
= Output
I2C™
= I2C/SMBus input buffer
Note 1: Default assignment for ECCP2 when Configuration bit, CCP2MX, is set.
2: Alternate assignment for ECCP2 when Configuration bit, CCP2MX, is cleared.
DS39646C-page 16
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
TABLE 1-3:
PIC18F6527/6622/6627/6722 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Number
TQFP
Pin
Type
Buffer
Type
Pin Name
Description
PORTD is a bidirectional I/O port.
RD0/PSP0
RD0
58
55
54
53
52
I/O
I/O
ST
TTL
Digital I/O.
Parallel Slave Port data.
PSP0
RD1/PSP1
RD1
I/O
I/O
ST
TTL
Digital I/O.
Parallel Slave Port data.
PSP1
RD2/PSP2
RD2
I/O
I/O
ST
TTL
Digital I/O.
Parallel Slave Port data.
PSP2
RD3/PSP3
RD3
I/O
I/O
ST
TTL
Digital I/O.
Parallel Slave Port data.
PSP3
RD4/PSP4/SDO2
RD4
I/O
I/O
O
ST
TTL
—
Digital I/O.
Parallel Slave Port data.
SPI data out.
PSP4
SDO2
RD5/PSP5/SDI2/SDA2
51
50
49
RD5
I/O
I/O
I
ST
TTL
ST
Digital I/O.
PSP5
SDI2
SDA2
Parallel Slave Port data.
SPI data in.
I/O I2C/SMB
I2C™ data I/O.
RD6/PSP6/SCK2/SCL2
RD6
I/O
I/O
I/O
ST
TTL
ST
Digital I/O.
Parallel Slave Port data.
PSP6
SCK2
SCL2
Synchronous serial clock input/output for SPI mode.
I/O I2C/SMB
Synchronous serial clock input/output for I2C mode.
RD7/PSP7/SS2
RD7
I/O
I/O
I
ST
TTL
TTL
Digital I/O.
Parallel Slave Port data.
SPI slave select input.
PSP7
SS2
Legend: TTL = TTL compatible input CMOS
= CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels Analog= Analog input
I
P
= Input
= Power
O
= Output
I2C™
= I2C/SMBus input buffer
Note 1: Default assignment for ECCP2 when Configuration bit, CCP2MX, is set.
2: Alternate assignment for ECCP2 when Configuration bit, CCP2MX, is cleared.
© 2008 Microchip Technology Inc.
DS39646C-page 17
PIC18F8722 FAMILY
TABLE 1-3:
Pin Name
PIC18F6527/6622/6627/6722 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Number
TQFP
Pin
Type
Buffer
Type
Description
PORTE is a bidirectional I/O port.
RE0/RD/P2D
RE0
2
1
I/O
I
O
ST
TTL
—
Digital I/O.
Read control for Parallel Slave Port.
ECCP2 PWM output D.
RD
P2D
RE1/WR/P2C
RE1
I/O
I
O
ST
TTL
—
Digital I/O.
Write control for Parallel Slave Port.
ECCP2 PWM output C.
WR
P2C
RE2/CS/P2B
RE2
64
I/O
I
O
ST
TTL
—
Digital I/O.
Chip select control for Parallel Slave Port.
ECCP2 PWM output B.
CS
P2B
RE3/P3C
RE3
63
62
61
60
59
I/O
O
ST
—
Digital I/O.
ECCP3 PWM output C.
P3C
RE4/P3B
RE4
I/O
O
ST
—
Digital I/O.
ECCP3 PWM output B.
P3B
RE5/P1C
RE5
I/O
O
ST
—
Digital I/O.
ECCP1 PWM output C.
P1C
RE6/P1B
RE6
I/O
O
ST
—
Digital I/O.
ECCP1 PWM output B.
P1B
RE7/ECCP2/P2A
RE7
I/O
I/O
ST
ST
Digital I/O.
ECCP2(2)
Enhanced Capture 2 input/Compare 2 output/
PWM 2 output.
ECCP2 PWM output A.
P2A(2)
O
—
Legend: TTL = TTL compatible input CMOS
= CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels Analog= Analog input
I
P
= Input
= Power
O
= Output
I2C™
= I2C/SMBus input buffer
Note 1: Default assignment for ECCP2 when Configuration bit, CCP2MX, is set.
2: Alternate assignment for ECCP2 when Configuration bit, CCP2MX, is cleared.
DS39646C-page 18
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
TABLE 1-3:
PIC18F6527/6622/6627/6722 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Number
TQFP
Pin
Type
Buffer
Type
Pin Name
Description
PORTF is a bidirectional I/O port.
RF0/AN5
RF0
18
17
I/O
I
ST
Analog
Digital I/O.
Analog input 5.
AN5
RF1/AN6/C2OUT
RF1
I/O
I
O
ST
Analog
—
Digital I/O.
Analog input 6.
Comparator 2 output.
AN6
C2OUT
RF2/AN7/C1OUT
RF2
16
I/O
I
O
ST
Analog
—
Digital I/O.
Analog input 7.
Comparator 1 output.
AN7
C1OUT
RF3/AN8
RF3
15
14
13
I/O
I
ST
Analog
Digital I/O.
Analog input 8.
AN8
RF4/AN9
RF4
I/O
I
ST
Analog
Digital I/O.
Analog input 9.
AN9
RF5/AN10/CVREF
RF5
I/O
I
O
ST
Analog
Analog
Digital I/O.
Analog input 10.
Comparator reference voltage output.
AN10
CVREF
RF6/AN11
RF6
12
11
I/O
I
ST
Analog
Digital I/O.
Analog input 11.
AN11
RF7/SS1
RF7
I/O
I
ST
TTL
Digital I/O.
SPI slave select input.
SS1
Legend: TTL = TTL compatible input CMOS
= CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels Analog= Analog input
I
P
= Input
= Power
O
= Output
I2C™
= I2C/SMBus input buffer
Note 1: Default assignment for ECCP2 when Configuration bit, CCP2MX, is set.
2: Alternate assignment for ECCP2 when Configuration bit, CCP2MX, is cleared.
© 2008 Microchip Technology Inc.
DS39646C-page 19
PIC18F8722 FAMILY
TABLE 1-3:
Pin Name
PIC18F6527/6622/6627/6722 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Number
TQFP
Pin
Type
Buffer
Type
Description
PORTG is a bidirectional I/O port.
RG0/ECCP3/P3A
RG0
3
I/O
I/O
ST
ST
Digital I/O.
ECCP3
Enhanced Capture 3 input/Compare 3 output/
PWM 3 output.
P3A
O
—
ECCP3 PWM output A.
RG1/TX2/CK2
RG1
4
5
6
8
I/O
O
I/O
ST
—
ST
Digital I/O.
TX2
CK2
EUSART2 asynchronous transmit.
EUSART2 synchronous clock (see related RX2/DT2).
RG2/RX2/DT2
RG2
I/O
I
I/O
ST
ST
ST
Digital I/O.
RX2
DT2
EUSART2 asynchronous receive.
EUSART2 synchronous data (see related TX2/CK2).
RG3/CCP4/P3D
RG3
I/O
I/O
O
ST
ST
—
Digital I/O.
CCP4
P3D
Capture 4 input/Compare 4 output/PWM 4 output.
ECCP3 PWM output D.
RG4/CCP5/P1D
RG4
I/O
I/O
O
ST
ST
—
Digital I/O.
CCP5
P1D
Capture 5 input/Compare 5 output/PWM 5 output.
ECCP1 PWM output D.
RG5
VSS
See RG5/MCLR/VPP pin.
9, 25, 41, 56
P
P
P
P
—
—
—
—
Ground reference for logic and I/O pins.
Positive supply for logic and I/O pins.
Ground reference for analog modules.
Positive supply for analog modules.
= CMOS compatible input or output
VDD
10, 26, 38, 57
AVSS
AVDD
20
19
Legend: TTL = TTL compatible input CMOS
ST = Schmitt Trigger input with CMOS levels Analog= Analog input
I
P
= Input
= Power
O
= Output
I2C™
= I2C/SMBus input buffer
Note 1: Default assignment for ECCP2 when Configuration bit, CCP2MX, is set.
2: Alternate assignment for ECCP2 when Configuration bit, CCP2MX, is cleared.
DS39646C-page 20
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
TABLE 1-4:
Pin Name
PIC18F8527/8622/8627/8722 PINOUT I/O DESCRIPTIONS
Pin Number
Pin
Buffer
Type
Description
Type
TQFP
RG5/MCLR/VPP
RG5
9
Master Clear (input) or programming voltage (input).
Digital input.
I
I
ST
ST
MCLR
Master Clear (Reset) input. This pin is an active-low
Reset to the device.
VPP
P
I
Programming voltage input.
OSC1/CLKI/RA7
OSC1
49
Oscillator crystal or external clock input.
Oscillator crystal input or external clock source input.
ST buffer when configured in RC mode, CMOS
otherwise.
ST
CMOS
TTL
CLKI
I
External clock source input. Always associated with
pin function OSC1. (See related OSC1/CLKI,
OSC2/CLKO pins.)
RA7
I/O
General purpose I/O pin.
OSC2/CLKO/RA6
OSC2
50
Oscillator crystal or clock output.
O
O
—
—
Oscillator crystal output. Connects to crystal or
resonator in Crystal Oscillator mode.
In RC mode, OSC2 pin outputs CLKO, which has 1/4 the
frequency of OSC1 and denotes the
instruction cycle rate.
CLKO
RA6
I/O
TTL
General purpose I/O pin.
Legend: TTL = TTL compatible input CMOS
= CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels Analog= Analog input
I
P
= Input
= Power
O
= Output
I2C™/SMB
= I2C/SMBus input buffer
Note 1: Alternate assignment for ECCP2 when Configuration bit, CCP2MX, is cleared (all operating modes except
Microcontroller mode).
2: Default assignment for ECCP2 in all operating modes (CCP2MX is set).
3: Alternate assignment for ECCP2 when CCP2MX is cleared (Microcontroller mode only).
4: Default assignment for P1B/P1C/P3B/P3C (ECCPMX is set).
5: Alternate assignment for P1B/P1C/P3B/P3C (ECCPMX is clear).
© 2008 Microchip Technology Inc.
DS39646C-page 21
PIC18F8722 FAMILY
TABLE 1-4:
Pin Name
PIC18F8527/8622/8627/8722 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Number
TQFP
Pin
Type
Buffer
Type
Description
PORTA is a bidirectional I/O port.
RA0/AN0
RA0
30
29
28
I/O
I
TTL
Analog
Digital I/O.
Analog input 0.
AN0
RA1/AN1
RA1
I/O
I
TTL
Analog
Digital I/O.
Analog input 1.
AN1
RA2/AN2/VREF-
RA2
I/O
TTL
Digital I/O.
AN2
VREF-
I
I
Analog
Analog
Analog input 2.
A/D reference voltage (low) input.
RA3/AN3/VREF+
RA3
27
I/O
TTL
Digital I/O.
AN3
VREF+
I
I
Analog
Analog
Analog input 3.
A/D reference voltage (high) input.
RA4/T0CKI
RA4
34
33
I/O
I
ST/OD
ST
Digital I/O. Open-drain when configured as output.
Timer0 external clock input.
T0CKI
RA5/AN4/HLVDIN
RA5
I/O
TTL
Digital I/O.
AN4
HLVDIN
I
I
Analog
Analog
Analog input 4.
High/Low-Voltage Detect input.
RA6
RA7
See the OSC2/CLKO/RA6 pin.
See the OSC1/CLKI/RA7 pin.
Legend: TTL = TTL compatible input CMOS
= CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels Analog= Analog input
I
P
= Input
= Power
O
= Output
I2C™/SMB
= I2C/SMBus input buffer
Note 1: Alternate assignment for ECCP2 when Configuration bit, CCP2MX, is cleared (all operating modes except
Microcontroller mode).
2: Default assignment for ECCP2 in all operating modes (CCP2MX is set).
3: Alternate assignment for ECCP2 when CCP2MX is cleared (Microcontroller mode only).
4: Default assignment for P1B/P1C/P3B/P3C (ECCPMX is set).
5: Alternate assignment for P1B/P1C/P3B/P3C (ECCPMX is clear).
DS39646C-page 22
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
TABLE 1-4:
Pin Name
PIC18F8527/8622/8627/8722 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Number
TQFP
Pin
Type
Buffer
Type
Description
PORTB is a bidirectional I/O port. PORTB can be software
programmed for internal weak pull-ups on all inputs.
RB0/INT0/FLT0
RB0
58
I/O
I
I
TTL
ST
ST
Digital I/O.
External interrupt 0.
PWM Fault input for ECCPx.
INT0
FLT0
RB1/INT1
RB1
57
56
55
I/O
I
TTL
ST
Digital I/O.
External interrupt 1.
INT1
RB2/INT2
RB2
I/O
I
TTL
ST
Digital I/O.
External interrupt 2.
INT2
RB3/INT3/ECCP2/P2A
RB3
I/O
I
O
TTL
ST
—
Digital I/O.
External interrupt 3.
Enhanced Capture 2 input/Compare 2 output/
PWM 2 output.
ECCP2 PWM output A.
INT3
ECCP2(1)
P2A(1)
O
—
RB4/KBI0
RB4
54
53
I/O
I
TTL
TTL
Digital I/O.
Interrupt-on-change pin.
KBI0
RB5/KBI1/PGM
RB5
I/O
I
I/O
TTL
TTL
ST
Digital I/O.
Interrupt-on-change pin.
Low-Voltage ICSP™ Programming enable pin.
KBI1
PGM
RB6/KBI2/PGC
RB6
52
47
I/O
I
I/O
TTL
TTL
ST
Digital I/O.
Interrupt-on-change pin.
In-Circuit Debugger and ICSP™ programming clock pin.
KBI2
PGC
RB7/KBI3/PGD
RB7
I/O
I
I/O
TTL
TTL
ST
Digital I/O.
Interrupt-on-change pin.
In-Circuit Debugger and ICSP programming data pin.
KBI3
PGD
Legend: TTL = TTL compatible input CMOS
= CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels Analog= Analog input
I
P
= Input
= Power
O
= Output
I2C™/SMB
= I2C/SMBus input buffer
Note 1: Alternate assignment for ECCP2 when Configuration bit, CCP2MX, is cleared (all operating modes except
Microcontroller mode).
2: Default assignment for ECCP2 in all operating modes (CCP2MX is set).
3: Alternate assignment for ECCP2 when CCP2MX is cleared (Microcontroller mode only).
4: Default assignment for P1B/P1C/P3B/P3C (ECCPMX is set).
5: Alternate assignment for P1B/P1C/P3B/P3C (ECCPMX is clear).
© 2008 Microchip Technology Inc.
DS39646C-page 23
PIC18F8722 FAMILY
TABLE 1-4:
Pin Name
PIC18F8527/8622/8627/8722 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Number
TQFP
Pin
Type
Buffer
Type
Description
PORTC is a bidirectional I/O port.
RC0/T1OSO/T13CKI
RC0
36
35
I/O
O
I
ST
—
ST
Digital I/O.
Timer1 oscillator output.
Timer1/Timer3 external clock input.
T1OSO
T13CKI
RC1/T1OSI/ECCP2/P2A
RC1
I/O
I
I/O
ST
CMOS
ST
Digital I/O.
T1OSI
Timer1 oscillator input.
Enhanced Capture 2 input/Compare 2 output/
PWM 2 output.
ECCP2(2)
P2A(2)
O
—
ECCP2 PWM output A.
RC2/ECCP1/P1A
RC2
43
I/O
I/O
ST
ST
Digital I/O.
ECCP1
Enhanced Capture 1 input/Compare 1 output/
PWM 1 output.
P1A
O
—
ECCP1 PWM output A.
RC3/SCK1/SCL1
RC3
44
45
I/O
I/O
I/O
ST
ST
ST
Digital I/O.
SCK1
SCL1
Synchronous serial clock input/output for SPI mode.
Synchronous serial clock input/output for I2C™ mode.
RC4/SDI1/SDA1
RC4
I/O
I
I/O
ST
ST
ST
Digital I/O.
SDI1
SDA1
SPI data in.
I2C data I/O.
RC5/SDO1
RC5
46
37
I/O
O
ST
—
Digital I/O.
SPI data out.
SDO1
RC6/TX1/CK1
RC6
I/O
O
I/O
ST
—
ST
Digital I/O.
TX1
CK1
EUSART1 asynchronous transmit.
EUSART1 synchronous clock (see related RX1/DT1).
RC7/RX1/DT1
RC7
38
I/O
I
I/O
ST
ST
ST
Digital I/O.
RX1
DT1
EUSART1 asynchronous receive.
EUSART1 synchronous data (see related TX1/CK1).
Legend: TTL = TTL compatible input CMOS
= CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels Analog= Analog input
I
P
= Input
= Power
O
= Output
I2C™/SMB
= I2C/SMBus input buffer
Note 1: Alternate assignment for ECCP2 when Configuration bit, CCP2MX, is cleared (all operating modes except
Microcontroller mode).
2: Default assignment for ECCP2 in all operating modes (CCP2MX is set).
3: Alternate assignment for ECCP2 when CCP2MX is cleared (Microcontroller mode only).
4: Default assignment for P1B/P1C/P3B/P3C (ECCPMX is set).
5: Alternate assignment for P1B/P1C/P3B/P3C (ECCPMX is clear).
DS39646C-page 24
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
TABLE 1-4:
Pin Name
PIC18F8527/8622/8627/8722 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Number
Pin
Buffer
Type
Description
Type
TQFP
PORTD is a bidirectional I/O port.
RD0/AD0/PSP0
RD0
72
69
68
67
66
I/O
I/O
I/O
ST
TTL
TTL
Digital I/O.
External memory address/data 0.
Parallel Slave Port data.
AD0
PSP0
RD1/AD1/PSP1
RD1
I/O
I/O
I/O
ST
TTL
TTL
Digital I/O.
External memory address/data 1.
Parallel Slave Port data.
AD1
PSP1
RD2/AD2/PSP2
RD2
I/O
I/O
I/O
ST
TTL
TTL
Digital I/O.
External memory address/data 2.
Parallel Slave Port data.
AD2
PSP2
RD3/AD3/PSP3
RD3
I/O
I/O
I/O
ST
TTL
TTL
Digital I/O.
External memory address/data 3.
Parallel Slave Port data.
AD3
PSP3
RD4/AD4/PSP4/SDO2
RD4
AD4
PSP4
SDO2
I/O
I/O
I/O
O
ST
TTL
TTL
—
Digital I/O.
External memory address/data 4.
Parallel Slave Port data.
SPI data out.
RD5/AD5/PSP5/
SDI2/SDA2
RD5
65
64
63
I/O
I/O
I/O
I
ST
TTL
TTL
ST
Digital I/O.
AD5
PSP5
SDI2
SDA2
External memory address/data 5.
Parallel Slave Port data.
SPI data in.
I/O I2C/SMB
I2C™ data I/O.
RD6/AD6/PSP6/
SCK2/SCL2
RD6
I/O
I/O
I/O
I/O
ST
TTL
TTL
ST
Digital I/O.
External memory address/data 6.
Parallel Slave Port data.
AD6
PSP6
SCK2
SCL2
Synchronous serial clock input/output for SPI mode.
I/O I2C/SMB
Synchronous serial clock input/output for I2C mode.
RD7/AD7/PSP7/SS2
RD7
AD7
PSP7
SS2
I/O
I/O
I/O
I
ST
Digital I/O.
TTL
TTL
TTL
External memory address/data 7.
Parallel Slave Port data.
SPI slave select input.
Legend: TTL = TTL compatible input CMOS
= CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels Analog= Analog input
I
P
= Input
= Power
O
= Output
I2C™/SMB
= I2C/SMBus input buffer
Note 1: Alternate assignment for ECCP2 when Configuration bit, CCP2MX, is cleared (all operating modes except
Microcontroller mode).
2: Default assignment for ECCP2 in all operating modes (CCP2MX is set).
3: Alternate assignment for ECCP2 when CCP2MX is cleared (Microcontroller mode only).
4: Default assignment for P1B/P1C/P3B/P3C (ECCPMX is set).
5: Alternate assignment for P1B/P1C/P3B/P3C (ECCPMX is clear).
© 2008 Microchip Technology Inc.
DS39646C-page 25
PIC18F8722 FAMILY
TABLE 1-4:
Pin Name
PIC18F8527/8622/8627/8722 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Number
TQFP
Pin
Type
Buffer
Type
Description
PORTE is a bidirectional I/O port.
RE0/AD8/RD/P2D
4
3
RE0
AD8
RD
I/O
I/O
I
ST
TTL
TTL
—
Digital I/O.
External memory address/data 8.
Read control for Parallel Slave Port.
ECCP2 PWM output D.
P2D
O
RE1/AD9/WR/P2C
RE1
AD9
WR
I/O
I/O
I
ST
TTL
TTL
—
Digital I/O.
External memory address/data 9.
Write control for Parallel Slave Port.
ECCP2 PWM output C.
P2C
O
RE2/AD10/CS/P2B
78
RE2
AD10
CS
I/O
I/O
I
ST
TTL
TTL
—
Digital I/O.
External memory address/data 10.
Chip select control for Parallel Slave Port.
ECCP2 PWM output B.
P2B
O
RE3/AD11/P3C
RE3
77
76
75
74
73
I/O
I/O
O
ST
TTL
—
Digital I/O.
External memory address/data 11.
ECCP3 PWM output C.
AD11
P3C(4)
RE4/AD12/P3B
RE4
I/O
I/O
O
ST
TTL
—
Digital I/O.
External memory address/data 12.
ECCP3 PWM output B.
AD12
P3B(4)
RE5/AD13/P1C
RE5
I/O
I/O
O
ST
TTL
—
Digital I/O.
External memory address/data 13.
ECCP1 PWM output C.
AD13
P1C(4)
RE6/AD14/P1B
RE6
I/O
I/O
O
ST
TTL
—
Digital I/O.
External memory address/data 14.
ECCP1 PWM output B.
AD14
P1B(4)
RE7/AD15/ECCP2/P2A
RE7
I/O
I/O
I/O
ST
TTL
ST
Digital I/O.
AD15
External memory address/data 15.
Enhanced Capture 2 input/Compare 2 output/
PWM 2 output.
ECCP2(3)
P2A(3)
O
—
ECCP2 PWM output A.
Legend: TTL = TTL compatible input CMOS
= CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels Analog= Analog input
I
P
= Input
= Power
O
= Output
I2C™/SMB
= I2C/SMBus input buffer
Note 1: Alternate assignment for ECCP2 when Configuration bit, CCP2MX, is cleared (all operating modes except
Microcontroller mode).
2: Default assignment for ECCP2 in all operating modes (CCP2MX is set).
3: Alternate assignment for ECCP2 when CCP2MX is cleared (Microcontroller mode only).
4: Default assignment for P1B/P1C/P3B/P3C (ECCPMX is set).
5: Alternate assignment for P1B/P1C/P3B/P3C (ECCPMX is clear).
DS39646C-page 26
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
TABLE 1-4:
Pin Name
PIC18F8527/8622/8627/8722 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Number
TQFP
Pin
Type
Buffer
Type
Description
PORTF is a bidirectional I/O port.
RF0/AN5
RF0
24
23
I/O
I
ST
Analog
Digital I/O.
Analog input 5.
AN5
RF1/AN6/C2OUT
RF1
I/O
I
O
ST
Analog
—
Digital I/O.
Analog input 6.
Comparator 2 output.
AN6
C2OUT
RF2/AN7/C1OUT
RF2
18
I/O
I
O
ST
Analog
—
Digital I/O.
Analog input 7.
Comparator 1 output.
AN7
C1OUT
RF3/AN8
RF3
17
16
15
I/O
I
ST
Analog
Digital I/O.
Analog input 8.
AN8
RF4/AN9
RF4
I/O
I
ST
Analog
Digital I/O.
Analog input 9.
AN9
RF5/AN10/CVREF
RF5
I/O
I
O
ST
Analog
Analog
Digital I/O.
Analog input 10.
Comparator reference voltage output.
AN10
CVREF
RF6/AN11
RF6
14
13
I/O
I
ST
Analog
Digital I/O.
Analog input 11.
AN11
RF7/SS1
RF7
I/O
I
ST
TTL
Digital I/O.
SPI slave select input.
SS1
Legend: TTL = TTL compatible input CMOS
= CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels Analog= Analog input
I
P
= Input
= Power
O
= Output
I2C™/SMB
= I2C/SMBus input buffer
Note 1: Alternate assignment for ECCP2 when Configuration bit, CCP2MX, is cleared (all operating modes except
Microcontroller mode).
2: Default assignment for ECCP2 in all operating modes (CCP2MX is set).
3: Alternate assignment for ECCP2 when CCP2MX is cleared (Microcontroller mode only).
4: Default assignment for P1B/P1C/P3B/P3C (ECCPMX is set).
5: Alternate assignment for P1B/P1C/P3B/P3C (ECCPMX is clear).
© 2008 Microchip Technology Inc.
DS39646C-page 27
PIC18F8722 FAMILY
TABLE 1-4:
Pin Name
PIC18F8527/8622/8627/8722 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Number
TQFP
Pin
Type
Buffer
Type
Description
PORTG is a bidirectional I/O port.
RG0/ECCP3/P3A
RG0
5
I/O
I/O
ST
ST
Digital I/O.
ECCP3
Enhanced Capture 3 input/Compare 3 output/
PWM 3 output.
P3A
O
—
ECCP3 PWM output A.
RG1/TX2/CK2
RG1
6
7
I/O
O
I/O
ST
—
ST
Digital I/O.
TX2
CK2
EUSART2 asynchronous transmit.
EUSART2 synchronous clock (see related RX2/DT2).
RG2/RX2/DT2
RG2
I/O
I
I/O
ST
ST
ST
Digital I/O.
RX2
DT2
EUSART2 asynchronous receive.
EUSART2 synchronous data (see related TX2/CK2).
RG3/CCP4/P3D
RG3
8
I/O
I/O
O
ST
ST
—
Digital I/O.
CCP4
P3D
Capture 4 input/Compare 4 output/PWM 4 output.
ECCP3 PWM output D.
RG4/CCP5/P1D
RG4
10
I/O
I/O
O
ST
ST
—
Digital I/O.
CCP5
P1D
Capture 5 input/Compare 5 output/PWM 5 output.
ECCP1 PWM output D.
RG5
See RG5/MCLR/VPP pin.
Legend: TTL = TTL compatible input CMOS
= CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels Analog= Analog input
I
P
= Input
= Power
O
= Output
I2C™/SMB
= I2C/SMBus input buffer
Note 1: Alternate assignment for ECCP2 when Configuration bit, CCP2MX, is cleared (all operating modes except
Microcontroller mode).
2: Default assignment for ECCP2 in all operating modes (CCP2MX is set).
3: Alternate assignment for ECCP2 when CCP2MX is cleared (Microcontroller mode only).
4: Default assignment for P1B/P1C/P3B/P3C (ECCPMX is set).
5: Alternate assignment for P1B/P1C/P3B/P3C (ECCPMX is clear).
DS39646C-page 28
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
TABLE 1-4:
Pin Name
PIC18F8527/8622/8627/8722 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Number
TQFP
Pin
Type
Buffer
Type
Description
PORTH is a bidirectional I/O port.
RH0/A16
RH0
79
80
1
I/O
I/O
ST
TTL
Digital I/O.
External memory address/data 16.
A16
RH1/A17
RH1
I/O
I/O
ST
TTL
Digital I/O.
External memory address/data 17.
A17
RH2/A18
RH2
I/O
I/O
ST
TTL
Digital I/O.
External memory address/data 18.
A18
RH3/A19
RH3
2
I/O
I/O
ST
TTL
Digital I/O.
External memory address/data 19.
A19
RH4/AN12/P3C
RH4
22
I/O
I
O
ST
Analog
—
Digital I/O.
Analog input 12.
ECCP3 PWM output C.
AN12
P3C(5)
RH5/AN13/P3B
RH5
21
20
19
I/O
I
O
ST
Analog
—
Digital I/O.
Analog input 13.
ECCP3 PWM output B.
AN13
P3B(5)
RH6/AN14/P1C
RH6
I/O
I
O
ST
Analog
—
Digital I/O.
Analog input 14.
ECCP1 PWM output C.
AN14
P1C(5)
RH7/AN15/P1B
RH7
I/O
I
O
ST
Analog
—
Digital I/O.
Analog input 15.
ECCP1 PWM output B.
AN15
P1B(5)
Legend: TTL = TTL compatible input CMOS
= CMOS compatible input or output
ST = Schmitt Trigger input with CMOS levels Analog= Analog input
I
P
= Input
= Power
O
= Output
I2C™/SMB
= I2C/SMBus input buffer
Note 1: Alternate assignment for ECCP2 when Configuration bit, CCP2MX, is cleared (all operating modes except
Microcontroller mode).
2: Default assignment for ECCP2 in all operating modes (CCP2MX is set).
3: Alternate assignment for ECCP2 when CCP2MX is cleared (Microcontroller mode only).
4: Default assignment for P1B/P1C/P3B/P3C (ECCPMX is set).
5: Alternate assignment for P1B/P1C/P3B/P3C (ECCPMX is clear).
© 2008 Microchip Technology Inc.
DS39646C-page 29
PIC18F8722 FAMILY
TABLE 1-4:
Pin Name
PIC18F8527/8622/8627/8722 PINOUT I/O DESCRIPTIONS (CONTINUED)
Pin Number
TQFP
Pin
Type
Buffer
Type
Description
PORTJ is a bidirectional I/O port.
RJ0/ALE
RJ0
62
61
60
59
39
40
41
42
I/O
O
ST
—
Digital I/O.
External memory address latch enable.
ALE
RJ1/OE
RJ1
I/O
O
ST
—
Digital I/O.
External memory output enable.
OE
RJ2/WRL
RJ2
I/O
O
ST
—
Digital I/O.
External memory write low control.
WRL
RJ3/WRH
RJ3
I/O
O
ST
—
Digital I/O.
External memory write high control.
WRH
RJ4/BA0
RJ4
I/O
O
ST
—
Digital I/O.
External memory byte address 0 control.
BA0
RJ5/CE
RJ4
I/O
O
ST
—
Digital I/O
External memory chip enable control.
CE
RJ6/LB
RJ6
I/O
O
ST
—
Digital I/O.
External memory low byte control.
LB
RJ7/UB
RJ7
I/O
O
ST
—
Digital I/O.
External memory high byte control.
UB
VSS
11, 31, 51, 70
P
P
P
P
—
—
—
—
Ground reference for logic and I/O pins.
Positive supply for logic and I/O pins.
Ground reference for analog modules.
Positive supply for analog modules.
= CMOS compatible input or output
VDD
12, 32, 48, 71
AVSS
AVDD
26
25
Legend: TTL = TTL compatible input CMOS
ST = Schmitt Trigger input with CMOS levels Analog= Analog input
I
P
= Input
= Power
O
= Output
I2C™/SMB
= I2C/SMBus input buffer
Note 1: Alternate assignment for ECCP2 when Configuration bit, CCP2MX, is cleared (all operating modes except
Microcontroller mode).
2: Default assignment for ECCP2 in all operating modes (CCP2MX is set).
3: Alternate assignment for ECCP2 when CCP2MX is cleared (Microcontroller mode only).
4: Default assignment for P1B/P1C/P3B/P3C (ECCPMX is set).
5: Alternate assignment for P1B/P1C/P3B/P3C (ECCPMX is clear).
DS39646C-page 30
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
FIGURE 2-1:
CRYSTAL/CERAMIC
RESONATOROPERATION
(XT, LP, HS OR HSPLL
CONFIGURATION)
2.0
2.1
OSCILLATOR
CONFIGURATIONS
Oscillator Types
(1)
C1
The PIC18F8722 family of devices can be operated in
ten different oscillator modes. The user can program the
Configuration bits, FOSC<3:0>, in Configuration
Register 1H to select one of these ten modes:
OSC1
To
Internal
Logic
(3)
RF
XTAL
1. LP
2. XT
3. HS
Low-Power Crystal
Sleep
(2)
RS
Crystal/Resonator
(1)
PIC18FXXXX
C2
OSC2
High-Speed Crystal/Resonator
4. HSPLL High-Speed Crystal/Resonator
with PLL enabled
Note 1: See Table 2-1 and Table 2-2 for initial values of
C1 and C2.
5. RC
External Resistor/Capacitor with
FOSC/4 output on RA6
2: A series resistor (RS) may be required for AT
strip cut crystals.
6. RCIO
External Resistor/Capacitor with I/O
on RA6
3: RF varies with the oscillator mode chosen.
7. INTIO1 Internal Oscillator with FOSC/4 output
on RA6 and I/O on RA7
TABLE 2-1:
CAPACITOR SELECTION FOR
CERAMIC RESONATORS
8. INTIO2 Internal Oscillator with I/O on RA6
and RA7
Typical Capacitor Values Used:
9. EC
External Clock with FOSC/4 output
External Clock with I/O on RA6
10. ECIO
Mode
Freq
OSC1
OSC2
XT
3.58 MHz
22 pF
22 pF
2.2
Crystal Oscillator/Ceramic
Resonators
Capacitor values are for design guidance only.
Different capacitor values may be required to produce
acceptable oscillator operation. The user should test
the performance of the oscillator over the expected
VDD and temperature range for the application. Refer
to the following application notes for oscillator specific
information:
• AN588 – PIC® Microcontroller Oscillator Design
Guide
• AN826 – Crystal Oscillator Basics and Crystal
Selection for rfPIC® and PIC® Devices
• AN849 – Basic PIC® Oscillator Design
• AN943 – Practical PIC® Oscillator Analysis and
Design
In XT, LP, HS or HSPLL Oscillator modes, a crystal or
ceramic resonator is connected to the OSC1 and
OSC2 pins to establish oscillation. Figure 2-1 shows
the pin connections.
The oscillator design requires the use of a parallel cut
crystal.
Note:
Use of a series cut crystal may give a
frequency out of the crystal manufacturer’s
specifications.
• AN949 – Making Your Oscillator Work
See the notes following Table 2-2 for additional
information.
Note:
When using resonators with frequencies
above 3.5 MHz, the use of HS mode,
rather than XT mode, is recommended.
HS mode may be used at any VDD for
which the controller is rated. If HS is
selected, it is possible that the gain of the
oscillator will overdrive the resonator.
Therefore, a series resistor may be placed
between the OSC2 pin and the resonator.
As
a
good starting point, the
recommended value of RS is 330Ω.
© 2008 Microchip Technology Inc.
DS39646C-page 31
PIC18F8722 FAMILY
An external clock source may also be connected to the
OSC1 pin in the HS mode, as shown in Figure 2-2.
When operated in this mode, parameters D033 and
D043 apply.
TABLE 2-2:
CAPACITOR SELECTION FOR
QUARTZ CRYSTALS
Typical Capacitor Values
Crystal
Freq
Tested:
Osc Type
FIGURE 2-2:
EXTERNAL CLOCK INPUT
OPERATION (HS OSC
CONFIGURATION)
C1
C2
LP
XT
32 kHz
22 pF
22 pF
1 MHz
4 MHz
22 pF
22 pF
22 pF
22 pF
OSC1
Clock from
Ext. System
HS
4 MHz
10 MHz
20 MHz
25 MHz
22 pF
22 pF
22 pF
22 pF
22 pF
22 pF
22 pF
22 pF
PIC18FXXXX
(HS Mode)
OSC2
Open
Capacitor values are for design guidance only.
Different capacitor values may be required to produce
acceptable oscillator operation. The user should test
the performance of the oscillator over the expected
VDD and temperature range for the application. Refer
to the following application notes for oscillator specific
information:
2.3
External Clock Input
The EC and ECIO Oscillator modes require an external
clock source to be connected to the OSC1 pin. There is
no oscillator start-up time required after a Power-on
Reset or after an exit from Sleep mode.
• AN588 – PIC® Microcontroller Oscillator Design
Guide
• AN826 – Crystal Oscillator Basics and Crystal
Selection for rfPIC® and PIC® Devices
• AN849 – Basic PIC® Oscillator Design
• AN943 – Practical PIC® Oscillator Analysis and
Design
In the EC Oscillator mode, the oscillator frequency
divided by 4 is available on the OSC2 pin. This signal
may be used for test purposes or to synchronize other
logic. Figure 2-3 shows the pin connections for the EC
Oscillator mode.
FIGURE 2-3:
EXTERNAL CLOCK
INPUT OPERATION
(EC CONFIGURATION)
• AN949 – Making Your Oscillator Work
See the notes following this table for additional
information.
OSC1/CLKI
Clock from
Ext. System
PIC18FXXXX
OSC2/CLKO
Note 1: Higher capacitance increases the stability
of the oscillator but also increases the
start-up time.
FOSC/4
The ECIO Oscillator mode functions like the EC mode,
except that the OSC2 pin becomes an additional
general purpose I/O pin. The I/O pin becomes bit 6 of
PORTA (RA6). Figure 2-4 shows the pin connections
for the ECIO Oscillator mode. When operated in this
mode, parameters D033A and D043A apply.
2: When operating below 3V VDD, or when
using certain ceramic resonators at any
voltage, it may be necessary to use the
HS mode or switch to a crystal oscillator.
3: Since each resonator/crystal has its own
characteristics, the user should consult
the resonator/crystal manufacturer for
FIGURE 2-4:
EXTERNAL CLOCK
INPUT OPERATION
(ECIO CONFIGURATION)
appropriate
values
of
external
components.
4: Rs may be required to avoid overdriving
crystals with low drive level specification.
OSC1/CLKI
PIC18FXXXX
I/O (OSC2)
Clock from
Ext. System
5: Always verify oscillator performance over
the VDD and temperature range that is
expected for the application.
RA6
DS39646C-page 32
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
2.4
RC Oscillator
2.5
PLL Frequency Multiplier
For timing insensitive applications, the RC and RCIO
Oscillator modes offer additional cost savings. The
actual oscillator frequency is a function of several
factors:
A Phase Locked Loop (PLL) circuit is provided as an
option for users who wish to use a lower frequency
oscillator circuit or to clock the device up to its highest
rated frequency from a crystal oscillator. This may be
useful for customers who are concerned with EMI due
to high-frequency crystals or users who require higher
clock speeds from an internal oscillator.
• supply voltage
• values of the external resistor (REXT) and
capacitor (CEXT)
• operating temperature
2.5.1
HSPLL OSCILLATOR MODE
Given the same device, operating voltage and tempera-
ture and component values, there will also be unit-to-unit
frequency variations. These are due to factors such as:
The HSPLL mode makes use of the HS mode oscillator
for frequencies up to 10 MHz. A PLL then multiplies the
oscillator output frequency by 4 to produce an internal
clock frequency up to 40 MHz. The PLLEN bit is not
available when this mode is configured as the primary
clock source.
• normal manufacturing variation
• difference in lead frame capacitance between
package types (especially for low CEXT values)
• variations within the tolerance of limits of REXT
and CEXT
The PLL is only available to the crystal oscillator when
the FOSC<3:0> Configuration bits are programmed for
HSPLL mode (= 0110).
In the RC Oscillator mode, the oscillator frequency
divided by 4 is available on the OSC2 pin. This signal
may be used for test purposes or to synchronize other
logic. Figure 2-5 shows how the R/C combination is
connected.
FIGURE 2-7:
HSPLLBLOCKDIAGRAM
HS Oscillator Enable
PLL Enable
(from Configuration Register 1H)
FIGURE 2-5:
RC OSCILLATOR MODE
VDD
OSC2
Phase
Comparator
HS Mode
Crystal
Osc
FIN
REXT
Internal
OSC1
OSC1
FOUT
Clock
CEXT
VSS
Loop
Filter
PIC18FXXXX
OSC2/CLKO
FOSC/4
÷4
VCO
Recommended values: 3 kΩ ≤ REXT ≤ 100 kΩ
20 pF ≤ CEXT ≤ 300 pF
SYSCLK
The RCIO Oscillator mode (Figure 2-6) functions like
the RC mode, except that the OSC2 pin becomes an
additional general purpose I/O pin. The I/O pin
becomes bit 6 of PORTA (RA6).
2.5.2
PLL AND INTOSC
The PLL is also available to the internal oscillator block
when the internal oscillator block is configured as the
primary clock source. In this configuration, the PLL is
enabled in software and generates a clock output of up
to 32 MHz. The operation of INTOSC with the PLL is
described in Section 2.6.4 “PLL in INTOSC Modes”.
FIGURE 2-6:
RCIO OSCILLATOR MODE
VDD
REXT
Internal
OSC1
Clock
CEXT
PIC18FXXXX
VSS
I/O (OSC2)
RA6
Recommended values: 3 kΩ ≤ REXT ≤ 100 kΩ
20 pF ≤ CEXT ≤ 300 pF
© 2008 Microchip Technology Inc.
DS39646C-page 33
PIC18F8722 FAMILY
2.6.2
INTOSC OUTPUT FREQUENCY
2.6
Internal Oscillator Block
The internal oscillator block is calibrated at the factory
to produce an INTOSC output frequency of 8 MHz.
The PIC18F8722 family of devices includes an internal
oscillator block which generates two different clock
signals; either can be used as the microcontroller’s
clock source. This may eliminate the need for external
oscillator circuits on the OSC1 and/or OSC2 pins.
The INTRC oscillator operates independently of the
INTOSC source. Any changes in INTOSC across
voltage and temperature are not necessarily reflected
by changes in INTRC or vice versa.
The main output (INTOSC) is an 8 MHz clock source,
which can be used to directly drive the device clock. It
also drives a postscaler, which can provide a range of
clock frequencies from 31 kHz to 4 MHz. The INTOSC
output is enabled when a clock frequency from 125 kHz
to 8 MHz is selected. The INTOSC output can also be
enabled when 31 kHz is selected, depending on the
INTSRC bit (OSCTUNE<7>).
2.6.3
OSCTUNE REGISTER
The INTOSC output has been calibrated at the
factory but can be adjusted in the user’s application.
This
is
done
by
writing
to
TUN<4:0>
(OSCTUNE<4:0>) in the OSCTUNE register
(Register ).
The other clock source is the internal RC oscillator
(INTRC), which provides a nominal 31 kHz output.
INTRC is enabled if it is selected as the device clock
source; it is also enabled automatically when any of the
following are enabled:
When the OSCTUNE register is modified, the INTOSC
frequency will begin shifting to the new frequency. The
INTOSC clock will stabilize within 1 ms. Code execu-
tion continues during this shift. There is no indication
that the shift has occurred. The INTRC is not affected
by OSCTUNE.
• Power-up Timer
The OSCTUNE register also implements the INTSRC
(OSCTUNE<7>) and PLLEN (OSCTUNE<6>) bits,
which control certain features of the internal oscillator
block. The INTSRC bit allows users to select which
internal oscillator provides the clock source when the
31 kHz frequency option is selected. This is covered in
greater detail in Section 2.7.1 “Oscillator Control
Register”.
• Fail-Safe Clock Monitor
• Watchdog Timer
• Two-Speed Start-up
These features are discussed in greater detail in
Section 25.0 “Special Features of the CPU”.
The clock source frequency (INTOSC direct, INTRC
direct or INTOSC postscaler) is selected by configuring
the IRCF bits of the OSCCON register (page 39).
The PLLEN bit controls the operation of the Phase
Locked Loop (PLL) in internal oscillator modes (see
Figure 2-10).
2.6.1
INTIO MODES
Using the internal oscillator as the clock source elimi-
nates the need for up to two external oscillator pins,
which can then be used for digital I/O. Two distinct
configurations are available:
FIGURE 2-10:
INTOSC AND PLL BLOCK
DIAGRAM
8 or 4 MHz
PLLEN
(OSCTUNE<6>)
• In INTIO1 mode, the OSC2 pin outputs FOSC/4,
while OSC1 functions as RA7 (see Figure 2-8) for
digital input and output.
• In INTIO2 mode, OSC1 functions as RA7 and
OSC2 functions as RA6 (see Figure 2-9), both for
digital input and output.
Phase
Comparator
FIN
INTOSC
FOUT
FIGURE 2-8: INTIO1 OSCILLATOR MODE
Loop
Filter
I/O (OSC1)
OSC2
RA7
PIC18FXXXX
FOSC/4
÷4
VCO
SYSCLK
CLKO
OSC2
FIGURE 2-9: INTIO2 OSCILLATOR MODE
I/O (OSC1)
I/O (OSC2)
RA7
RA6
PIC18FXXXX
RA6
DS39646C-page 34
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
2.6.4
PLL IN INTOSC MODES
2.6.5
INTOSC FREQUENCY DRIFT
The 4x Phase Locked Loop (PLL) can be used with the
internal oscillator block to produce faster device clock
speeds than are normally possible with the internal
oscillator sources. When enabled, the PLL produces a
clock speed of 16 MHz or 32 MHz.
The factory calibrates the internal oscillator block
output (INTOSC) for 8 MHz. However, this frequency
may drift as VDD or temperature changes and can
affect the controller operation in a variety of ways. It is
possible to adjust the INTOSC frequency by modifying
the value in the OSCTUNE register. Depending on the
device, this may have no effect on the INTRC clock
source frequency.
Unlike HSPLL mode, the PLL is controlled through
software. The control bit, PLLEN (OSCTUNE<6>), is
used to enable or disable its operation.
Tuning the INTOSC source requires knowing when to
make the adjustment, in which direction it should be
made and in some cases, how large a change is
needed. Three compensation techniques are discussed
in Section 2.6.5.1 “Compensating with the
EUSART”, Section 2.6.5.2 “Compensating with the
Timers” and Section 2.6.5.3 “Compensating with the
CCP Module in Capture Mode” but other techniques
may be used.
The PLL is available when the device is configured to
use the internal oscillator block as its primary clock
source (FOSC<3:0> = 1001or 1000). Additionally, the
PLL will only function when the selected output fre-
quency is either 4 MHz or 8 MHz (OSCCON<6:4> = 111
or 110). If both of these conditions are not met, the PLL
is disabled and the PLLEN bit remains clear (writes are
ignored).
REGISTER 2-1:
OSCTUNE: OSCILLATOR TUNING REGISTER
R/W-0
INTSRC
bit 7
R/W-0
PLLEN(1)
U-0
—
R/W-0
TUN4
R/W-0
TUN3
R/W-0
TUN2
R/W-0
TUN1
R/W-0
TUN0
bit 0
Legend:
R = Readable bit
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
-n = Value at POR
bit 7
bit 6
INTSRC: Internal Oscillator Low-Frequency Source Select bit
1= 31.25 kHz device clock derived from 8 MHz INTOSC source (divide-by-256 enabled)
0= 31 kHz device clock derived directly from INTRC internal oscillator
PLLEN: Frequency Multiplier PLL for INTOSC Enable bit(1)
1= PLL enabled for INTOSC (4 MHz and 8 MHz only)
0= PLL disabled
bit 5
Unimplemented: Read as ‘0’
TUN<4:0>: Frequency Tuning bits
01111= Maximum frequency
bit 4-0
•
•
•
•
00001
00000= Center frequency. Oscillator module is running at the calibrated frequency.
11111
•
•
•
•
10000= Minimum frequency
Note 1: Available only in certain oscillator configurations; otherwise, this bit is unavailable and reads as ‘0’. See
Section 2.6.4 “PLL in INTOSC Modes” for details.
© 2008 Microchip Technology Inc.
DS39646C-page 35
PIC18F8722 FAMILY
2.6.5.1
Compensating with the EUSART
2.6.5.3
Compensating with the CCP Module
in Capture Mode
An adjustment may be required when the EUSART
begins to generate framing errors or receives data with
errors while in Asynchronous mode. Framing errors
indicate that the device clock frequency is too high. To
adjust for this, decrement the value in OSCTUNE to
reduce the clock frequency. On the other hand, errors
in data may suggest that the clock speed is too low. To
compensate, increment OSCTUNE to increase the
clock frequency.
A CCP module can use free running Timer1 (or
Timer3), clocked by the internal oscillator block and an
external event with a known period (i.e., AC power
frequency). The time of the first event is captured in the
CCPRxH:CCPRxL registers and is recorded for use
later. When the second event causes a capture, the
time of the first event is subtracted from the time of the
second event. Since the period of the external event is
known, the time difference between events can be
calculated.
2.6.5.2
Compensating with the Timers
This technique compares device clock speed to some
reference clock. Two timers may be used; one timer is
clocked by the peripheral clock, while the other is
clocked by a fixed reference source, such as the
Timer1 oscillator.
If the measured time is much greater than the
calculated time, the internal oscillator block is running
too fast. To compensate, decrement the OSCTUNE
register. If the measured time is much less than the
calculated time, the internal oscillator block is running
too slow. To compensate, increment the OSCTUNE
register.
Both timers are cleared, but the timer clocked by the
reference generates interrupts. When an interrupt
occurs, the internally clocked timer is read and both
timers are cleared. If the internally clocked timer value
is much greater than expected, then the internal
oscillator block is running too fast. To adjust for this,
decrement the OSCTUNE register.
DS39646C-page 36
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
The secondary oscillators are those external sources
not connected to the OSC1 or OSC2 pins. These
sources may continue to operate even after the
controller is placed in a power-managed mode.
2.7
Clock Sources and Oscillator
Switching
The PIC18F8722 family of devices includes a feature
that allows the device clock source to be switched from
the main oscillator to an alternate clock source. These
devices also offer two alternate clock sources. When
an alternate clock source is enabled, the various
power-managed operating modes are available.
The PIC18F8722 family of devices offers the Timer1
oscillator as a secondary oscillator. This oscillator, in all
power-managed modes, is often the time base for
functions such as a real-time clock.
Most often, a 32.768 kHz watch crystal is connected
between the RC0/T1OSO/T13CKI and RC1/T1OSI
pins. Like the LP mode oscillator circuit, loading
capacitors are also connected from each pin to ground.
Essentially, there are three clock sources for these
devices:
• Primary oscillators
• Secondary oscillators
• Internal oscillator block
The Timer1 oscillator is discussed in greater detail in
Section 13.3 “Timer1 Oscillator”.
The primary oscillators include the External Crystal
and Resonator modes, the External RC modes, the
External Clock modes and the internal oscillator block.
The particular mode is defined by the FOSC<3:0>
Configuration bits. The details of these modes are
covered earlier in this chapter.
In addition to being a primary clock source, the internal
oscillator block is available as a power-managed
mode clock source. The INTRC source is also used as
the clock source for several special features, such as
the WDT and Fail-Safe Clock Monitor.
The clock sources for the PIC18F8722 family of devices
are shown in Figure 2-11. See Section 25.0 “Special
Features of the CPU” for Configuration register details.
FIGURE 2-11:
PIC18F8722 FAMILY CLOCK DIAGRAM
PIC18F6527/6622/6627/6722/8527/8622/8627/8722
Primary Oscillator
LP, XT, HS, RC, EC
HSPLL, INTOSC/PLL
T1OSC
OSC2
Sleep
4 x PLL
OSC1
OSCTUNE<6>
Peripherals
Secondary Oscillator
T1OSO
T1OSCEN
Enable
Oscillator
T1OSI
OSCCON<6:4>
Internal Oscillator
CPU
8 MHz
OSCCON<6:4>
111
110
101
4 MHz
2 MHz
Internal
Oscillator
Block
IDLEN
Clock
1 MHz
Control
100
011
010
001
000
8 MHz
Source
500 kHz
250 kHz
125 kHz
31 kHz
8 MHz
(INTOSC)
INTRC
Source
FOSC<3:0>
OSCCON<1:0>
Clock Source Option
for other Modules
1
0
31 kHz (INTRC)
OSCTUNE<7>
WDT, PWRT, FSCM
and Two-Speed Start-up
© 2008 Microchip Technology Inc.
DS39646C-page 37
PIC18F8722 FAMILY
the primary clock is providing the device clock in
primary clock modes. The IOFS bit indicates when the
internal oscillator block has stabilized and is providing
the device clock in RC Clock modes. The T1RUN bit
(T1CON<6>) indicates when the Timer1 oscillator is
providing the device clock in secondary clock modes.
In power-managed modes, only one of these three bits
will be set at any time. If none of these bits are set, the
INTRC is providing the clock or the internal oscillator
block has just started and is not yet stable.
2.7.1
OSCILLATOR CONTROL REGISTER
The OSCCON register (Register 2-2) controls several
aspects of the device clock’s operation, both in full
power operation and in power-managed modes.
The System Clock Select bits, SCS<1:0>, select the
clock source. The available clock sources are the
primary clock (defined by the FOSC<3:0> Configura-
tion bits), the secondary clock (Timer1 oscillator) and
the internal oscillator block. The clock source changes
immediately after either of the SCS<1:0> bits are
changed, following a brief clock transition interval. The
SCS bits are reset on all forms of Reset.
The IDLEN bit controls whether the device goes into
Sleep mode or one of the Idle modes when the SLEEP
instruction is executed.
The Internal Oscillator Frequency Select bits
(IRCF<2:0>) select the frequency output of the internal
oscillator block to drive the device clock. The choices
are the INTRC source (31 kHz), the INTOSC source
(8 MHz) or one of the frequencies derived from the
INTOSC postscaler (31.25 kHz to 4 MHz). If the
internal oscillator block is supplying the device clock,
changing the states of these bits will have an immedi-
ate change on the internal oscillator’s output. On
device Resets, the default output frequency of the
internal oscillator block is set at 1 MHz.
The use of the flag and control bits in the OSCCON
register is discussed in more detail in Section 3.0
“Power-Managed Modes”.
Note 1: The Timer1 oscillator must be enabled to
select the secondary clock source. The
Timer1 oscillator is enabled by setting the
T1OSCEN bit in the Timer1 Control regis-
ter (T1CON<3>). If the Timer1 oscillator
is not enabled, then any attempt to select
a secondary clock source will be ignored.
When a nominal output frequency of 31 kHz is selected
(IRCF<2:0> = 000), users may choose which internal
oscillator acts as the source. This is done with the
INTSRC bit in the OSCTUNE register (OSCTUNE<7>).
Setting this bit selects INTOSC as a 31.25 kHz clock
source derived from the INTOSC postscaler. Clearing
INTSRC selects INTRC (nominally 31 kHz) as the
clock source and disables the INTOSC to reduce
current consumption.
2: It is recommended that the Timer1
oscillator be operating and stable before
selecting the secondary clock source or a
very long delay may occur while the
Timer1 oscillator starts.
2.7.2
OSCILLATOR TRANSITIONS
The PIC18F8722 family of devices contains circuitry to
prevent clock “glitches” when switching between clock
sources. A short pause in the device clock occurs dur-
ing the clock switch. The length of this pause is the sum
of two cycles of the old clock source and three to four
cycles of the new clock source. This formula assumes
that the new clock source is stable.
This option allows users to select the tunable and more
precise INTOSC as a clock source, while maintaining
power savings with a very low clock speed. Addition-
ally, the INTOSC source will already be stable should a
switch to a higher frequency be needed quickly.
Regardless of the setting of INTSRC, INTRC always
remains the clock source for features such as the
Watchdog Timer and the Fail-Safe Clock Monitor.
Clock transitions are discussed in greater detail in
Section 3.1.2 “Entering Power-Managed Modes”.
The OSTS, IOFS and T1RUN bits indicate which clock
source is currently providing the device clock. The
OSTS bit indicates that the Oscillator Start-up Timer
and PLL Start-up Timer (if enabled) have timed out and
DS39646C-page 38
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
REGISTER 2-2:
OSCCON: OSCILLATOR CONTROL REGISTER
R/W-0
IDLEN
bit 7
R/W-1
IRCF2
R/W-0
IRCF1
R/W-0
IRCF0
R(1)
R-0
R/W-0
SCS1
R/W-0
SCS0
OSTS
IOFS
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7
IDLEN: Idle Enable bit
1= Device enters an Idle mode when a SLEEPinstruction is executed
0= Device enters Sleep mode when a SLEEPinstruction is executed
bit 6-4
IRCF<2:0>: Internal Oscillator Frequency Select bits(5)
111= 8 MHz (INTOSC drives clock directly)
110= 4 MHz
101= 2 MHz
100= 1 MHz(3)
011= 500 kHz
010= 250 kHz
001= 125 kHz
000= 31 kHz (from either INTOSC/256 or INTRC directly)(2)
bit 3
OSTS: Oscillator Start-up Time-out Status bit(1)
1= Oscillator Start-up Timer (OST) time-out has expired; primary oscillator is running
0= Oscillator Start-up Timer (OST) time-out is running; primary oscillator is not ready
bit 2
IOFS: INTOSC Frequency Stable bit
1= INTOSC frequency is stable
0= INTOSC frequency is not stable
bit 1-0
SCS<1:0>: System Clock Select bits(4)
1x= Internal oscillator block
01= Secondary (Timer1) oscillator
00= Primary oscillator
Note 1: Reset state depends on state of the IESO Configuration bit.
2: Source selected by the INTSRC bit (OSCTUNE<7>), see text.
3: Default output frequency of INTOSC on Reset.
4: Modifying the SCS<1:0> bits will cause an immediate clock source switch.
5: Modifying the IRCF<3:0> bits will cause an immediate clock frequency switch if the internal oscillator is
providing the device clocks.
© 2008 Microchip Technology Inc.
DS39646C-page 39
PIC18F8722 FAMILY
2.8
Effects of Power-Managed Modes
on the Various Clock Sources
2.9
Power-up Delays
Power-up delays are controlled by two or three timers,
so that no external Reset circuitry is required for most
applications. The delays ensure that the device is kept
in Reset until the device power supply is stable under
normal circumstances and the primary clock is operat-
ing and stable. For additional information on power-up
delays, see Section 4.5 “Device Reset Timers”.
When PRI_IDLE mode is selected, the configured
oscillator continues to run without interruption. For all
other power-managed modes, the oscillator using the
OSC1 pin is disabled. The OSC1 pin (and OSC2 pin in
crystal oscillator modes) will stop oscillating.
In secondary clock modes (SEC_RUN and
SEC_IDLE), the Timer1 oscillator is operating and
providing the device clock. The Timer1 oscillator may
also run in all power-managed modes if required to
clock Timer1 or Timer3.
The first timer is the Power-up Timer (PWRT) which
provides a fixed delay on power-up (parameter 33,
Table 28-12). It is enabled by clearing (= 0) the
PWRTEN Configuration bit (CONFIG2L<0>).
In internal oscillator modes (RC_RUN and RC_IDLE),
the internal oscillator block provides the device clock
source. The 31 kHz INTRC output can be used directly
to provide the clock and may be enabled to support
various special features, regardless of the power-
managed mode (see Section 25.2 “Watchdog Timer
(WDT)” and Section 25.4 “Fail-Safe Clock Monitor”
for more information). The INTOSC output at 8 MHz
may be used directly to clock the device or may be
divided down by the postscaler. The INTOSC output is
disabled if the clock is provided directly from the INTRC
output. The INTOSC output is also enabled for Two-
Speed Start-up at 1 MHz after Resets and when
configured for wake from Sleep mode.
2.9.1
DELAYS FOR POWER-UP AND
RETURN TO PRIMARY CLOCK
The second timer is the Oscillator Start-up Timer
(OST), intended to delay execution until the crystal
oscillator is stable (LP, XT and HS modes). The OST
does this by counting 1024 oscillator cycles before
allowing the oscillator to clock the device.
When the HSPLL Oscillator mode is selected, a third
timer delays execution for an additional 2 ms following
the HS mode OST delay, so the PLL can lock to the
incoming clock frequency. At the end of these delays,
the OSTS bit (OSCCON<3>) is set.
There is a delay of interval TCSD (parameter 38,
Table 28-12), once execution is allowed to start, when
the controller becomes ready to execute instructions.
This delay runs concurrently with any other delays.
This may be the only delay that occurs when any of the
EC, RC or INTIO modes are used as the primary clock
source.
If the Sleep mode is selected, all clock sources are
stopped. Since all the transistor switching currents
have been stopped, Sleep mode achieves the lowest
current consumption of the device (only leakage
currents).
Enabling any on-chip feature that will operate during
Sleep will increase the current consumed during Sleep.
The INTRC is required to support WDT operation. The
Timer1 oscillator may be operating to support a real-
time clock. Other features may be operating that do not
require a device clock source (i.e., SSP slave, PSP,
INTx pins and others). Peripherals that may add
significant current consumption are listed in
Section 28.2 “DC Characteristics”.
TABLE 2-3:
OSC1 AND OSC2 PIN STATES IN SLEEP MODE
OSC Mode
OSC1 Pin
OSC2 Pin
RC, INTIO1
RCIO
Floating, external resistor pulls high
Floating, external resistor pulls high
Configured as PORTA, bit 7
At logic low (clock/4 output)
Configured as PORTA, bit 6
Configured as PORTA, bit 6
Configured as PORTA, bit 6
At logic low (clock/4 output)
INTIO2
ECIO
Floating, driven by external clock
Floating, driven by external clock
EC
LP, XT and HS
Feedback inverter disabled at quiescent
voltage level
Feedback inverter disabled at quiescent
voltage level
Note:
See Table 4-2 in Section 4.0 “Reset” for time-outs due to Sleep and MCLR Reset.
DS39646C-page 40
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
3.1.1
CLOCK SOURCES
3.0
POWER-MANAGED MODES
The SCS1:SCS0 bits allow the selection of one of three
clock sources for power-managed modes. They are:
The PIC18F8722 family of devices offers a total of
seven operating modes for more efficient power man-
agement. These modes provide a variety of options for
selective power conservation in applications where
resources may be limited (i.e., battery-powered
devices).
• the primary clock, as defined by the FOSC<3:0>
Configuration bits
• the secondary clock (the Timer1 oscillator)
• the internal oscillator block (for INTOSC modes)
There are three categories of power-managed modes:
3.1.2
ENTERING POWER-MANAGED
MODES
• Run modes
• Idle modes
• Sleep mode
Switching from one power-managed mode to another
begins by loading the OSCCON register. The
SCS<1:0> bits select the clock source and determine
which Run or Idle mode is to be used. Changing these
bits causes an immediate switch to the new clock
source, assuming that it is running. The switch may
also be subject to clock transition delays. These are
discussed in Section 3.1.3 “Clock Transitions and
Status Indicators” and subsequent sections.
These categories define which portions of the device
are clocked and sometimes, what speed. The Run and
Idle modes may use any of the three available clock
sources (primary, secondary or internal oscillator
block); the Sleep mode does not use a clock source.
The power-managed modes include several power-
saving features offered on previous PIC® devices. One
is the clock switching feature, offered in other PIC18
devices, allowing the controller to use the Timer1 oscil-
lator in place of the primary oscillator. Also included is
the Sleep mode, offered by all PIC devices, where all
device clocks are stopped.
Entry to the power-managed Idle or Sleep modes is
triggered by the execution of a SLEEPinstruction. The
actual mode that results depends on the status of the
IDLEN bit.
Depending on the current mode and the mode being
switched to, a change to a power-managed mode does
not always require setting all of these bits. Many
transitions may be done by changing the oscillator select
bits, or changing the IDLEN bit, prior to issuing a SLEEP
instruction. If the IDLEN bit is already configured
correctly, it may only be necessary to perform a SLEEP
instruction to switch to the desired mode.
3.1
Selecting Power-Managed Modes
Selecting
a power-managed mode requires two
decisions: if the CPU is to be clocked or not and the
selection of clock source. The IDLEN bit
(OSCCON<7>) controls CPU clocking, while the
SCS<1:0> bits (OSCCON<1:0>) select the clock
source. The individual modes, bit settings, clock sources
and affected modules are summarized in Table 3-1.
a
TABLE 3-1:
Mode
POWER-MANAGED MODES
OSCCON Bits
Module Clocking
Available Clock and Oscillator Source
IDLEN<7>(1) SCS<1:0>
CPU
Peripherals
Sleep
0
N/A
Off
Off
None – All clocks are disabled
PRI_RUN
N/A
00
Clocked
Clocked
Primary – LP, XT, HS, HSPLL, RC, EC and
Internal Oscillator Block(2)
.
This is the normal full power execution mode.
Secondary – Timer1 Oscillator
Internal Oscillator Block(2)
SEC_RUN
RC_RUN
PRI_IDLE
SEC_IDLE
RC_IDLE
N/A
N/A
1
01
1x
00
01
1x
Clocked
Clocked
Off
Clocked
Clocked
Clocked
Clocked
Clocked
Primary – LP, XT, HS, HSPLL, RC, EC
Secondary – Timer1 Oscillator
Internal Oscillator Block(2)
1
Off
1
Off
Note 1: IDLEN reflects its value when the SLEEPinstruction is executed.
2: Includes INTOSC and INTOSC postscaler, as well as the INTRC source.
© 2008 Microchip Technology Inc.
DS39646C-page 41
PIC18F8722 FAMILY
3.1.3
CLOCK TRANSITIONS AND STATUS
INDICATORS
3.2
Run Modes
In the Run modes, clocks to both the core and
peripherals are active. The difference between these
modes is the clock source.
The length of the transition between clock sources is
the sum of two cycles of the old clock source and three
to four cycles of the new clock source. This formula
assumes that the new clock source is stable.
3.2.1
PRI_RUN MODE
Three bits indicate the current clock source and its
status. They are:
The PRI_RUN mode is the normal, full power execution
mode of the microcontroller. This is also the default
mode upon a device Reset, unless Two-Speed Start-up
is enabled (see Section 25.3 “Two-Speed Start-up”
for details). In this mode, the OSTS bit is set. The IOFS
bit may be set if the internal oscillator block is the
primary clock source (see Section 2.7.1 “Oscillator
Control Register”).
• OSTS (OSCCON<3>)
• IOFS (OSCCON<2>)
• T1RUN (T1CON<6>)
In general, only one of these bits will be set while in a
given power-managed mode. When the OSTS bit is
set, the primary clock is providing the device clock.
When the IOFS bit is set, the INTOSC output is
providing a stable 8 MHz clock source to a divider that
actually drives the device clock. When the T1RUN bit is
set, the Timer1 oscillator is providing the clock. If none
of these bits are set, then either the INTRC clock
source is clocking the device, or the INTOSC source is
not yet stable.
3.2.2
SEC_RUN MODE
The SEC_RUN mode is the compatible mode to the
“clock switching” feature offered in other PIC18
devices. In this mode, the CPU and peripherals are
clocked from the Timer1 oscillator. This gives users the
option of lower power consumption while still using a
high accuracy clock source.
If the internal oscillator block is configured as the pri-
mary clock source by the FOSC<3:0> Configuration
bits, then both the OSTS and IOFS bits may be set
when in PRI_RUN or PRI_IDLE modes. This indicates
that the primary clock (INTOSC output) is generating a
stable 8 MHz output. Entering another INTOSC power-
managed mode at the same frequency would clear the
OSTS bit.
SEC_RUN mode is entered by setting the SCS<1:0>
bits to ‘01’. The device clock source is switched to the
Timer1 oscillator (see Figure 3-1), the primary oscilla-
tor is shut down, the T1RUN bit (T1CON<6>) is set and
the OSTS bit is cleared.
Note:
The Timer1 oscillator should already be
running prior to entering SEC_RUN mode.
If the T1OSCEN bit is not set when the
SCS<1:0> bits are set to ‘01’, entry to
SEC_RUN mode will not occur. If the
Timer1 oscillator is enabled, but not yet
running, device clocks will be delayed until
the oscillator has started; in such situa-
tions, initial oscillator operation is far from
stable and unpredictable operation may
result.
Note 1: Caution should be used when modifying a
single IRCF bit. If VDD is less than 3V, it is
possible to select a higher clock speed
than is supported by the low VDD.
Improper device operation may result if
the VDD/FOSC specifications are violated.
2: Executing a SLEEP instruction does not
necessarily place the device into Sleep
mode. It acts as the trigger to place the
controller into either the Sleep mode or
one of the Idle modes, depending on the
setting of the IDLEN bit.
On transitions from SEC_RUN mode to PRI_RUN, the
peripherals and CPU continue to be clocked from the
Timer1 oscillator while the primary clock is started.
When the primary clock becomes ready, a clock switch
back to the primary clock occurs (see Figure 3-2).
When the clock switch is complete, the T1RUN bit is
cleared, the OSTS bit is set and the primary clock is
providing the clock. The IDLEN and SCS bits are not
affected by the wake-up; the Timer1 oscillator
continues to run.
3.1.4
MULTIPLE SLEEP COMMANDS
The power-managed mode that is invoked with the
SLEEP instruction is determined by the setting of the
IDLEN bit at the time the instruction is executed. If
another SLEEPinstruction is executed, the device will
enter the power-managed mode specified by IDLEN at
that time. If IDLEN has changed, the device will enter
the new power-managed mode specified by the new
setting.
DS39646C-page 42
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
FIGURE 3-1:
TRANSITION TIMING FOR ENTRY TO SEC_RUN MODE
Q1 Q2 Q3 Q4 Q1
Q2
Q3
Q4
Q1
Q2
Q3
1
2
3
n-1
n
T1OSI
Clock Transition(1)
OSC1
CPU
Clock
Peripheral
Clock
Program
Counter
PC
PC + 2
PC + 4
Note 1: Clock transition typically occurs within 2-4 TOSC.
FIGURE 3-2:
TRANSITION TIMING FROM SEC_RUN MODE TO PRI_RUN MODE (HSPLL)
Q1
Q2
Q3
Q4
Q1
Q2 Q3 Q4 Q1 Q2 Q3
T1OSI
OSC1
(1)
TOST
(1)
TPLL
1
2
n-1
n
PLL Clock
Output
Clock
Transition(2)
CPU Clock
Peripheral
Clock
Program
Counter
PC + 2
PC + 4
PC
OSTS bit Set
SCS1:SCS0 bits Changed
Note1:TOST = 1024 TOSC; TPLL = 2 ms (approx). These intervals are not shown to scale.
2: Clock transition typically occurs within 2-4 TOSC.
This mode is entered by setting the SCS1 bit to ‘1’.
Although it is ignored, it is recommended that the SCS0
bit also be cleared; this is to maintain software compat-
ibility with future devices. When the clock source is
switched to the INTOSC multiplexer (see Figure 3-3),
the primary oscillator is shut down and the OSTS bit is
cleared. The IRCF bits may be modified at any time to
immediately change the clock speed.
3.2.3
RC_RUN MODE
In RC_RUN mode, the CPU and peripherals are
clocked from the internal oscillator block using the
INTOSC multiplexer. In this mode, the primary clock is
shut down. When using the INTRC source, this mode
provides the best power conservation of all the Run
modes, while still executing code. It works well for user
applications which are not highly timing-sensitive or do
not require high-speed clocks at all times.
Note:
Caution should be used when modifying a
single IRCF bit. If VDD is less than 3V, it is
possible to select a higher clock speed
than is supported by the low VDD.
Improper device operation may result if
the VDD/FOSC specifications are violated.
If the primary clock source is the internal oscillator
block (either INTRC or INTOSC), there are no distin-
guishable differences between PRI_RUN and
RC_RUN modes during execution. However, a clock
switch delay will occur during entry to and exit from
RC_RUN mode. Therefore, if the primary clock source
is the internal oscillator block, the use of RC_RUN
mode is not recommended.
© 2008 Microchip Technology Inc.
DS39646C-page 43
PIC18F8722 FAMILY
If the IRCF bits and the INTSRC bit are all clear, the
INTOSC output is not enabled and the IOFS bit will
remain clear; there will be no indication of the current
clock source. The INTRC source is providing the
device clocks.
On transitions from RC_RUN mode to PRI_RUN mode,
the device continues to be clocked from the INTOSC
multiplexer while the primary clock is started. When the
primary clock becomes ready, a clock switch to the
primary clock occurs (see Figure 3-4). When the clock
switch is complete, the IOFS bit is cleared, the OSTS
bit is set and the primary clock is providing the device
clock. The IDLEN and SCS bits are not affected by the
switch. The INTRC source will continue to run if either
the WDT or the Fail-Safe Clock Monitor is enabled.
If the IRCF bits are changed from all clear (thus,
enabling the INTOSC output) or if INTSRC is set, the
IOFS bit becomes set after the INTOSC output
becomes stable. Clocks to the device continue while
the INTOSC source stabilizes after an interval of
TIOBST (parameter 39, Table 28-12).
If the IRCF bits were previously at a non-zero value, or
if INTSRC was set before setting SCS1 and the
INTOSC source was already stable, the IOFS bit will
remain set.
FIGURE 3-3:
TRANSITION TIMING TO RC_RUN MODE
Q1 Q2 Q3 Q4 Q1
Q2
Q3
Q4
Q1
Q2
Q3
1
2
3
n-1
n
INTRC
OSC1
Clock Transition(1)
CPU
Clock
Peripheral
Clock
Program
Counter
PC
PC + 2
PC + 4
Note 1: Clock transition typically occurs within 2-4 TOSC.
FIGURE 3-4:
TRANSITION TIMING FROM RC_RUN MODE TO PRI_RUN MODE
Q3
Q4
Q1
Q2 Q3 Q4 Q1 Q2 Q3
Q1
Q2
INTOSC
Multiplexer
OSC1
(1)
TOST
(1)
TPLL
1
2
n-1
n
PLL Clock
Output
Clock
Transition(2)
CPU Clock
Peripheral
Clock
Program
Counter
PC + 2
PC + 4
PC
SCS1:SCS0 bits Changed
OSTS bit Set
Note1: TOST = 1024 TOSC; TPLL = 2 ms (approx). These intervals are not shown to scale.
2: Clock transition typically occurs within 2-4 TOSC.
DS39646C-page 44
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
3.3
Sleep Mode
3.4
Idle Modes
The power-managed Sleep mode in the PIC18F8722
family of devices is identical to the legacy Sleep mode
offered in all other PIC devices. It is entered by clearing
the IDLEN bit (the default state on device Reset) and
executing the SLEEP instruction. This shuts down the
selected oscillator (Figure 3-5). All clock source status
bits are cleared.
The Idle modes allow the controller’s CPU to be
selectively shut down while the peripherals continue to
operate. Selecting a particular Idle mode allows users
to further manage power consumption.
If the IDLEN bit is set to a ‘1’ when a SLEEPinstruction is
executed, the peripherals will be clocked from the clock
source selected using the SCS<1:0> bits; however, the
CPU will not be clocked. The clock source status bits are
not affected. Setting IDLEN and executing a SLEEP
instruction provides a quick method of switching from a
given Run mode to its corresponding Idle mode.
Entering the Sleep mode from any other mode does not
require a clock switch. This is because no clocks are
needed once the controller has entered Sleep. If the
WDT is selected, the INTRC source will continue to
operate. If the Timer1 oscillator is enabled, it will also
continue to run.
If the WDT is selected, the INTRC source will continue
to operate. If the Timer1 oscillator is enabled, it will also
continue to run.
When a wake event occurs in Sleep mode (by interrupt,
Reset or WDT time-out), the device will not be clocked
until the clock source selected by the SCS<1:0> bits
becomes ready (see Figure 3-6), or it will be clocked
from the internal oscillator block if either the Two-Speed
Start-up or the Fail-Safe Clock Monitor are enabled
(see Section 25.0 “Special Features of the CPU”). In
either case, the OSTS bit is set when the primary clock
is providing the device clocks. The IDLEN and SCS bits
are not affected by the wake-up.
Since the CPU is not executing instructions, the only
exits from any of the Idle modes are by interrupt, WDT
time-out or a Reset. When a wake event occurs, CPU
execution is delayed by an interval of TCSD
(parameter 38, Table 28-12) while it becomes ready to
execute code. When the CPU begins executing code,
it resumes with the same clock source for the current
Idle mode. For example, when waking from RC_IDLE
mode, the internal oscillator block will clock the CPU
and peripherals (in other words, RC_RUN mode). The
IDLEN and SCS bits are not affected by the wake-up.
While in any Idle mode or the Sleep mode, a WDT
time-out will result in a WDT wake-up to the Run mode
currently specified by the SCS<1:0> bits.
FIGURE 3-5:
TRANSITION TIMING FOR ENTRY TO SLEEP MODE
Q1 Q2 Q3 Q4 Q1
OSC1
CPU
Clock
Peripheral
Clock
Sleep
Program
Counter
PC
PC + 2
FIGURE 3-6:
TRANSITION TIMING FOR WAKE FROM SLEEP (HSPLL)
Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q2 Q3 Q4 Q1 Q2
Q1
OSC1
(1)
(1)
TOST
TPLL
PLL Clock
Output
CPU Clock
Peripheral
Clock
Program
Counter
PC
PC + 2
PC + 4
PC + 6
Wake Event
Note1:TOST = 1024 TOSC; TPLL = 2 ms (approx). These intervals are not shown to scale.
OSTS bit Set
© 2008 Microchip Technology Inc.
DS39646C-page 45
PIC18F8722 FAMILY
3.4.1
PRI_IDLE MODE
3.4.2
SEC_IDLE MODE
This mode is unique among the three low-power Idle
modes, in that it does not disable the primary device
clock. For timing sensitive applications, this allows for
the fastest resumption of device operation with its more
accurate primary clock source, since the clock source
does not have to “warm-up” or transition from another
oscillator.
In SEC_IDLE mode, the CPU is disabled but the
peripherals continue to be clocked from the Timer1
oscillator. This mode is entered from SEC_RUN by set-
ting the IDLEN bit and executing a SLEEPinstruction. If
the device is in another Run mode, set the IDLEN bit
first, then set the SCS<1:0> bits to ‘01’ and execute
SLEEP. When the clock source is switched to the
Timer1 oscillator, the primary oscillator is shut down,
the OSTS bit is cleared and the T1RUN bit is set.
PRI_IDLE mode is entered from PRI_RUN mode by
setting the IDLEN bit and executing a SLEEP instruc-
tion. If the device is in another Run mode, set IDLEN
first, then clear the SCS bits and execute SLEEP.
Although the CPU is disabled, the peripherals continue
to be clocked from the primary clock source specified
by the FOSC<3:0> Configuration bits. The OSTS bit
remains set (see Figure 3-7).
When a wake event occurs, the peripherals continue to
be clocked from the Timer1 oscillator. After an interval
of TCSD following the wake event, the CPU begins exe-
cuting code being clocked by the Timer1 oscillator. The
IDLEN and SCS bits are not affected by the wake-up;
the Timer1 oscillator continues to run (see Figure 3-8).
When a wake event occurs, the CPU is clocked from the
primary clock source. A delay of interval TCSD
(parameter 39, Table 28-12) is required between the
wake event and when code execution starts. This is
required to allow the CPU to become ready to execute
instructions. After the wake-up, the OSTS bit remains
set. The IDLEN and SCS bits are not affected by the
wake-up (see Figure 3-8).
Note:
The Timer1 oscillator should already be
running prior to entering SEC_IDLE mode.
If the T1OSCEN bit is not set when the
SLEEPinstruction is executed, the SLEEP
instruction will be ignored and entry to
SEC_IDLE mode will not occur. If the
Timer1 oscillator is enabled but not yet
running, peripheral clocks will be delayed
until the oscillator has started. In such
situations, initial oscillator operation is far
from stable and unpredictable operation
may result.
FIGURE 3-7:
TRANSITION TIMING FOR ENTRY TO IDLE MODE
Q3
Q4
Q1
Q1
Q2
OSC1
CPU Clock
Peripheral
Clock
Program
Counter
PC
PC + 2
FIGURE 3-8:
TRANSITION TIMING FOR WAKE FROM IDLE TO RUN MODE
Q1
Q3
Q4
Q2
OSC1
TCSD
CPU Clock
Peripheral
Clock
Program
Counter
PC
Wake Event
DS39646C-page 46
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
On all exits from Idle or Sleep modes by interrupt, code
execution branches to the interrupt vector if the GIE/
GIEH bit (INTCON<7>) is set. Otherwise, code execu-
tion continues or resumes without branching (see
Section 10.0 “Interrupts”).
3.4.3
RC_IDLE MODE
In RC_IDLE mode, the CPU is disabled but the periph-
erals continue to be clocked from the internal oscillator
block using the INTOSC multiplexer. This mode allows
for controllable power conservation during Idle periods.
A fixed delay of interval TCSD following the wake event
is required when leaving Sleep and Idle modes. This
delay is required for the CPU to prepare for execution.
Instruction execution resumes on the first clock cycle
following this delay.
From RC_RUN, this mode is entered by setting the
IDLEN bit and executing a SLEEP instruction. If the
device is in another Run mode, first set IDLEN, then set
the SCS1 bit and execute SLEEP. Although its value is
ignored, it is recommended that SCS0 also be cleared;
this is to maintain software compatibility with future
devices. The INTOSC multiplexer may be used to
select a higher clock frequency by modifying the IRCF
bits before executing the SLEEPinstruction. When the
clock source is switched to the INTOSC multiplexer, the
primary oscillator is shut down and the OSTS bit is
cleared.
3.5.2
EXIT BY WDT TIME-OUT
A WDT time-out will cause different actions depending
on which power-managed mode the device is in when
the time-out occurs.
If the device is not executing code (all Idle modes and
Sleep mode), the time-out will result in an exit from the
power-managed mode (see Section 3.2 “Run
Modes” and Section 3.3 “Sleep Mode”). If the device
is executing code (all Run modes), the time-out will
result in a WDT Reset (see Section 25.2 “Watchdog
Timer (WDT)”).
If the IRCF bits are set to any non-zero value, or the
INTSRC bit is set, the INTOSC output is enabled. The
IOFS bit becomes set, after the INTOSC output
becomes stable, after an interval of TIOBST
(parameter 39, Table 28-12). Clocks to the peripherals
continue while the INTOSC source stabilizes. If the
IRCF bits were previously at a non-zero value, or
INTSRC was set before the SLEEPinstruction was exe-
cuted and the INTOSC source was already stable, the
IOFS bit will remain set. If the IRCF bits and INTSRC
are all clear, the INTOSC output will not be enabled, the
IOFS bit will remain clear and there will be no indication
of the current clock source.
The WDT timer and postscaler are cleared by
executing a SLEEPor CLRWDTinstruction, the loss of a
currently selected clock source (if the Fail-Safe Clock
Monitor is enabled) and modifying the IRCF bits in the
OSCCON register if the internal oscillator block is the
device clock source.
3.5.3
EXIT BY RESET
When a wake event occurs, the peripherals continue to
be clocked from the INTOSC multiplexer. After a delay
of TCSD (parameter 38, Table 28-12) following the wake
event, the CPU begins executing code being clocked
by the INTOSC multiplexer. The IDLEN and SCS bits
are not affected by the wake-up. The INTRC source will
continue to run if either the WDT or the Fail-Safe Clock
Monitor is enabled.
Normally, the device is held in Reset by the Oscillator
Start-up Timer (OST) until the primary clock becomes
ready. At that time, the OSTS bit is set and the device
begins executing code. If the internal oscillator block is
the new clock source, the IOFS bit is set instead.
The exit delay time from Reset to the start of code
execution depends on both the clock sources before
and after the wake-up and the type of oscillator if the
new clock source is the primary clock. Exit delays are
summarized in Table 3-2.
3.5
Exiting Idle and Sleep Modes
An exit from Sleep mode or any of the Idle modes is
triggered by an interrupt, a Reset or a WDT time-out.
This section discusses the triggers that cause exits
from power-managed modes. The clocking subsystem
actions are discussed in each of the power-managed
modes (see Section 3.2 “Run Modes”, Section 3.3
“Sleep Mode” and Section 3.4 “Idle Modes”).
Code execution can begin before the primary clock
becomes ready. If either the Two-Speed Start-up (see
Section 25.3 “Two-Speed Start-up”) or Fail-Safe
Clock Monitor (see Section 25.4 “Fail-Safe Clock
Monitor”) is enabled, the device may begin execution
as soon as the Reset source has cleared. Execution is
clocked by the INTOSC multiplexer driven by the inter-
nal oscillator block. Execution is clocked by the internal
oscillator block until either the primary clock becomes
ready or a power-managed mode is entered before the
primary clock becomes ready; the primary clock is then
shut down.
3.5.1
EXIT BY INTERRUPT
Any of the available interrupt sources can cause the
device to exit from an Idle mode or the Sleep mode to
a Run mode. To enable this functionality, an interrupt
source must be enabled by setting its enable bit in one
of the INTCON or PIE registers. The exit sequence is
initiated when the corresponding interrupt flag bit is set.
© 2008 Microchip Technology Inc.
DS39646C-page 47
PIC18F8722 FAMILY
In these instances, the primary clock source either
does not require an oscillator start-up delay since it is
already running (PRI_IDLE), or normally does not
require an oscillator start-up delay (RC, EC and INTIO
Oscillator modes). However, a fixed delay of interval
TCSD following the wake event is still required when
leaving Sleep and Idle modes to allow the CPU to
prepare for execution. Instruction execution resumes
on the first clock cycle following this delay.
3.5.4
EXIT WITHOUT AN OSCILLATOR
START-UP DELAY
Certain exits from power-managed modes do not
invoke the OST at all. There are two cases:
• PRI_IDLE mode, where the primary clock source
is not stopped and
• the primary clock source is not any of the LP, XT,
HS or HSPLL modes.
TABLE 3-2:
EXIT DELAY ON WAKE-UP BY RESET FROM SLEEP MODE OR ANY IDLE MODE
(BY CLOCK SOURCES)
Clock Source
before Wake-up
Clock Source
after Wake-up
Clock Ready Status
Bit (OSCCON)
Exit Delay
LP, XT, HS
HSPLL
OSTS
IOFS
OSTS
IOFS
OSTS
IOFS
OSTS
IOFS
Primary Device Clock
(PRI_IDLE mode)
(1)
TCSD
EC, RC
INTOSC(2)
LP, XT, HS
HSPLL
(3)
TOST
(3)
TOST + trc
T1OSC or INTRC
INTOSC(2)
(1)
EC, RC
TCSD
INTOSC(2)
LP, XT, HS
HSPLL
TIOBST
(4)
(4)
TOST
(3)
TOST + trc
(1)
EC, RC
TCSD
INTOSC(2)
LP, XT, HS
HSPLL
None
(3)
TOST
(3)
TOST + trc
None
(Sleep mode)
(1)
EC, RC
INTOSC(2)
TCSD
(4)
TIOBST
Note 1: TCSD (parameter 38, Table 28-12) is a required delay when waking from Sleep and all Idle modes and runs
concurrently with any other required delays (see Section 3.4 “Idle Modes”).
2: Includes both the INTOSC 8 MHz source and postscaler derived frequencies. On Reset, INTOSC defaults
to 1 MHz.
3: TOST is the Oscillator Start-up Timer (parameter 32, Table 28-12). trc is the PLL Lock-out Timer
(parameter F12, Table 28-7); it is also designated as TPLL.
4: Execution continues during TIOBST (parameter 39, Table 28-12), the INTOSC stabilization period.
DS39646C-page 48
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
A simplified block diagram of the On-Chip Reset Circuit
is shown in Figure 4-1.
4.0
RESET
The PIC18F8722 family of devices differentiates
between various kinds of Reset:
4.1
RCON Register
a) Power-on Reset (POR)
Device Reset events are tracked through the RCON
register (Register 4-1). The lower five bits of the regis-
ter indicate that a specific Reset event has occurred. In
most cases, these bits can only be cleared by the event
and must be set by the application after the event. The
state of these flag bits, taken together, can be read to
indicate the type of Reset that just occurred. This is
described in more detail in Section 4.6 “Reset State
of Registers”.
b) MCLR Reset during normal operation
c) MCLR Reset during power-managed modes
d) Watchdog Timer (WDT) Reset (during
execution)
e) Programmable Brown-out Reset (BOR)
f) RESETInstruction
g) Stack Full Reset
h) Stack Underflow Reset
The RCON register also has control bits for setting
interrupt priority (IPEN) and software control of the
BOR (SBOREN). Interrupt priority is discussed in
Section 10.0 “Interrupts”. BOR is covered in
Section 4.4 “Brown-out Reset (BOR)”.
This section discusses Resets generated by MCLR,
POR and BOR and covers the operation of the various
start-up timers. Stack Reset events are covered in
Section 5.1.3.4 “Stack Full and Underflow Resets”.
WDT Resets are covered in Section 25.2 “Watchdog
Timer (WDT)”.
FIGURE 4-1:
SIMPLIFIED BLOCK DIAGRAM OF ON-CHIP RESET CIRCUIT
RESET
Instruction
Stack Full/Underflow Reset
Stack
Pointer
External Reset
MCLRE
MCLR
( )_IDLE
Sleep
WDT
Time-out
VDD Rise
Detect
POR Pulse
BOREN
VDD
Brown-out
Reset
S
OST/PWRT
OST
10-bit Ripple Counter
1024 Cycles
Chip_Reset
R
Q
OSC1
31 μs
64 ms
PWRT
11-Bit Ripple Counter
INTRC(1)
Enable PWRT
(2)
Enable OST
Note 1: This is the INTRC source from the internal oscillator block and is separate from the RC oscillator of the CLKI pin.
2: See Table 4-2 for time-out situations.
© 2008 Microchip Technology Inc.
DS39646C-page 49
PIC18F8722 FAMILY
REGISTER 4-1:
RCON: RESET CONTROL REGISTER
R/W-0
IPEN
R/W-1(1)
U-0
—
R/W-1
RI
R-1
TO
R-1
PD
R/W-0(2)
POR
R/W-0
BOR
SBOREN
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
-n = Value at POR
bit 7
bit 6
IPEN: Interrupt Priority Enable bit
1= Enable priority levels on interrupts
0= Disable priority levels on interrupts (PIC16CXXX Compatibility mode)
SBOREN: BOR Software Enable bit(1)
If BOREN<1:0> = 01:
1= BOR is enabled
0= BOR is disabled
If BOREN<1:0> = 00, 10 or 11:
Bit is disabled and read as ‘0’
bit 5
bit 4
Unimplemented: Read as ‘0’
RI: RESETInstruction Flag bit
1= The RESETinstruction was not executed (set by firmware only)
0= The RESET instruction was executed causing a device Reset (must be set in software after a
Brown-out Reset occurs)
bit 3
bit 2
bit 1
bit 0
TO: Watchdog Time-out Flag bit
1= Set by power-up, CLRWDTinstruction or SLEEPinstruction
0= A WDT time-out occurred
PD: Power-down Detection Flag bit
1= Set by power-up or by the CLRWDTinstruction
0= Set by execution of the SLEEPinstruction
POR: Power-on Reset Status bit(2)
1= A Power-on Reset has not occurred (set by firmware only)
0= A Power-on Reset occurred (must be set in software after a Power-on Reset occurs)
BOR: Brown-out Reset Status bit
1= A Brown-out Reset has not occurred (set by firmware only)
0= A Brown-out Reset occurred (must be set in software after a Brown-out Reset occurs)
Note 1: If SBOREN is enabled, its Reset state is ‘1’; otherwise, it is ‘0’.
2: The actual Reset value of POR is determined by the type of device Reset. See the notes following this
register and Section 4.6 “Reset State of Registers” for additional information.
Note 1: It is recommended that the POR bit be set after a Power-on Reset has been detected so that subsequent
Power-on Resets may be detected.
2: Brown-out Reset is said to have occurred when BOR is ‘0’ and POR is ‘1’ (assuming that POR was set to
‘1’ by software immediately after POR).
DS39646C-page 50
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
FIGURE 4-2:
EXTERNAL POWER-ON
RESET CIRCUIT (FOR
SLOWVDDPOWER-UP)(1)
4.2
Master Clear (MCLR)
The MCLR pin provides a method for triggering an
external Reset of the device. A Reset is generated by
holding the pin low. These devices have a noise filter in
the MCLR Reset path which detects and ignores small
pulses.
VDD
VDD
D
(2)
The MCLR pin is not driven low by any internal Resets,
including the WDT.
R
(3)
R1
MCLR
In the PIC18F8722 family of devices, the MCLR input
can be disabled with the MCLRE Configuration bit.
When MCLR is disabled, the pin becomes a digital
input. See Section 11.5 “PORTE, TRISE and LATE
Registers” for more information.
PIC18FXXXX
C
Note 1: External Power-on Reset circuit is required
only if the VDD power-up slope is too slow.
The diode D helps discharge the capacitor
quickly when VDD powers down.
4.3
Power-on Reset (POR)
A
Power-on Reset pulse is generated on-chip
2: R < 40 kΩ is recommended to make sure that
the voltage drop across R does not violate
the device’s electrical specification.
whenever VDD rises above a certain threshold. This
allows the device to start in the initialized state when
VDD is adequate for operation.
3: R1 ≥ 1 kΩ will limit any current flowing into
MCLR from external capacitor C, in the event
of MCLR/VPP pin breakdown, due to
Electrostatic Discharge (ESD) or Electrical
Overstress (EOS).
To take advantage of the POR circuitry, tie the MCLR pin
through a resistor (1 kΩ to 10 kΩ) to VDD. This will
eliminate external RC components usually needed to
create a Power-on Reset delay. A minimum rise rate for
VDD is specified (parameter D004, “Section 28.2 “DC
Characteristics: Power-Down and Supply Current”).
For a slow rise time, see Figure 4-2.
When the device starts normal operation (i.e., exits the
Reset condition), device operating parameters (volt-
age, frequency, temperature, etc.) must be met to
ensure operation. If these conditions are not met, the
device must be held in Reset until the operating
conditions are met.
POR events are captured by the POR bit (RCON<1>).
The state of the bit is set to ‘0’ whenever a POR occurs;
it does not change for any other Reset event. POR is
not reset to ‘1’ by any hardware event. To capture
multiple events, the user manually resets the bit to ‘1’
in software following any POR.
© 2008 Microchip Technology Inc.
DS39646C-page 51
PIC18F8722 FAMILY
Placing the BOR under software control gives the user
the additional flexibility of tailoring the application to its
environment without having to reprogram the device to
change the BOR configuration. It also allows the user
to tailor device power consumption in software by
eliminating the incremental current that the BOR con-
sumes. While the BOR current is typically very small, it
may have some impact in low-power applications.
4.4
Brown-out Reset (BOR)
The PIC18F8722 family of devices implements a BOR
circuit that provides the user with a number of con-
figuration and power-saving options. The BOR is
controlled by the BORV<1:0> and BOREN<1:0>
Configuration bits. There are a total of four BOR
configurations which are summarized in Table 4-1.
The BOR threshold is set by the BORV<1:0> bits. If
BOR is enabled (any values of BOREN<1:0>, except
‘00’), any drop of VDD below VBOR (parameter D005,
Section 28.1 “DC Characteristics”) for greater than
TBOR (parameter 35, Table 28-12) will reset the device.
A Reset may or may not occur if VDD falls below VBOR
for less than TBOR. The chip will remain in Brown-out
Reset until VDD rises above VBOR.
Note:
Even when BOR is under software control,
the BOR Reset voltage level is still set by
the BORV<1:0> Configuration bits. It
cannot be changed in software.
4.4.2
DETECTING BOR
When BOR is enabled, the BOR bit always resets to ‘0’
on any BOR or POR event. This makes it difficult to
determine if a BOR event has occurred just by reading
the state of BOR alone. A more reliable method is to
simultaneously check the state of both POR and BOR.
This assumes that the POR bit is reset to ‘1’ in software
immediately after any POR event. If BOR is ‘0’ while
POR is ‘1’, it can be reliably assumed that a BOR event
has occurred.
If the Power-up Timer is enabled, it will be invoked after
VDD rises above VBOR; it then will keep the chip in
Reset for an additional time delay, TPWRT
(parameter 33, Table 28-12). If VDD drops below VBOR
while the Power-up Timer is running, the chip will go
back into a Brown-out Reset and the Power-up Timer
will be initialized. Once VDD rises above VBOR, the
Power-up Timer will execute the additional time delay.
4.4.3
DISABLING BOR IN SLEEP MODE
BOR and the Power-on Timer (PWRT) are
independently configured. Enabling BOR Reset does
not automatically enable the PWRT.
When BOREN<1:0> = 10, the BOR remains under
hardware control and operates as previously
described. Whenever the device enters Sleep mode,
however, the BOR is automatically disabled. When the
device returns to any other operating mode, BOR is
automatically re-enabled.
4.4.1
SOFTWARE ENABLED BOR
When BOREN<1:0> = 01, the BOR can be enabled or
disabled by the user in software. This is done with the
control bit, SBOREN (RCON<6>). Setting SBOREN
enables the BOR to function as previously described.
Clearing SBOREN disables the BOR entirely. The
SBOREN bit operates only in this mode; otherwise it is
read as ‘0’.
This mode allows for applications to recover from
brown-out situations, while actively executing code,
when the device requires BOR protection the most. At
the same time, it saves additional power in Sleep mode
by eliminating the small incremental BOR current.
TABLE 4-1:
BOREN1
BOR CONFIGURATIONS
BOR Configuration
Status of
SBOREN
BOR Operation
BOREN0
(RCON<6>)
0
0
1
0
1
0
Unavailable BOR disabled; must be enabled by reprogramming the Configuration bits.
Available BOR enabled in software; operation controlled by SBOREN.
Unavailable BOR enabled in hardware in Run and Idle modes, disabled during
Sleep mode.
1
1
Unavailable BOR enabled in hardware; must be disabled by reprogramming the
Configuration bits.
DS39646C-page 52
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
4.5.3
PLL LOCK TIME-OUT
4.5
Device Reset Timers
With the PLL enabled in its PLL mode, the time-out
sequence following a Power-on Reset is slightly differ-
ent from other oscillator modes. A separate timer is
used to provide a fixed time-out that is sufficient for the
PLL to lock to the main oscillator frequency. This PLL
lock time-out (TPLL) is typically 2 ms and follows the
oscillator start-up time-out.
The PIC18F8722 family of devices incorporates three
separate on-chip timers that help regulate the Power-on
Reset process. Their main function is to ensure that the
device clock is stable before code is executed. These
timers are:
• Power-up Timer (PWRT)
• Oscillator Start-up Timer (OST)
• PLL Lock Time-out
4.5.4
TIME-OUT SEQUENCE
On power-up, the time-out sequence is as follows:
4.5.1
POWER-UP TIMER (PWRT)
1. After the POR pulse has cleared, PWRT time-out
is invoked (if enabled).
The Power-up Timer (PWRT) of the PIC18F8722
family of devices is an 11-bit counter which uses the
INTRC source as the clock input. While the PWRT is
counting, the device is held in Reset.
2. Then, the OST is activated.
The total time-out will vary based on oscillator configu-
ration and the status of the PWRT. Figure 4-3,
Figure 4-4, Figure 4-5, Figure 4-6 and Figure 4-7 all
depict time-out sequences on power-up, with the
Power-up Timer enabled and the device operating in
HS Oscillator mode. Figures 4-3 through 4-6 also apply
to devices operating in XT or LP modes. For devices in
RC mode and with the PWRT disabled, on the other
hand, there will be no time-out at all.
The power-up time delay depends on the INTRC clock
and will vary from chip-to-chip due to temperature and
process variation. See DC parameter 33 in Table 28-12
for details.
The PWRT is enabled by clearing the PWRTEN
Configuration bit.
4.5.2
OSCILLATOR START-UP TIMER
(OST)
Since the time-outs occur from the POR pulse, if MCLR
is kept low long enough, all time-outs will expire. Bring-
ing MCLR high will begin execution immediately
(Figure 4-5). This is useful for testing purposes or to
synchronize more than one PIC18F8722 family device
operating in parallel.
The Oscillator Start-up Timer (OST) provides a 1024
oscillator cycle (from OSC1 input) delay after the
PWRT delay is over (parameter 33, Table 28-12). This
ensures that the crystal oscillator or resonator has
started and stabilized.
The OST time-out is invoked only for XT, LP, HS and
HSPLL modes and only on Power-on Reset, or on exit
from most power-managed modes.
TABLE 4-2:
Oscillator
TIME-OUT IN VARIOUS SITUATIONS
Power-up(2) and Brown-out
Exit from
Configuration
Power-Managed Mode
PWRTEN = 0
PWRTEN = 1
(2)
(2)
(2)
HSPLL
TPWRT(1) + 1024 TOSC + TPLL
1024 TOSC + TPLL
1024 TOSC + TPLL
HS, XT, LP
EC, ECIO
TPWRT(1) + 1024 TOSC
1024 TOSC
1024 TOSC
(1)
TPWRT
—
—
—
—
—
—
(1)
RC, RCIO
TPWRT
(1)
INTIO1, INTIO2
TPWRT
Note 1: See parameter 33, Table 28-12.
2: 2 ms is the nominal time required for the PLL to lock.
© 2008 Microchip Technology Inc.
DS39646C-page 53
PIC18F8722 FAMILY
FIGURE 4-3:
TIME-OUT SEQUENCE ON POWER-UP (MCLR TIED TO VDD, VDD RISE < TPWRT)
VDD
MCLR
INTERNAL POR
TPWRT
PWRT TIME-OUT
OST TIME-OUT
TOST
INTERNAL RESET
FIGURE 4-4:
TIME-OUT SEQUENCE ON POWER-UP (MCLR NOT TIED TO VDD): CASE 1
VDD
MCLR
INTERNAL POR
TPWRT
PWRT TIME-OUT
OST TIME-OUT
TOST
INTERNAL RESET
FIGURE 4-5:
TIME-OUT SEQUENCE ON POWER-UP (MCLR NOT TIED TO VDD): CASE 2
VDD
MCLR
INTERNAL POR
TPWRT
PWRT TIME-OUT
OST TIME-OUT
TOST
INTERNAL RESET
DS39646C-page 54
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
FIGURE 4-6:
SLOW RISE TIME (MCLR TIED TO VDD, VDD RISE > TPWRT)
VDD
MCLR
INTERNAL POR
TPWRT
PWRT TIME-OUT
TOST
OST TIME-OUT
INTERNAL RESET
FIGURE 4-7:
TIME-OUT SEQUENCE ON POR w/PLL ENABLED (MCLR TIED TO VDD)
VDD
MCLR
INTERNAL POR
TPWRT
PWRT TIME-OUT
OST TIME-OUT
TOST
TPLL
PLL TIME-OUT
INTERNAL RESET
Note:
TOST = 1024 clock cycles.
TPLL ≈ 2 ms is the nominal time required for the PLL to lock.
© 2008 Microchip Technology Inc.
DS39646C-page 55
PIC18F8722 FAMILY
Table 4-4 describes the Reset states for all of the
Special Function Registers. These are categorized by
Power-on and Brown-out Resets, Master Clear and
WDT Resets and WDT wake-ups.
4.6
Reset State of Registers
Most registers are unaffected by a Reset. Their status
is unknown on POR and unchanged by all other
Resets. All other registers are forced to a “Reset state”
depending on the type of Reset that occurred.
Most registers are not affected by a WDT wake-up,
since this is viewed as the resumption of normal oper-
ation. Status bits from the RCON register, RI, TO, PD,
POR and BOR, are set or cleared differently in different
Reset situations, as indicated in Table 4-3. These bits
are used in software to determine the nature of the
Reset.
TABLE 4-3:
STATUS BITS, THEIR SIGNIFICANCE AND THE INITIALIZATION CONDITION
FOR RCON REGISTER
RCON Register
STKPTR Register
Program
Counter
Condition
SBOREN
RI
TO
PD POR BOR STKFUL STKUNF
Power-on Reset
RESETInstruction
Brown-out Reset
0000h
0000h
0000h
0000h
1
1
0
1
u
1
u
1
1
1
u
1
u
0
u
u
u
0
u
0
u
0
u
u
u
0
u
u
u
u(2)
u(2)
u(2)
MCLR during Power-Managed
Run Modes
MCLR during Power-Managed
Idle Modes and Sleep Mode
0000h
0000h
0000h
u(2)
u(2)
u(2)
u
u
u
1
0
u
0
u
u
u
u
u
u
u
u
u
u
u
u
u
u
WDT Time-out during Full Power
or Power-Managed Run Mode
MCLR during Full Power
Execution
Stack Full Reset (STVREN = 1)
0000h
0000h
u(2)
u(2)
u
u
u
u
u
u
u
u
u
u
1
u
u
1
Stack Underflow Reset
(STVREN = 1)
Stack Underflow Error (not an
actual Reset, STVREN = 0)
0000h
u(2)
u(2)
u
u
u
0
u
0
u
u
u
u
u
u
1
u
WDT Time-out during
Power-Managed Idle or
Sleep Modes
PC + 2
Interrupt Exit from
PC + 2(1)
u(2)
u
u
0
u
u
u
u
Power-Managed Modes
Legend: u= unchanged
Note 1: When the wake-up is due to an interrupt and the GIEH or GIEL bits are set, the PC is loaded with the
interrupt vector (008h or 0018h).
2: Reset state is ‘1’ for POR and unchanged for all other Resets when software BOR is enabled
(BOREN<1:0> Configuration bits = 01and SBOREN = 1). Otherwise, the Reset state is ‘0’.
DS39646C-page 56
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
TABLE 4-4:
INITIALIZATION CONDITIONS FOR ALL REGISTERS
MCLR Resets,
WDT Reset,
RESET Instruction,
Stack Resets
Power-on Reset,
Brown-out Reset
Wake-up via WDT
or Interrupt
Register
Applicable Devices
(3)
TOSU
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
---0 0000
0000 0000
0000 0000
00-0 0000
---0 0000
0000 0000
0000 0000
--00 0000
0000 0000
0000 0000
0000 0000
xxxx xxxx
xxxx xxxx
0000 000x
1111 1111
1100 0000
N/A
---0 0000
0000 0000
0000 0000
uu-u uuuu
---0 0000
0000 0000
0000 0000
--00 0000
0000 0000
0000 0000
0000 0000
uuuu uuuu
uuuu uuuu
0000 000u
1111 1111
1100 0000
N/A
---0 uuuu
(3)
TOSH
uuuu uuuu
(3)
TOSL
uuuu uuuu
(3)
STKPTR
PCLATU
PCLATH
PCL
uu-u uuuu
---u uuuu
uuuu uuuu
(2)
PC + 2
TBLPTRU
TBLPTRH
TBLPTRL
TABLAT
PRODH
PRODL
--uu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
(1)
INTCON
INTCON2
INTCON3
INDF0
uuuu uuuu
(1)
uuuu uuuu
(1)
uuuu uuuu
N/A
N/A
POSTINC0
POSTDEC0
PREINC0
PLUSW0
FSR0H
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
---- 0000
xxxx xxxx
xxxx xxxx
N/A
---- 0000
uuuu uuuu
uuuu uuuu
N/A
---- uuuu
uuuu uuuu
uuuu uuuu
N/A
FSR0L
WREG
INDF1
POSTINC1
POSTDEC1
PREINC1
PLUSW1
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
Legend:
u= unchanged, x= unknown, -= unimplemented bit, read as ‘0’, q= value depends on condition.
Shaded cells indicate conditions do not apply for the designated device.
Note 1: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up).
2: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the PC is loaded with the interrupt vector
(0008h or 0018h).
3: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the TOSU, TOSH and TOSL are updated with
the current value of the PC. The STKPTR is modified to point to the next location in the hardware stack.
4: See Table 4-3 for Reset value for specific condition.
5: Bits 6 and 7 of PORTA, LATA and TRISA are enabled, depending on the oscillator mode selected. When not enabled
as PORTA pins, they are disabled and read ‘0’.
© 2008 Microchip Technology Inc.
DS39646C-page 57
PIC18F8722 FAMILY
TABLE 4-4:
INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED)
MCLR Resets,
WDT Reset,
RESET Instruction,
Stack Resets
Power-on Reset,
Brown-out Reset
Wake-up via WDT
or Interrupt
Register
Applicable Devices
FSR1H
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
---- uuuu
uuuu uuuu
---- uuuu
N/A
---- 0000
xxxx xxxx
---- 0000
N/A
---- 0000
uuuu uuuu
---- 0000
N/A
FSR1L
BSR
INDF2
POSTINC2
POSTDEC2
PREINC2
PLUSW2
FSR2H
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
---- uuuu
uuuu uuuu
---u uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuqu
u-uu uuuu
---- ---u
uq-u qquu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
-uuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
---- 0000
xxxx xxxx
---x xxxx
0000 0000
xxxx xxxx
1111 1111
0100 q000
0-00 0101
---- ---0
0q-1 11q0
xxxx xxxx
xxxx xxxx
0000 0000
0000 0000
1111 1111
-000 0000
xxxx xxxx
0000 0000
0000 0000
0000 0000
0000 0000
---- 0000
uuuu uuuu
---u uuuu
0000 0000
uuuu uuuu
1111 1111
0100 q000
0-00 0101
---- ---0
0q-q qquu
uuuu uuuu
uuuu uuuu
u0uu uuuu
0000 0000
uuuu uuuu
-000 0000
uuuu uuuu
0000 0000
0000 0000
0000 0000
0000 0000
FSR2L
STATUS
TMR0H
TMR0L
T0CON
OSCCON
HLVDCON
WDTCON
(4)
RCON
TMR1H
TMR1L
T1CON
TMR2
PR2
T2CON
SSP1BUF
SSP1ADD
SSP1STAT
SSP1CON1
SSP1CON2
Legend:
u= unchanged, x= unknown, -= unimplemented bit, read as ‘0’, q= value depends on condition.
Shaded cells indicate conditions do not apply for the designated device.
Note 1: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up).
2: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the PC is loaded with the interrupt vector
(0008h or 0018h).
3: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the TOSU, TOSH and TOSL are updated with
the current value of the PC. The STKPTR is modified to point to the next location in the hardware stack.
4: See Table 4-3 for Reset value for specific condition.
5: Bits 6 and 7 of PORTA, LATA and TRISA are enabled, depending on the oscillator mode selected. When not enabled
as PORTA pins, they are disabled and read ‘0’.
DS39646C-page 58
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
TABLE 4-4:
INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED)
MCLR Resets,
WDT Reset,
RESET Instruction,
Stack Resets
Power-on Reset,
Brown-out Reset
Wake-up via WDT
or Interrupt
Register
Applicable Devices
ADRESH
ADRESL
ADCON0
ADCON1
ADCON2
CCPR1H
CCPR1L
CCP1CON
CCPR2H
CCPR2L
CCP2CON
CCPR3H
CCPR3L
CCP3CON
ECCP1AS
CVRCON
CMCON
TMR3H
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
xxxx xxxx
xxxx xxxx
--00 0000
--00 0000
0-00 0000
xxxx xxxx
xxxx xxxx
0000 0000
xxxx xxxx
xxxx xxxx
0000 0000
xxxx xxxx
xxxx xxxx
0000 0000
0000 0000
0000 0000
0000 0111
xxxx xxxx
xxxx xxxx
0000 0000
0000 ----
0000 0000
0000 0000
0000 0000
0000 0010
0000 000x
---- --00
0000 0000
0000 0000
0000 0000
xx-0 x000
uuuu uuuu
uuuu uuuu
--00 0000
--00 0000
0-00 0000
uuuu uuuu
uuuu uuuu
0000 0000
uuuu uuuu
uuuu uuuu
0000 0000
uuuu uuuu
uuuu uuuu
0000 0000
0000 0000
0000 0000
0000 0111
uuuu uuuu
uuuu uuuu
uuuu uuuu
0000 ----
0000 0000
0000 0000
0000 0000
0000 0010
0000 000x
---- --00
0000 0000
0000 0000
0000 0000
uu-0 u000
uuuu uuuu
uuuu uuuu
--uu uuuu
--uu uuuu
u-uu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu ----
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
---- --uu
uuuu uuuu
uuuu uuuu
0000 0000
uu-u uuuu
TMR3L
T3CON
PSPCON
SPBRG1
RCREG1
TXREG1
TXSTA1
RCSTA1
EEADRH
EEADR
EEDATA
EECON2
EECON1
Legend:
u= unchanged, x= unknown, -= unimplemented bit, read as ‘0’, q= value depends on condition.
Shaded cells indicate conditions do not apply for the designated device.
Note 1: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up).
2: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the PC is loaded with the interrupt vector
(0008h or 0018h).
3: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the TOSU, TOSH and TOSL are updated with
the current value of the PC. The STKPTR is modified to point to the next location in the hardware stack.
4: See Table 4-3 for Reset value for specific condition.
5: Bits 6 and 7 of PORTA, LATA and TRISA are enabled, depending on the oscillator mode selected. When not enabled
as PORTA pins, they are disabled and read ‘0’.
© 2008 Microchip Technology Inc.
DS39646C-page 59
PIC18F8722 FAMILY
TABLE 4-4:
INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED)
MCLR Resets,
WDT Reset,
RESET Instruction,
Stack Resets
Power-on Reset,
Brown-out Reset
Wake-up via WDT
or Interrupt
Register
Applicable Devices
IPR3
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
1111 1111
0000 0000
0000 0000
11-1 1111
00-0 0000
00-0 0000
1111 1111
0000 0000
0000 0000
0-00 --00
00-0 0000
1111 1111
1111 1111
---1 1111
1111 1111
1111 1111
1111 1111
1111 1111
1111 1111
1111 1111
0000 0000
0000 0000
11-1 1111
00-0 0000
00-0 0000
1111 1111
0000 0000
0000 0000
0-00 --00
00-0 0000
1111 1111
1111 1111
---1 1111
1111 1111
1111 1111
1111 1111
1111 1111
1111 1111
uuuu uuuu
(1)
PIR3
uuuu uuuu
PIE3
uuuu uuuu
uu-u uuuu
IPR2
(1)
PIR2
uu-u uuuu
PIE2
uu-u uuuu
uuuu uuuu
IPR1
(1)
PIR1
uuuu uuuu
PIE1
uuuu uuuu
u-uu --uu
uu-u uuuu
uuuu uuuu
uuuu uuuu
---u uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
MEMCON
OSCTUNE
TRISJ
TRISH
TRISG
TRISF
TRISE
TRISD
TRISC
TRISB
(5)
(5)
(5)
(5)
TRISA
1111 1111
1111 1111
uuuu uuuu
LATJ
LATH
LATG
LATF
LATE
LATD
LATC
LATB
xxxx xxxx
xxxx xxxx
--xx xxxx
xxxx xxxx
xxxx xxxx
xxxx xxxx
xxxx xxxx
xxxx xxxx
uuuu uuuu
uuuu uuuu
--uu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
--uu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
(5)
(5)
(5)
(5)
LATA
xxxx xxxx
uuuu uuuu
uuuu uuuu
PORTJ
PORTH
PORTG
PORTF
PORTE
PORTD
PORTC
PORTB
xxxx xxxx
0000 xxxx
--xx xxxx
x000 0000
xxxx xxxx
xxxx xxxx
xxxx xxxx
xxxx xxxx
uuuu uuuu
uuuu uuuu
--uu uuuu
u000 0000
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
--uu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
Legend:
u= unchanged, x= unknown, -= unimplemented bit, read as ‘0’, q= value depends on condition.
Shaded cells indicate conditions do not apply for the designated device.
Note 1: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up).
2: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the PC is loaded with the interrupt vector
(0008h or 0018h).
3: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the TOSU, TOSH and TOSL are updated with
the current value of the PC. The STKPTR is modified to point to the next location in the hardware stack.
4: See Table 4-3 for Reset value for specific condition.
5: Bits 6 and 7 of PORTA, LATA and TRISA are enabled, depending on the oscillator mode selected. When not enabled
as PORTA pins, they are disabled and read ‘0’.
DS39646C-page 60
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
TABLE 4-4:
INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED)
MCLR Resets,
WDT Reset,
RESET Instruction,
Stack Resets
Power-on Reset,
Brown-out Reset
Wake-up via WDT
or Interrupt
Register
Applicable Devices
(5)
(5)
(5)
(5)
PORTA
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X27
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
6X22
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X27
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
8X22
xx0x 0000
uu0u 0000
uuuu uuuu
SPBRGH1
BAUDCON1
SPBRGH2
BAUDCON2
ECCP1DEL
TMR4
0000 0000
01-0 0-00
0000 0000
01-0 0-00
0000 0000
0000 0000
1111 1111
-000 0000
xxxx xxxx
xxxx xxxx
--00 0000
xxxx xxxx
xxxx xxxx
--00 0000
0000 0000
0000 0000
0000 0000
0000 0010
0000 000x
0000 0000
0000 0000
0000 0000
0000 0000
xxxx xxxx
0000 0000
0000 0000
0000 0000
0000 0000
0000 0000
01-0 0-00
0000 0000
01-0 0-00
0000 0000
0000 0000
uuuu uuuu
-000 0000
uuuu uuuu
uuuu uuuu
--00 0000
uuuu uuuu
uuuu uuuu
--00 0000
0000 0000
0000 0000
0000 0000
0000 0010
0000 000x
0000 0000
0000 0000
0000 0000
0000 0000
uuuu uuuu
0000 0000
0000 0000
0000 0000
0000 0000
uuuu uuuu
uu-u u-uu
uuuu uuuu
uu-u u-uu
uuuu uuuu
uuuu uuuu
uuuu uuuu
-uuu uuuu
uuuu uuuu
uuuu uuuu
--uu uuuu
uuuu uuuu
uuuu uuuu
--uu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
uuuu uuuu
PR4
T4CON
CCPR4H
CCPR4L
CCP4CON
CCPR5H
CCPR5L
CCP5CON
SPBRG2
RCREG2
TXREG2
TXSTA2
RCSTA2
ECCP3AS
ECCP3DEL
ECCP2AS
ECCP2DEL
SSP2BUF
SSP2ADD
SSP2STAT
SSP2CON1
SSP2CON2
Legend:
u= unchanged, x= unknown, -= unimplemented bit, read as ‘0’, q= value depends on condition.
Shaded cells indicate conditions do not apply for the designated device.
Note 1: One or more bits in the INTCONx or PIRx registers will be affected (to cause wake-up).
2: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the PC is loaded with the interrupt vector
(0008h or 0018h).
3: When the wake-up is due to an interrupt and the GIEL or GIEH bit is set, the TOSU, TOSH and TOSL are updated with
the current value of the PC. The STKPTR is modified to point to the next location in the hardware stack.
4: See Table 4-3 for Reset value for specific condition.
5: Bits 6 and 7 of PORTA, LATA and TRISA are enabled, depending on the oscillator mode selected. When not enabled
as PORTA pins, they are disabled and read ‘0’.
© 2008 Microchip Technology Inc.
DS39646C-page 61
PIC18F8722 FAMILY
NOTES:
DS39646C-page 62
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
5.1.1
PIC18F8527/8622/8627/8722
PROGRAM MEMORY MODES
5.0
MEMORY ORGANIZATION
There are three types of memory in PIC18 Enhanced
microcontroller devices:
PIC18F8527/8622/8627/8722 devices differ signifi-
cantly from their PIC18 predecessors in their utilization
of program memory. In addition to available on-chip
Flash program memory, these controllers can also
address up to 2 Mbytes of external program memory
through the external memory interface. There are four
distinct operating modes available to the controllers:
• Program Memory
• Data RAM
• Data EEPROM
As Harvard architecture devices, the data and program
memories use separate busses; this allows for concur-
rent access of the two memory spaces. The data
EEPROM, for practical purposes, can be regarded as
a peripheral device, since it is addressed and accessed
through a set of control registers.
• Microprocessor (MP)
• Microprocessor with Boot Block (MPBB)
• Extended Microcontroller (EMC)
• Microcontroller (MC)
Additional detailed information on the operation of the
Flash program memory is provided in Section 6.0
“Flash Program Memory”. Data EEPROM is
discussed separately in Section 8.0 “Data EEPROM
Memory”.
The program memory mode is determined by setting
the two Least Significant bits of the Configuration
Register 3L (CONFIG3L) as shown in Register 25-4
(see Section 25.1 “Configuration Bits” for additional
details on the device Configuration bits).
The program memory modes operate as follows:
5.1
Program Memory Organization
• The Microprocessor Mode permits access only
to external program memory; the contents of the
on-chip Flash memory are ignored. The 21-bit
program counter permits access to a 2-Mbyte
linear program memory space.
PIC18 microcontrollers implement a 21-bit program
counter, which is capable of addressing a 2-Mbyte
program memory space. Accessing a location between
the upper boundary of the physically implemented
memory and the 2-Mbyte address will return all ‘0’s (a
NOPinstruction).
• The Microprocessor with Boot Block Mode
accesses on-chip Flash memory from the boot
block. Above this, external program memory is
accessed all the way up to the 2-Mbyte limit.
Program execution automatically switches
between the two memories as required. The boot
block is configurable to 1, 2 or 4 Kbytes.
• The Microcontroller Mode accesses only
on-chip Flash memory. Attempts to read above the
physical limit of the on-chip Flash (0BFFFh for the
PIC18F8527, 0FFFFh for the PIC18F8622,
17FFFh for the PIC18F8627, 1FFFFh for the
PIC18F8722) causes a read of all ‘0’s (a NOP
instruction).
The PIC18F6527 and PIC18F8527 each have 48 Kbytes
of Flash memory and can store up to 24,576 single-word
instructions.
The PIC18F6622 and PIC18F8622 each have 64 Kbytes
of Flash memory and can store up to 32,768 single-word
instructions.
The PIC18F6627 and PIC18F8627 each have 96 Kbytes
of Flash memory and can store up to 49,152 single-word
instructions.
The PIC18F6722 and PIC18F8722 each have
128 Kbytes of Flash memory and can store up to
65,536 single-word instructions.
The Microcontroller mode is also the only operating
mode available to PIC18F6527/6622/6627/6722
devices.
PIC18 devices have two interrupt vectors. The Reset
vector address is at 0000h and the interrupt vector
addresses are at 0008h and 0018h.
• The Extended Microcontroller Mode allows
access to both internal and external program
memories as a single block. The device can
access its entire on-chip Flash memory; above
this, the device accesses external program
memory up to the 2-Mbyte program space limit.
As with Boot Block mode, execution automatically
switches between the two memories as required.
The program memory map for the PIC18F8722 family
of devices is shown in Figure 5-1.
In all modes, the microcontroller has complete access
to data RAM and EEPROM.
Figure 5-2 compares the memory maps of the different
program memory modes. The differences between
on-chip and external memory access limitations are
more fully explained in Table 5-1.
© 2008 Microchip Technology Inc.
DS39646C-page 63
PIC18F8722 FAMILY
FIGURE 5-1:
PROGRAM MEMORY MAP AND STACK FOR PIC18F8722 FAMILY DEVICES
PC<20:0>
21
CALL,RCALL,RETURN
RETFIE,RETLW
Stack Level 1
•
•
•
Stack Level 31
0000h
Reset Vector
High-Priority Interrupt Vector
Low-Priority Interrupt Vector
0008h
0018h
On-Chip
Program Memory
On-Chip
Program Memory
On-Chip
Program Memory
On-Chip
Program Memory
PIC18FX527
PIC18FX627
PIC18FX622
PIC18FX722
0BFFFh
0C000h
0FFFFh
10000h
017FFFh
018000h
Read ‘0’
Read ‘0’
Read ‘0’
01FFFFh
1FFFFFh
TABLE 5-1:
Operating Mode
Microprocessor
MEMORY ACCESS FOR PIC18F8527/8622/8627/8722 PROGRAM MEMORY MODES
Internal Program Memory
External Program Memory
Execution
From
Table Read
Execution
From
Table Read
From
Table Write To
Table Write To
From
No Access
Yes
No Access
Yes
No Access
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Microprocessor
w/ Boot Block
Microcontroller
Yes
Yes
Yes
Yes
Yes
Yes
No Access
Yes
No Access
Yes
No Access
Yes
Extended
Microcontroller
DS39646C-page 64
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
FIGURE 5-2:
MEMORY MAPS FOR PIC18F8722 FAMILY PROGRAM MEMORY MODES
Microprocessor
with Boot Block
Mode
Extended
Microcontroller
Mode
Microprocessor
Microcontroller
Mode(5)
Mode
000000h
000000h
000000h
000000h
On-Chip
Program
On-Chip
On-Chip
On-Chip
Program
Memory
Program
Memory
Program
Memory
Memory
(No
access)
0007FFh(6) or
000FFFh(6) or
001FFFh(6)
0BFFFh(1)
0FFFFh(2)
017FFFh(3)
01FFFFh(4)
0C000h(1)
010000h(2)
018000h(3)
020000h(4)
0BFFFh(1)
0FFFFh(2)
017FFFh(3)
01FFFFh(4)
0C000h(1)
010000h(2)
018000h(3)
020000h(4)
000800h(6) or
001000h(6) or
002000h(6)
External
Program
Memory
Reads
‘0’s
External
Program
Memory
External
Program
Memory
1FFFFFh
1FFFFFh
1FFFFFh
1FFFFFh
External
Memory
External On-Chip
Memory Flash
External
Memory
On-Chip
Flash
On-Chip
Flash
On-Chip
Flash
Note 1:
PIC18F6527 and PIC18F8527.
PIC18F6622 and PIC18F8622.
PIC18F6627 and PIC18F8627.
PIC18F6722 and PIC18F8722.
This is the only mode available on PIC18F6527/6622/6627/6722 devices.
Boot block size is determined by the BBSIZ<1:0> bits in CONFIG4L.
2:
3:
4:
5:
6:
© 2008 Microchip Technology Inc.
DS39646C-page 65
PIC18F8722 FAMILY
The stack operates as a 31-word by 21-bit RAM and a
5-bit Stack Pointer, STKPTR. The stack space is not
part of either program or data space. The Stack Pointer
is readable and writable and the address on the top of
the stack is readable and writable through the top-of-
stack Special File Registers. Data can also be pushed
to, or popped from the stack, using these registers.
5.1.2
PROGRAM COUNTER
The Program Counter (PC) specifies the address of the
instruction to fetch for execution. The PC is 21 bits wide
and is contained in three separate 8-bit registers. The
low byte, known as the PCL register, is both readable
and writable. The high byte, or PCH register, contains
the PC<15:8> bits; it is not directly readable or writable.
Updates to the PCH register are performed through the
PCLATH register. The upper byte is called PCU. This
register contains the PC<20:16> bits; it is also not
directly readable or writable. Updates to the PCU
register are performed through the PCLATU register.
A CALLtype instruction causes a push onto the stack;
the Stack Pointer is first incremented and the location
pointed to by the Stack Pointer is written with the
contents of the PC (already pointing to the instruction
following the CALL). A RETURNtype instruction causes
a POP from the stack; the contents of the location
pointed to by the STKPTR are transferred to the PC
and then the Stack Pointer is decremented.
The contents of PCLATH and PCLATU are transferred
to the program counter by any operation that writes
PCL. Similarly, the upper two bytes of the program
counter are transferred to PCLATH and PCLATU by an
operation that reads PCL. This is useful for computed
offsets to the PC (see Section 5.1.5.1 “Computed
GOTO”).
The Stack Pointer is initialized to ‘00000’ after all
Resets. There is no RAM associated with the location
corresponding to a Stack Pointer value of ‘00000’; this
is only a Reset value. Status bits indicate if the stack is
full or has overflowed or has underflowed.
The PC addresses bytes in the program memory. To
prevent the PC from becoming misaligned with word
instructions, the Least Significant bit of PCL is fixed to
a value of ‘0’. The PC increments by 2 to address
sequential instructions in the program memory.
5.1.3.1
Top-of-Stack Access
Only the top of the return address stack (TOS) is
readable and writable. A set of three registers,
TOSU:TOSH:TOSL, hold the contents of the stack loca-
tion pointed to by the STKPTR register (Figure 5-3). This
allows users to implement a software stack if necessary.
After a CALL, RCALLor interrupt, the software can read
the pushed value by reading the TOSU:TOSH:TOSL
registers. These values can be placed on a user defined
software stack. At return time, the software can return
these values to TOSU:TOSH:TOSL and do a return.
The CALL, RCALL, GOTO and program branch
instructions write to the program counter directly. For
these instructions, the contents of PCLATH and
PCLATU are not transferred to the program counter.
5.1.3
RETURN ADDRESS STACK
The return address stack allows any combination of up
to 31 program calls and interrupts to occur. The PC is
pushed onto the stack when a CALLor RCALLinstruc-
tion is executed or an interrupt is Acknowledged. The
PC value is pulled off the stack on a RETURN, RETLW
or a RETFIEinstruction. PCLATU and PCLATH are not
affected by any of the RETURNor CALLinstructions.
The user must disable the global interrupt enable bits
while accessing the stack to prevent inadvertent stack
corruption.
FIGURE 5-3:
RETURN ADDRESS STACK AND ASSOCIATED REGISTERS
Return Address Stack <20:0>
11111
11110
11101
Top-of-Stack Registers
Stack Pointer
STKPTR<4:0>
TOSU
00h
TOSH
1Ah
TOSL
34h
00010
00011
00010
00001
00000
001A34h
000D58h
Top-of-Stack
DS39646C-page 66
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
When the stack has been popped enough times to
unload the stack, the next POP will return a value of
zero to the PC and set the STKUNF bit, while the Stack
Pointer remains at zero. The STKUNF bit will remain
set until cleared by software or until a POR occurs.
5.1.3.2
Return Stack Pointer (STKPTR)
The STKPTR register (Register 5-1) contains the Stack
Pointer value, the STKFUL (Stack Full) status bit and
the STKUNF (Stack Underflow) status bits. The value
of the Stack Pointer can be 0 through 31. The Stack
Pointer increments before values are pushed onto the
stack and decrements after values are popped off the
stack. On Reset, the Stack Pointer value will be zero.
The user may read and write the Stack Pointer value.
This feature can be used by a Real-Time Operating
System (RTOS) for return stack maintenance.
Note:
Returning a value of zero to the PC on an
underflow has the effect of vectoring the
program to the Reset vector, where the
stack conditions can be verified and
appropriate actions can be taken. This is
not the same as a Reset, as the contents
of the SFRs are not affected.
After the PC is pushed onto the stack 31 times (without
popping any values off the stack), the STKFUL bit is
set. The STKFUL bit is cleared by software or by a
POR.
5.1.3.3
PUSHand POPInstructions
Since the Top-of-Stack is readable and writable, the
ability to push values onto the stack and pull values off
the stack without disturbing normal program execution
is a desirable feature. The PIC18 instruction set
includes two instructions, PUSH and POP, that permit
the TOS to be manipulated under software control.
TOSU, TOSH and TOSL can be modified to place data
or a return address on the stack.
The action that takes place when the stack becomes
full depends on the state of the STVREN (Stack Over-
flow Reset Enable) Configuration bit. (Refer to
Section 25.1 “Configuration Bits” for a description of
the device Configuration bits.) If STVREN is set
(default), the 31st PUSH will push the (PC + 2) value
onto the stack, set the STKFUL bit and reset the
device. The STKFUL bit will remain set and the Stack
Pointer will be set to zero.
The PUSHinstruction places the current PC value onto
the stack. This increments the Stack Pointer and loads
the current PC value onto the stack.
If STVREN is cleared, the STKFUL bit will be set on the
31st PUSHand the Stack Pointer will increment to 31.
Any additional pushes will not overwrite the 31st PUSH
and STKPTR will remain at 31.
The POPinstruction discards the current TOS by decre-
menting the Stack Pointer. The previous value pushed
onto the stack then becomes the TOS value.
REGISTER 5-1:
STKPTR: STACK POINTER REGISTER
R/C-0
STKFUL(1)
bit 7
R/C-0
STKUNF(1)
U-0
—
R/W-0
SP4
R/W-0
SP3
R/W-0
SP2
R/W-0
SP1
R/W-0
SP0
bit 0
Legend:
R = Readable bit
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
-n = Value at POR
bit 7
bit 6
STKFUL: Stack Full Flag bit(1)
1= Stack became full or overflowed
0= Stack has not become full or overflowed
STKUNF: Stack Underflow Flag bit(1)
1= Stack underflow occurred
0= Stack underflow did not occur
bit 5
Unimplemented: Read as ‘0’
bit 4-0
SP<4:0>: Stack Pointer Location bits
Note 1: Bit 7 and bit 6 are cleared by user software or by a POR.
© 2008 Microchip Technology Inc.
DS39646C-page 67
PIC18F8722 FAMILY
5.1.3.4
Stack Full and Underflow Resets
EXAMPLE 5-1:
FAST REGISTER STACK
CODE EXAMPLE
;STATUS, WREG, BSR
;SAVED IN FAST REGISTER
;STACK
Device Resets on stack overflow and stack underflow
conditions are enabled by setting the STVREN bit in
Configuration Register 4L. When STVREN is set, a full
or underflow will set the appropriate STKFUL or
STKUNF bit and then cause a device Reset. When
STVREN is cleared, a full or underflow condition will set
the appropriate STKFUL or STKUNF bit, but not cause
a device Reset. The STKFUL or STKUNF bits are
cleared by the user software or a Power-on Reset.
CALL SUB1, FAST
•
•
SUB1
•
•
RETURN, FAST
;RESTORE VALUES SAVED
;IN FAST REGISTER STACK
5.1.4
FAST REGISTER STACK
5.1.5
LOOK-UP TABLES IN PROGRAM
MEMORY
A fast register stack is provided for the STATUS,
WREG and BSR registers, to provide a “fast return”
option for interrupts. The stack for each register is only
one level deep and is neither readable nor writable. It is
loaded with the current value of the corresponding reg-
ister when the processor vectors for an interrupt. All
interrupt sources will push values into the Stack regis-
ters. The values in the registers are then loaded back
into their associated registers if the RETFIE, FAST
instruction is used to return from the interrupt.
There may be programming situations that require the
creation of data structures, or look-up tables, in
program memory. For PIC18 devices, look-up tables
can be implemented in two ways:
• Computed GOTO
• Table Reads
5.1.5.1
Computed GOTO
If both low and high-priority interrupts are enabled, the
stack registers cannot be used reliably to return from
low-priority interrupts. If a high-priority interrupt occurs
while servicing a low-priority interrupt, the Stack regis-
ter values stored by the low-priority interrupt will be
overwritten. In these cases, users must save the key
registers in software during a low-priority interrupt.
A computed GOTOis accomplished by adding an offset
to the program counter. An example is shown in
Example 5-2.
A look-up table can be formed with an ADDWF PCL
instruction and a group of RETLW nninstructions. The W
register is loaded with an offset into the table before exe-
cuting a call to that table. The first instruction of the called
routine is the ADDWFPCLinstruction. The next instruction
executed will be one of the RETLW nn instructions that
returns the value ‘nn’ to the calling function.
If interrupt priority is not used, all interrupts may use the
fast register stack for returns from interrupt. If no inter-
rupts are used, the fast register stack can be used to
restore the STATUS, WREG and BSR registers at the
end of a subroutine call. To use the fast register stack
for a subroutine call, a CALLlabel, FASTinstruction
must be executed to save the STATUS, WREG and
The offset value (in WREG) specifies the number of
bytes that the program counter should advance and
should be multiples of 2 (LSb = 0).
BSR registers to the fast register stack.
RETURN, FASTinstruction is then executed to restore
these registers from the fast register stack.
A
In this method, only one data byte may be stored in
each instruction location and room on the return
address stack is required.
Example 5-1 shows a source code example that uses
the fast register stack during a subroutine call and return.
Note:
The “ADDWF PCL” instruction does not
update the PCLATH and PCLATU registers.
A read operation on PCL must be performed
to update PCLATH and PCLATU.
EXAMPLE 5-2:
COMPUTED GOTO USING AN OFFSET VALUE
MAIN: ORG
MOVLW
CALL
0x0000
0x00
TABLE
…
ORG
0x8000
PCL, F
W, W
PCL
‘A’
‘B’
‘C’
‘D’
‘E’
TABLE MOVF
RLNCF
ADDWF
RETLW
RETLW
RETLW
RETLW
RETLW
END
; A simple read of PCL will update PCLATH, PCLATU
; Multiply by 2 to get correct offset in table
; Add the modified offset to force jump into table
DS39646C-page 68
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
memory and latched into the instruction register during
Q4. The instruction is decoded and executed during the
following Q1 through Q4. The clocks and instruction
execution flow are shown in Figure 5-4.
5.1.5.2
Table Reads and Table Writes
A better method of storing data in program memory
allows two bytes of data to be stored in each instruction
location.
Look-up table data may be stored two bytes per pro-
gram word by using table reads and writes. The Table
Pointer (TBLPTR) register specifies the byte address
and the Table Latch (TABLAT) register contains the
data that is read from or written to program memory.
Data is transferred to or from program memory one
byte at a time.
5.2.2
INSTRUCTION FLOW/PIPELINING
An “Instruction Cycle” consists of four Q cycles: Q1
through Q4. The instruction fetch and execute are
pipelined in such a manner that a fetch takes one
instruction cycle, while the decode and execute take
another instruction cycle. However, due to the pipe-
lining, each instruction effectively executes in one
cycle. If an instruction causes the program counter to
change (e.g., GOTO), then two cycles are required to
complete the instruction (Example 5-3).
Table read and table write operations are discussed
further in Section 6.1 “Table Reads and Table
Writes”.
A fetch cycle begins with the program counter
incrementing in Q1.
5.2
PIC18 Instruction Cycle
In the execution cycle, the fetched instruction is latched
into the Instruction Register (IR) in cycle Q1. This
instruction is then decoded and executed during the
Q2, Q3 and Q4 cycles. Data memory is read during Q2
(operand read) and written during Q4 (destination
write).
5.2.1
CLOCKING SCHEME
The microcontroller clock input, whether from an internal
or external source, is internally divided by four to gener-
ate four non-overlapping quadrature clocks (Q1, Q2, Q3
and Q4). Internally, the program counter is incremented
on every Q1; the instruction is fetched from the program
FIGURE 5-4:
CLOCK/INSTRUCTION CYCLE
Q2
Q3
Q4
Q2
Q3
Q4
Q2
Q3
Q4
Q1
Q1
Q1
OSC1
Q1
Q2
Q3
Q4
Internal
Phase
Clock
PC
PC
PC + 2
PC + 4
OSC2/CLKO
(RC mode)
Execute INST (PC – 2)
Fetch INST (PC)
Execute INST (PC)
Fetch INST (PC + 2)
Execute INST (PC + 2)
Fetch INST (PC + 4)
EXAMPLE 5-3:
INSTRUCTION PIPELINE FLOW
TCY0
TCY1
TCY2
TCY3
TCY4
TCY5
1. MOVLW 55h
2. MOVWF PORTB
3. BRA SUB_1
Fetch 1
Execute 1
Fetch 2
Execute 2
Fetch 3
Execute 3
Fetch 4
4. BSF
PORTA, BIT3 (Forced NOP)
Flush (NOP)
5. Instruction @ address SUB_1
Fetch SUB_1 Execute SUB_1
All instructions are single cycle, except for any program branches. These take two cycles since the fetch instruction
is “flushed” from the pipeline while the new instruction is being fetched and then executed.
© 2008 Microchip Technology Inc.
DS39646C-page 69
PIC18F8722 FAMILY
The CALLand GOTOinstructions have the absolute pro-
gram memory address embedded into the instruction.
Since instructions are always stored on word boundar-
ies, the data contained in the instruction is a word
address. The word address is written to PC<20:1>,
which accesses the desired byte address in program
memory. Instruction #2 in Figure 5-5 shows how the
instruction GOTO 0006h is encoded in the program
memory. Program branch instructions, which encode a
relative address offset, operate in the same manner. The
offset value stored in a branch instruction represents the
number of single-word instructions that the PC will be
offset by. Section 26.0 “Instruction Set Summary”
provides further details of the instruction set.
5.2.3
INSTRUCTIONS IN PROGRAM
MEMORY
The program memory is addressed in bytes. Instruc-
tions are stored as two bytes or four bytes in program
memory. The Least Significant Byte of an instruction
word is always stored in a program memory location
with an even address (LSb = 0). To maintain alignment
with instruction boundaries, the PC increments in steps
of 2 and the LSb will always read ‘0’ (see Section 5.1.2
“Program Counter”).
Figure 5-5 shows an example of how instruction words
are stored in the program memory.
FIGURE 5-5:
INSTRUCTIONS IN PROGRAM MEMORY
Word Address
LSB = 1
LSB = 0
↓
Program Memory
Byte Locations →
000000h
000002h
000004h
000006h
000008h
00000Ah
00000Ch
00000Eh
000010h
000012h
000014h
Instruction 1:
Instruction 2:
MOVLW
GOTO
055h
0006h
0Fh
EFh
F0h
C1h
F4h
55h
03h
00h
23h
56h
Instruction 3:
MOVFF
123h, 456h
DS39646C-page 70
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
the instruction sequence. If the first word is skipped for
some reason and the second word is executed by itself,
a NOPis executed instead. This is necessary for cases
when the two-word instruction is preceded by a condi-
tional instruction that changes the PC. Example 5-4
shows how this works.
5.2.4
TWO-WORD INSTRUCTIONS
The standard PIC18 instruction set has 8 two-word
instructions: CALL, MOVFF, GOTO, LSFR, ADDULNK,
CALLW, MOVSS and SUBULNK. In all cases, the
second word of the instructions always has ‘1111’ as
its four Most Significant bits; the other 12 bits are literal
data, usually a data memory address.
Note:
See Section 5.6 “PIC18 Instruction
Execution and the Extended Instruc-
tion Set” for information on two-word
instructions in the extended instruction set.
The use of ‘1111’ in the 4 MSbs of an instruction spec-
ifies a special form of NOP. If the instruction is executed
in proper sequence – immediately after the first word –
the data in the second word is accessed and used by
EXAMPLE 5-4:
CASE 1:
TWO-WORD INSTRUCTIONS
Source Code
Object Code
0110 0110 0000 0000 TSTFSZ
REG1
REG1, REG2 ; No, skip this word
; Execute this word as a NOP
; continue code
; is RAM location 0?
1100 0001 0010 0011
1111 0100 0101 0110
0010 0100 0000 0000
CASE 2:
MOVFF
ADDWF
REG3
Object Code
Source Code
TSTFSZ
0110 0110 0000 0000
1100 0001 0010 0011
1111 0100 0101 0110
0010 0100 0000 0000
REG1
; is RAM location 0?
MOVFF
REG1, REG2 ; Yes, execute this word
; 2nd word of instruction
ADDWF
REG3
; continue code
© 2008 Microchip Technology Inc.
DS39646C-page 71
PIC18F8722 FAMILY
5.3.1
BANK SELECT REGISTER (BSR)
5.3
Data Memory Organization
Large areas of data memory require an efficient
addressing scheme to make rapid access to any
address possible. Ideally, this means that an entire
address does not need to be provided for each read or
write operation. For PIC18 devices, this is accom-
plished with a RAM banking scheme. This divides the
memory space into 16 contiguous banks of 256 bytes.
Depending on the instruction, each location can be
addressed directly by its full 12-bit address, or an 8-bit
low-order address and a 4-bit Bank Pointer.
Note:
The operation of some aspects of data
memory are changed when the PIC18
extended instruction set is enabled. See
Section 5.5 “Data Memory and the
Extended Instruction Set” for more
information.
The data memory in PIC18 devices is implemented as
static RAM. Each register in the data memory has a
12-bit address, allowing up to 4096 bytes of data
memory. The memory space is divided into as many as
16 banks that contain 256 bytes each; the PIC18F8722
family of devices implements all 16 banks. Figure 5-6
shows the data memory organization for the
PIC18F8722 family of devices.
Most instructions in the PIC18 instruction set make use
of the Bank Pointer, known as the Bank Select Register
(BSR). This SFR holds the 4 Most Significant bits of a
location’s address; the instruction itself includes the
8 Least Significant bits. Only the four lower bits of the
BSR are implemented (BSR<3:0>). The upper four bits
are unused; they will always read ‘0’ and cannot be
written to. The BSR can be loaded directly by using the
MOVLBinstruction.
The data memory contains Special Function Registers
(SFRs) and General Purpose Registers (GPRs). The
SFRs are used for control and status of the controller
and peripheral functions, while GPRs are used for data
storage and scratchpad operations in the user’s
application. Any read of an unimplemented location will
read as ‘0’s.
The value of the BSR indicates the bank in data
memory; the 8 bits in the instruction show the location
in the bank and can be thought of as an offset from the
bank’s lower boundary. The relationship between the
BSR’s value and the bank division in data memory is
shown in Figure 5-7.
The instruction set and architecture allow operations
across all banks. The entire data memory may be
accessed by Direct, Indirect or Indexed Addressing
modes. Addressing modes are discussed later in this
subsection.
Since up to 16 registers may share the same low-order
address, the user must always be careful to ensure that
the proper bank is selected before performing a data
read or write. For example, writing what should be
program data to an 8-bit address of F9h while the BSR
is 0Fh will end up resetting the program counter.
To ensure that commonly used registers (SFRs and
select GPRs) can be accessed in a single cycle, PIC18
devices implement an Access Bank. This is a 256-byte
memory space that provides fast access to SFRs and
the lower portion of GPR Bank 0 without using the
BSR. Section 5.3.2 “Access Bank” provides a
detailed description of the Access RAM.
While any bank can be selected, only those banks that
are actually implemented can be read or written to.
Writes to unimplemented banks are ignored, while
reads from unimplemented banks will return ‘0’s. Even
so, the STATUS register will still be affected as if the
operation was successful. The data memory map in
Figure 5-6 indicates which banks are implemented.
In the core PIC18 instruction set, only the MOVFF
instruction fully specifies the 12-bit address of the
source and target registers. This instruction ignores the
BSR completely when it executes. All other instructions
include only the low-order address as an operand and
must use either the BSR or the Access Bank to locate
their target registers.
DS39646C-page 72
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
FIGURE 5-6:
DATA MEMORY MAP FOR THE PIC18F8722 FAMILY OF DEVICES
When ‘a’ = 0:
The BSR is ignored and the
BSR<3:0>
Data Memory Map
Access Bank is used.
000h
05Fh
060h
0FFh
100h
00h
Access RAM
GPR
= 0000
= 0001
= 0010
The first 96 bytes are
general purpose RAM
(from Bank 0).
Bank 0
FFh
00h
The second 160 bytes are
Special Function Registers
(from Bank 15).
GPR
GPR
GPR
Bank 1
Bank 2
1FFh
200h
FFh
00h
FFh
00h
2FFh
300h
When ‘a’ = 1:
= 0011
The BSR specifies the Bank
used by the instruction.
Bank 3
Bank 4
Bank 5
Bank 6
Bank 7
Bank 8
Bank 9
Bank 10
Bank 11
Bank 12
Bank 13
3FFh
400h
FFh
00h
= 0100
= 0101
GPR
GPR
GPR
4FFh
500h
FFh
00h
5FFh
600h
FFh
00h
= 0110
= 0111
Access Bank
FFh
00h
6FFh
700h
00h
Access RAM Low
5Fh
Access RAM High
GPR
GPR
60h
FFh
00h
7FFh
800h
(SFRs)
= 1000
= 1001
FFh
8FFh
900h
FFh
00h
GPR
GPR
9FFh
A00h
FFh
00h
= 1010
= 1011
= 1100
= 1101
AFFh
B00h
FFh
00h
GPR
GPR
BFFh
C00h
FFh
00h
CFFh
D00h
FFh
00h
GPR
GPR
DFFh
E00h
FFh
00h
= 1110
= 1111
Bank 14
Bank 15
EFFh
F00h
F5Fh
F60h
FFFh
FFh
00h
GPR
SFR
FFh
© 2008 Microchip Technology Inc.
DS39646C-page 73
PIC18F8722 FAMILY
FIGURE 5-7:
USE OF THE BANK SELECT REGISTER (DIRECT ADDRESSING)
Memory
Data
(2)
(1)
From Opcode
BSR
000h
100h
7
0
7
0
00h
Bank 0
1
1
1
1
1
1
1
1
0
0
0
0
0
0
1
1
FFh
00h
Bank 1
Bank 2
(2)
Bank Select
FFh
00h
200h
300h
FFh
00h
Bank 3
through
Bank 13
FFh
00h
E00h
Bank 14
Bank 15
FFh
00h
F00h
FFFh
FFh
Note 1: The Access RAM bit of the instruction can be used to force an override of the selected bank (BSR<3:0>) to
the registers of the Access Bank.
2: The MOVFFinstruction embeds the entire 12-bit address in the instruction.
however, the instruction is forced to use the Access
Bank address map; the current value of the BSR is
ignored entirely.
5.3.2
ACCESS BANK
While the use of the BSR with an embedded 8-bit
address allows users to address the entire range of
data memory, it also means that the user must always
ensure that the correct bank is selected. Otherwise,
data may be read from or written to the wrong location.
This can be disastrous if a GPR is the intended target
of an operation, but an SFR is written to instead.
Verifying and/or changing the BSR for each read or
write to data memory can become very inefficient.
Using this “forced” addressing allows the instruction to
operate on a data address in a single cycle, without
updating the BSR first. For 8-bit addresses of 60h and
above, this means that users can evaluate and operate
on SFRs more efficiently. The Access RAM below 60h
is a good place for data values that the user might need
to access rapidly, such as immediate computational
results or common program variables. Access RAM
also allows for faster and more code efficient context
saving and switching of variables.
To streamline access for the most commonly used data
memory locations, the data memory is configured with
an Access Bank, which allows users to access a
mapped block of memory without specifying a BSR.
The Access Bank consists of the first 96 bytes of
memory (00h-5Fh) in Bank 0 and the last 160 bytes of
memory (60h-FFh) in Block 15. The lower half is known
as the “Access RAM” and is composed of GPRs. This
upper half is also where the device’s SFRs are
mapped. These two areas are mapped contiguously in
the Access Bank and can be addressed in a linear
fashion by an 8-bit address (Figure 5-6).
The mapping of the Access Bank is slightly different
when the extended instruction set is enabled (XINST
Configuration bit = 1). This is discussed in more detail
in Section 5.5.3 “Mapping the Access Bank in
Indexed Literal Offset Mode”.
5.3.3
GENERAL PURPOSE REGISTER
FILE
PIC18 devices may have banked memory in the GPR
area. This is data RAM, which is available for use by all
instructions. GPRs start at the bottom of Bank 0
(address 000h) and grow upwards towards the bottom of
the SFR area. GPRs are not initialized by a Power-on
Reset and are unchanged on all other Resets.
The Access Bank is used by core PIC18 instructions
that include the Access RAM bit (the ‘a’ parameter in
the instruction). When ‘a’ is equal to ‘1’, the instruction
uses the BSR and the 8-bit address included in the
opcode for the data memory address. When ‘a’ is ‘0’,
DS39646C-page 74
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
The SFRs can be classified into two sets: those
associated with the “core” device functionality (ALU,
Resets and interrupts) and those related to the
peripheral functions. The Reset and interrupt registers
are described in their respective chapters, while the
ALU’s STATUS register is described later in this sec-
tion. Registers related to the operation of a peripheral
feature are described in the chapter for that peripheral.
5.3.4
SPECIAL FUNCTION REGISTERS
The Special Function Registers (SFRs) are registers
used by the CPU and peripheral modules for controlling
the desired operation of the device. These registers are
implemented as static RAM. SFRs start at the top of
data memory (FFFh) and extend downward to occupy
the top half of Bank 15 (F60h to FFFh). A list of these
registers is given in Table 5-2 and Table 5-3.
The SFRs are typically distributed among the
peripherals whose functions they control. Unused SFR
locations are unimplemented and read as ‘0’s.
TABLE 5-2:
SPECIAL FUNCTION REGISTER MAP FOR THE PIC18F8722 FAMILY OF DEVICES
Address
Name
Address
Name
Address
Name
Address
Name
Address
Name
(1)
FFFh
FFEh
FFDh
TOSU
TOSH
TOSL
FDFh
INDF2
FBFh
FBEh
CCPR1H
CCPR1L
F9Fh
F9Eh
F9Dh
IPR1
PIR1
PIE1
F7Fh
SPBRGH1
(1)
(1)
FDEh POSTINC2
F7Eh BAUDCON1
F7Dh SPBRGH2
FDDh POSTDEC2
FBDh CCP1CON
(1)
FFCh
FFBh
FFAh
FF9h
FF8h
FF7h
FF6h
FF5h
FF4h
FF3h
FF2h
FF1h
FF0h
FEFh
STKPTR
PCLATU
PCLATH
PCL
FDCh PREINC2
FBCh
FBBh
CCPR2H
CCPR2L
F9Ch MEMCON
F7Ch BAUDCON2
(1)
(2)
FDBh PLUSW2
F9Bh OSCTUNE
F7Bh
F7Ah
—
—
(3)
(2)
FDAh
FD9h
FD8h
FD7h
FD6h
FD5h
FD4h
FD3h
FD2h
FD1h
FD0h
FCFh
FCEh
FCDh
FCCh
FCBh
FCAh
FC9h
FC8h
FSR2H
FSR2L
STATUS
TMR0H
TMR0L
T0CON
FBAh CCP2CON
F9Ah
F99h
F98h
F97h
F96h
F95h
F94h
F93h
F92h
F91h
F90h
F8Fh
F8Eh
F8Dh
F8Ch
F8Bh
F8Ah
F89h
F88h
F87h
F86h
F85h
F84h
F83h
F82h
F81h
F80h
TRISJ
TRISH
(3)
FB9h
FB8h
CCPR3H
CCPR3L
F79h ECCP1DEL
TBLPTRU
TBLPTRH
TBLPTRL
TABLAT
PRODH
PRODL
TRISG
TRISF
TRISE
TRISD
TRISC
TRISB
TRISA
F78h
F77h
F76h
F75h
F74h
F73h
F72h
F71h
F70h
F6Fh
F6Eh
F6Dh
F6Ch
F6Bh
F6Ah
TMR4
PR4
FB7h CCP3CON
FB6h ECCP1AS
T4CON
FB5h
FB4h
FB3h
FB2h
FB1h
FB0h
FAFh
FAEh
FADh
FACh
FABh
FAAh
FA9h
FA8h
CVRCON
CMCON
TMR3H
CCPR4H
CCPR4L
CCP4CON
CCPR5H
CCPR5L
CCP5CON
SPBRG2
RCREG2
TXREG2
TXSTA2
RCSTA2
ECCP3AS
(2)
—
OSCCON
HLVDCON
WDTCON
RCON
INTCON
INTCON2
INTCON3
TMR3L
(3)
T3CON
LATJ
(3)
PSPCON
SPBRG1
RCREG1
TXREG1
TXSTA1
RCSTA1
EEADRH
EEADR
LATH
(1)
INDF0
TMR1H
TMR1L
LATG
LATF
LATE
LATD
LATC
LATB
LATA
(1)
(1)
FEEh POSTINC0
FEDh POSTDEC0
T1CON
TMR2
(1)
FECh PREINC0
(1)
FEBh PLUSW0
PR2
FEAh
FE9h
FE8h
FE7h
FSR0H
FSR0L
WREG
T2CON
SSP1BUF
SSP1ADD
F69h ECCP3DEL
F68h ECCP2AS
F67h ECCP2DEL
(3)
EEDATA
PORTJ
PORTH
(1)
(1)
(3)
INDF1
FC7h SSP1STAT
FC6h SSP1CON1
FC5h SSP1CON2
FA7h EECON2
(1)
(1)
FE6h POSTINC1
FA6h
FA5h
FA4h
FA3h
FA2h
FA1h
FA0h
EECON1
PORTG
PORTF
PORTE
PORTD
PORTC
PORTB
PORTA
F66h
F65h
SSP2BUF
SSP2ADD
FE5h POSTDEC1
IPR3
PIR3
PIE3
IPR2
PIR2
PIE2
(1)
FE4h PREINC1
FC4h
FC3h
FC2h
FC1h
FC0h
ADRESH
ADRESL
ADCON0
ADCON1
ADCON2
F64h SSP2STAT
F63h SSP2CON1
(1)
FE3h PLUSW1
FE2h
FE1h
FE0h
FSR1H
FSR1L
BSR
F62h SSP2CON2
(2)
F61h
F60h
—
—
(2)
Note 1: This is not a physical register.
2: Unimplemented registers are read as ‘0’.
3: This register is not available on 64-pin devices.
© 2008 Microchip Technology Inc.
DS39646C-page 75
PIC18F8722 FAMILY
TABLE 5-3:
File Name
TOSU
REGISTER FILE SUMMARY
Value on
POR, BOR on page:
Details
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
—
—
—
Top-of-Stack Upper Byte (TOS<20:16>)
---0 0000 57, 66
0000 0000 57, 66
0000 0000 57, 66
00-0 0000 57, 67
---0 0000 57, 66
0000 0000 57, 66
0000 0000 57, 66
--00 0000 57, 90
0000 0000 57, 90
0000 0000 57, 90
0000 0000 57, 90
xxxx xxxx 57, 117
xxxx xxxx 57, 117
0000 000x 57, 121
1111 1111 57, 122
1100 0000 57, 123
TOSH
Top-of-Stack High Byte (TOS<15:8>)
TOSL
Top-of-Stack Low Byte (TOS<7:0>)
STKPTR
PCLATU
PCLATH
PCL
STKFUL(6) STKUNF(6)
—
—
SP4
SP3
SP2
SP1
SP0
—
—
Holding Register for PC<20:16>
Holding Register for PC<15:8>
PC Low Byte (PC<7:0>)
TBLPTRU
TBLPTRH
TBLPTRL
TABLAT
PRODH
PRODL
INTCON
INTCON2
INTCON3
INDF0
—
—
bit 21(7)
Program Memory Table Pointer Upper Byte (TBLPTR<20:16>)
Program Memory Table Pointer High Byte (TBLPTR<15:8>)
Program Memory Table Pointer Low Byte (TBLPTR<7:0>)
Program Memory Table Latch
Product Register High Byte
Product Register Low Byte
GIE/GIEH
RBPU
PEIE/GIEL
INTEDG0
INT1IP
TMR0IE
INTEDG1
INT3IE
INT0IE
INTEDG2
INT2IE
RBIE
INTEDG3
INT1IE
TMR0IF
TMR0IP
INT3IF
INT0IF
INT3IP
INT2IF
RBIF
RBIP
INT2IP
INT1IF
Uses contents of FSR0 to address data memory – value of FSR0 not changed (not a physical register)
Uses contents of FSR0 to address data memory – value of FSR0 post-incremented (not a physical register)
N/A
N/A
N/A
N/A
N/A
57, 82
57, 82
57, 82
57, 82
57, 82
POSTINC0
POSTDEC0 Uses contents of FSR0 to address data memory – value of FSR0 post-decremented (not a physical register)
PREINC0
PLUSW0
Uses contents of FSR0 to address data memory – value of FSR0 pre-incremented (not a physical register)
Uses contents of FSR0 to address data memory – value of FSR0 pre-incremented (not a physical register) –
value of FSR0 offset by W
FSR0H
FSR0L
—
—
—
—
Indirect Data Memory Address Pointer 0 High
---- 0000 57, 82
xxxx xxxx 57, 82
Indirect Data Memory Address Pointer 0 Low Byte
Working Register
WREG
xxxx xxxx
N/A
57
INDF1
Uses contents of FSR1 to address data memory – value of FSR1 not changed (not a physical register)
Uses contents of FSR1 to address data memory – value of FSR1 post-incremented (not a physical register)
57, 82
57, 82
57, 82
57, 82
57, 82
POSTINC1
N/A
POSTDEC1 Uses contents of FSR1 to address data memory – value of FSR1 post-decremented (not a physical register)
N/A
PREINC1
PLUSW1
Uses contents of FSR1 to address data memory – value of FSR1 pre-incremented (not a physical register)
N/A
Uses contents of FSR1 to address data memory – value of FSR1 pre-incremented (not a physical register) –
value of FSR1 offset by W
N/A
FSR1H
FSR1L
BSR
—
—
—
—
Indirect Data Memory Address Pointer 1 High
---- 0000 58, 82
xxxx xxxx 58, 82
---- 0000 58, 72
Indirect Data Memory Address Pointer 1 Low Byte
—
—
—
—
Bank Select Register
INDF2
Uses contents of FSR2 to address data memory – value of FSR2 not changed (not a physical register)
Uses contents of FSR2 to address data memory – value of FSR2 post-incremented (not a physical register)
N/A
N/A
N/A
N/A
N/A
58, 82
58, 82
58, 82
58, 82
58, 82
POSTINC2
POSTDEC2 Uses contents of FSR2 to address data memory – value of FSR2 post-decremented (not a physical register)
PREINC2
PLUSW2
Uses contents of FSR2 to address data memory – value of FSR2 pre-incremented (not a physical register)
Uses contents of FSR2 to address data memory – value of FSR2 pre-incremented (not a physical register) –
value of FSR2 offset by W
FSR2H
FSR2L
—
—
—
—
Indirect Data Memory Address Pointer 2 High
---- 0000 58, 82
xxxx xxxx 58, 82
Indirect Data Memory Address Pointer 2 Low Byte
Legend:
Note 1:
2:
x= unknown, u= unchanged, -= unimplemented, q= value depends on condition
The SBOREN bit is only available when the BOREN<1:0> Configuration bits = 01; otherwise, this bit reads as ‘0’.
These registers and/or bits are not implemented on 64-pin devices and are read as ‘0’. Reset values are shown for 80-pin devices;
individual unimplemented bits should be interpreted as ‘-’.
3:
4:
The PLLEN bit is only available in specific oscillator configuration; otherwise, it is disabled and reads as ‘0’. See Section 2.6.4 “PLL in
INTOSC Modes”.
RA6/RA7 and their associated latch and direction bits are individually configured as port pins based on various primary oscillator modes.
When disabled, these bits read as ‘0’.
5:
6:
7:
RG5 and LATG5 are only available when Master Clear is disabled (MCLRE Configuration bit = 0); otherwise, RG5 and LATG5 read as ‘0’.
Bit 7 and Bit 6 are cleared by user software or by a POR.
Bit 21 of TBLPTRU allows access to the device Configuration bits.
DS39646C-page 76
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
TABLE 5-3:
File Name
REGISTER FILE SUMMARY (CONTINUED)
Value on
POR, BOR on page:
Details
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
STATUS
—
—
—
N
OV
Z
DC
C
---x xxxx 58, 80
0000 0000 58, 163
xxxx xxxx 58, 163
1111 1111 58, 161
0100 q000 39, 58
0-00 0101 58, 291
--- ---0 58, 313
TMR0H
Timer0 Register High Byte
Timer0 Register Low Byte
TMR0L
T0CON
TMR0ON
IDLEN
VDIRMAG
—
T08BIT
IRCF2
—
T0CS
IRCF1
IRVST
—
T0SE
IRCF0
HLVDEN
—
PSA
OSTS
HLVDL3
—
T0PS2
IOFS
HLVDL2
—
T0PS1
SCS1
HLVDL1
—
T0PS0
SCS0
OSCCON
HLVDCON
WDTCON
RCON
HLVDL0
SWDTEN
BOR
—
IPEN
SBOREN(1)
—
RI
TO
PD
POR
0q-1 11q0 50, 56,
58, 133
TMR1H
TMR1L
Timer1 Register High Byte
Timer1 Register Low Byte
xxxx xxxx 58, 169
xxxx xxxx 58, 169
T1CON
TMR2
RD16
T1RUN
T1CKPS1
T1CKPS0
T1OSCEN
T1SYNC
TMR2ON
TMR1CS
T2CKPS1
TMR1ON 0000 0000 58, 165
0000 0000 58, 172
Timer2 Register
PR2
Timer2 Period Register
T2OUTPS3 T2OUTPS2 T2OUTPS1 T2OUTPS0
MSSP1 Receive Buffer/Transmit Register
1111 1111 58, 172
T2CON
SSP1BUF
—
T2CKPS0 -000 0000 58, 171
xxxx xxxx 58, 169,
170
SSP1ADD
SSP1STAT
MSSP1 Address Register in I2C™ Slave mode. MSSP1 Baud Rate Reload Register in I2C Master mode.
0000 0000 58, 170
SMP
WCOL
GCEN
CKE
D/A
P
S
R/W
SSPM2
PEN
UA
BF
0000 0000 58, 162,
171
SSP1CON1
SSPOV
SSPEN
ACKDT
CKP
SSPM3
RCEN
SSPM1
RSEN
SSPM0
SEN
0000 0000 58, 163,
172
SSP1CON2
ADRESH
ADRESL
ACKSTAT
ACKEN
0000 0000 58, 173
xxxx xxxx 59, 280
xxxx xxxx 59, 280
A/D Result Register High Byte
A/D Result Register Low Byte
ADCON0
ADCON1
ADCON2
CCPR1H
CCPR1L
CCP1CON
CCPR2H
CCPR2L
CCP2CON
CCPR3H
CCPR3L
CCP3CON
ECCP1AS
CVRCON
CMCON
TMR3H
—
—
—
—
—
CHS3
VCFG1
ACQT2
CHS2
VCFG0
ACQT1
CHS1
PCFG3
ACQT0
CHS0
PCFG2
ADCS2
GO/DONE
PCFG1
ADON
PCFG0
ADCS0
--00 0000 59, 271
--00 0000 59, 272
0-00 0000 59, 273
xxxx xxxx 59, 180
xxxx xxxx 59, 180
ADFM
ADCS1
Enhanced Capture/Compare/PWM Register 1 High Byte
Enhanced Capture/Compare/PWM Register 1 Low Byte
P1M1
P1M0
DC1B1
DC1B0
CCP1M3
CCP2M3
CCP3M3
CCP1M2
CCP2M2
CCP1M1
CCP2M1
CCP1M0 0000 0000 59, 187
xxxx xxxx 59, 180
Enhanced Capture/Compare/PWM Register 2 High Byte
Enhanced Capture/Compare/PWM Register 2 Low Byte
xxxx xxxx 59, 180
P2M1
P2M0
DC2B1
DC2B0
CCP2M0 0000 0000 59, 179
xxxx xxxx 59, 180
Enhanced Capture/Compare/PWM Register 3 High Byte
Enhanced Capture/Compare/PWM Register 3 Low Byte
xxxx xxxx 59, 180
P3M1
P3M0
DC3B1
DC3B0
CCP3M2
PSS1AC0
CVR2
CCP3M1
PSS1BD1
CVR1
CCP3M0 0000 0000 59, 179
PSS1BD0 0000 0000 59, 201
ECCP1ASE ECCP1AS2 ECCP1AS1 ECCP1AS0 PSS1AC1
CVREN
C2OUT
CVROE
C1OUT
CVRR
C2INV
CVRSS
C1INV
CVR3
CIS
CVR0
CM0
0000 0000 59, 287
0000 0111 59, 289
xxxx xxxx 59, 175
xxxx xxxx 59, 175
CM2
CM1
Timer3 Register High Byte
Timer3 Register Low Byte
TMR3L
T3CON
RD16
T3CCP2
T3CKPS1
T3CKPS0
T3CCP1
T3SYNC
TMR3CS
TMR3ON 0000 0000 59, 173
Legend:
Note 1:
2:
x= unknown, u= unchanged, -= unimplemented, q= value depends on condition
The SBOREN bit is only available when the BOREN<1:0> Configuration bits = 01; otherwise, this bit reads as ‘0’.
These registers and/or bits are not implemented on 64-pin devices and are read as ‘0’. Reset values are shown for 80-pin devices;
individual unimplemented bits should be interpreted as ‘-’.
3:
4:
The PLLEN bit is only available in specific oscillator configuration; otherwise, it is disabled and reads as ‘0’. See Section 2.6.4 “PLL in
INTOSC Modes”.
RA6/RA7 and their associated latch and direction bits are individually configured as port pins based on various primary oscillator modes.
When disabled, these bits read as ‘0’.
5:
6:
7:
RG5 and LATG5 are only available when Master Clear is disabled (MCLRE Configuration bit = 0); otherwise, RG5 and LATG5 read as ‘0’.
Bit 7 and Bit 6 are cleared by user software or by a POR.
Bit 21 of TBLPTRU allows access to the device Configuration bits.
© 2008 Microchip Technology Inc.
DS39646C-page 77
PIC18F8722 FAMILY
TABLE 5-3:
File Name
REGISTER FILE SUMMARY (CONTINUED)
Value on
POR, BOR on page:
Details
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
PSPCON
IBF
OBF
IBOV
PSPMODE
—
—
—
—
0000 ---- 59, 252
0000 0000 59, 252
0000 0000 59, 260
0000 0000 59, 257
0000 0010 59, 248
0000 000x 59, 249
---- --00 59, 111
SPBRG1
RCREG1
TXREG1
TXSTA1
RCSTA1
EEADRH
EUSART1 Baud Rate Generator Register Low Byte
EUSART1 Receive Register
EUSART1 Transmit Register
CSRC
SPEN
—
TX9
RX9
—
TXEN
SREN
—
SYNC
CREN
—
SENDB
ADDEN
—
BRGH
FERR
—
TRMT
OERR
TX9D
RX9D
EEPROM Address
Register High Byte
EEADR
EEDATA
EECON2
EECON1
IPR3
EEPROM Address Register Low Byte
EEPROM Data Register
0000 0000 59, 111
0000 0000 59, 111
0000 0000 59, 88
xx-0 x000 59, 89
1111 1111 60, 131
0000 0000 60, 125
0000 0000 60, 129
11-1 1111 60, 131
00-0 0000 60, 125
00-0 0000 60, 128
1111 1111 60, 130
0000 0000 60, 124
0000 0000 60, 127
0-00 --00 60, 96
00-0 0000 35, 60
1111 1111 60, 157
1111 1111 60, 155
---1 1111 60, 153
1111 1111 60, 150
1111 1111 60, 148
1111 1111 60, 143
1111 1111 60, 140
1111 1111 60, 137
1111 1111 60, 135
xxxx xxxx 60, 156
xxxx xxxx 60, 154
--xx xxxx 60, 151
xxxx xxxx 60, 149
xxxx xxxx 60, 146
xxxx xxxx 60, 143
xxxx xxxx 60, 140
xxxx xxxx 60, 137
xxxx xxxx 60, 135
EEPROM Control Register 2 (not a physical register)
EEPGD
SSP2IP
SSP2IF
SSP2IE
OSCFIP
OSCFIF
OSCFIE
PSPIP
PSPIF
CFGS
BCL2IP
BCL2IF
BCL2IE
CMIP
—
RC2IP
RC2IF
RC2IE
—
FREE
TX2IP
TX2IF
WRERR
TMR4IP
TMR4IF
TMR4IE
BCL1IP
BCL1IF
BCL1IE
SSP1IP
SSP1IF
SSP1IE
—
WREN
CCP5IP
CCP5IF
CCP5IE
HLVDIP
HLVDIF
HLVDIE
CCP1IP
CCP1IF
CCP1IE
—
WR
RD
CCP4IP
CCP4IF
CCP4IE
TMR3IP
TMR3IF
TMR3IE
TMR2IP
TMR2IF
TMR2IE
WM1
CCP3IP
CCP3IF
CCP3IE
CCP2IP
CCP2IF
CCP2IE
TMR1IP
TMR1IF
TMR1IE
WM0
PIR3
PIE3
TX2IE
EEIP
IPR2
PIR2
CMIF
—
EEIF
PIE2
CMIE
—
EEIE
IPR1
ADIP
RC1IP
RC1IF
RC1IE
WAIT1
—
TX1IP
TX1IF
PIR1
ADIF
PIE1
PSPIE
EBDIS
INTSRC
TRISJ7
TRISH7
—
ADIE
TX1IE
WAIT0
TUN4
MEMCON(2)
OSCTUNE
TRISJ(2)
TRISH(2)
TRISG
TRISF
TRISE
TRISD
TRISC
TRISB
TRISA
LATJ(2)
LATH(2)
LATG
—
PLLEN(3)
TRISJ6
TRISH6
—
TUN3
TUN2
TUN1
TUN0
TRISJ5
TRISH5
—
TRISJ4
TRISH4
TRISG4
TRISF4
TRISE4
TRISD4
TRISC4
TRISB4
TRISA4
LATJ4
LATH4
LATG4
LATF4
LATE4
LATD4
LATC4
LATB4
LATA4
TRISJ3
TRISH3
TRISG3
TRISF3
TRISE3
TRISD3
TRISC3
TRISB3
TRISA3
LATJ3
TRISJ2
TRISH2
TRISG2
TRISF2
TRISE2
TRISD2
TRISC2
TRISB2
TRISA2
LATJ2
TRISJ1
TRISH1
TRISG1
TRISF1
TRISE1
TRISD1
TRISC1
TRISB1
TRISA1
LATJ1
TRISJ0
TRISH0
TRISG0
TRISF0
TRISE0
TRISD0
TRISC0
TRISB0
TRISA0
LATJ0
TRISF7
TRISE7
TRISD7
TRISC7
TRISB7
TRISA7(4)
LATJ7
TRISF6
TRISE6
TRISD6
TRISC6
TRISB6
TRISA6(4)
LATJ6
LATH6
—
TRISF5
TRISE5
TRISD5
TRISC5
TRISB5
TRISA5
LATJ5
LATH5
LATG5(5)
LATF5
LATE5
LATD5
LATC5
LATB5
LATA5
LATH7
—
LATH3
LATG3
LATF3
LATH2
LATG2
LATF2
LATH1
LATG1
LATF1
LATH0
LATG0
LATF0
LATF
LATF7
LATF6
LATE6
LATD6
LATC6
LATB6
LATA6(4)
LATE
LATE7
LATD7
LATC7
LATB7
LATA7(4)
LATE3
LATD3
LATC3
LATB3
LATA3
LATE2
LATD2
LATC2
LATB2
LATA2
LATE1
LATE0
LATD
LATD1
LATC1
LATB1
LATD0
LATC0
LATB0
LATC
LATB
LATA
LATA1
LATA0
Legend:
Note 1:
2:
x= unknown, u= unchanged, -= unimplemented, q= value depends on condition
The SBOREN bit is only available when the BOREN<1:0> Configuration bits = 01; otherwise, this bit reads as ‘0’.
These registers and/or bits are not implemented on 64-pin devices and are read as ‘0’. Reset values are shown for 80-pin devices;
individual unimplemented bits should be interpreted as ‘-’.
3:
4:
The PLLEN bit is only available in specific oscillator configuration; otherwise, it is disabled and reads as ‘0’. See Section 2.6.4 “PLL in
INTOSC Modes”.
RA6/RA7 and their associated latch and direction bits are individually configured as port pins based on various primary oscillator modes.
When disabled, these bits read as ‘0’.
5:
6:
7:
RG5 and LATG5 are only available when Master Clear is disabled (MCLRE Configuration bit = 0); otherwise, RG5 and LATG5 read as ‘0’.
Bit 7 and Bit 6 are cleared by user software or by a POR.
Bit 21 of TBLPTRU allows access to the device Configuration bits.
DS39646C-page 78
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
TABLE 5-3:
REGISTER FILE SUMMARY (CONTINUED)
Value on
POR, BOR on page:
Details
File Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
PORTJ(2)
PORTH(2)
PORTG
PORTF
PORTE
PORTD
PORTC
PORTB
PORTA
RJ7
RH7
—
RJ6
RH6
—
RJ5
RH5
RG5(5)
RF5
RJ4
RH4
RG4
RF4
RE4
RD4
RC4
RB4
RA4
RJ3
RH3
RG3
RF3
RE3
RD3
RC3
RB3
RA3
RJ2
RH2
RG2
RF2
RE2
RD2
RC2
RB2
RA2
RJ1
RH1
RG1
RF1
RE1
RD1
RC1
RB1
RA1
RJ0
RH0
RG0
RF0
RE0
RD0
RC0
RB0
RA0
xxxx xxxx 60, 156
0000 xxxx 60, 154
--xx xxxx 60, 151
x000 0000 60, 149
xxxx xxxx 60, 146
xxxx xxxx 60, 143
xxxx xxxx 60, 140
xxxx xxxx 60, 137
xx0x 0000 61, 135
0000 0000 61, 252
01-0 0-00 61, 250
0000 0000 61, 252
01-0 0-00 61, 250
0000 0000 61, 200
0000 0000 61, 178
1111 1111 61, 178
RF7
RE7
RD7
RC7
RB7
RA7(4)
RF6
RE6
RD6
RC6
RB6
RA6(4)
RE5
RD5
RC5
RB5
RA5
SPBRGH1
BAUDCON1
SPBRGH2
BAUDCON2
ECCP1DEL
TMR4
EUSART1 Baud Rate Generator Register High Byte
ABDOVF RCIDL SCKP
EUSART2 Baud Rate Generator Register High Byte
—
BRG16
—
WUE
ABDEN
ABDOVF
P1RSEN
RCIDL
P1DC6
—
SCKP
BRG16
P1DC3
—
WUE
ABDEN
P1DC0
P1DC5
P1DC4
P1DC2
P1DC1
Timer4 Register
PR4
Timer4 Period Register
T4OUTPS3 T4OUTPS2 T4OUTPS1 T4OUTPS0
T4CON
—
TMR4ON
CCP4M2
CCP5M2
T4CKPS1
CCP4M1
CCP5M1
T4CKPS0 -000 0000 61, 178
xxxx xxxx 61, 180
CCPR4H
CCPR4L
Capture/Compare/PWM Register 4 High Byte
Capture/Compare/PWM Register 4 Low Byte
xxxx xxxx 61, 180
CCP4CON
CCPR5H
CCPR5L
—
—
DC4B1
DC4B0
CCP4M3
CCP5M3
CCP4M0 --00 0000 61, 179
xxxx xxxx 61, 180
Capture/Compare/PWM Register 5 High Byte
Capture/Compare/PWM Register 5 Low Byte
xxxx xxxx 61, 180
CCP5CON
SPBRG2
RCREG2
TXREG2
TXSTA2
—
—
DC5B1
DC5B0
CCP5M0 --00 0000 61, 179
0000 0000 61, 252
EUSART2 Baud Rate Generator Register Low Byte
EUSART2 Receive Register
0000 0000 61, 260
EUSART2 Transmit Register
0000 0000 61, 257
CSRC
SPEN
TX9
RX9
TXEN
SREN
SYNC
CREN
SENDB
ADDEN
BRGH
FERR
TRMT
OERR
TX9D
RX9D
0000 0010 61, 248
0000 000x 61, 249
RCSTA2
ECCP3AS
ECCP3DEL
ECCP2AS
ECCP2DEL
SSP2BUF
SSP2ADD
ECCP3ASE ECCP3AS2 ECCP3AS1 ECCP3AS0 PSS3AC1
P3RSEN P3DC6 P3DC5 P3DC4 P3DC3
ECCP2ASE ECCP2AS2 ECCP2AS1 ECCP2AS0 PSS2AC1
P2RSEN P2DC6 P2DC5 P2DC4 P2DC3
MSSP2 Receive Buffer/Transmit Register
MSSP2 Address Register in I2C™ Slave mode. MSSP2 Baud Rate Reload Register in I2C Master mode.
PSS3AC0
PSS3BD1
PSS3BD0 0000 0000 61, 201
P3DC0 0000 0000 61, 200
PSS2BD0 0000 0000 61, 201
P3DC2
P3DC1
PSS2AC0
P2DC2
PSS2BD1
P2DC1
P2DC0
0000 0000 61, 200
xxxx xxxx 61, 170
0000 0000 61, 170
SSP2STAT
SSP2CON1
SSP2CON2
SMP
WCOL
GCEN
CKE
D/A
P
S
R/W
SSPM2
PEN
UA
BF
0000 0000 61, 216
0000 0000 61, 217
0000 0000 61, 218
SSPOV
ACKSTAT
SSPEN
ACKDT
CKP
SSPM3
RCEN
SSPM1
RSEN
SSPM0
SEN
ACKEN
Legend:
Note 1:
2:
x= unknown, u= unchanged, -= unimplemented, q= value depends on condition
The SBOREN bit is only available when the BOREN<1:0> Configuration bits = 01; otherwise, this bit reads as ‘0’.
These registers and/or bits are not implemented on 64-pin devices and are read as ‘0’. Reset values are shown for 80-pin devices;
individual unimplemented bits should be interpreted as ‘-’.
3:
4:
The PLLEN bit is only available in specific oscillator configuration; otherwise, it is disabled and reads as ‘0’. See Section 2.6.4 “PLL in
INTOSC Modes”.
RA6/RA7 and their associated latch and direction bits are individually configured as port pins based on various primary oscillator modes.
When disabled, these bits read as ‘0’.
5:
6:
7:
RG5 and LATG5 are only available when Master Clear is disabled (MCLRE Configuration bit = 0); otherwise, RG5 and LATG5 read as ‘0’.
Bit 7 and Bit 6 are cleared by user software or by a POR.
Bit 21 of TBLPTRU allows access to the device Configuration bits.
© 2008 Microchip Technology Inc.
DS39646C-page 79
PIC18F8722 FAMILY
It is recommended that only BCF, BSF, SWAPF, MOVFF
and MOVWFinstructions are used to alter the STATUS
register, because these instructions do not affect the Z,
C, DC, OV or N bits in the STATUS register.
5.3.5
STATUS REGISTER
The STATUS register, shown in Register 5-2, contains
the arithmetic status of the ALU. As with any other SFR,
it can be the operand for any instruction.
For other instructions that do not affect Status bits, see
the instruction set summaries in Table 26-2 and
Table 26-3.
If the STATUS register is the destination for an instruction
that affects the Z, DC, C, OV or N bits, the results of the
instruction are not written; instead, the STATUS register
is updated according to the instruction performed. There-
fore, the result of an instruction with the STATUS register
as its destination may be different than intended. As an
example, CLRF STATUSwill set the Z bit and leave the
remaining Status bits unchanged (‘000u u1uu’).
Note:
The C and DC bits operate as the borrow
and digit borrow bits, respectively, in
subtraction.
REGISTER 5-2:
STATUS: ARITHMETIC STATUS REGISTER
U-0
—
U-0
—
U-0
—
R/W-x
N
R/W-x
OV
R/W-x
Z
R/W-x
DC(1)
R/W-x
C(2)
bit 7
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7-5
bit 4
Unimplemented: Read as ‘0’
N: Negative bit
This bit is used for signed arithmetic (2’s complement). It indicates whether the result was
negative (ALU MSB = 1).
1= Result was negative
0= Result was positive
bit 3
OV: Overflow bit
This bit is used for signed arithmetic (2’s complement). It indicates an overflow of the 7-bit
magnitude which causes the sign bit (bit 7 of the result) to change state.
1= Overflow occurred for signed arithmetic (in this arithmetic operation)
0= No overflow occurred
bit 2
bit 1
Z: Zero bit
1= The result of an arithmetic or logic operation is zero
0= The result of an arithmetic or logic operation is not zero
DC: Digit Carry/borrow bit(1)
For ADDWF, ADDLW, SUBLWand SUBWFinstructions:
1= A carry-out from the 4th low-order bit of the result occurred
0= No carry-out from the 4th low-order bit of the result
bit 0
C: Carry/borrow bit(2)
For ADDWF, ADDLW, SUBLWand SUBWFinstructions:
1= A carry-out from the Most Significant bit of the result occurred
0= No carry-out from the Most Significant bit of the result occurred
Note 1: For borrow, the polarity is reversed. A subtraction is executed by adding the 2’s complement of the second
operand. For rotate (RRF, RLF) instructions, this bit is loaded with either bit 4 or bit 3 of the source register.
2: For borrow, the polarity is reversed. A subtraction is executed by adding the 2’s complement of the second
operand. For rotate (RRF, RLF) instructions, this bit is loaded with either the high or low-order bit of the
source register.
DS39646C-page 80
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
The Access RAM bit ‘a’ determines how the address is
interpreted. When ‘a’ is ‘1’, the contents of the BSR
(Section 5.3.1 “Bank Select Register (BSR)”) are
used with the address to determine the complete 12-bit
address of the register. When ‘a’ is ‘0’, the address is
interpreted as being a register in the Access Bank.
Addressing that uses the Access RAM is sometimes
also known as Direct Forced Addressing mode.
5.4
Data Addressing Modes
Note:
The execution of some instructions in the
core PIC18 instruction set are changed
when the PIC18 extended instruction set is
enabled. See Section 5.5 “Data Memory
and the Extended Instruction Set” for
more information.
A few instructions, such as MOVFF, include the entire
12-bit address (either source or destination) in their
opcodes. In these cases, the BSR is ignored entirely.
The data memory space can be addressed in several
ways. For most instructions, the addressing mode is
fixed. Other instructions may use up to three modes,
depending on which operands are used and whether or
not the extended instruction set is enabled.
The destination of the operation’s results is determined
by the destination bit ‘d’. When ‘d’ is ‘1’, the results are
stored back in the source register, overwriting its origi-
nal contents. When ‘d’ is ‘0’, the results are stored in
the W register. Instructions without the ‘d’ argument
have a destination that is implicit in the instruction; their
destination is either the target register being operated
on or the W register.
The addressing modes are:
• Inherent
• Literal
• Direct
• Indirect
An additional addressing mode, Indexed Literal Offset,
is available when the extended instruction set is
enabled (XINST Configuration bit = 1). Its operation is
discussed in greater detail in Section 5.5.1 “Indexed
Addressing with Literal Offset”.
5.4.3
INDIRECT ADDRESSING
Indirect Addressing allows the user to access a location
in data memory without giving a fixed address in the
instruction. This is done by using File Select Registers
(FSRs) as pointers to the locations to be read or written
to. Since the FSRs are themselves located in RAM as
Special File Registers, they can also be directly manip-
ulated under program control. This makes FSRs very
useful in implementing data structures, such as tables
and arrays in data memory.
5.4.1
INHERENT AND LITERAL
ADDRESSING
Many PIC18 control instructions do not need any argu-
ment at all; they either perform an operation that globally
affects the device or they operate implicitly on one
register. This addressing mode is known as Inherent
Addressing. Examples include SLEEP, RESETand DAW.
The registers for Indirect Addressing are also
implemented with Indirect File Operands (INDFs) that
permit automatic manipulation of the pointer value with
auto-incrementing, auto-decrementing or offsetting
with another value. This allows for efficient code, using
loops, such as the example of clearing an entire RAM
bank in Example 5-5.
Other instructions work in a similar way but require an
additional explicit argument in the opcode. This is
known as Literal Addressing mode because they
require some literal value as an argument. Examples
include ADDLWand MOVLW, which respectively, add or
move a literal value to the W register. Other examples
include CALL and GOTO, which include a 20-bit
program memory address.
EXAMPLE 5-5:
HOW TO CLEAR RAM
(BANK 1) USING
INDIRECT ADDRESSING
5.4.2
DIRECT ADDRESSING
LFSR
FSR0, 100h ;
NEXT
CLRF
POSTINC0
; Clear INDF
Direct Addressing specifies all or part of the source
and/or destination address of the operation within the
opcode itself. The options are specified by the
arguments accompanying the instruction.
; register then
; inc pointer
; All done with
; Bank1?
; NO, clear next
; YES, continue
BTFSS
BRA
FSR0H, 1
NEXT
In the core PIC18 instruction set, bit-oriented and byte-
oriented instructions use some version of Direct
Addressing by default. All of these instructions include
some 8-bit literal address as their Least Significant
Byte. This address specifies either a register address in
one of the banks of data RAM (Section 5.3.3 “General
Purpose Register File”) or a location in the Access
Bank (Section 5.3.2 “Access Bank”) as the data
source for the instruction.
CONTINUE
© 2008 Microchip Technology Inc.
DS39646C-page 81
PIC18F8722 FAMILY
5.4.3.1
FSR Registers and the
INDF Operand
5.4.3.2
FSR Registers and POSTINC,
POSTDEC, PREINC and PLUSW
At the core of Indirect Addressing are three sets of
registers: FSR0, FSR1 and FSR2. Each represents a
pair of 8-bit registers, FSRnH and FSRnL. The four
upper bits of the FSRnH register are not used so each
FSR pair holds a 12-bit value. This represents a value
that can address the entire range of the data memory
in a linear fashion. The FSR register pairs, then, serve
as pointers to data memory locations.
In addition to the INDF operand, each FSR register pair
also has four additional indirect operands. Like INDF,
these are “virtual” registers that cannot be indirectly
read or written to. Accessing these registers actually
accesses the associated FSR register pair, but also
performs a specific action on its stored value. They are:
• POSTDEC: accesses the FSR value, then
automatically decrements it by 1 afterwards
• POSTINC: accesses the FSR value, then
automatically increments it by 1 afterwards
• PREINC: increments the FSR value by 1, then
uses it in the operation
• PLUSW: adds the signed value of the W register
(range of -127 to 128) to that of the FSR and uses
the new value in the operation.
Indirect Addressing is accomplished with a set of
Indirect File Operands, INDF0 through INDF2. These
can be thought of as “virtual” registers: they are
mapped in the SFR space but are not physically imple-
mented. Reading or writing to a particular INDF register
actually accesses its corresponding FSR register pair.
A read from INDF1, for example, reads the data at the
address indicated by FSR1H:FSR1L. Instructions that
use the INDF registers as operands actually use the
contents of their corresponding FSR as a pointer to the
instruction’s target. The INDF operand is just a
convenient way of using the pointer.
In this context, accessing an INDF register uses the
value in the FSR registers without changing them.
Similarly, accessing a PLUSW register gives the FSR
value offset by the value in the W register; neither value
is actually changed in the operation. Accessing the
other virtual registers changes the value of the FSR
registers.
Because Indirect Addressing uses a full 12-bit address,
data RAM banking is not necessary. Thus, the current
contents of the BSR and the Access RAM bit have no
effect on determining the target address.
Operations on the FSRs with POSTDEC, POSTINC
and PREINC affect the entire register pair; that is, roll-
overs of the FSRnL register from FFh to 00h carry over
to the FSRnH register. On the other hand, results of
these operations do not change the value of any flags
in the STATUS register (e.g., Z, N, OV, etc.).
FIGURE 5-8:
INDIRECT ADDRESSING
000h
Using an instruction with one of the
Indirect Addressing registers as the
operand....
Bank 0
Bank 1
ADDWF, INDF1, 1
100h
200h
300h
Bank 2
FSR1H:FSR1L
...uses the 12-bit address stored in
the FSR pair associated with that
register....
7
0
7
0
Bank 3
through
Bank 13
x x x x 1 1 1 0
1 1 0 0 1 1 0 0
...to determine the data memory
location to be used in that operation.
E00h
In this case, the FSR1 pair contains
ECCh. This means the contents of
location ECCh will be added to that
of the W register and stored back in
ECCh.
Bank 14
Bank 15
F00h
FFFh
Data Memory
DS39646C-page 82
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
The PLUSW register can be used to implement a form
of Indexed Addressing in the data memory space. By
manipulating the value in the W register, users can
reach addresses that are fixed offsets from pointer
addresses. In some applications, this can be used to
implement some powerful program control structure,
such as software stacks, inside of data memory.
5.5.1
INDEXED ADDRESSING WITH
LITERAL OFFSET
Enabling the PIC18 extended instruction set changes
the behavior of Indirect Addressing using the FSR2
register pair within Access RAM. Under the proper
conditions, instructions that use the Access Bank – that
is, most bit-oriented and byte-oriented instructions –
can invoke a form of Indexed Addressing using an
offset specified in the instruction. This special address-
ing mode is known as Indexed Addressing with Literal
Offset, or Indexed Literal Offset mode.
5.4.3.3
Operations by FSRs on FSRs
Indirect Addressing operations that target other FSRs
or virtual registers represent special cases. For exam-
ple, using an FSR to point to one of the virtual registers
will not result in successful operations. As a specific
case, assume that FSR0H:FSR0L contains FE7h, the
address of INDF1. Attempts to read the value of the
INDF1 using INDF0 as an operand will return 00h.
Attempts to write to INDF1 using INDF0 as the operand
will result in a NOP.
When using the extended instruction set, this
addressing mode requires the following:
• The use of the Access Bank is forced (‘a’ = 0) and
• The file address argument is less than or equal to
5Fh.
Under these conditions, the file address of the instruc-
tion is not interpreted as the lower byte of an address
(used with the BSR in Direct Addressing), or as an 8-bit
address in the Access Bank. Instead, the value is
interpreted as an offset value to an address pointer,
specified by FSR2. The offset and the contents of
FSR2 are added to obtain the target address of the
operation.
On the other hand, using the virtual registers to write to
an FSR pair may not occur as planned. In these cases,
the value will be written to the FSR pair but without any
incrementing or decrementing. Thus, writing to INDF2
or POSTDEC2 will write the same value to the
FSR2H:FSR2L.
Since the FSRs are physical registers mapped in the
SFR space, they can be manipulated through all direct
operations. Users should proceed cautiously when
working on these registers, particularly if their code
uses Indirect Addressing.
5.5.2
INSTRUCTIONS AFFECTED BY
INDEXED LITERAL OFFSET MODE
Any of the core PIC18 instructions that can use Direct
Addressing are potentially affected by the Indexed
Literal Offset Addressing mode. This includes all
byte-oriented and bit-oriented instructions, or almost
one-half of the standard PIC18 instruction set.
Instructions that only use Inherent or Literal Addressing
modes are unaffected.
Similarly, operations by Indirect Addressing are gener-
ally permitted on all other SFRs. Users should exercise
the appropriate caution that they do not inadvertently
change settings that might affect the operation of the
device.
Additionally, byte-oriented and bit-oriented instructions
are not affected if they do not use the Access Bank
(Access RAM bit is ‘1’), or include a file address of 60h
or above. Instructions meeting these criteria will
continue to execute as before. A comparison of the dif-
ferent possible addressing modes when the extended
instruction set is enabled in shown in Figure 5-9.
5.5
Data Memory and the Extended
Instruction Set
Enabling the PIC18 extended instruction set (XINST
Configuration bit = 1) significantly changes certain
aspects of data memory and its addressing. Specifi-
cally, the use of the Access Bank for many of the core
PIC18 instructions is different; this is due to the
introduction of a new addressing mode for the data
memory space.
Those who desire to use byte-oriented or bit-oriented
instructions in the Indexed Literal Offset mode should
note the changes to assembler syntax for this mode.
This is described in more detail in Section 26.2.1
“Extended Instruction Syntax”.
What does not change is just as important. The size of
the data memory space is unchanged, as well as its
linear addressing. The SFR map remains the same.
Core PIC18 instructions can still operate in both Direct
and Indirect Addressing mode; inherent and literal
instructions do not change at all. Indirect Addressing
with FSR0 and FSR1 also remain unchanged.
© 2008 Microchip Technology Inc.
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FIGURE 5-9:
COMPARING ADDRESSING OPTIONS FOR BIT-ORIENTED AND
BYTE-ORIENTED INSTRUCTIONS (EXTENDED INSTRUCTION SET ENABLED)
EXAMPLE INSTRUCTION: ADDWF, f, d, a (Opcode: 0010 01da ffff ffff)
000h
When ‘a’ = 0 and f ≥ 60h:
060h
080h
The instruction executes in
Direct Forced mode. ‘f’ is inter-
Bank 0
preted as a location in the
Access RAM between 060h
and 0FFh. This is the same as
locations 060h to 07Fh
(Bank 0) and F80h to FFFh
(Bank 15) of data memory.
100h
00h
Bank 1
through
Bank 14
60h
80h
Valid range
for ‘f’
FFh
F00h
Access RAM
Locations below 60h are not
available in this addressing
mode.
Bank 15
SFRs
F80h
FFFh
Data Memory
When ‘a’ = 0 and f ≤ 5Fh:
000h
080h
100h
Bank 0
The instruction executes in
Indexed Literal Offset mode. ‘f’
is interpreted as an offset to the
address value in FSR2. The
two are added together to
obtain the address of the target
register for the instruction. The
address can be anywhere in
the data memory space.
001001da ffffffff
Bank 1
through
Bank 14
FSR2H
FSR2L
F00h
F80h
Note that in this mode, the
correct syntax is now:
Bank 15
SFRs
ADDWF [k], d
where ‘k’ is the same as ‘f’.
FFFh
Data Memory
BSR
000h
080h
100h
00000000
When ‘a’ = 1 (all values of f):
Bank 0
The instruction executes in
Direct mode (also known as
Direct Long mode). ‘f’ is inter-
preted as a location in one of
the 16 banks of the data
memory space. The bank is
designated by the Bank Select
Register (BSR). The address
can be in any implemented
bank in the data memory
space.
001001da ffffffff
Bank 1
through
Bank 14
F00h
F80h
Bank 15
SFRs
FFFh
Data Memory
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Remapping of the Access Bank applies only to opera-
tions using the Indexed Literal Offset mode. Operations
that use the BSR (Access RAM bit is ‘1’) will continue
to use Direct Addressing as before.
5.5.3
MAPPING THE ACCESS BANK IN
INDEXED LITERAL OFFSET MODE
The use of Indexed Literal Offset Addressing mode
effectively changes how the first 96 locations of Access
RAM (00h to 5Fh) are mapped. Rather than containing
just the contents of the bottom half of Bank 0, this mode
maps the contents from Bank 0 and a user defined
“window” that can be located anywhere in the data
memory space. The value of FSR2 establishes the
lower boundary of the addresses mapped into the
window, while the upper boundary is defined by FSR2
plus 95 (5Fh). Addresses in the Access RAM above
5Fh are mapped as previously described (see
Section 5.3.2 “Access Bank”). An example of Access
Bank remapping in this addressing mode is shown in
Figure 5-10.
5.6
PIC18 Instruction Execution and
the Extended Instruction Set
Enabling the extended instruction set adds eight
additional commands to the existing PIC18 instruction
set. These instructions are executed as described in
Section 26.2 “Extended Instruction Set”.
FIGURE 5-10:
REMAPPING THE ACCESS BANK WITH INDEXED LITERAL
OFFSET ADDRESSING
Example Situation:
000h
ADDWF f, d, a
FSR2H:FSR2L = 120h
Bank 0
05Fh
07Fh
Locations in the region
from the FSR2 Pointer
(120h) to the pointer plus
05Fh (17Fh) are mapped
to the bottom of the
Access RAM (000h-05Fh).
Bank 0
100h
120h
17Fh
Bank 1
Window
00h
Bank 1
Bank 1 “Window”
200h
5Fh
Locations in Bank 0 from
060h to 07Fh are mapped,
as usual, to the middle half
of the Access Bank.
Bank 0
7Fh
80h
Bank 2
through
Bank 14
SFRs
Special File Registers at
F80h through FFFh are
mapped to 80h through
FFh, as usual.
FFh
Access Bank
F00h
Bank 15
SFRs
Bank 0 addresses below
5Fh can still be addressed
by using the BSR.
F80h
FFFh
Data Memory
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NOTES:
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6.1
Table Reads and Table Writes
6.0
FLASH PROGRAM MEMORY
In order to read and write program memory, there are
two operations that allow the processor to move bytes
between the program memory space and the data RAM:
The Flash program memory is readable, writable and
erasable during normal operation over the entire VDD
range.
• Table Read (TBLRD)
• Table Write (TBLWT)
A read from program memory is executed on one byte
at a time. A write to program memory is executed on
blocks of 64 bytes at a time. Program memory is
erased in blocks of 64 bytes at a time. A bulk erase
operation may not be issued from user code.
The program memory space is 16 bits wide, while the
data RAM space is 8 bits wide. Table reads and table
writes move data between these two memory spaces
through an 8-bit register (TABLAT).
Writing or erasing program memory will cease
instruction fetches until the operation is complete. The
program memory cannot be accessed during the write
or erase, therefore, code cannot execute. An internal
programming timer terminates program memory writes
and erases.
Table read operations retrieve data from program
memory and place it into the data RAM space.
Figure 6-1 shows the operation of a table read with
program memory and data RAM.
Table write operations store data from the data memory
space into holding registers in program memory. The
procedure to write the contents of the holding registers
into program memory is detailed in Section 6.5 “Writing
to Flash Program Memory”. Figure 6-2 shows the
operation of a table write with program memory and data
RAM.
A value written to program memory does not need to be
a valid instruction. Executing a program memory
location that forms an invalid instruction results in a
NOP.
Table operations work with byte entities. A table block
containing data, rather than program instructions, is not
required to be word aligned. Therefore, a table block can
start and end at any byte address. If a table write is being
used to write executable code into program memory,
program instructions will need to be word aligned.
FIGURE 6-1:
TABLE READ OPERATION
Instruction: TBLRD*
Program Memory
(1)
Table Pointer
Table Latch (8-bit)
TABLAT
TBLPTRU TBLPTRH TBLPTRL
Program Memory
(TBLPTR)
Note 1:Table Pointer register points to a byte in program memory.
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FIGURE 6-2:
TABLE WRITE OPERATION
Instruction: TBLWT*
Program Memory
Holding Registers
(1)
Table Pointer
Table Latch (8-bit)
TABLAT
TBLPTRU TBLPTRH TBLPTRL
Program Memory
(TBLPTR)
Note1:
Table Pointer actually points to one of 64 holding registers, the address of which is determined by
TBLPTRL<5:0>. The process for physically writing data to the program memory array is discussed in
Section 6.5 “Writing to Flash Program Memory”.
registers regardless of EEPGD (see Section 25.0
“Special Features of the CPU”). When clear, memory
selection access is determined by EEPGD.
6.2
Control Registers
Several control registers are used in conjunction with
the TBLRDand TBLWTinstructions. These include the:
The FREE bit, when set, will allow a program memory
erase operation. When FREE is set, the erase
operation is initiated on the next WR command. When
FREE is clear, only writes are enabled.
• EECON1 register
• EECON2 register
• TABLAT register
• TBLPTR registers
The WREN bit, when set, will allow a write operation.
On power-up, the WREN bit is clear. The WRERR bit is
set in hardware when the WR bit is set and cleared
when the internal programming timer expires and the
write operation is complete.
6.2.1
EECON1 AND EECON2 REGISTERS
The EECON1 register (Register 6-1) is the control
register for memory accesses. The EECON2 register is
not a physical register; it is used exclusively in the
memory write and erase sequences. Reading
EECON2 will read all ‘0’s.
Note:
During normal operation, the WRERR is
read as ‘1’. This can indicate that a write
operation was prematurely terminated by
The EEPGD control bit determines if the access will be
a program or data EEPROM memory access. When
clear, any subsequent operations will operate on the
data EEPROM memory. When set, any subsequent
operations will operate on the program memory.
a
Reset, or
a write operation was
attempted improperly.
The WR control bit initiates write operations. The bit
cannot be cleared, only set, in software; it is cleared in
hardware at the completion of the write operation.
The CFGS control bit determines if the access will be
to the Configuration/Calibration registers or to program
memory/data EEPROM memory. When set,
subsequent operations will operate on Configuration
Note:
The EEIF interrupt flag bit (PIR2<4>) is set
when the write is complete. It must be
cleared in software.
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REGISTER 6-1:
EECON1: EEPROM CONTROL REGISTER 1
R/W-x
EEPGD
bit 7
R/W-x
CFGS
U-0
—
R/W-0
FREE
R/W-x
WRERR(1)
R/W-0
WREN
R/S-0
WR
R/S-0
RD
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7
bit 6
EEPGD: Flash Program or Data EEPROM Memory Select bit
1= Access Flash program memory
0= Access data EEPROM memory
CFGS: Flash Program/Data EEPROM or Configuration Select bit
1= Access Configuration registers
0= Access Flash program or data EEPROM memory
bit 5
bit 4
Unimplemented: Read as ‘0’
FREE: Flash Row Erase Enable bit
1= Erase the program memory row addressed by TBLPTR on the next WR command
(cleared by completion of erase operation)
0= Perform write only
bit 3
WRERR: Flash Program/Data EEPROM Error Flag bit(1)
1= A write operation is prematurely terminated (any Reset during self-timed programming in normal
operation, or an improper write attempt)
0= The write operation completed
bit 2
bit 1
WREN: Flash Program/Data EEPROM Write Enable bit
1= Allows write cycles to Flash program/data EEPROM
0= Inhibits write cycles to Flash program/data EEPROM
WR: Write Control bit
1= Initiates a data EEPROM erase/write cycle or a program memory erase cycle or write cycle.
(The operation is self-timed and the bit is cleared by hardware once write is complete.
The WR bit can only be set (not cleared) in software.)
0= Write cycle to the EEPROM is complete
bit 0
RD: Read Control bit
1= Initiates an EEPROM read (Read takes one cycle. RD is cleared in hardware. The RD bit can only
be set (not cleared) in software. RD bit cannot be set when EEPGD = 1or CFGS = 1.)
0= Does not initiate an EEPROM read
Note 1: When a WRERR occurs, the EEPGD and CFGS bits are not cleared.
This allows tracing of the error condition.
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6.2.2
TABLAT – TABLE LATCH REGISTER
6.2.4
TABLE POINTER BOUNDARIES
The Table Latch (TABLAT) is an 8-bit register mapped
into the SFR space. The Table Latch register is used to
hold 8-bit data during data transfers between program
memory and data RAM.
TBLPTR is used in reads, writes and erases of the
Flash program memory.
When a TBLRDis executed, all 22 bits of the TBLPTR
determine which byte is read from program memory
into TABLAT.
6.2.3
TBLPTR – TABLE POINTER
REGISTER
When a TBLWTis executed, the six LSbs of the Table
Pointer register (TBLPTR<5:0>) determine which of
the 64 program memory holding registers is written to.
When the timed write to program memory begins (via
the WR bit), the 16 MSbs of the TBLPTR
(TBLPTR<21:6>) determine which program memory
block of 64 bytes is written to. For more detail, see
Section 6.5 “Writing to Flash Program Memory”.
The Table Pointer (TBLPTR) register addresses a byte
within the program memory. The TBLPTR is comprised
of three SFR registers: Table Pointer Upper Byte, Table
Pointer High Byte and Table Pointer Low Byte
(TBLPTRU:TBLPTRH:TBLPTRL). These three regis-
ters join to form a 22-bit wide pointer. The low-order
21 bits allow the device to address up to 2 Mbytes of
program memory space. The 22nd bit allows access to
the device ID, the user ID and the Configuration bits.
When an erase of program memory is executed, the
16 MSbs of the Table Pointer register (TBLPTR<21:6>)
point to the 64-byte block that will be erased. The Least
Significant bits (TBLPTR<5:0>) are ignored.
The Table Pointer register, TBLPTR, is used by the
TBLRDand TBLWTinstructions. These instructions can
update the TBLPTR in one of four ways based on the
table operation. These operations are shown in
Table 6-1. These operations on the TBLPTR only affect
the low-order 21 bits.
Figure 6-3 describes the relevant boundaries of
TBLPTR based on Flash program memory operations.
TABLE 6-1:
Example
TABLE POINTER OPERATIONS WITH TBLRD AND TBLWT INSTRUCTIONS
Operation on Table Pointer
TBLRD*
TBLWT*
TBLPTR is not modified
TBLRD*+
TBLWT*+
TBLPTR is incremented after the read/write
TBLPTR is decremented after the read/write
TBLPTR is incremented before the read/write
TBLRD*-
TBLWT*-
TBLRD+*
TBLWT+*
FIGURE 6-3:
TABLE POINTER BOUNDARIES BASED ON OPERATION
21
16 15
TBLPTRH
8
7
TBLPTRL
0
TBLPTRU
TABLE ERASE/WRITE
TBLPTR<21:6>
TABLE WRITE
TBLPTR<5:0>
TABLE READ – TBLPTR<21:0>
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TBLPTR points to a byte address in program space.
Executing TBLRD places the byte pointed to into
TABLAT. In addition, TBLPTR can be modified
automatically for the next table read operation.
6.3
Reading the Flash Program
Memory
The TBLRD instruction is used to retrieve data from
program memory and places it into data RAM. Table
reads from program memory are performed one byte at
a time.
The internal program memory is typically organized by
words. The Least Significant bit of the address selects
between the high and low bytes of the word. Figure 6-4
shows the interface between the internal program
memory and the TABLAT.
FIGURE 6-4:
READS FROM FLASH PROGRAM MEMORY
Program Memory
(Even Byte Address)
(Odd Byte Address)
TBLPTR = xxxxx1
TBLPTR = xxxxx0
Instruction Register
(IR)
TABLAT
Read Register
FETCH
TBLRD
EXAMPLE 6-1:
READING A FLASH PROGRAM MEMORY WORD
MOVLW
MOVWF
MOVLW
MOVWF
MOVLW
MOVWF
CODE_ADDR_UPPER
TBLPTRU
CODE_ADDR_HIGH
TBLPTRH
CODE_ADDR_LOW
TBLPTRL
; Load TBLPTR with the base
; address of the word
READ_WORD
TBLRD*+
MOVF
MOVWF
TBLRD*+
MOVF
; read into TABLAT and increment
; get data
TABLAT, W
WORD_EVEN
; read into TABLAT and increment
; get data
TABLAT, W
WORD_ODD
MOVF
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6.4.1
FLASH PROGRAM MEMORY
ERASE SEQUENCE
6.4
Erasing Flash Program Memory
The minimum erase block is 32 words or 64 bytes. Only
through the use of an external programmer, or through
ICSP control, can larger blocks of program memory be
bulk erased. Word erase in the Flash array is not
supported.
The sequence of events for erasing a block of internal
program memory location is:
1. Load Table Pointer register with address of row
being erased.
When initiating an erase sequence from the micro-
controller itself, a block of 64 bytes of program memory
is erased. The Most Significant 16 bits of the
TBLPTR<21:6> point to the block being erased.
TBLPTR<5:0> are ignored.
2. Set the EECON1 register for the erase operation:
• set EEPGD bit to point to program memory;
• clear the CFGS bit to access program memory;
• set WREN bit to enable writes;
• set FREE bit to enable the erase.
3. Disable interrupts.
The EECON1 register commands the erase operation.
The EEPGD bit must be set to point to the Flash
program memory. The WREN bit must be set to enable
write operations. The FREE bit is set to select an erase
operation.
4. Write 55h to EECON2.
5. Write 0AAh to EECON2.
6. Set the WR bit. This will begin the row erase
cycle.
For protection, the write initiate sequence for EECON2
must be used.
7. The CPU will stall for duration of the erase for
TIW (see parameter D133A).
A long write is necessary for erasing the internal Flash.
Instruction execution is halted while in a long write
cycle. The long write will be terminated by the internal
programming timer.
8. Re-enable interrupts.
EXAMPLE 6-2:
ERASING A FLASH PROGRAM MEMORY ROW
MOVLW
MOVWF
MOVLW
MOVWF
MOVLW
MOVWF
CODE_ADDR_UPPER
TBLPTRU
CODE_ADDR_HIGH
TBLPTRH
CODE_ADDR_LOW
TBLPTRL
; load TBLPTR with the base
; address of the memory block
ERASE_ROW
BSF
BCF
BSF
BSF
EECON1, EEPGD
EECON1, CFGS
EECON1, WREN
EECON1, FREE
INTCON, GIE
55h
EECON2
0AAh
EECON2
EECON1, WR
INTCON, GIE
; point to Flash program memory
; access Flash program memory
; enable write to memory
; enable Row Erase operation
; disable interrupts
BCF
Required
Sequence
MOVLW
MOVWF
MOVLW
MOVWF
BSF
; write 55h
; write 0AAh
; start erase (CPU stall)
; re-enable interrupts
BSF
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The long write is necessary for programming the inter-
nal Flash. Instruction execution is halted while in a long
write cycle. The long write will be terminated by the
internal programming timer.
6.5
Writing to Flash Program Memory
The minimum programming block is 32 words or
64 bytes. Word or byte programming is not supported.
Table writes are used internally to load the holding
registers needed to program the Flash memory. There
are 64 holding registers used by the table writes for
programming.
The EEPROM on-chip timer controls the write time.
The write/erase voltages are generated by an on-chip
charge pump, rated to operate over the voltage range
of the device.
Since the Table Latch (TABLAT) is only a single byte, the
TBLWTinstruction may need to be executed 64 times for
each programming operation. All of the table write oper-
ations will essentially be short writes because only the
holding registers are written. At the end of updating the
64 holding registers, the EECON1 register must be
written to in order to start the programming operation
with a long write.
Note:
The default value of the holding registers on
device Resets and after write operations is
FFh. A write of FFh to a holding register
does not modify that byte. This means that
individual bytes of program memory may be
modified, provided that the change does not
attempt to change any bit from a ‘0’ to a ‘1’.
When modifying individual bytes, it is not
necessary to load all 64 holding registers
before executing a write operation.
FIGURE 6-5:
TABLE WRITES TO FLASH PROGRAM MEMORY
TABLAT
Write Register
8
8
8
8
TBLPTR = xxxxx0
TBLPTR = xxxxx1
TBLPTR = xxxxx2
TBLPTR = xxxx3F
Holding Register
Holding Register
Holding Register
Holding Register
Program Memory
8. Disable interrupts.
6.5.1
FLASH PROGRAM MEMORY WRITE
SEQUENCE
9. Write 55h to EECON2.
10. Write 0AAh to EECON2.
The sequence of events for programming an internal
program memory location should be:
11. Set the WR bit. This will begin the write cycle.
12. The CPU will stall for duration of the write for TIW
(see parameter D133A).
1. Read 64 bytes into RAM.
2. Update data values in RAM as necessary.
13. Re-enable interrupts.
3. Load Table Pointer register with address being
erased.
14. Verify the memory (table read).
An example of the required code is shown in
Example 6-3 on the following page.
4. Execute the row erase procedure.
5. Load Table Pointer register with address of first
byte being written.
Note:
Before setting the WR bit, the Table
Pointer address needs to be within the
intended address range of the 64 bytes in
the holding register.
6. Write the 64 bytes into the holding registers with
auto-increment.
7. Set the EECON1 register for the write operation:
• set EEPGD bit to point to program memory;
• clear the CFGS bit to access program memory;
• set WREN to enable byte writes.
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EXAMPLE 6-3:
WRITING TO FLASH PROGRAM MEMORY
MOVLW
MOVWF
MOVLW
MOVWF
MOVLW
MOVWF
MOVLW
MOVWF
MOVLW
MOVWF
MOVLW
MOVWF
D'64'
COUNTER
BUFFER_ADDR_HIGH
FSR0H
BUFFER_ADDR_LOW
FSR0L
CODE_ADDR_UPPER
TBLPTRU
CODE_ADDR_HIGH
TBLPTRH
CODE_ADDR_LOW
TBLPTRL
; number of bytes in erase block
; point to buffer
; Load TBLPTR with the base
; address of the memory block
READ_BLOCK
TBLRD*+
MOVF
MOVWF
; read into TABLAT, and inc
; get data
; store data
; done?
TABLAT, W
POSTINC0
DECFSZ COUNTER
BRA
READ_BLOCK
; repeat
MODIFY_WORD
MOVLWD ATA_ADDR_HIGH
; point to buffer
MOVWF
MOVLW
MOVWF
MOVLW
MOVWF
MOVLW
MOVWF
FSR0H
DATA_ADDR_LOW
FSR0L
NEW_DATA_LOW
POSTINC0
NEW_DATA_HIGH
INDF0
; update buffer word
ERASE_BLOCK
MOVLW
MOVWF
MOVLW
MOVWF
MOVLW
MOVWF
BSF
BCF
BSF
BSF
BCF
MOVLW
MOVWF
MOVLW
MOVWF
BSF
CODE_ADDR_UPPER
TBLPTRU
CODE_ADDR_HIGH
TBLPTRH
CODE_ADDR_LOW
TBLPTRL
EECON1, EEPGD
EECON1, CFGS
EECON1, WREN
EECON1, FREE
INTCON, GIE
55h
EECON2
0AAh
EECON2
EECON1, WR
INTCON, GIE
; load TBLPTR with the base
; address of the memory block
; point to Flash program memory
; access Flash program memory
; enable write to memory
; enable Row Erase operation
; disable interrupts
Required
Sequence
; write 55h
; write 0AAh
; start erase (CPU stall)
; re-enable interrupts
; dummy read decrement
; point to buffer
BSF
TBLRD*-
MOVLW
MOVWF
MOVLW
MOVWF
BUFFER_ADDR_HIGH
FSR0H
BUFFER_ADDR_LOW
FSR0L
WRITE_BUFFER_BACK
MOVLW
D'64'
; number of bytes in holding register
MOVWF
WRITE_BYTE_TO_HREGS
MOVFF
COUNTER
POSTINC0, WREG
TABLAT
; get low byte of buffer data
; present data to table latch
; write data, perform a short write
; to internal TBLWT holding register.
; loop until buffers are full
MOVWF
TBLWT+*
DECFSZ COUNTER
BRA WRITE_WORD_TO_HREGS
DS39646C-page 94
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
EXAMPLE 6-3:
WRITING TO FLASH PROGRAM MEMORY (CONTINUED)
PROGRAM_MEMORY
BSF
EECON1, EEPGD ; point to Flash program memory
BCF
BSF
BCF
MOVLW
MOVWF
MOVLW
MOVWF
BSF
EECON1, CFGS
EECON1, WREN
INTCON, GIE
55h
EECON2
0AAh
; access Flash program memory
; enable write to memory
; disable interrupts
Required
Sequence
; write 55h
EECON2
; write 0AAh
EECON1, WR
INTCON, GIE
EECON1, WREN
; start program (CPU stall)
; re-enable interrupts
; disable write to memory
BSF
BCF
6.5.2
WRITE VERIFY
6.5.4
PROTECTION AGAINST
SPURIOUS WRITES
Depending on the application, good programming
practice may dictate that the value written to the
memory should be verified against the original value.
This should be used in applications where excessive
writes can stress bits near the specification limit.
To protect against spurious writes to Flash program
memory, the write initiate sequence must also be
followed. See Section 25.0 “Special Features of the
CPU” for more detail.
6.5.3
UNEXPECTED TERMINATION OF
WRITE OPERATION
6.6
Flash Program Operation During
Code Protection
If a write is terminated by an unplanned event, such as
loss of power or an unexpected Reset, the memory
location just programmed should be verified and repro-
grammed if needed. If the write operation is interrupted
by a MCLR Reset or a WDT Time-out Reset during
normal operation, the user can check the WRERR bit
and rewrite the location(s) as needed.
See Section 25.5 “Program Verification and Code
Protection” for details on code protection of Flash
program memory.
TABLE 6-2:
Name
REGISTERS ASSOCIATED WITH PROGRAM FLASH MEMORY
Reset
Valueson
page
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
TBLPTRU
—
—
bit 21(1) Program Memory Table Pointer Upper Byte (TBLPTR<20:16>)
57
57
57
57
57
59
59
60
60
60
TBPLTRH Program Memory Table Pointer High Byte (TBLPTR<15:8>)
TBLPTRL Program Memory Table Pointer Low Byte (TBLPTR<7:0>)
TABLAT
INTCON
Program Memory Table Latch
GIE/GIEH PEIE/GIEL TMR0IE INT0IE
RBIE
TMR0IF
INT0IF
RBIF
EECON2 EEPROM Control Register 2 (not a physical register)
EECON1
IPR2
EEPGD
OSCFIP
OSCFIF
OSCFIE
CFGS
CMIP
CMIF
CMIE
—
—
—
—
FREE
EEIP
EEIF
EEIE
WRERR
BCL1IP
BCL1IF
BCL1IE
WREN
HLVDIP
HLVDIF
HLVDIE
WR
RD
TMR3IP
TMR3IF
TMR3IE
CCP2IP
CCP2IF
CCP2IE
PIR2
PIE2
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used during Flash/EEPROM access.
Note 1: Bit 21 of TBLPTRU allows access to the device Configuration bits.
© 2008 Microchip Technology Inc.
DS39646C-page 95
PIC18F8722 FAMILY
NOTES:
DS39646C-page 96
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
The bus is implemented with 28 pins, multiplexed
across four I/O ports. Three ports (PORTD, PORTE
and PORTH) are multiplexed with the address/data bus
for a total of 20 available lines, while PORTJ is
multiplexed with the bus control signals.
7.0
EXTERNAL MEMORY BUS
Note:
The External Memory Bus is not imple-
mented on PIC18F6527/6622/6627/6722
(64-pin) devices.
A list of the pins and their functions is provided in
Table 7-1.
The External Memory Bus (EMB) allows the device to
access external memory devices (such as Flash,
EPROM, SRAM, etc.) as program or data memory. It
supports both 8-bit and 16-bit Data Width modes and
four address widths from 8 to 20 bits.
TABLE 7-1:
Name
PIC18F8527/8622/8627/8722 EXTERNAL BUS – I/O PORT FUNCTIONS
Port
Bit
External Memory Bus Function
RD0/AD0
RD1/AD1
RD2/AD2
RD3/AD3
RD4/AD4
RD5/AD5
RD6/AD6
RD7/AD7
RE0/AD8
RE1/AD9
RE2/AD10
RE3/AD11
RE4/AD12
RE5/AD13
RE6/AD14
RE7/AD15
RH0/A16
RH1/A17
RH2/A18
RH3/A19
RJ0/ALE
RJ1/OE
PORTD
PORTD
PORTD
PORTD
PORTD
PORTD
PORTD
PORTD
PORTE
PORTE
PORTE
PORTE
PORTE
PORTE
PORTE
PORTE
PORTH
PORTH
PORTH
PORTH
PORTJ
PORTJ
PORTJ
PORTJ
PORTJ
PORTJ
PORTJ
PORTJ
0
1
2
3
4
5
6
7
0
1
2
3
4
5
6
7
0
1
2
3
0
1
2
3
4
5
6
7
Address bit 0 or Data bit 0
Address bit 1 or Data bit 1
Address bit 2 or Data bit 2
Address bit 3 or Data bit 3
Address bit 4 or Data bit 4
Address bit 5 or Data bit 5
Address bit 6 or Data bit 6
Address bit 7 or Data bit 7
Address bit 8 or Data bit 8
Address bit 9 or Data bit 9
Address bit 10 or Data bit 10
Address bit 11 or Data bit 11
Address bit 12 or Data bit 12
Address bit 13 or Data bit 13
Address bit 14 or Data bit 14
Address bit 15 or Data bit 15
Address bit 16
Address bit 17
Address bit 18
Address bit 19
Address Latch Enable (ALE) Control pin
Output Enable (OE) Control pin
Write Low (WRL) Control pin
Write High (WRH) Control pin
Byte Address bit 0 (BA0)
Chip Enable (CE) Control pin
Lower Byte Enable (LB) Control pin
Upper Byte Enable (UB) Control pin
RJ2/WRL
RJ3/WRH
RJ4/BA0
RJ5/CE
RJ6/LB
RJ7/UB
Note:
For the sake of clarity, only I/O port and external bus assignments are shown here. One or more additional
multiplexed features may be available on some pins.
© 2008 Microchip Technology Inc.
DS39646C-page 97
PIC18F8722 FAMILY
The operation of the EBDIS bit is also influenced by the
program memory mode being used. This is discussed
in more detail in Section 7.4 “Program Memory
Modes and the External Memory Bus”.
7.1
External Memory Bus Control
The operation of the interface is controlled by the
MEMCON register (Register 7-1). This register is
available in all program memory operating modes
except Microcontroller mode. In this mode, the register
is disabled and cannot be written to.
The WAIT bits allow for the addition of wait states to
external memory operations. The use of these bits is
discussed in Section 7.3 “Wait States”.
The EBDIS bit (MEMCON<7>) controls the operation
of the bus and related port functions. Clearing EBDIS
enables the interface and disables the I/O functions of
the ports, as well as any other functions multiplexed to
those pins. Setting the bit enables the I/O ports and
other functions but allows the interface to override
everything else on the pins when an external memory
operation is required. By default, the external bus is
always enabled and disables all other I/O.
The WM bits select the particular operating mode used
when the bus is operating in 16-bit Data Width mode.
These are discussed in more detail in Section 7.5
“16-Bit Data Width Modes”. These bits have no effect
when an 8-bit Data Width mode is selected.
WM<1:0>: TBLWTOperation with 16-Bit Data Bus
Width Select bits
1x= Word Write mode: TABLAT0 and TABLAT1 word
output, WRH active when TABLAT1 written
01= Byte Select mode: TABLAT data copied on both
MSB and LSB; WRH and (UB or LB) will activate
REGISTER 7-1:
MEMCON: EXTERNAL MEMORY BUS CONTROL REGISTER
R/W-0
EBDIS
bit 7
U-0
—
R/W-0
WAIT1
R/W-0
WAIT0
U-0
—
U-0
—
R/W-0
WM1
R/W-0
WM0
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7
EBDIS: External Bus Disable bit
1= External bus enabled when microcontroller accesses external memory;
otherwise, all external bus drivers are mapped as I/O ports
0= External bus always enabled, I/O ports are disabled
bit 6
Unimplemented: Read as ‘0’
bit 5-4
WAIT<1:0>: Table Reads and Writes Bus Cycle Wait Count bits
11= Table reads and writes will wait 0 TCY
10= Table reads and writes will wait 1 TCY
01= Table reads and writes will wait 2 TCY
00= Table reads and writes will wait 3 TCY
bit 3-2
bit 1-0
Unimplemented: Read as ‘0’
WM<1:0>: TBLWTOperation with 16-Bit Data Bus Width Select bits
1= Result was negative
0= Result was positive
DS39646C-page 98
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
7.2.1
21-BIT ADDRESSING
7.2
Address and Data Width
As an extension of 20-bit address width operation, the
External Memory Bus can also fully address a 2 Mbyte
memory space. This is done by using the Bus Address
bit 0 (BA0) control line as the Least Significant bit of the
address. The UB and LB control signals may also be
used with certain memory devices to select the upper
and lower bytes within a 16-bit wide data word.
PIC18F8527/8622/8627/8722 devices can be indepen-
dently configured for different address and data widths
on the same memory bus. Both address and data width
are set by Configuration bits in the CONFIG3L register.
As Configuration bits, this means that these options
can only be configured by programming the device and
are not controllable in software.
This addressing mode is available in both 8-bit and
certain 16-bit Data Width modes. Additional details are
provided in Section 7.5.3 “16-bit Byte Select Mode”
and Section 7.6 “8-Bit Data Width Modes”.
The BW bit selects an 8-bit or 16-bit data bus width.
Setting this bit (default) selects a data width of 16 bits.
The ADW<1:0> bits determine the address bus width.
The available options are 20-bit (default), 16-bit, 12-bit
and 8-bit. Selecting any of the options other than 20-bit
width makes a corresponding number of high-order
lines available for I/O functions; these pins are no
longer affected by the setting of the EBDIS bit. For
7.3
Wait States
While it may be assumed that external memory devices
will operate at the microcontroller clock rate, this is
often not the case. In fact, many devices require longer
times to write or retrieve data than the time allowed by
the execution of table read or table write operations.
example, selecting
a
16-bit Address mode
(ADW<1:0> = 10) disables A<19:16> and allows
PORTH<3:0> to function without interruptions from the
bus. Using smaller address widths allows users to tailor
the memory bus to the size of the external memory
space for a particular design while freeing up pins for
dedicated I/O operation.
To compensate for this, the External Memory Bus can
be configured to add a fixed delay to each table opera-
tion using the bus. Wait states are enabled by setting
the WAITx bit. When enabled, the amount of delay is
set by the WAIT<1:0> bits (MEMCON<5:4>). The delay
is based on multiples of microcontroller instruction
cycle time and are added following the instruction cycle
when the table operation is executed. The range is
from no delay to 3 TCY (default value).
Because the ADW bits have the effect of disabling pins
for memory bus operations, it is important to always
select an address width at least equal to the data width.
If 8-bit or 12-bit address widths are used with a 16-bit
data width, the upper bits of data will not be available
on the bus.
All combinations of address and data widths require
multiplexing of address and data information on the
same lines. The address and data multiplexing, as well
as I/O ports made available by the use of smaller
address widths, are summarized in Table 7-2.
TABLE 7-2:
Data Width
ADDRESS AND DATA LINES FOR DIFFERENT ADDRESS AND DATA WIDTHS
Multiplexed Data and
Address Lines (and
Address-Only
Lines (and
Ports Available
for I/O
Address Width
Corresponding Ports) Corresponding Ports)
All of PORTE and
PORTH
8-bit
12-bit
16-bit
—
AD<11:8>
(PORTE<3:0>)
PORTE<7:4>,
All of PORTH
AD<7:0>
(PORTD<7:0>)
8-bit
AD<15:8>
(PORTE<7:0>)
All of PORTH
A<19:16>, AD<15:8>
(PORTH<3:0>,
20-bit
—
PORTE<7:0>)
16-bit
20-bit
—
All of PORTH
—
AD<15:0>
(PORTD<7:0>,
PORTE<7:0>)
16-bit
A<19:16>
(PORTH<3:0>)
© 2008 Microchip Technology Inc.
DS39646C-page 99
PIC18F8722 FAMILY
7.4
Program Memory Modes and the
External Memory Bus
7.5
16-Bit Data Width Modes
In 16-Bit Data Width mode, the External Memory Bus
can be connected to external memories in three
different configurations:
PIC18F8527/8622/8627/8722 devices are capable of
operating in any one of four program memory modes,
using combinations of on-chip and external program
memory. The functions of the multiplexed port pins
depends on the program memory mode selected, as
well as the setting of the EBDIS bit.
• 16-bit Byte Write
• 16-bit Word Write
• 16-bit Byte Select
The configuration to be used is determined by the
WM1:WM0 bits in the MEMCON register
(MEMCON<1:0>). These three different configurations
allow the designer maximum flexibility in using both
8-bit and 16-bit devices with 16-bit data.
In Microcontroller Mode, the bus is not active and the
pins have their port functions only. Writes to the
MEMCOM register are not permitted. The Reset value
of EBDIS (‘0’) is ignored and EMB pins behave as I/O
ports.
For all 16-bit modes, the Address Latch Enable (ALE)
pin indicates that the address bits AD<15:0> are
available on the external memory interface bus.
Following the address latch, the Output Enable signal
(OE) will enable both bytes of program memory at once
to form a 16-bit instruction word. The Chip Enable
signal (CE) is active at any time that the microcontroller
accesses external memory, whether reading or writing;
it is inactive (asserted high) whenever the device is in
Sleep mode.
In Microprocessor Mode, the external bus is always
active and the port pins have only the external bus
function. The value of EBDIS is ignored.
In Microprocessor with Boot Block or Extended
Microcontroller Mode, the external program memory
bus shares I/O port functions on the pins. When the
device is fetching or doing table read/table write opera-
tions on the external program memory space, the pins
will have the external bus function. If the device is
fetching and accessing internal program memory loca-
tions only, the EBDIS control bit will change the pins
from external memory to I/O port functions. When
EBDIS = 0, the pins function as the external bus. When
EBDIS = 1, the pins function as I/O ports.
In Byte Select mode, JEDEC standard Flash memories
will require BA0 for the byte address line and one I/O
line to select between Byte and Word mode. The other
16-bit modes do not need BA0. JEDEC standard static
RAM memories will use the UB or LB signals for byte
selection.
If the device fetches or accesses external memory
while EBDIS = 1, the pins will switch from I/O to exter-
nal bus. If the EBDIS bit is set by a program executing
from external memory, the action of setting the bit will
be delayed until the program branches into the internal
memory. At that time, the pins will change from external
bus to I/O ports.
If the device is executing out of internal memory when
EBDIS = 0, the memory bus address/data and control
pins will not be active. They will go to a state where the
active address/data pins are tri-state; the CE, OE,
WRH, WRL, UB and LB signals are ‘1’; and ALE and
BA0 are ‘0’. Note that only those pins associated with
the current address width are forced to tri-state; the
other pins continue to function as I/O. In the case of
16-bit address width, for example, only AD<15:0>
(PORTD and PORTE) are affected; A<19:16>
(PORTH<3:0>) continue to function as I/O.
In all external memory modes, the bus takes priority
over any other peripherals that may share pins with it.
This includes the Parallel Slave Port and serial commu-
nications modules which would otherwise take priority
over the I/O port.
DS39646C-page 100
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
During a TBLWTinstruction cycle, the TABLAT data is
presented on the upper and lower bytes of the
AD<15:0> bus. The appropriate WRH or WRL control
line is strobed on the LSb of the TBLPTR.
7.5.1
16-BIT BYTE WRITE MODE
Figure 7-1 shows an example of 16-bit Byte Write
mode for PIC18F8527/8622/8627/8722 devices. This
mode is used for two separate 8-bit memories con-
nected for 16-bit operation. This generally includes
basic EPROM and Flash devices. It allows table writes
to byte-wide external memories.
FIGURE 7-1:
16-BIT BYTE WRITE MODE EXAMPLE
D<7:0>
(MSB)
A<x:0>
(LSB)
PIC18F8X27/8X22
A<19:0>
D<15:8>
AD<7:0>
373
373
A<x:0>
D<7:0>
D<7:0>
CE
D<7:0>
CE
AD<15:8>
ALE
(2)
(2)
OE WR
OE WR
(1)
A<19:16>
CE
OE
WRH
WRL
Address Bus
Data Bus
Control Lines
Note 1: Upper-order address lines are used only for 20-bit address widths.
2: This signal only applies to table writes. See Section 6.1 “Table Reads and Table Writes”.
© 2008 Microchip Technology Inc.
DS39646C-page 101
PIC18F8722 FAMILY
During
a
TBLWT cycle to an odd address
7.5.2
16-BIT WORD WRITE MODE
(TBLPTR<0> = 1), the TABLAT data is presented on
the upper byte of the AD15:AD0 bus. The contents of
the holding latch are presented on the lower byte of the
AD<15:0> bus.
Figure 7-2 shows an example of 16-bit Word Write
mode for PIC18F8527/8622/8627/8722 devices. This
mode is used for word-wide memories which includes
some of the EPROM and Flash-type memories. This
mode allows opcode fetches and table reads from all
forms of 16-bit memory and table writes to any type of
word-wide external memories. This method makes a
distinction between TBLWT cycles to even or odd
addresses.
The WRH signal is strobed for each write cycle; the
WRL pin is unused. The signal on the BA0 pin indicates
the Least Significant bit of TBLPTR but it is left
unconnected. Instead, the UB and LB signals are
active to select both bytes. The obvious limitation to
this method is that the table write must be done in pairs
on a specific word boundary to correctly write a word
location.
During
a
TBLWT cycle to an even address
(TBLPTR<0> = 0), the TABLAT data is transferred to a
holding latch and the external address data bus is
tri-stated for the data portion of the bus cycle. No write
signals are activated.
FIGURE 7-2:
16-BIT WORD WRITE MODE EXAMPLE
PIC18F8X27/8X22
A<20:1>
D<15:0>
JEDEC Word
EPROM Memory
AD<7:0>
373
A<x:0>
D<15:0>
CE
(2)
OE
WR
AD<15:8>
ALE
373
(1)
A<19:16>
CE
OE
WRH
Address Bus
Data Bus
Control Lines
Note 1: Upper-order address lines are used only for 20-bit address widths.
2: This signal only applies to table writes. See Section 6.1 “Table Reads and Table Writes”.
DS39646C-page 102
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
Flash and SRAM devices use different control signal
combinations to implement Byte Select mode. JEDEC
standard Flash memories require that a controller I/O
port pin be connected to the memory’s BYTE/WORD
pin to provide the select signal. They also use the BA0
signal from the controller as a byte address. JEDEC
standard static RAM memories, on the other hand, use
the UB or LB signals to select the byte.
7.5.3
16-BIT BYTE SELECT MODE
Figure 7-3 shows an example of 16-bit Byte Select
mode. This mode allows table write operations to
word-wide external memories with byte selection
capability. This generally includes both word-wide
Flash and SRAM devices.
During a TBLWTcycle, the TABLAT data is presented
on the upper and lower byte of the AD<15:0> bus. The
WRH signal is strobed for each write cycle; the WRL
pin is not used. The BA0 or UB/LB signals are used to
select the byte to be written, based on the Least
Significant bit of the TBLPTR register.
FIGURE 7-3:
16-BIT BYTE SELECT MODE EXAMPLE
PIC18F8X27/8X22
A<20:1>
AD<7:0>
373
373
JEDEC Word
Flash Memory
A<x:1>
D<15:0>
D<15:0>
(3)
138
CE
A0
AD<15:8>
ALE
(1)
BYTE/WORD OE WR
(2)
A<19:16>
OE
WRH
WRL
A<20:1>
JEDEC Word
A<x:1>
SRAM Memory
BA0
I/O
D<15:0>
D<15:0>
CE
LB
LB
(1)
UB
OE WR
UB
Address Bus
Data Bus
Control Lines
Note 1: This signal only applies to table writes. See Section 6.1 “Table Reads and Table Writes”.
2: Upper-order address lines are used only for 20-bit address width.
3: Demultiplexing is only required when multiple memory devices are accessed.
© 2008 Microchip Technology Inc.
DS39646C-page 103
PIC18F8722 FAMILY
7.5.4
16-BIT MODE TIMING
The presentation of control signals on the External
Memory Bus is different for the various operating
modes. Typical signal timing diagrams are shown in
Figure 7-4 through Figure 7-6. All examples assume
either 20-bit or 21-bit address widths.
FIGURE 7-4:
EXTERNAL MEMORY BUS TIMING FOR TBLRD WITH A 1 TCY WAIT STATE
(MICROPROCESSOR MODE)
Q1
Q1
Q2
Q2
Q3
Q3
Q4
Q4
Q1
Q1
Q2
Q2
Q3
Q3
Q4
Q4
Q4
Q1
Q4
Q2
Q4
Q3
Q4
Q4
Apparent Q
Actual Q
00h
0Ch
A<19:16>
3AABh
0E55h
9256h
AD<15:0>
CF33h
BA0
ALE
OE
WRH
‘1’
‘1’
WRL ‘1’
CE ‘0’
‘1’
‘0’
1 TCY Wait
Memory
Cycle
Opcode Fetch
MOVLW55h
Table Read
of 92h
from 007556h
from 199E67h
Instruction
Execution
TBLRDCycle 1
TBLRDCycle 2
FIGURE 7-5:
EXTERNAL MEMORY BUS TIMING FOR TBLRD
(EXTENDED MICROCONTROLLER MODE)
Q1 Q2
Q3
Q4
Q1 Q2
Q3 Q4
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
0Ch
A<19:16>
CF33h
9256h
AD<15:0>
CE
ALE
OE
Opcode Fetch
TBLRD *
from 000100h
Opcode Fetch
MOVLW55h
from 000102h
TBLRD92h
from 199E67h
Opcode Fetch
ADDLW55h
from 000104h
Memory
Cycle
Instruction
Execution
INST(PC – 2)
TBLRDCycle 1
TBLRDCycle 2
MOVLW
DS39646C-page 104
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
FIGURE 7-6:
EXTERNAL MEMORY BUS TIMING FOR SLEEP (MICROPROCESSOR MODE)
Q1 Q2
Q3
Q4
Q1 Q2
Q3 Q4
Q1
00h
00h
A<19:16>
AD<15:0>
0E55h
0003h
3AABh
3AAAh
CE
ALE
OE
Memory
Cycle
(1)
Opcode Fetch
MOVLW55h
Sleep Mode, Bus Inactive
Opcode Fetch
SLEEP
from 007554h
from 007556h
Instruction
Execution
INST(PC – 2)
SLEEP
Note 1: Bus becomes inactive regardless of power-managed mode entered when SLEEPis executed.
© 2008 Microchip Technology Inc.
DS39646C-page 105
PIC18F8722 FAMILY
The Address Latch Enable (ALE) pin indicates that the
address bits A<15:0> are available on the External
Memory Interface bus. The Output Enable signal (OE)
will enable one byte of program memory for a portion of
the instruction cycle, then BA0 will change and the sec-
ond byte will be enabled to form the 16-bit instruction
word. The least significant bit of the address, BA0,
must be connected to the memory devices in this
mode. The Chip Enable signal (CE) is active at any
time that the microcontroller accesses external
memory, whether reading or writing; it is inactive
(asserted high) whenever the device is in Sleep mode.
7.6
8-Bit Data Width Modes
In 8-Bit Data Width mode, the External Memory Bus
operates only in Multiplexed mode; that is, data shares
the 8 least significant bits of the address bus.
Figure 7-7 shows an example of 8-bit Multiplexed
mode for PIC18F8527/8622/8627/8722 devices. This
mode is used for a single 8-bit memory connected for
16-bit operation. The instructions will be fetched as two
8-bit bytes on a shared data/address bus. The two
bytes are sequentially fetched within one instruction
cycle (TCY). Therefore, the designer must choose
external memory devices according to timing calcula-
tions based on 1/2 TCY (2 times the instruction rate).
For proper memory speed selection, glue logic
propagation delay times must be considered along with
setup and hold times.
This generally includes basic EPROM and Flash
devices. It allows table writes to byte-wide external
memories.
The appropriate level of BA0 control line is strobed on
the LSb of the TBLPTR.
FIGURE 7-7:
8-BIT MULTIPLEXED MODE EXAMPLE
D<7:0>
PIC18F8X27/8X22
A<19:0>
A<x:1>
AD<7:0>
373
ALE
A0
D<15:8>
D<7:0>
CE
(1)
AD<15:8>
(1)
A<19:16>
(2)
OE WR
BA0
CE
OE
WRL
Address Bus
Data Bus
Control Lines
Note 1: Upper-order address bits are used only for 20-bit address width. The upper AD byte is used
for all address widths except 8-bit.
2: This signal only applies to table writes. See Section 6.1 “Table Reads and Table Writes”.
DS39646C-page 106
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
7.6.1
8-BIT MODE TIMING
The presentation of control signals on the External
Memory Bus is different for the various operating
modes. Typical signal timing diagrams are shown in
Figure 7-8 through Figure 7-11.
FIGURE 7-8:
EXTERNAL BUS TIMING FOR TBLRD (MICROPROCESSOR MODE)
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
AD<15:8>,
A<19:16>
03Ah
03Ah
CCFh
03Ah
(1)
AAh
08h 00h
ABh
55h 0Eh
33h
92h
ACh
55h 0Fh
AD<7:0>
BA0
ALE
OE
‘1’
‘1’
WRH
‘1’
‘1’
WRL
Opcode Fetch
Opcode Fetch
Table Read 92h
from 199E67h
Opcode Fetch
Memory
Cycle
TBLRD *
MOVLW55h
ADDLW55h
from 007554h
from 007556h
from 007558h
Instruction
Execution
INST(PC – 2)
TBLRDCycle 1
TBLRDCycle 2
MOVLW
Note 1: The address lines actually used depends on the address width selected. This example assumes 20-bit addressing.
FIGURE 7-9:
EXTERNAL BUS TIMING FOR TBLRD (EXTENDED MICROCONTROLLER MODE)
Q1 Q2
Q3
Q4
Q1 Q2
Q3 Q4
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
(1)
0Ch
CFh
A<19:16>
(1)
AD<15:8>
33h
92h
AD<7:0>
CE
ALE
OE
Opcode Fetch
TBLRD *
from 000100h
Opcode Fetch
MOVLW55h
from 000102h
TBLRD92h
from 199E67h
Opcode Fetch
ADDLW55h
from 000104h
Memory
Cycle
Instruction
Execution
INST(PC – 2)
TBLRDCycle 1
TBLRDCycle 2
MOVLW
Note 1: The address lines actually used depends on the address width selected. This example assumes 20-bit addressing.
© 2008 Microchip Technology Inc.
DS39646C-page 107
PIC18F8722 FAMILY
FIGURE 7-10:
EXTERNAL MEMORY BUS TIMING FOR SLEEP (MICROPROCESSOR MODE)
Q1 Q2
Q3
Q4
Q1 Q2
Q3 Q4
Q1
(1)
00h
00h
A<19:16>
(1)
AD<15:8>
3Ah
3Ah
00h 03h
AD<7:0>
AAh
ABh
0Eh 55h
BA0
CE
ALE
OE
(2)
Sleep Mode, Bus Inactive
Memory
Cycle
Opcode Fetch
MOVLW55h
Opcode Fetch
SLEEP
from 007554h
from 007556h
Instruction
Execution
INST(PC – 2)
SLEEP
Note 1: The address lines actually used depends on the address width selected. This example assumes 20-bit addressing.
2: Bus becomes inactive regardless of power-managed mode entered when SLEEPis executed.
FIGURE 7-11:
TYPICAL OPCODE FETCH, 8-BIT MODE
Q1
Q2
Q3
Q4
(1)
AD<15:8>
03Ah
AD<7:0>
BA0
0Eh
55h
55h
ALE
OE
‘1’
‘1’
WRL
Opcode Fetch MOVLW55h from 007556h
Memory
Cycle
Note 1: The address lines actually used depends on the address width selected. This example assumes 16-bit addressing.
DS39646C-page 108
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
In Sleep and Idle modes, the microcontroller core does
not need to access data; bus operations are sus-
pended. The state of the external bus is frozen with the
address/data pins and most of the control pins holding
at the same state they were in when the mode was
invoked. The only potential changes are the CE, LB
and UB pins which are held at logic high.
7.7
Operation in Power-Managed
Modes
In alternate power-managed Run modes, the external
bus continues to operate normally. If a clock source
with a lower speed is selected, bus operations will run
at that speed. In these cases, excessive access times
for the external memory may result if wait states have
been enabled and added to external memory opera-
tions. If operations in a lower power Run mode are
anticipated, users should provide in their applications
for adjusting memory access times at the lower clock
speeds.
TABLE 7-3:
Name
SUMMARY OF REGISTERS ASSOCIATED WITH POWER-MANAGED MODES
Reset
Values
on page
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
MEMCON(1)
CONFIG3L(2)
CONFIG3H
EBDIS
WAIT
—
BW
—
WAIT1
ABW1
—
WAIT0
ABW0
—
—
—
—
—
—
WM1
PM1
WM0
PM0
60
302
303
MCLRE
LPT1OSC ECCPMX(2) CCP2MX
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by the External Memory Bus.
Note 1: This register is not implemented on 64-pin devices.
2: Unimplemented in PIC18F6527/6622/6627/6722 devices.
© 2008 Microchip Technology Inc.
DS39646C-page 109
PIC18F8722 FAMILY
NOTES:
DS39646C-page 110
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
8.2
EECON1 and EECON2 Registers
8.0
DATA EEPROM MEMORY
Access to the data EEPROM is controlled by two
registers: EECON1 and EECON2. These are the same
registers which control access to the program memory
and are used in a similar manner for the data
EEPROM.
The data EEPROM is a nonvolatile memory array,
separate from the data RAM and program memory, that
is used for long-term storage of program data. It is not
directly mapped in either the register file or program
memory space, but is indirectly addressed through the
Special Function Registers (SFRs). The EEPROM is
readable and writable during normal operation over the
entire VDD range.
The EECON1 register (Register ) is the control register
for data and program memory access. Control bit
EEPGD determines if the access will be to program or
data EEPROM memory. When clear, operations will
access the data EEPROM memory. When set, program
memory is accessed.
Five SFRs are used to read and write to the data
EEPROM, as well as the program memory. They are:
• EECON1
• EECON2
• EEDATA
• EEADR
Control bit CFGS determines if the access will be to the
Configuration registers or to program memory/data
EEPROM memory. When set, subsequent operations
access Configuration registers. When CFGS is clear,
the EEPGD bit selects either program Flash or data
EEPROM memory.
• EEADRH
The data EEPROM allows byte read and write. When
interfacing to the data memory block, EEDATA holds
the 8-bit data for read/write and the EEADRH:EEADR
register pair holds the address of the EEPROM location
being accessed.
The WREN bit, when set, will allow a write operation.
On power-up, the WREN bit is clear. The WRERR bit is
set in hardware when the WREN bit is set and cleared
when the internal programming timer expires and the
write operation is complete.
The EEPROM data memory is rated for high erase/write
cycle endurance. A byte write automatically erases the
location and writes the new data (erase-before-write).
The write time is controlled by an on-chip timer; it will
vary with voltage and temperature, as well as from chip-
to-chip. Please refer to parameter D122 (Table 28-1 in
Section 28.0 “Electrical Characteristics”) for exact
limits.
Note:
During normal operation, the WRERR is
read as ‘1’. This can indicate that a write
operation was prematurely terminated by
a
Reset, or
a write operation was
attempted improperly.
The WR control bit initiates write operations. The bit
cannot be cleared, only set, in software; it is cleared in
hardware at the completion of the write operation.
8.1
EEADR and EEADRH Registers
Note:
The EEIF interrupt flag bit (PIR2<4>) is set
when the write is complete. It must be
cleared in software.
The EEADRH:EEADR register pair is used to address
the data EEPROM for read and write operations.
EEADRH holds the two MSbs of the address; the upper
6 bits are ignored. The 10-bit range of the pair can
address a memory range of 1024 bytes (00h to 3FFh).
Control bits, RD and WR, start read and erase/write
operations, respectively. These bits are set by firmware
and cleared by hardware at the completion of the
operation.
The RD bit cannot be set when accessing program
memory (EEPGD = 1). Program memory is read using
table read instructions. See Section 6.1 “Table Reads
and Table Writes” regarding table reads.
The EECON2 register is not a physical register. It is
used exclusively in the memory write and erase
sequences. Reading EECON2 will read all ‘0’s.
© 2008 Microchip Technology Inc.
DS39646C-page 111
PIC18F8722 FAMILY
REGISTER 8-1:
EECON1: DATA EEPROM CONTROL REGISTER 1
R/W-x
EEPGD
bit 7
R/W-x
CFGS
U-0
—
R/W-0
FREE
R/W-x
WRERR(1)
R/W-0
WREN
R/S-0
WR
R/S-0
RD
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7
bit 6
EEPGD: Flash Program or Data EEPROM Memory Select bit
1= Access Flash program memory
0= Access data EEPROM memory
CFGS: Flash Program/Data EEPROM or Configuration Select bit
1= Access Configuration registers
0= Access Flash program or data EEPROM memory
bit 5
bit 4
Unimplemented: Read as ‘0’
FREE: Flash Row Erase Enable bit
1= Erase the program memory row addressed by TBLPTR on the next WR command (cleared by
completion of erase operation)
0= Perform write only
bit 3
WRERR: Flash Program/Data EEPROM Error Flag bit(1)
1= A write operation is prematurely terminated (any Reset during self-timed programming in normal
operation, or an improper write attempt)
0= The write operation completed
bit 2
bit 1
WREN: Flash Program/Data EEPROM Write Enable bit
1= Allows write cycles to Flash program/data EEPROM
0= Inhibits write cycles to Flash program/data EEPROM
WR: Write Control bit
1= Initiates a data EEPROM erase/write cycle or a program memory erase cycle or write cycle.
(The operation is self-timed and the bit is cleared by hardware once write is complete.
The WR bit can only be set (not cleared) in software.)
0= Write cycle to the EEPROM is complete
bit 0
RD: Read Control bit
1= Initiates an EEPROM read
(Read takes one cycle. RD is cleared in hardware. The RD bit can only be set (not cleared) in
software. RD bit cannot be set when EEPGD = 1or CFGS = 1.)
0= Does not initiate an EEPROM read
Note 1: When a WRERR occurs, the EEPGD and CFGS bits are not cleared. This allows tracing of the error
condition.
DS39646C-page 112
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
Additionally, the WREN bit in EECON1 must be set to
enable writes. This mechanism prevents accidental
writes to data EEPROM due to unexpected code exe-
cution (i.e., runaway programs). The WREN bit should
be kept clear at all times, except when updating the
EEPROM. The WREN bit is not cleared by hardware.
8.3
Reading the Data EEPROM
Memory
To read a data memory location, the user must write the
address to the EEADRH:EEADR register pair, clear the
EEPGD control bit (EECON1<7>) and then set control
bit, RD (EECON1<0>). The data is available on the
very next instruction cycle; therefore, the EEDATA
register can be read by the next instruction. EEDATA
will hold this value until another read operation, or until
it is written to by the user (during a write operation).
After a write sequence has been initiated, EECON1,
EEADRH:EEADR and EEDATA cannot be modified.
The WR bit will be inhibited from being set unless the
WREN bit is set. The WREN bit must be set on a
previous instruction. Both WR and WREN cannot be
set with the same instruction.
The basic process is shown in Example 8-1.
At the completion of the write cycle, the WR bit is
cleared in hardware and the EEPROM Interrupt Flag bit
(EEIF) is set. The user may either enable this interrupt,
or poll this bit. EEIF must be cleared by software.
8.4
Writing to the Data EEPROM
Memory
To write an EEPROM data location, the address must
first be written to the EEADRH:EEADR register pair
and the data written to the EEDATA register. The
sequence in Example 8-2 must be followed to initiate
the write cycle.
8.5
Write Verify
Depending on the application, good programming
practice may dictate that the value written to the
memory should be verified against the original value.
This should be used in applications where excessive
writes can stress bits near the specification limit.
The write will not begin if this sequence is not exactly
followed (write 55h to EECON2, write 0AAh to
EECON2, then set WR bit) for each byte. It is strongly
recommended that interrupts be disabled during this
code segment.
EXAMPLE 8-1:
DATA EEPROM READ
MOVLW
MOVWF
MOVLW
MOVWF
BCF
BCF
BSF
MOVF
DATA_EE_ADDRH
EEADRH
DATA_EE_ADDR
EEADR
EECON1, EEPGD
EECON1, CFGS
EECON1, RD
EEDATA, W
;
; Upper bits of Data Memory Address to read
;
; Lower bits of Data Memory Address to read
; Point to DATA memory
; Access EEPROM
; EEPROM Read
; W = EEDATA
EXAMPLE 8-2:
DATA EEPROM WRITE
MOVLW
DATA_EE_ADDRH
EEADRH
DATA_EE_ADDR
EEADR
DATA_EE_DATA
EEDATA
EECON1, EPGD
EECON1, CFGS
EECON1, WREN
;
MOVWF
MOVLW
MOVWF
MOVLW
MOVWF
BCF
; Upper bits of Data Memory Address to write
;
; Lower bits of Data Memory Address to write
;
; Data Memory Value to write
; Point to DATA memory
; Access EEPROM
BCF
BSF
; Enable writes
BCF
INTCON, GIE
55h
EECON2
0AAh
EECON2
; Disable Interrupts
;
; Write 55h
;
; Write 0AAh
; Set WR bit to begin write
; Enable Interrupts
MOVLW
MOVWF
MOVLW
MOVWF
BSF
Required
Sequence
EECON1, WR
INTCON, GIE
BSF
; User code execution
BCF
EECON1, WREN
; Disable writes on write complete (EEIF set)
© 2008 Microchip Technology Inc.
DS39646C-page 113
PIC18F8722 FAMILY
8.6
Operation During Code-Protect
8.8
Using the Data EEPROM
Data EEPROM memory has its own code-protect bits in
Configuration Words. External read and write
operations are disabled if code protection is enabled.
The data EEPROM is a high-endurance, byte address-
able array that has been optimized for the storage of
frequently changing information (e.g., program
variables or other data that are updated often).
Frequently changing values will typically be updated
more often than specification D124. If this is not the
case, an array refresh must be performed. For this
reason, variables that change infrequently (such as
constants, IDs, calibration, etc.) should be stored in
Flash program memory.
The microcontroller itself can both read and write to the
internal data EEPROM regardless of the state of the
code-protect Configuration bit. Refer to Section 25.0
“Special Features of the CPU” for additional
information.
8.7
Protection Against Spurious Write
A simple data EEPROM refresh routine is shown in
Example 8-3.
There are conditions when the device may not want to
write to the data EEPROM memory. To protect against
spurious EEPROM writes, various mechanisms have
been implemented. On power-up, the WREN bit is
cleared. In addition, writes to the EEPROM are blocked
during the Power-up Timer period (TPWRT,
parameter 33).
Note:
If data EEPROM is only used to store
constants and/or data that changes often,
an array refresh is likely not required. See
specification D124.
The write initiate sequence and the WREN bit together
help prevent an accidental write during brown-out,
power glitch or software malfunction.
EXAMPLE 8-3:
DATA EEPROM REFRESH ROUTINE
CLRF
CLRF
BCF
BCF
BCF
EEADR
EEADRH
EECON1, CFGS
EECON1, EEPGD
INTCON, GIE
EECON1, WREN
; Start at address 0
;
; Set for memory
; Set for Data EEPROM
; Disable interrupts
; Enable writes
; Loop to refresh array
; Read current address
;
; Write 55h
;
; Write 0AAh
; Set WR bit to begin write
; Wait for write to complete
BSF
Loop
BSF
EECON1, RD
55h
EECON2
0AAh
EECON2
EECON1, WR
EECON1, WR
$-2
MOVLW
MOVWF
MOVLW
MOVWF
BSF
BTFSC
BRA
INCFSZ EEADR, F
; Increment address
BRA
LOOP
; Not zero, do it again
; Increment the high address
; Not zero, do it again
INCFSZ EEADRH, F
BRA
LOOP
BCF
BSF
EECON1, WREN
INTCON, GIE
; Disable writes
; Enable interrupts
DS39646C-page 114
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
TABLE 8-1:
Name
REGISTERS ASSOCIATED WITH DATA EEPROM MEMORY
Reset
Values
on page
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
INTCON
EEADRH
GIE/GIEH PEIE/GIEL TMR0IE
INT0IE
—
RBIE
—
TMR0IF
—
INT0IF
RBIF
57
59
—
—
—
EEPROM Address
Register High Byte
EEADR
EEPROM Address Register Low Byte
59
59
59
59
60
60
60
EEDATA EEPROM Data Register
EECON2 EEPROM Control Register 2 (not a physical register)
EECON1
IPR2
EEPGD
OSCFIP
OSCFIF
OSCFIE
CFGS
CMIP
CMIF
CMIE
—
—
—
—
FREE
EEIP
EEIF
EEIE
WRERR
BCL1IP
BCL1IF
BCL1IE
WREN
HLVDIP
HLVDIF
HLVDIE
WR
RD
TMR3IP
TMR3IF
TMR3IE
CCP2IP
CCP2IF
CCP2IE
PIR2
PIE2
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used during Flash/EEPROM access.
© 2008 Microchip Technology Inc.
DS39646C-page 115
PIC18F8722 FAMILY
NOTES:
DS39646C-page 116
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
EXAMPLE 9-1:
8 x 8 UNSIGNED
MULTIPLY ROUTINE
9.0
9.1
8 x 8 HARDWARE MULTIPLIER
Introduction
MOVF
MULWF
ARG1, W
ARG2
;
; ARG1 * ARG2 ->
; PRODH:PRODL
All PIC18 devices include an 8 x 8 hardware multiplier
as part of the ALU. The multiplier performs an unsigned
operation and yields a 16-bit result that is stored in the
product register pair, PRODH:PRODL. The multiplier’s
operation does not affect any flags in the STATUS
register.
EXAMPLE 9-2:
8 x 8 SIGNED MULTIPLY
ROUTINE
Making multiplication a hardware operation allows it to
be completed in a single instruction cycle. This has the
advantages of higher computational throughput and
reduced code size for multiplication algorithms and
allows the PIC18 devices to be used in many applica-
tions previously reserved for digital signal processors.
A comparison of various hardware and software
multiply operations, along with the savings in memory
and execution time, is shown in Table 9-1.
MOVF
MULWF
ARG1, W
ARG2
; ARG1 * ARG2 ->
; PRODH:PRODL
; Test Sign Bit
; PRODH = PRODH
BTFSC
SUBWF
ARG2, SB
PRODH, F
;
- ARG1
MOVF
BTFSC
SUBWF
ARG2, W
ARG1, SB
PRODH, F
; Test Sign Bit
; PRODH = PRODH
;
- ARG2
9.2
Operation
Example 9-1 shows the instruction sequence for an 8 x 8
unsigned multiplication. Only one instruction is required
when one of the arguments is already loaded in the
WREG register.
Example 9-2 shows the sequence to do an 8 x 8 signed
multiplication. To account for the sign bits of the argu-
ments, each argument’s Most Significant bit (MSb) is
tested and the appropriate subtractions are done.
TABLE 9-1:
Routine
PERFORMANCE COMPARISON FOR VARIOUS MULTIPLY OPERATIONS
Program
Memory
(Words)
Time
Cycles
(Max)
Multiply Method
@ 40 MHz @ 10 MHz @ 4 MHz
Without hardware multiply
Hardware multiply
13
1
69
1
6.9 μs
100 ns
9.1 μs
600 ns
24.2 μs
2.8 μs
25.4 μs
4.0 μs
27.6 μs
400 ns
36.4 μs
2.4 μs
69 μs
1 μs
8 x 8 unsigned
8 x 8 signed
Without hardware multiply
Hardware multiply
33
6
91
6
91 μs
6 μs
Without hardware multiply
Hardware multiply
21
28
52
35
242
28
254
40
96.8 μs
11.2 μs
102.6 μs
16.0 μs
242 μs
28 μs
254 μs
40 μs
16 x 16 unsigned
16 x 16 signed
Without hardware multiply
Hardware multiply
© 2008 Microchip Technology Inc.
DS39646C-page 117
PIC18F8722 FAMILY
Example 9-3 shows the sequence to do a 16 x 16
unsigned multiplication. Equation 9-1 shows the
algorithm that is used. The 32-bit result is stored in four
registers (RES3:RES0).
EQUATION 9-2:
16 x 16 SIGNED
MULTIPLICATION
ALGORITHM
RES3:RES0=ARG1H:ARG1L • ARG2H:ARG2L
16
= (ARG1H • ARG2H • 2 ) +
(ARG1H • ARG2L • 2 ) +
(ARG1L • ARG2H • 2 ) +
(ARG1L • ARG2L) +
(-1 • ARG2H<7> • ARG1H:ARG1L • 2 ) +
(-1 • ARG1H<7> • ARG2H:ARG2L • 2
8
EQUATION 9-1:
16 x 16 UNSIGNED
MULTIPLICATION
ALGORITHM
8
16
RES3:RES0
=
=
ARG1H:ARG1L • ARG2H:ARG2L
16
)
16
(ARG1H • ARG2H • 2 ) +
8
(ARG1H • ARG2L • 2 ) +
8
(ARG1L • ARG2H • 2 ) +
EXAMPLE 9-4:
16 x 16 SIGNED
MULTIPLY ROUTINE
(ARG1L • ARG2L)
MOVF
ARG1L, W
MULWF
ARG2L
; ARG1L * ARG2L ->
; PRODH:PRODL
;
;
EXAMPLE 9-3:
16 x 16 UNSIGNED
MULTIPLY ROUTINE
MOVFF
MOVFF
PRODH, RES1
PRODL, RES0
MOVF
MULWF
ARG1L, W
ARG2L
; ARG1L * ARG2L->
; PRODH:PRODL
;
;
;
;
MOVF
MULWF
ARG1H, W
ARG2H
MOVFF
MOVFF
PRODH, RES1
PRODL, RES0
; ARG1H * ARG2H ->
; PRODH:PRODL
;
;
;
;
MOVFF
MOVFF
PRODH, RES3
PRODL, RES2
MOVF
MULWF
ARG1H, W
ARG2H
; ARG1H * ARG2H->
; PRODH:PRODL
;
;
MOVF
MULWF
ARG1L, W
ARG2H
MOVFF
MOVFF
PRODH, RES3
PRODL, RES2
; ARG1L * ARG2H ->
; PRODH:PRODL
;
; Add cross
; products
;
;
;
MOVF
ADDWF
MOVF
ADDWFC RES2, F
CLRF WREG
ADDWFC RES3, F
PRODL, W
RES1, F
PRODH, W
MOVF
MULWF
ARG1L, W
ARG2H
; ARG1L * ARG2H->
; PRODH:PRODL
;
; Add cross
; products
;
;
;
MOVF
ADDWF
MOVF
PRODL, W
RES1, F
PRODH, W
;
ADDWFC RES2, F
CLRF WREG
ADDWFC RES3, F
MOVF
MULWF
ARG1H, W
ARG2L
;
; ARG1H * ARG2L ->
; PRODH:PRODL
;
; Add cross
; products
;
;
;
;
MOVF
ADDWF
MOVF
ADDWFC RES2, F
CLRF WREG
ADDWFC RES3, F
PRODL, W
RES1, F
PRODH, W
MOVF
MULWF
ARG1H, W
ARG2L
;
; ARG1H * ARG2L->
; PRODH:PRODL
;
; Add cross
; products
;
;
;
MOVF
ADDWF
MOVF
PRODL, W
RES1, F
PRODH, W
;
;
ADDWFC RES2, F
CLRF WREG
ADDWFC RES3, F
BTFSS
BRA
MOVF
SUBWF
MOVF
ARG2H, 7
SIGN_ARG1
ARG1L, W
RES2
; ARG2H:ARG2L neg?
; no, check ARG1
;
;
;
Example 9-4 shows the sequence to do a 16 x 16
signed multiply. Equation 9-2 shows the algorithm
used. The 32-bit result is stored in four registers
(RES<3:0>). To account for the sign bits of the argu-
ments, the MSb for each argument pair is tested and
the appropriate subtractions are done.
ARG1H, W
SUBWFB RES3
SIGN_ARG1
BTFSS
BRA
ARG1H, 7
CONT_CODE
ARG2L, W
RES2
; ARG1H:ARG1L neg?
; no, done
;
;
;
MOVF
SUBWF
MOVF
ARG2H, W
SUBWFB RES3
;
CONT_CODE
:
DS39646C-page 118
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
When the IPEN bit is cleared (default state), the
interrupt priority feature is disabled and interrupts are
compatible with PIC® mid-range devices. In
Compatibility mode, the interrupt priority bits for each
source have no effect. INTCON<6> is the PEIE bit,
which enables/disables all peripheral interrupt sources.
INTCON<7> is the GIE bit, which enables/disables all
interrupt sources. All interrupts branch to address
0008h in Compatibility mode.
10.0 INTERRUPTS
The PIC18F8722 family of devices have multiple
interrupt sources and an interrupt priority feature that
allows most interrupt sources to be assigned a high-
priority level or a low-priority level. The high-priority
interrupt vector is at 0008h and the low-priority interrupt
vector is at 0018h. High-priority interrupt events will
interrupt any low-priority interrupts that may be in
progress.
When an interrupt is responded to, the global interrupt
enable bit is cleared to disable further interrupts. If the
IPEN bit is cleared, this is the GIE bit. If interrupt priority
levels are used, this will be either the GIEH or GIEL bit.
High-priority interrupt sources can interrupt a low-
priority interrupt. Low-priority interrupts are not
processed while high-priority interrupts are in progress.
There are ten registers which are used to control
interrupt operation. These registers are:
• RCON
• INTCON
• INTCON2
• INTCON3
The return address is pushed onto the stack and the
PC is loaded with the interrupt vector address (0008h
or 0018h). Once in the Interrupt Service Routine, the
source(s) of the interrupt can be determined by polling
the interrupt flag bits. The interrupt flag bits must be
cleared in software before re-enabling interrupts to
avoid recursive interrupts.
• PIR1, PIR2, PIR3
• PIE1, PIE2, PIE3
• IPR1, IPR2, IPR3
It is recommended that the Microchip header files
supplied with MPLAB® IDE be used for the symbolic bit
names in these registers. This allows the assembler/
compiler to automatically take care of the placement of
these bits within the specified register.
The “return from interrupt” instruction, RETFIE, exits
the interrupt routine and sets the GIE bit (GIEH or GIEL
if priority levels are used), which re-enables interrupts.
In general, interrupt sources have three bits to control
their operation. They are:
For external interrupt events, such as the INTx pins or
the PORTB input change interrupt, the interrupt latency
will be three to four instruction cycles. The exact
latency is the same for one or two-cycle instructions.
Individual interrupt flag bits are set, regardless of the
status of their corresponding enable bit or the GIE bit.
• Flag bit to indicate that an interrupt event
occurred
• Enable bit that allows program execution to
branch to the interrupt vector address when the
flag bit is set
• Priority bit to select high priority or low priority
Note:
Do not use the MOVFFinstruction to modify
any of the interrupt control registers while
any interrupt is enabled. Doing so may
cause erratic microcontroller behavior.
The interrupt priority feature is enabled by setting the
IPEN bit (RCON<7>). When interrupt priority is
enabled, there are two bits which enable interrupts
globally. Setting the GIEH bit (INTCON<7>) enables all
interrupts that have the priority bit set (high priority).
Setting the GIEL bit (INTCON<6>) enables all
interrupts that have the priority bit cleared (low priority).
When the interrupt flag, enable bit and appropriate
global interrupt enable bit are set, the interrupt will
vector immediately to address 0008h or 0018h,
depending on the priority bit setting. Individual
interrupts can be disabled through their corresponding
enable bits.
© 2008 Microchip Technology Inc.
DS39646C-page 119
PIC18F8722 FAMILY
FIGURE 10-1:
PIC18F8722 FAMILY INTERRUPT LOGIC
Wake-up if in
Idle or Sleep modes
TMR0IF
TMR0IE
TMR0IP
RBIF
RBIE
RBIP
INT0IF
INT0IE
INT1IF
INT1IE
INT1IP
INT2IF
INT2IE
INT2IP
INT3IF
INT3IE
INT3IP
Interrupt to CPU
Vector to Location
0008h
PIR1<7:0>
PIE1<7:0>
IPR1<7:0>
GIEH/GIE
PIR2<7:6, 4:0>
PIE2<7:6, 4:0>
IPR2<7:6, 4:0>
IPEN
PIR3<7:0>
PIE3<7:0>
IPR3<7:0>
IPEN
GIEL/PEIE
IPEN
High-Priority Interrupt Generation
Low-Priority Interrupt Generation
PIR1<7:0>
PIE1<7:0>
IPR1<7:0>
PIR2<7:6, 4:0>
PIE2<7:6, 4:0>
IPR2<7:6, 4:0>
Interrupt to CPU
Vector to Location
0018h
TMR0IF
TMR0IE
TMR0IP
IPEN
PIR3<7:0>
PIE3<7:0>
IPR3<7:0>
RBIF
RBIE
RBIP
GIEH/GIE
GIEL/PEIE
INT1IF
INT1IE
INT1IP
INT2IF
INT2IE
INT2IP
INT3IF
INT3IE
INT3IP
DS39646C-page 120
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
10.1 INTCON Registers
Note:
Interrupt flag bits are set when an interrupt
condition occurs, regardless of the state of
its corresponding enable bit or the global
interrupt enable bit. User software should
ensure the appropriate interrupt flag bits
are clear prior to enabling an interrupt.
This feature allows for software polling.
The INTCON registers are readable and writable
registers which contain various enable, priority and flag
bits.
REGISTER 10-1: INTCON: INTERRUPT CONTROL REGISTER
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
RBIE
R/W-0
R/W-0
INT0IF
R/W-x
RBIF(1)
GIE/GIEH
PEIE/GIEL
TMR0IE
INT0IE
TMR0IF
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
-n = Value at POR
bit 7
GIE/GIEH: Global Interrupt Enable bit
When IPEN = 0:
1= Enables all unmasked interrupts
0= Disables all interrupts
When IPEN = 1:
1= Enables all high-priority interrupts
0= Disables all interrupts
bit 6
PEIE/GIEL: Peripheral Interrupt Enable bit
When IPEN = 0:
1= Enables all unmasked peripheral interrupts
0= Disables all peripheral interrupts
When IPEN = 1:
1= Enables all low-priority peripheral interrupts
0= Disables all low-priority peripheral interrupts
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
TMR0IE: TMR0 Overflow Interrupt Enable bit
1= Enables the TMR0 overflow interrupt
0= Disables the TMR0 overflow interrupt
INT0IE: INT0 External Interrupt Enable bit
1= Enables the INT0 external interrupt
0= Disables the INT0 external interrupt
RBIE: RB Port Change Interrupt Enable bit
1= Enables the RB port change interrupt
0= Disables the RB port change interrupt
TMR0IF: TMR0 Overflow Interrupt Flag bit
1= TMR0 register has overflowed (must be cleared in software)
0= TMR0 register did not overflow
INT0IF: INT0 External Interrupt Flag bit
1= The INT0 external interrupt occurred (must be cleared in software)
0= The INT0 external interrupt did not occur
RBIF: RB Port Change Interrupt Flag bit(1)
1= At least one of the RB7:RB4 pins changed state (must be cleared in software)
0= None of the RB7:RB4 pins have changed state
Note 1: A mismatch condition will continue to set this bit. Reading PORTB will end the mismatch condition and
allow the bit to be cleared.
© 2008 Microchip Technology Inc.
DS39646C-page 121
PIC18F8722 FAMILY
REGISTER 10-2: INTCON2: INTERRUPT CONTROL REGISTER 2
R/W-1
RBPU
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
R/W-1
RBIP
INTEDG0
INTEDG1
INTEDG2
INTEDG3
TMR0IP
INT3IP
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
-n = Value at POR
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
RBPU: PORTB Pull-up Enable bit
1= All PORTB pull-ups are disabled
0= PORTB pull-ups are enabled by individual port latch values
INTEDG0: External Interrupt 0 Edge Select bit
1= Interrupt on rising edge
0= Interrupt on falling edge
INTEDG1: External Interrupt 1 Edge Select bit
1= Interrupt on rising edge
0= Interrupt on falling edge
INTEDG2: External Interrupt 2 Edge Select bit
1= Interrupt on rising edge
0= Interrupt on falling edge
INTEDG3: External Interrupt 3 Edge Select bit
1= Interrupt on rising edge
0= Interrupt on falling edge
TMR0IP: TMR0 Overflow Interrupt Priority bit
1= High priority
0= Low priority
INT3IP: INT3 External Interrupt Priority bit
1= High priority
0= Low priority
RBIP: RB Port Change Interrupt Priority bit
1= High priority
0= Low priority
Note:
Interrupt flag bits are set when an interrupt condition occurs, regardless of the state of its corresponding
enable bit or the global interrupt enable bit. User software should ensure the appropriate interrupt flag bits
are clear prior to enabling an interrupt. This feature allows for software polling.
DS39646C-page 122
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
REGISTER 10-3: INTCON3: INTERRUPT CONTROL REGISTER 3
R/W-1
R/W-1
R/W-0
R/W-0
R/W-0
R/W-0
INT3IF
R/W-0
INT2IF
R/W-0
INT1IF
INT2IP
INT1IP
INT3IE
INT2IE
INT1IE
bit 7
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
INT2IP: INT2 External Interrupt Priority bit
1= High priority
0= Low priority
INT1IP: INT1 External Interrupt Priority bit
1= High priority
0= Low priority
INT3IE: INT3 External Interrupt Enable bit
1= Enables the INT3 external interrupt
0= Disables the INT3 external interrupt
INT2IE: INT2 External Interrupt Enable bit
1= Enables the INT2 external interrupt
0= Disables the INT2 external interrupt
INT1IE: INT1 External Interrupt Enable bit
1= Enables the INT1 external interrupt
0= Disables the INT1 external interrupt
INT3IF: INT3 External Interrupt Flag bit
1= The INT3 external interrupt occurred (must be cleared in software)
0= The INT3 external interrupt did not occur
INT2IF: INT2 External Interrupt Flag bit
1= The INT2 external interrupt occurred (must be cleared in software)
0= The INT2 external interrupt did not occur
INT1IF: INT1 External Interrupt Flag bit
1= The INT1 external interrupt occurred (must be cleared in software)
0= The INT1 external interrupt did not occur
Note:
Interrupt flag bits are set when an interrupt condition occurs, regardless of the state of its corresponding
enable bit or the global interrupt enable bit. User software should ensure the appropriate interrupt flag bits
are clear prior to enabling an interrupt. This feature allows for software polling.
© 2008 Microchip Technology Inc.
DS39646C-page 123
PIC18F8722 FAMILY
10.2 PIR Registers
Note 1: Interrupt flag bits are set when an interrupt
condition occurs, regardless of the state of
its corresponding enable bit or the Global
Interrupt Enable bit, GIE (INTCON<7>).
The PIR registers contain the individual flag bits for the
peripheral interrupts. Due to the number of peripheral
interrupt sources, there are three Peripheral Interrupt
Request (Flag) registers (PIR1, PIR2, PIR3).
2: User software should ensure the
appropriate interrupt flag bits are cleared
prior to enabling an interrupt and after
servicing that interrupt.
REGISTER 10-4: PIR1: PERIPHERAL INTERRUPT REQUEST (FLAG) REGISTER 1
R/W-0
PSPIF
R/W-0
ADIF
R-0
R-0
R/W-0
R/W-0
R/W-0
R/W-0
RC1IF
TX1IF
SSP1IF
CCP1IF
TMR2IF
TMR1IF
bit 7
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
PSPIF: Parallel Slave Port Read/Write Interrupt Flag bit
1= A read or a write operation has taken place (must be cleared in software)
0= No read or write has occurred
ADIF: A/D Converter Interrupt Flag bit
1= An A/D conversion completed (must be cleared in software)
0= The A/D conversion is not complete
RC1IF: EUSART1 Receive Interrupt Flag bit
1= The EUSART1 receive buffer, RCREG1, is full (cleared when RCREG1 is read)
0= The EUSART1 receive buffer is empty
TX1IF: EUSART1 Transmit Interrupt Flag bit
1= The EUSART1 transmit buffer, TXREG1, is empty (cleared when TXREG1 is written)
0= The EUSART1 transmit buffer is full
SSP1IF: MSSP1 Interrupt Flag bit
1= The transmission/reception is complete (must be cleared in software)
0= Waiting to transmit/receive
CCP1IF: ECCP1 Interrupt Flag bit
Capture mode:
1= A TMR1/TMR3 register capture occurred (must be cleared in software)
0= No TMR1/TMR3 register capture occurred
Compare mode:
1= A TMR1/TMR3 register compare match occurred (must be cleared in software)
0= No TMR1/TMR3 register compare match occurred
PWM mode:
Unused in this mode.
bit 1
bit 0
TMR2IF: TMR2 to PR2 Match Interrupt Flag bit
1= TMR2 to PR2 match occurred (must be cleared in software)
0= No TMR2 to PR2 match occurred
TMR1IF: TMR1 Overflow Interrupt Flag bit
1= TMR1 register overflowed (must be cleared in software)
0= TMR1 register did not overflow
DS39646C-page 124
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
REGISTER 10-5: PIR2: PERIPHERAL INTERRUPT REQUEST (FLAG) REGISTER 2
R/W-0
R/W-0
CMIF
U-0
—
R/W-0
EEIF
R/W-0
R/W-0
R/W-0
R/W-0
OSCFIF
BCL1IF
HLVDIF
TMR3IF
CCP2IF
bit 7
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7
bit 6
OSCFIF: Oscillator Fail Interrupt Flag bit
1= Device oscillator failed, clock input has changed to INTOSC (must be cleared in software)
0= Device clock operating
CMIF: Comparator Interrupt Flag bit
1= Comparator input has changed (must be cleared in software)
0= Comparator input has not changed
bit 5
bit 4
Unimplemented: Read as ‘0’
EEIF: EEPROM or Flash Write Operation Interrupt Flag bit
1= The write operation is complete (must be cleared in software)
0= The write operation is not complete or has not been started
bit 3
BCL1IF: MSSP1 Bus Collision Interrupt Flag bit
1= A bus collision occurred while the MSSP1 module configured in I2C™ Master mode was
transmitting (must be cleared in software)
0= No bus collision occurred
bit 2
bit 1
bit 0
HLVDIF: High/Low-Voltage Detect Interrupt Flag bit
1= A low-voltage condition occurred (must be cleared in software)
0= The device voltage is above the Low-Voltage Detect trip point
TMR3IF: TMR3 Overflow Interrupt Flag bit
1= TMR3 register overflowed (must be cleared in software)
0= TMR3 register did not overflow
CCP2IF: ECCP2 Interrupt Flag bit
Capture mode:
1= A TMR1/TMR3 register capture occurred (must be cleared in software)
0= No TMR1/TMR3 register capture occurred
Compare mode:
1= A TMR1/TMR3 register compare match occurred (must be cleared in software)
0= No TMR1/TMR3 register compare match occurred
PWM mode:
Unused in this mode.
© 2008 Microchip Technology Inc.
DS39646C-page 125
PIC18F8722 FAMILY
REGISTER 10-6: PIR3: PERIPHERAL INTERRUPT REQUEST (FLAG) REGISTER 3
R/W-0
R/W-0
R-0
R-0
R/W-0
R/W-0
R/W-0
R/W-0
SSP2IF
BCL2IF
RC2IF
TX2IF
TMR4IF
CCP5IF
CCP4IF
CCP3IF
bit 7
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7
bit 6
SSP2IF: MSSP2 Interrupt Flag bit
1= The transmission/reception is complete (must be cleared in software)
0= Waiting to transmit/receive
BCL2IF: MSSP2 Bus Collision Interrupt Flag bit
1= A bus collision has occurred while the MSSP2 module configured in I2C™ master was
transmitting (must be cleared in software)
0= No bus collision occurred
bit 5
bit 4
bit 3
bit 2
RC2IF: EUSART2 Receive Interrupt Flag bit
1= The EUSART2 receive buffer, RCREG2, is full (cleared when RCREG2 is read)
0= The EUSART2 receive buffer is empty
TX2IF: EUSART2 Transmit Interrupt Flag bit
1= The EUSART2 transmit buffer, TXREG2, is empty (cleared when TXREG2 is written)
0= The EUSART2 transmit buffer is full
TMR4IF: TMR4 to PR4 Match Interrupt Flag bit
1= TMR4 to PR4 match occurred (must be cleared in software)
0= No TMR4 to PR4 match occurred
CCP5IF: CCP5 Interrupt Flag bit
Capture mode:
1= A TMR register capture occurred (must be cleared in software)
0= No TMR register capture occurred
Compare mode:
1= A TMR register compare match occurred (must be cleared in software)
0= No TMR register compare match occurred
PWM Mode:
bit 1
CCP4IF: CCP4 Interrupt Flag bit
Capture mode:
1= A TMR register capture occurred (must be cleared in software)
0= No TMR register capture occurred
Compare mode:
1= A TMR register compare match occurred (must be cleared in software)
0= No TMR register compare match occurred
PWM mode:
Not used in PWM mode.
bit 0
CCP3IF: ECCP3 Interrupt Flag bit
Capture mode:
1= A TMR register capture occurred (must be cleared in software)
0= No TMR register capture occurred
Compare mode:
1= A TMR register compare match occurred (must be cleared in software)
0= No TMR register compare match occurred
PWM mode:
Not used in PWM mode.
DS39646C-page 126
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
10.3 PIE Registers
The PIE registers contain the individual enable bits for
the peripheral interrupts. Due to the number of
peripheral interrupt sources, there are three Peripheral
Interrupt Enable registers (PIE1, PIE2, PIE3). When
IPEN = 0, the PEIE bit must be set to enable any of
these peripheral interrupts.
REGISTER 10-7: PIE1: PERIPHERAL INTERRUPT ENABLE REGISTER 1
R/W-0
PSPIE
R/W-0
ADIE
R/W-0
RC1IE
R/W-0
TX1IE
R/W-0
R/W-0
R/W-0
R/W-0
SSP1IE
CCP1IE
TMR2IE
TMR1IE
bit 7
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
PSPIE: Parallel Slave Port Read/Write Interrupt Enable bit
1= Enables the PSP read/write interrupt
0= Disables the PSP read/write interrupt
ADIE: A/D Converter Interrupt Enable bit
1= Enables the A/D interrupt
0= Disables the A/D interrupt
RC1IE: EUSART1 Receive Interrupt Enable bit
1= Enables the EUSART1 receive interrupt
0= Disables the EUSART1 receive interrupt
TX1IE: EUSART1 Transmit Interrupt Enable bit
1= Enables the EUSART1 transmit interrupt
0= Disables the EUSART1 transmit interrupt
SSP1IE: MSSP1 Interrupt Enable bit
1= Enables the MSSP1 interrupt
0= Disables the MSSP1 interrupt
CCP1IE: ECCP1 Interrupt Enable bit
1= Enables the ECCP1 interrupt
0= Disables the ECCP1 interrupt
TMR2IE: TMR2 to PR2 Match Interrupt Enable bit
1= Enables the TMR2 to PR2 match interrupt
0= Disables the TMR2 to PR2 match interrupt
TMR1IE: TMR1 Overflow Interrupt Enable bit
1= Enables the TMR1 overflow interrupt
0= Disables the TMR1 overflow interrupt
© 2008 Microchip Technology Inc.
DS39646C-page 127
PIC18F8722 FAMILY
REGISTER 10-8: PIE2: PERIPHERAL INTERRUPT ENABLE REGISTER 2
R/W-0
R/W-0
CMIE
U-0
—
R/W-0
EEIE
R/W-0
R/W-0
R/W-0
R/W-0
OSCFIE
BCL1IE
HLVDIE
TMR3IE
CCP2IE
bit 7
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7
bit 6
OSCFIE: Oscillator Fail Interrupt Enable bit
1= Enabled
0= Disabled
CMIE: Comparator Interrupt Enable bit
1= Enabled
0= Disabled
bit 5
bit 4
Unimplemented: Read as ‘0’
EEIE: Interrupt Enable bit
1= Enabled
0= Disabled
bit 3
bit 2
bit 1
bit 0
BCL1IE: MSSP1 Bus Collision Interrupt Enable bit
1= Enabled
0= Disabled
HLVDIE: High/Low-Voltage Detect Interrupt Enable bit
1= Enabled
0= Disabled
TMR3IE: TMR3 Overflow Interrupt Enable bit
1= Enabled
0= Disabled
CCP2IE: ECCP2 Interrupt Enable bit
1= Enabled
0= Disabled
DS39646C-page 128
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
REGISTER 10-9: PIE3: PERIPHERAL INTERRUPT ENABLE REGISTER 3
R/W-0
R/W-0
R-0
R-0
R/W-0
R/W-0
R/W-0
R/W-0
SSP2IE
BCL2IE
RC2IE
TX2IE
TMR4IE
CCP5IE
CCP4IE
CCP3IE
bit 7
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
SSP2IE: MSSP2 Interrupt Enable bit
1= Enables the MSSP2 interrupt
0= Disables the MSSP2 interrupt
BCL2IE: MSSP2 Bus Collision Interrupt Enable bit
1= Enabled
0= Disabled
RC2IE: EUSART2 Receive Interrupt Enable bit
1= Enabled
0= Disabled
TX2IE: EUSART2 Transmit Interrupt Enable bit
1= Enabled
0= Disabled
TMR4IE: TMR4 to PR4 Match Interrupt Enable bit
1= Enabled
0= Disabled
CCP5IE: CCP5 Interrupt Enable bit
1= Enabled
0= Disabled
CCP4IE: CCP4 Interrupt Enable bit
1= Enabled
0= Disabled
CCP3IE: ECCP3 Interrupt Enable bit
1= Enabled
0= Disabled
© 2008 Microchip Technology Inc.
DS39646C-page 129
PIC18F8722 FAMILY
10.4 IPR Registers
The IPR registers contain the individual priority bits for
the peripheral interrupts. Due to the number of
peripheral interrupt sources, there are three Peripheral
Interrupt Priority registers (IPR1, IPR2, IPR3). Using
the priority bits requires that the Interrupt Priority
Enable (IPEN) bit be set.
REGISTER 10-10: IPR1: PERIPHERAL INTERRUPT PRIORITY REGISTER 1
R/W-1
PSPIP
R/W-1
ADIP
R/W-1
RC1IP
R/W-1
TX1IP
R/W-1
R/W-1
R/W-1
R/W-1
SSP1IP
CCP1IP
TMR2IP
TMR1IP
bit 7
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7
bit 6
bit 5
bit 4
PSPIP: Parallel Slave Port Read/Write Interrupt Priority bit
1= High priority
0= Low priority
ADIP: A/D Converter Interrupt Priority bit
1= High priority
0= Low priority
RC1IP: EUSART1 Receive Interrupt Priority bit
1= High priority
0= Low priority
TX1IP: EUSART1 Transmit Interrupt Priority bit
1= High priority
0= Low priority
bit 3
bit 2
bit 1
bit 0
SSP1IP: MSSP1 Interrupt Priority bit
1= High priority
0= Low priority
CCP1IP: ECCP1 Interrupt Priority bit
1= High priority
0= Low priority
TMR2IP: TMR2 to PR2 Match Interrupt Priority bit
1= High priority
0= Low priority
TMR1IP: TMR1 Overflow Interrupt Priority bit
1= High priority
0= Low priority
DS39646C-page 130
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
REGISTER 10-11: IPR2: PERIPHERAL INTERRUPT PRIORITY REGISTER 2
R/W-1
R/W-1
CMIP
U-0
—
R/W-1
EEIP
R/W-1
R/W-1
R/W-1
R/W-1
OSCFIP
BCL1IP
HLVDIP
TMR3IP
CCP2IP
bit 7
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7
bit 6
OSCFIP: Oscillator Fail Interrupt Priority bit
1= High priority
0= Low priority
CMIP: Comparator Interrupt Priority bit
1= High priority
0= Low priority
bit 5
bit 4
Unimplemented: Read as ‘0’
EEIP: Interrupt Priority bit
1= High priority
0= Low priority
bit 3
bit 2
bit 1
bit 0
BCL1IP: MSSP1 Bus Collision Interrupt Priority bit
1= High priority
0= Low priority
HLVDIP: High/Low-Voltage Detect Interrupt Priority bit
1= High priority
0= Low priority
TMR3IP: TMR3 Overflow Interrupt Priority bit
1= High priority
0= Low priority
CCP2IP: ECCP2 Interrupt Priority bit
1= High priority
0= Low priority
© 2008 Microchip Technology Inc.
DS39646C-page 131
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REGISTER 10-12: IPR3: PERIPHERAL INTERRUPT PRIORITY REGISTER 3
R/W-0
R/W-0
R/W-1
RC2IP
R/W-1
TX2IP
R/W-1
R/W-1
R/W-1
R/W-1
SSP2IP
BCL2IP
TMR4IP
CCP5IP
CCP4IP
CCP3IP
bit 7
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
SSP2IP: MSSP2 Interrupt Priority bit
1= High priority
0= Low priority
BCL2IP: MSSP2 Bus Collision Interrupt Priority bit
1= High priority
0= Low priority
RC2IP: EUSART2 Receive Interrupt Priority bit
1= High priority
0= Low priority
TX2IP: EUSART2 Transmit Interrupt Priority bit
1= High priority
0= Low priority
TMR4IP: TMR4 to PR4 Match Interrupt Priority bit
1= High priority
0= Low priority
CCP5IP: CCP5 Interrupt Priority bit
1= High priority
0= Low priority
CCP4IP: CCP4 Interrupt Priority bit
1= High priority
0= Low priority
CCP3IP: ECCP3 Interrupt Priority bit
1= High priority
0= Low priority
DS39646C-page 132
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
10.5 RCON Register
The RCON register contains bits used to determine the
cause of the last Reset or wake-up from Idle or Sleep
modes. RCON also contains the bit that enables
interrupt priorities (IPEN).
REGISTER 10-13: RCON: RESET CONTROL REGISTER
R/W-0
IPEN
R/W-1
U-0
—
R/W-1
RI
R-1
TO
R-1
PD
R/W-0
POR
R/W-0
BOR
SBOREN
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
-n = Value at POR
bit 7
bit 6
IPEN: Interrupt Priority Enable bit
1= Enable priority levels on interrupts
0= Disable priority levels on interrupts (PIC16CXXX Compatibility mode)
SBOREN: Software BOR Enable bit
For details of bit operation and Reset state, see Register 4-1.
Unimplemented: Read as ‘0’
bit 5
bit 4
RI: RESETInstruction Flag bit
For details of bit operation, see Register 4-1.
TO: Watchdog Timer Time-out Flag bit
bit 3
bit 2
bit 1
bit 0
For details of bit operation, see Register 4-1.
PD: Power-Down Detection Flag bit
For details of bit operation, see Register 4-1.
POR: Power-on Reset Status bit
For details of bit operation, see Register 4-1.
BOR: Brown-out Reset Status bit
For details of bit operation, see Register 4-1.
© 2008 Microchip Technology Inc.
DS39646C-page 133
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10.6 INTx Pin Interrupts
10.7 TMR0 Interrupt
External interrupts on the RB0/INT0, RB1/INT1, RB2/
INT2 and RB3/INT3 pins are edge-triggered. If the
corresponding INTEDGx bit in the INTCON2 register is
set (= 1), the interrupt is triggered by a rising edge; if
the bit is clear, the trigger is on the falling edge. When
a valid edge appears on the RBx/INTx pin, the
corresponding flag bit, INTxIF, is set. This interrupt can
be disabled by clearing the corresponding enable bit,
INTxIE. Flag bit, INTxIF, must be cleared in software in
the Interrupt Service Routine before re-enabling the
interrupt.
In 8-bit mode (which is the default), an overflow in the
TMR0 register (FFh → 00h) will set flag bit, TMR0IF. In
16-bit mode, an overflow in the TMR0H:TMR0L register
pair (FFFFh → 0000h) will set TMR0IF. The interrupt can
be enabled/disabled by setting/clearing enable bit,
TMR0IE (INTCON<5>). Interrupt priority for Timer0 is
determined by the value contained in the interrupt
priority bit, TMR0IP (INTCON2<2>). See Section 12.0
“Timer0 Module” for further details on the Timer0
module.
10.8 PORTB Interrupt-on-Change
All external interrupts (INT0, INT1, INT2 and INT3) can
wake-up the processor from the power-managed
modes if bit INTxIE was set prior to going into power-
managed modes. If the Global Interrupt Enable bit,
GIE, is set, the processor will branch to the interrupt
vector following wake-up.
An input change on PORTB<7:4> sets flag bit, RBIF
(INTCON<0>). The interrupt can be enabled/disabled
by setting/clearing enable bit, RBIE (INTCON<3>).
Interrupt priority for PORTB interrupt-on-change is
determined by the value contained in the interrupt
priority bit, RBIP (INTCON2<0>).
Interrupt priority for INT1, INT2 and INT3 is determined
by the value contained in the interrupt priority bits,
INT1IP (INTCON3<6>), INT2IP (INTCON3<7>) and
INT3IP (INTCON2<1>). There is no priority bit
associated with INT0. It is always a high-priority
interrupt source.
10.9 Context Saving During Interrupts
During interrupts, the return PC address is saved on
the stack. Additionally, the WREG, STATUS and BSR
registers are saved on the fast return stack. If a fast
return from interrupt is not used (see Section 5.3
“Data Memory Organization”), the user may need to
save the WREG, STATUS and BSR registers on entry
to the Interrupt Service Routine. Depending on the
user’s application, other registers may also need to be
saved. Example 10-1 saves and restores the WREG,
STATUS and BSR registers during an Interrupt Service
Routine.
EXAMPLE 10-1:
SAVING STATUS, WREG AND BSR REGISTERS IN RAM
MOVWF
MOVFF
MOVFF
;
W_TEMP
STATUS, STATUS_TEMP
BSR, BSR_TEMP
; W_TEMP is in virtual bank
; STATUS_TEMP located anywhere
; BSR_TMEP located anywhere
; USER ISR CODE
;
MOVFF
MOVF
MOVFF
BSR_TEMP, BSR
W_TEMP, W
STATUS_TEMP, STATUS
; Restore BSR
; Restore WREG
; Restore STATUS
DS39646C-page 134
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
11.1 PORTA, TRISA and
LATA Registers
11.0 I/O PORTS
Depending on the device selected and features
enabled, there are up to nine ports available. Some
pins of the I/O ports are multiplexed with an alternate
function from the peripheral features on the device. In
general, when a peripheral is enabled, that pin may not
be used as a general purpose I/O pin.
PORTA is an 8-bit wide, bidirectional port. The corre-
sponding data direction register is TRISA. Setting a
TRISA bit (= 1) will make the corresponding PORTA pin
an input (i.e., put the corresponding output driver in a
high-impedance mode). Clearing a TRISA bit (= 0) will
make the corresponding PORTA pin an output (i.e., put
the contents of the output latch on the selected pin).
Each port has three registers for its operation. These
registers are:
Reading the PORTA register reads the status of the
pins, whereas writing to it, will write to the port latch.
• TRIS register (Data Direction register)
• Port register (reads the levels on the pins of the
device)
The Data Latch register (LATA) is also memory
mapped. Read-modify-write operations on the LATA
register read and write the latched output value for
PORTA.
• LAT register (output latch)
The Data Latch (LAT register) is useful for
read-modify-write operations on the value that the I/O
pins are driving.
The RA4 pin is multiplexed with the Timer0 module
clock input to become the RA4/T0CKI pin. Pins RA6
and RA7 are multiplexed with the main oscillator pins;
they are enabled as oscillator or I/O pins by the selec-
tion of the main oscillator in the Configuration register
(see Section 25.1 “Configuration Bits” for details).
When they are not used as port pins, RA6 and RA7 and
their associated TRIS and LAT bits are read as ‘0’.
A simplified model of a generic I/O port, without the
interfaces to other peripherals, is shown in Figure 11-1.
FIGURE 11-1:
GENERIC I/O PORT
OPERATION
RD LAT
The other PORTA pins are multiplexed with the analog
VREF+ and VREF- inputs. The operation of pins
RA5:RA0 as A/D converter inputs is selected by
clearing or setting the PCFG<3:0> control bits in the
ADCON1 register.
Data
Bus
D
Q
WR LAT
or Port
I/O pin(1)
CKx
Data Latch
Note:
On a Power-on Reset, RA5 and RA<3:0>
are configured as analog inputs and read
as ‘0’. RA4 is configured as a digital input.
D
Q
WR TRIS
RD TRIS
The RA4/T0CKI pin is a Schmitt Trigger input and an
open-drain output. All other PORTA pins have TTL
input levels and full CMOS output drivers.
CKx
TRIS Latch
Input
Buffer
The TRISA register controls the direction of the PORTA
pins, even when they are being used as analog inputs.
The user must ensure the bits in the TRISA register are
maintained set when using them as analog inputs.
Q
D
EN
EXAMPLE 11-1:
INITIALIZING PORTA
RD Port
CLRF
PORTA
LATA
0Fh
; Initialize PORTA by
; clearing output
; data latches
; Alternate method
; to clear output
; data latches
Note 1: I/O pins have diode protection to VDD and VSS.
CLRF
MOVLW
MOVWF
MOVLW
; Configure A/D
ADCON1 ; for digital inputs
0CFh
; Value used to
; initialize data
; direction
MOVWF
TRISA
; Set RA<3:0> as inputs
; RA<5:4> as outputs
© 2008 Microchip Technology Inc.
DS39646C-page 135
PIC18F8722 FAMILY
TABLE 11-1: PORTA FUNCTIONS
TRIS
Setting
I/O
Type
Pin Name
RA0/AN0
Function
I/O
Description
RA0
0
1
1
O
I
DIG LATA<0> data output; not affected by analog input.
TTL PORTA<0> data input; disabled when analog input enabled.
AN0
RA1
I
ANA A/D input channel 0. Default input configuration on POR; does not affect
digital output.
RA1/AN1
0
1
1
O
I
DIG LATA<1> data output; not affected by analog input.
TTL PORTA<1> data input; disabled when analog input enabled.
AN1
RA2
I
ANA A/D input channel 1. Default input configuration on POR; does not affect
digital output.
RA2/AN2/VREF-
0
1
1
1
0
1
1
1
O
I
DIG LATA<2> data output; not affected by analog input.
TTL PORTA<2> data input. Disabled when analog functions enabled.
ANA A/D input channel 2. Default input configuration on POR.
ANA Comparator voltage reference low input and A/D voltage reference low input.
DIG LATA<3> data output; not affected by analog input.
AN2
VREF-
RA3
I
I
RA3/AN3/VREF+
O
I
TTL PORTA<3> data input; disabled when analog input enabled.
ANA A/D input channel 3. Default input configuration on POR.
AN3
I
VREF+
I
ANA Comparator voltage reference high input and A/D voltage reference
high input.
RA4/T0CKI
RA4
0
1
x
0
1
1
1
x
x
O
I
DIG LATA<4> data output.
ST
ST
PORTA<4> data input; default configuration on POR.
Timer0 clock input.
T0CKI
RA5
I
RA5/AN4/HLVDIN
O
I
DIG LATA<5> data output; not affected by analog input.
TTL PORTA<5> data input; disabled when analog input enabled.
ANA A/D input channel 4. Default configuration on POR.
AN4
I
HLVDIN
I
ANA High/Low-Voltage Detect external trip point input.
OSC2/CLKO/RA6 OSC2
CLKO
O
O
ANA Main oscillator feedback output connection (XT, HS, HSPLL and LP modes).
DIG System cycle clock output (FOSC/4) in all oscillator modes except RC,
INTIO7 and EC.
RA6
0
1
x
x
0
1
O
I
DIG LATA<6> data output. Enabled in RCIO, INTIO2 and ECIO modes only.
TTL PORTA<6> data input. Enabled in RCIO, INTIO2 and ECIO modes only.
ANA Main oscillator input connection.
OSC1/CLKI/RA7
OSC1
CLKI
RA7
I
I
ANA Main clock input connection.
O
I
DIG LATA<7> data output. Disabled in external oscillator modes.
TTL PORTA<7> data input. Disabled in external oscillator modes.
Legend:
PWR = Power Supply, O = Output, I = Input, ANA = Analog Signal, DIG = Digital Output, ST= Schmitt Buffer Input,
TTL = TTL Buffer Input, x= Don’t care (TRIS bit does not affect port direction or is overridden for this option).
TABLE 11-2: SUMMARY OF REGISTERS ASSOCIATED WITH PORTA
Reset
Values
on page
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
PORTA
RA7(1)
LATA7(1) LATA6(1)
TRISA7(1) TRISA6(1) TRISA5
RA6(1)
RA5
RA4
RA3
RA2
RA1
RA0
61
60
60
59
LATA
LATA5
LATA4
TRISA4
VCFG0
LATA3
TRISA3
PCFG3
LATA2
TRISA2
PCFG2
LATA1
TRISA1
PCFG1
LATA0
TRISA0
PCFG0
TRISA
ADCON1
—
—
VCFG1
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by PORTA.
Note 1: RA<7:6> and their associated latch and data direction bits are enabled as I/O pins based on oscillator
configuration; otherwise, they are read as ‘0’.
DS39646C-page 136
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
Four of the PORTB pins (RB<7:4>) have an
interrupt-on-change feature. Only pins configured as
inputs can cause this interrupt to occur (i.e., any
RB7:RB4 pin configured as an output is excluded from
the interrupt-on-change comparison). The input pins (of
RB7:RB4) are compared with the old value latched on
the last read of PORTB. The “mismatch” outputs of
RB7:RB4 are ORed together to generate the RB Port
Change Interrupt with Flag bit, RBIF (INTCON<0>).
11.2 PORTB, TRISB and
LATB Registers
PORTB is an 8-bit wide, bidirectional port. The corre-
sponding Data Direction register is TRISB. Setting a
TRISB bit (= 1) will make the corresponding PORTB
pin an input (i.e., put the corresponding output driver in
a high-impedance mode). Clearing a TRISB bit (= 0)
will make the corresponding PORTB pin an output
(i.e., put the contents of the output latch on the
selected pin).
This interrupt can wake the device from
power-managed modes. The user, in the Interrupt
Service Routine, can clear the interrupt in the following
manner:
The Data Latch register (LATB) is also memory
mapped. Read-modify-write operations on the LATB
register read and write the latched output value for
PORTB.
a) Any read or write of PORTB (except with the
MOVSF, MOVSS, MOVFF (ANY), PORTB
instruction). This will end the mismatch
condition.
EXAMPLE 11-2:
INITIALIZING PORTB
CLRF
PORTB
; Initialize PORTB by
; clearing output
; data latches
; Alternate method
; to clear output
; data latches
; Value used to
; initialize data
; direction
b) Clear flag bit, RBIF.
A mismatch condition will continue to set flag bit, RBIF.
Reading PORTB will end the mismatch condition and
allow flag bit, RBIF, to be cleared.
CLRF
LATB
The interrupt-on-change feature is recommended for
wake-up on key depression operation and operations
where PORTB is only used for the interrupt-on-change
feature. Polling of PORTB is not recommended while
using the interrupt-on-change feature.
MOVLW
MOVWF
0CFh
TRISB
; Set RB<3:0> as inputs
; RB<5:4> as outputs
; RB<7:6> as inputs
For 80-pin devices, RB3 can be configured as the
alternate peripheral pin for the ECCP2 module by
clearing the CCP2MX Configuration bit. This applies
only when the device is in one of the operating modes
other than the default Microcontroller mode. If the
device is in Microcontroller mode, the alternate
assignment for ECCP2 is RE7. As with other ECCP2
configurations, the user must ensure that the
TRISB<3> bit is set appropriately for the intended
operation.
Each of the PORTB pins has a weak internal pull-up. A
single control bit can turn on all the pull-ups. This is
performed by clearing bit RBPU (INTCON2<7>). The
weak pull-up is automatically turned off when the port
pin is configured as an output. The pull-ups are
disabled on a Power-on Reset.
© 2008 Microchip Technology Inc.
DS39646C-page 137
PIC18F8722 FAMILY
TABLE 11-3: PORTB FUNCTIONS
TRIS
Setting
I/O
Type
Pin Name
Function
I/O
Description
RB0/INT0/FLT0
RB0
0
1
1
1
0
1
1
0
1
1
0
1
O
I
DIG
TTL
ST
LATB<0> data output.
PORTB<0> data input; weak pull-up when RBPU bit is cleared.
External interrupt 0 input.
INT0
FLT0
RB1
I
I
ST
ECCPx PWM Fault input, enabled in software.
LATB<1> data output.
RB1/INT1
RB2/INT2
O
I
DIG
TTL
ST
PORTB<1> data input; weak pull-up when RBPU bit is cleared.
External interrupt 1 input.
INT1
RB2
I
O
I
DIG
TTL
ST
LATB<2> data output.
PORTB<2> data input; weak pull-up when RBPU bit is cleared.
External interrupt 2 input.
INT2
RB3
I
RB3/INT3/
ECCP2/P2A
O
I
DIG
TTL
LATB<3> data output.
PORTB<3> data input; weak pull-up when RBPU bit is cleared and
capture input is disabled.
INT3
1
0
I
ST
External interrupt 3 input.
(1)
ECCP2
O
DIG
ECCP2 compare output and ECCP2 PWM output. Takes priority over
port data.
1
0
I
ST
ECCP2 capture input.
(1)
O
DIG
ECCP2 Enhanced PWM output, channel A. May be configured for
tri-state during Enhanced PWM shutdown events. Takes priority over
port data.
P2A
RB4/KBI0
RB4
0
1
1
0
1
1
x
O
I
DIG
TTL
TTL
DIG
TTL
TTL
ST
LATB<4> data output.
PORTB<4> data input; weak pull-up when RBPU bit is cleared.
Interrupt-on-pin change.
KBI0
RB5
I
RB5/KBI1/PGM
O
I
LATB<5> data output
PORTB<5> data input; weak pull-up when RBPU bit is cleared.
Interrupt-on-pin change.
KBI1
PGM
I
I
Single-Supply Programming mode entry (ICSP). Enabled by LVP
Configuration bit; all other pin functions disabled.
RB6/KBI2/PGC
RB7/KBI3/PGD
RB6
0
1
1
x
0
1
1
x
x
O
I
DIG
TTL
TTL
ST
LATB<6> data output.
PORTB<6> data input; weak pull-up when RBPU bit is cleared.
KBI2
PGC
RB7
I
Interrupt-on-pin change.
(2)
I
Serial execution (ICSP™) clock input for ICSP and ICD operation
LATB<7> data output.
.
O
I
DIG
TTL
TTL
DIG
ST
PORTB<7> data input; weak pull-up when RBPU bit is cleared.
KBI3
PGD
I
Interrupt-on-pin change.
(2)
O
I
Serial execution data output for ICSP and ICD operation .
(2)
Serial execution data input for ICSP and ICD operation
.
Legend:
PWR = Power Supply, O = Output, I = Input, ANA = Analog Signal, DIG = Digital Output, ST = Schmitt Buffer Input,
TTL = TTL Buffer Input, x= Don’t care (TRIS bit does not affect port direction or is overridden for this option).
Note 1: Alternate assignment for ECCP2 when the CCP2MX Configuration bit is cleared (Microprocessor, Extended
Microcontroller and Microcontroller with Boot Block modes, 80-pin devices only). Default assignment is RC1.
2: All other pin functions are disabled when ICSP or ICD operations are enabled.
DS39646C-page 138
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
TABLE 11-4: SUMMARY OF REGISTERS ASSOCIATED WITH PORTB
Reset
Values
on page
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
PORTB
RB7
RB6
RB5
RB4
RB3
RB2
RB1
RB0
60
60
60
57
57
57
LATB
LATB7
TRISB7
LATB6
TRISB6
LATB5
LATB4
LATB3
LATB2
LATB1
LATB0
TRISB
TRISB5 TRISB4 TRISB3 TRISB2 TRISB1 TRISB0
INTCON
INTCON2
INTCON3
GIE/GIEH PEIE/GIEL TMR0IE
INT0IE
INTEDG0 INTEDG1 INTEDG2 INTEDG3 TMR0IP
INT1IP INT3IE INT2IE INT1IE INT3IF
RBIE
TMR0IF
INT0IF
INT3IP
INT2IF
RBIF
RBIP
RBPU
INT2IP
INT1IF
Legend: Shaded cells are not used by PORTB.
© 2008 Microchip Technology Inc.
DS39646C-page 139
PIC18F8722 FAMILY
11.3 PORTC, TRISC and
LATC Registers
Note:
On a Power-on Reset, these pins are
configured as digital inputs.
PORTC is an 8-bit wide, bidirectional port. The corre-
sponding Data Direction register is TRISC. Setting a
TRISC bit (= 1) will make the corresponding PORTC
pin an input (i.e., put the corresponding output driver in
a high-impedance mode). Clearing a TRISC bit (= 0)
will make the corresponding PORTC pin an output
(i.e., put the contents of the output latch on the
selected pin).
The contents of the TRISC register are affected by
peripheral overrides. Reading TRISC always returns
the current contents, even though a peripheral device
may be overriding one or more of the pins.
EXAMPLE 11-3:
INITIALIZING PORTC
CLRF
PORTC
; Initialize PORTC by
; clearing output
; data latches
The Data Latch register (LATC) is also memory
mapped. Read-modify-write operations on the LATC
register read and write the latched output value for
PORTC.
CLRF
LATC
; Alternate method
; to clear output
; data latches
MOVLW
MOVWF
0CFh
; Value used to
; initialize data
; direction
; Set RC<3:0> as inputs
; RC<5:4> as outputs
; RC<7:6> as inputs
PORTC is multiplexed with several peripheral
functions. All port pins have Schmitt Trigger input
buffers. RC1 is normally configured by Configuration
bit, CCP2MX, as the default peripheral pin of the
ECCP2 module (default/erased state, CCP2MX = 1).
TRISC
When enabling peripheral functions, care should be
taken in defining TRIS bits for each PORTC pin. Some
peripherals override the TRIS bit to make a pin an output,
while other peripherals override the TRIS bit to make a
pin an input. The user should refer to the corresponding
peripheral section for the correct TRIS bit settings.
DS39646C-page 140
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
TABLE 11-5: PORTC FUNCTIONS
TRIS
Setting
Pin Name
Function
I/O I/O Type
Description
RC0/T1OSO/T13CKI
RC0
0
1
x
O
I
DIG
ST
LATC<0> data output.
PORTC<0> data input.
T1OSO
O
ANA Timer1 oscillator output; enabled when Timer1 oscillator enabled.
Disables digital I/O.
T13CKI
RC1
1
0
1
x
I
O
I
ST
DIG
ST
Timer1/Timer3 counter input.
LATC<1> data output.
RC1/T1OSI/
ECCP2/P2A
PORTC<1> data input.
T1OSI
I
ANA Timer1 oscillator input; enabled when Timer1 oscillator enabled.
Disables digital I/O.
(1)
ECCP2
0
O
DIG
ECCP2 compare output and ECCP2 PWM output. Takes priority over
port data.
1
0
I
ST
ECCP2 capture input.
(1)
P2A
O
DIG
ECCP2 Enhanced PWM output, channel A. May be configured for
tri-state during Enhanced PWM shutdown events. Takes priority over
port data.
RC2/ECCP1/P1A
RC2
0
1
0
O
I
DIG
ST
LATC<2> data output.
PORTC<2> data input.
ECCP1
O
DIG
ECCP1 compare output and ECCP1 PWM output. Takes priority over
port data.
1
0
I
ST
ECCP1 capture input.
P1A
O
DIG
ECCP1 Enhanced PWM output, channel A. May be configured for
tri-state during Enhanced PWM shutdown events. Takes priority over
port data.
RC3/SCK1/SCL1
RC3
SCK1
SCL1
0
1
0
1
0
1
O
I
DIG
ST
LATC<3> data output.
PORTC<3> data input.
O
I
DIG
ST
SPI clock output (MSSP1 module). Takes priority over port data.
SPI clock input (MSSP1 module).
2
O
I
DIG
I C™ clock output (MSSP1 module). Takes priority over port data.
2
2
I C/SMB I C clock input (MSSP1 module); input type depends on module
setting.
RC4/SDI1/SDA1
RC4
0
1
1
1
1
0
1
0
O
I
DIG
ST
LATC<4> data output.
PORTC<4> data input.
SDI1
I
ST
SPI data input (MSSP1 module).
2
SDA1
O
I
DIG
I C data output (MSSP1 module). Takes priority over port data.
2
2
I C/SMB I C data input (MSSP1 module); input type depends on module setting.
RC5/SDO1
RC5
O
I
DIG
ST
LATC<5> data output.
PORTC<5> data input.
SDO1
O
DIG
SPI data output (MSSP1 module). Takes priority over port data.
Legend:
DIG = Digital level output; TTL = TTL input buffer; ST = Schmitt Trigger input buffer; ANA = Analog level input/output;
2
2
I C/SMB = I C/SMBus input buffer; x= Don’t care (TRIS bit does not affect port direction or is overridden for this option).
Note 1: Default assignment for ECCP2 when CCP2MX Configuration bit is set.
© 2008 Microchip Technology Inc.
DS39646C-page 141
PIC18F8722 FAMILY
TABLE 11-5: PORTC FUNCTIONS (CONTINUED)
TRIS
Setting
Pin Name
Function
I/O I/O Type
Description
RC6/TX1/CK1
RC6
0
1
0
O
I
DIG
ST
LATC<6> data output.
PORTC<6> data input.
TX1
CK1
O
DIG
Asynchronous serial transmit data output (EUSART1 module). Takes
priority over port data.
0
O
DIG
Synchronous serial clock output (EUSART1 module). Takes priority
over port data.
1
0
1
1
1
I
O
I
ST
DIG
ST
Synchronous serial clock input (EUSART1 module).
LATC<7> data output.
RC7/RX1/DT1
RC7
PORTC<7> data input.
RX1
DT1
I
ST
Asynchronous serial receive data input (EUSART1 module)
O
DIG
Synchronous serial data output (EUSART1 module). Takes priority
over port data. User must configure as input.
1
I
ST
Synchronous serial data input (EUSART1 module). User must
configure as an input.
Legend:
DIG = Digital level output; TTL = TTL input buffer; ST = Schmitt Trigger input buffer; ANA = Analog level input/output;
I C/SMB = I C/SMBus input buffer; x= Don’t care (TRIS bit does not affect port direction or is overridden for this option).
2
2
Note 1: Default assignment for ECCP2 when CCP2MX Configuration bit is set.
TABLE 11-6: SUMMARY OF REGISTERS ASSOCIATED WITH PORTC
Reset
Values
on page
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
PORTC
RC7
RC6
RC5
RC4
RC3
RC2
RC1
RC0
60
60
60
LATC
LATC7
LATC6
LATC5
LATC4
LATC3
LATC2
LATC1
LATC0
TRISC
TRISC7 TRISC6 TRISC5 TRISC4 TRISC3 TRISC2 TRISC1 TRISC0
DS39646C-page 142
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
PORTD can also be configured to function as an 8-bit
wide parallel microprocessor port by setting the
PSPMODE control bit (PSPCON<4>). In this mode,
parallel port data takes priority over other digital I/O (but
not the external memory interface). When the parallel
port is active, the input buffers are TTL. For more
information, refer to Section 11.10 “Parallel Slave
Port”.
11.4 PORTD, TRISD and
LATD Registers
PORTD is an 8-bit wide, bidirectional port. The corre-
sponding Data Direction register is TRISD. Setting a
TRISD bit (= 1) will make the corresponding PORTD
pin an input (i.e., put the corresponding output driver in
a high-impedance mode). Clearing a TRISD bit (= 0)
will make the corresponding PORTD pin an output
(i.e., put the contents of the output latch on the
selected pin).
EXAMPLE 11-4:
INITIALIZING PORTD
CLRF
PORTD
; Initialize PORTD by
; clearing output
; data latches
The Data Latch register (LATD) is also memory
mapped. Read-modify-write operations on the LATD
register read and write the latched output value for
PORTD.
CLRF
LATD
; Alternate method
; to clear output
; data latches
All pins on PORTD are implemented with Schmitt
Trigger input buffers. Each pin is individually
configurable as an input or output.
MOVLW
MOVWF
0CFh
; Value used to
; initialize data
; direction
; Set RD<3:0> as inputs
; RD<5:4> as outputs
; RD<7:6> as inputs
TRISD
Note: On a Power-on Reset, these pins are
configured as digital inputs.
In 80-pin devices, PORTD is multiplexed with the
system bus as part of the external memory interface.
I/O port and other functions are only available when the
interface is disabled by setting the EBDIS bit
(MEMCON<7>). When the interface is enabled,
PORTD is the low-order byte of the multiplexed
address/data bus (AD<7:0>). The TRISD bits are also
overridden.
© 2008 Microchip Technology Inc.
DS39646C-page 143
PIC18F8722 FAMILY
TABLE 11-7: PORTD FUNCTIONS
TRIS
Setting
Pin Name
Function
I/O
I/O Type
Description
RD0/AD0/PSP0
RD0
0
1
x
O
I
DIG
ST
LATD<0> data output.
PORTD<0> data input.
(1)
AD0
O
DIG
External memory interface, address/data bit 0 output. Takes priority
over PSP and port data.
x
x
x
0
1
x
I
O
I
TTL
DIG
TTL
DIG
ST
External memory interface, data bit 0 input.
PSP read data output (LATD<0>). Takes priority over port data.
PSP write data input.
PSP0
RD1
RD1/AD1/PSP1
RD2/AD2/PSP2
RD3/AD3/PSP3
O
I
LATD<1> data output.
PORTD<1> data input.
(1)
AD1
O
DIG
External memory interface, address/data bit 1 output. Takes priority
over PSP and port data.
x
x
x
0
1
x
I
O
I
TTL
DIG
TTL
DIG
ST
External memory interface, data bit 1 input.
PSP read data output (LATD<1>). Takes priority over port data.
PSP write data input.
PSP1
RD2
O
I
LATD<2> data output.
PORTD<2> data input.
(1)
AD2
O
DIG
External memory interface, address/data bit 2 output. Takes priority
over PSP and port data.
x
x
x
0
1
x
I
O
I
TTL
DIG
TTL
DIG
ST
External memory interface, data bit 2 input.
PSP read data output (LATD<2>). Takes priority over port data.
PSP write data input.
PSP2
RD3
O
I
LATD<3> data output.
PORTD<3> data input.
(1)
AD3
O
DIG
External memory interface, address/data bit 3 output. Takes priority
over PSP and port data.
x
x
x
0
1
x
I
O
I
TTL
DIG
TTL
DIG
ST
External memory interface, data bit 3 input.
PSP read data output (LATD<3>). Takes priority over port data.
PSP write data input.
PSP3
RD4
RD4/AD4/
PSP4/SDO2
O
I
LATD<4> data output.
PORTD<4> data input.
(1)
AD4
O
DIG
External memory interface, address/data bit 4 output. Takes priority
over PSP, MSSP and port data.
x
x
I
TTL
DIG
External memory interface, data bit 4 input.
PSP4
SDO2
O
PSP read data output (LATD<4>). Takes priority over port and PSP
data.
x
0
I
TTL
DIG
PSP write data input.
O
SPI data output (MSSP2 module). Takes priority over PSP and port
data.
Legend:
PWR = Power Supply, O = Output, I = Input, ANA = Analog Signal, DIG = Digital Output, ST = Schmitt Buffer Input,
TTL = TTL Buffer Input, x= Don’t care (TRIS bit does not affect port direction or is overridden for this option).
Note 1: Implemented on 80-pin devices only.
DS39646C-page 144
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
TABLE 11-7: PORTD FUNCTIONS (CONTINUED)
TRIS
Setting
Pin Name
Function
I/O
I/O Type
Description
RD5/AD5/
PSP5/SDI2
/SDA2
RD5
0
1
x
O
I
DIG
ST
LATD<5> data output.
PORTD<5> data input.
(1)
AD5
O
DIG
External memory interface, address/data bit 5 output. Takes priority
over PSP, MSSP and port data.
x
x
x
1
1
I
O
I
TTL
DIG
TTL
ST
External memory interface, data bit 5 input.
PSP read data output (LATD<5>). Takes priority over port data.
PSP write data input.
PSP5
SDI2
I
SPI data input (MSSP2 module).
2
SDA2
O
DIG
I C™ data output (MSSP2 module). Takes priority over PSP and port
data.
2
2
1
I
I C/SMB I C data input (MSSP2 module); input type depends on module
setting.
RD6/AD6/
PSP6/SCK2/
SCL2
RD6
0
1
x
O
I
DIG
ST
LATD<6> data output.
PORTD<6> data input.
(1)
AD6
O
DIG-3 External memory interface, address/data bit 6 output. Takes priority
over PSP, MSSP and port data.
x
x
x
0
I
TTL
DIG
TTL
DIG
External memory interface, data bit 6 input.
PSP read data output (LATD<6>). Takes priority over port data.
PSP write data input.
PSP6
SCK2
O
I
O
SPI clock output (MSSP2 module). Takes priority over PSP and port
data.
1
0
I
ST
SPI clock input (MSSP2 module).
2
SCL2
O
DIG
I C clock output (MSSP2 module). Takes priority over PSP and port
data.
2
2
1
I
I C/SMB I C clock input (MSSP2 module); input type depends on module
setting.
RD7/AD7/
PSP7/SS2
RD7
0
1
x
O
I
DIG
ST
LATD<7> data output.
PORTD<7> data input.
(1)
AD7
O
DIG
External memory interface, address/data bit 7 output. Takes priority
over PSP and port data.
x
x
x
1
I
O
I
TTL
DIG
TTL
TTL
External memory interface, data bit 7 input.
PSP read data output (LATD<7>). Takes priority over port data.
PSP write data input.
PSP7
SS2
I
Slave select input for SSP (MSSP2 module).
Legend:
PWR = Power Supply, O = Output, I = Input, ANA = Analog Signal, DIG = Digital Output, ST = Schmitt Buffer Input,
TTL = TTL Buffer Input, x= Don’t care (TRIS bit does not affect port direction or is overridden for this option).
Note 1: Implemented on 80-pin devices only.
TABLE 11-8: SUMMARY OF REGISTERS ASSOCIATED WITH PORTD
Reset
Values
on page
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
PORTD
LATD
RD7
RD6
RD5
RD4
RD3
RD2
RD1
RD0
60
60
60
LATD7
TRISD7
LATD6
TRISD6
LATD5
TRISD5
LATD4
TRISD4
LATD3
TRISD3
LATD2
TRISD2
LATD1
TRISD1
LATD0
TRISD0
TRISD
© 2008 Microchip Technology Inc.
DS39646C-page 145
PIC18F8722 FAMILY
When the Parallel Slave Port is active on PORTD,
three of the PORTE pins (RE0/AD8/RD/P2D,
RE1/AD9/WR/P2C and RE2/AD10/CS/P2B) are config-
ured as digital control inputs for the port. The control
functions are summarized in Table 11-9. The reconfigu-
ration occurs automatically when the PSPMODE control
bit (PSPCON<4>) is set. Users must still make certain
the corresponding TRISE bits are set to configure these
pins as digital inputs.
11.5 PORTE, TRISE and
LATE Registers
PORTE is an 8-bit wide, bidirectional port. The
corresponding Data Direction register is TRISE. Setting
a TRISE bit (= 1) will make the corresponding PORTE
pin an input (i.e., put the corresponding output driver in
a high-impedance mode). Clearing a TRISE bit (= 0)
will make the corresponding PORTE pin an output
(i.e., put the contents of the output latch on the
selected pin).
EXAMPLE 11-5:
INITIALIZING PORTE
The Data Latch register (LATE) is also memory
mapped. Read-modify-write operations on the LATE
register read and write the latched output value for
PORTE.
CLRF
PORTE
LATE
03h
; Initialize PORTE by
; clearing output
; data latches
; Alternate method
; to clear output
; data latches
; Value used to
; initialize data
; direction
CLRF
All pins on PORTE are implemented with Schmitt
Trigger input buffers. Each pin is individually
configurable as an input or output.
MOVLW
MOVWF
TRISE
; Set RE<1:0> as inputs
; RE<7:2> as outputs
Note: On a Power-on Reset, these pins are
configured as digital inputs.
When the device is operating in Microcontroller mode,
pin RE7 can be configured as the alternate peripheral
pin for the ECCP2 module. This is done by clearing the
CCP2MX Configuration bit.
In 80-pin devices, PORTE is multiplexed with the
system bus as part of the external memory interface.
I/O port and other functions are only available when the
interface is disabled by setting the EBDIS bit
(MEMCON<7>). When the interface is enabled (80-pin
devices only), PORTE is the high-order byte of the
multiplexed address/data bus (AD<15:8>). The TRISE
bits are also overridden.
DS39646C-page 146
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
TABLE 11-9: PORTE FUNCTIONS
TRIS
Setting
I/O
Type
Pin Name
Function
I/O
Description
RE0/AD8/
RD/P2D
RE0
0
1
x
O
I
DIG
ST
LATE<0> data output.
PORTE<0> data input.
(2)
AD8
O
DIG
External memory interface, address/data bit 8 output. Takes priority
over ECCP and port data.
x
1
0
I
I
TTL
TTL
DIG
External memory interface, data bit 8 input.
Parallel Slave Port read enable control input.
RD
P2D
O
ECCP2 Enhanced PWM output, channel D. May be configured for
tri-state during Enhanced PWM shutdown events. Takes priority over
port data.
RE1/AD9/
WR/P2C
RE1
0
1
x
O
I
DIG
ST
LATE<1> data output.
PORTE<1> data input.
(2)
AD9
O
DIG
External memory interface, address/data bit 9 output. Takes priority
over ECCP and port data.
x
1
0
I
I
TTL
TTL
DIG
External memory interface, data bit 9 input.
Parallel Slave Port write enable control input.
WR
P2C
O
ECCP2 Enhanced PWM output, channel C. May be configured for
tri-state during Enhanced PWM shutdown events. Takes priority over
port data.
RE2/AD10/
CS/P2B
RE2
0
1
x
O
I
DIG
ST
LATE<2> data output.
PORTE<2> data input.
(2)
AD10
O
DIG
External memory interface, address/data bit 10 output. Takes priority
over ECCP and port data.
x
1
0
I
I
TTL
TTL
DIG
External memory interface, data bit 10 input.
Parallel Slave Port chip select control input.
CS
P2B
O
ECCP2 Enhanced PWM output, channel B. May be configured for
tri-state during Enhanced PWM shutdown events. Takes priority over
port data.
RE3/AD11/P3C
RE3
0
1
x
O
I
DIG
ST
LATE<3> data output.
PORTE<3> data input.
(2)
AD11
O
DIG
External memory interface, address/data bit 11 output. Takes priority
over ECCP and port data.
x
0
I
TTL
DIG
External memory interface, data bit 11 input.
P3C
RE4
O
ECCP3 Enhanced PWM output, channel C. May be configured for
tri-state during Enhanced PWM shutdown events. Takes priority over
port data.
RE4/AD12/P3B
0
1
x
O
I
DIG
ST
LATE<4> data output.
PORTE<4> data input.
(2)
AD12
O
DIG
External memory interface, address/data bit 12 output. Takes priority
over ECCP and port data.
x
0
I
TTL
DIG
External memory interface, data bit 12 input.
P3B
O
ECCP3 Enhanced PWM output, channel B. May be configured for
tri-state during Enhanced PWM shutdown events. Takes priority over
port data.
Legend:
PWR = Power Supply, O = Output, I = Input, ANA = Analog Signal, DIG = Digital Output, ST = Schmitt Buffer Input,
TTL = TTL Buffer Input, x= Don’t care (TRIS bit does not affect port direction or is overridden for this option).
Note 1: Alternate assignment for ECCP2 when CCP2MX Configuration bit is cleared (all devices in Microcontroller mode).
2: Implemented on 80-pin devices only.
© 2008 Microchip Technology Inc.
DS39646C-page 147
PIC18F8722 FAMILY
TABLE 11-9: PORTE FUNCTIONS (CONTINUED)
TRIS
Setting
I/O
Type
Pin Name
Function
I/O
Description
RE5/AD13/P1C
RE5
0
1
x
O
I
DIG
ST
LATE<5> data output.
PORTE<5> data input.
(2)
AD13
O
DIG
External memory interface, address/data bit 13 output. Takes priority
over ECCP and port data.
x
0
I
TTL
DIG
External memory interface, data bit 13 input.
P1C
RE6
O
ECCP1 Enhanced PWM output, channel C. May be configured for
tri-state during Enhanced PWM shutdown events. Takes priority over
port data.
RE6/AD14/P1B
0
1
x
O
I
DIG
ST
LATE<6> data output.
PORTE<6> data input.
(2)
AD14
O
DIG
External memory interface, address/data bit 14 output. Takes priority
over ECCP and port data.
x
0
I
TTL
DIG
External memory interface, data bit 14 input.
P1B
RE7
O
ECCP1 Enhanced PWM output, channel B. May be configured for
tri-state during Enhanced PWM shutdown events. Takes priority over
port data.
RE7/AD15/
ECCP2/P2A
0
1
x
O
I
DIG
ST
LATE<7> data output.
PORTE<7> data input.
(2)
AD15
O
DIG
External memory interface, address/data bit 15 output. Takes priority
over ECCP and port data.
x
0
I
TTL
DIG
External memory interface, data bit 15 input.
(1)
ECCP2
O
ECCP2 compare output and ECCP2 PWM output. Takes priority over
port data.
1
0
I
ST
ECCP2 capture input.
(1)
P2A
O
DIG
ECCP2 Enhanced PWM output, channel A. Takes priority over port and
data. May be configured for tri-state during Enhanced PWM shutdown
events.
Legend:
PWR = Power Supply, O = Output, I = Input, ANA = Analog Signal, DIG = Digital Output, ST = Schmitt Buffer Input,
TTL = TTL Buffer Input, x= Don’t care (TRIS bit does not affect port direction or is overridden for this option).
Note 1: Alternate assignment for ECCP2 when CCP2MX Configuration bit is cleared (all devices in Microcontroller mode).
2: Implemented on 80-pin devices only.
TABLE 11-10: SUMMARY OF REGISTERS ASSOCIATED WITH PORTE
Reset
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Values
on page
PORTE
LATE
RE7
RE6
RE5
RE4
RE3
RE2
RE1
RE0
60
60
60
LATE7
TRISE7
LATE6
TRISE6
LATE5
TRISE5
LATE4
TRISE4
LATE3
TRISE3
LATE2
TRISE2
LATE1
TRISE1
LATE0
TRISE0
TRISE
DS39646C-page 148
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
11.6 PORTF, LATF and TRISF Registers
Note 1: On a Power-on Reset, the RF<6:0> pins
are configured as analog inputs and read
as ‘0’.
PORTF is an 8-bit wide, bidirectional port. The corre-
sponding Data Direction register is TRISF. Setting a
TRISF bit (= 1) will make the corresponding PORTF pin
an input (i.e., put the corresponding output driver in a
high-impedance mode). Clearing a TRISF bit (= 0) will
make the corresponding PORTF pin an output (i.e., put
the contents of the output latch on the selected pin).
2: To configure PORTF as digital I/O, set the
ADCON1 register.
EXAMPLE 11-6:
INITIALIZING PORTF
CLRF
PORTF
LATF
0x0F
; Initialize PORTF by
; clearing output
; data latches
; Alternate method
; to clear output
; data latches
;
The Data Latch register (LATF) is also memory
mapped. Read-modify-write operations on the LATF
register read and write the latched output value for
PORTF.
CLRF
All pins on PORTF are implemented with Schmitt
Trigger input buffers. Each pin is individually
configurable as an input or output.
MOVLW
MOVWF
MOVLW
ADCON1 ; Set PORTF as digital I/O
0xCF
; Value used to
; initialize data
; direction
; Set RF3:RF0 as inputs
; RF5:RF4 as outputs
; RF7:RF6 as inputs
PORTF is multiplexed with several analog peripheral
functions, including the A/D converter and comparator
inputs, as well as the comparator outputs. Pins RF1
through RF2 may be used as comparator inputs or
outputs by setting the appropriate bits in the CMCON
register. To use RF<6:0:> as digital inputs, it is
necessary to turn off the A/D inputs.
MOVWF
TRISF
© 2008 Microchip Technology Inc.
DS39646C-page 149
PIC18F8722 FAMILY
TABLE 11-11: PORTF FUNCTIONS
TRIS
Setting
I/O
Type
Pin Name
RF0/AN5
Function
I/O
Description
RF0
0
1
1
0
1
1
0
0
1
1
0
0
1
1
O
I
DIG
ST
LATF<0> data output; not affected by analog input.
PORTF<0> data input; disabled when analog input enabled.
AN5
RF1
I
ANA A/D input channel 5. Default configuration on POR.
RF1/AN6/C2OUT
RF2/AN7/C1OUT
O
I
DIG
ST
LATF<1> data output; not affected by analog input.
PORTF<1> data input; disabled when analog input enabled.
AN6
C2OUT
RF2
I
ANA A/D input channel 6. Default configuration on POR.
O
O
I
DIG
DIG
ST
Comparator 2 output; takes priority over port data.
LATF<2> data output; not affected by analog input.
PORTF<2> data input; disabled when analog input enabled.
AN7
C1OUT
RF3
I
ANA A/D input channel 7. Default configuration on POR.
O
O
I
TTL
DIG
ST
Comparator 1 output; takes priority over port data.
LATF<3> data output; not affected by analog input.
PORTF<3> data input; disabled when analog input enabled.
RF3/AN8
AN8
RF4
I
ANA A/D input channel 8 and Comparator C2+ input. Default input
configuration on POR; not affected by analog output.
RF4/AN9
0
1
1
O
I
DIG
ST
LATF<4> data output; not affected by analog input.
PORTF<4> data input; disabled when analog input enabled.
AN9
RF5
I
ANA A/D input channel 9 and Comparator C2- input. Default input
configuration on POR; does not affect digital output.
RF5/AN10/CVREF
0
1
1
x
O
I
DIG
LATF<5> data output; not affected by analog input. Disabled when
CVREF output enabled.
ST
PORTF<5> data input; disabled when analog input enabled. Disabled
when CVREF output enabled.
AN10
CVREF
RF6
I
ANA A/D input channel 10 and Comparator C1+ input. Default input
configuration on POR; not affected by analog output.
O
ANA Comparator voltage reference output. Enabling this feature disables
digital I/O.
RF6/AN11
RF7/SS1
0
1
1
O
I
DIG
ST
LATF<6> data output; not affected by analog input.
PORTF<6> data input; disabled when analog input enabled.
AN11
RF7
I
ANA A/D input channel 11 and Comparator C1- input. Default input
configuration on POR; does not affect digital output.
0
1
1
O
I
DIG
ST
LATF<7> data output.
PORTF<7> data input.
SS1
I
TTL
Slave select input for SSP (MSSP1 module).
Legend:
PWR = Power Supply, O = Output, I = Input, ANA = Analog Signal, DIG = Digital Output, ST = Schmitt Buffer Input,
TTL = TTL Buffer Input, x= Don’t care (TRIS bit does not affect port direction or is overridden for this option).
TABLE 11-12: SUMMARY OF REGISTERS ASSOCIATED WITH PORTF
Reset
Values
on page
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
TRISF
TRISF7
RF7
TRISF6
RF6
TRISF5 TRISF4 TRISF3 TRISF2 TRISF1 TRISF0
60
60
60
59
59
PORTF
LATF
RF5
RF4
RF3
LATF3
PCFG3
CIS
RF2
LATF2
PCFG2
CM2
RF1
LATF1
PCFG1
CM1
RF0
LATF0
PCFG0
CM0
LATF7
—
LATF6
—
LATF5
VCFG1
C2INV
LATF4
VCFG0
C1INV
ADCON1
CMCON
C2OUT
C1OUT
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by PORTF.
DS39646C-page 150
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
The sixth pin of PORTG (RG5/MCLR/VPP) is an input
only pin. Its operation is controlled by the MCLRE
Configuration bit. When selected as a port pin
(MCLRE = 0), it functions as a digital input only pin; as
such, it does not have TRIS or LAT bits associated with
its operation. Otherwise, it functions as the device’s
Master Clear input. In either configuration, RG5 also
functions as the programming voltage input during
programming.
11.7 PORTG, TRISG and
LATG Registers
PORTG is a 6-bit wide, bidirectional port. The corre-
sponding Data Direction register is TRISG. Setting a
TRISG bit (= 1) will make the corresponding PORTG
pin an input (i.e., put the corresponding output driver in
a high-impedance mode). Clearing a TRISG bit (= 0)
will make the corresponding PORTG pin an output
(i.e., put the contents of the output latch on the
selected pin).
Note:
On a Power-on Reset, RG5 is enabled as
digital input only if Master Clear
a
functionality is disabled. All other 5 pins
are configured as digital inputs.
The Data Latch register (LATG) is also memory
mapped. Read-modify-write operations on the LATG
register, read and write the latched output value for
PORTG.
EXAMPLE 11-7:
INITIALIZING PORTG
CLRF
PORTG
; Initialize PORTG by
; clearing output
; data latches
; Alternate method
; to clear output
; data latches
; Value used to
; initialize data
; direction
PORTG is multiplexed with EUSART and CCP
functions (Table 11-13). PORTG pins have Schmitt
Trigger input buffers.
CLRF
LATG
When enabling peripheral functions, care should be
taken in defining TRIS bits for each PORTG pin. Some
peripherals override the TRIS bit to make a pin an
output, while other peripherals override the TRIS bit to
make a pin an input. The user should refer to the
corresponding peripheral section for the correct TRIS
bit settings. The pin override value is not loaded into
the TRIS register. This allows read-modify-write of the
TRIS register without concern due to peripheral
overrides.
MOVLW
MOVWF
0x04
TRISG
; Set RG1:RG0 as outputs
; RG2 as input
; RG4:RG3 as inputs
© 2008 Microchip Technology Inc.
DS39646C-page 151
PIC18F8722 FAMILY
TABLE 11-13: PORTG FUNCTIONS
TRIS
Setting
I/O
Type
Pin Name
Function
I/O
Description
RG0/ECCP3/P3A
RG0
0
1
0
O
I
DIG
ST
LATG<0> data output.
PORTG<0> data input.
ECCP3
O
DIG
ECCP3 compare and ECCP3 PWM output. Takes priority over
port data.
1
0
I
ST
ECCP3 capture input.
P3A
RG1
O
DIG
ECCP3 Enhanced PWM output, channel B. May be configured for
tri-state during Enhanced PWM shutdown events. Takes priority over
port data.
RG1/TX2/CK2
RG2/RX2/DT2
RG3/CCP4/P3D
0
1
0
O
I
DIG
ST
LATG<1> data output.
PORTG<1> data input.
TX2
CK2
O
DIG
Asynchronous serial transmit data output (EUSART2 module). Takes
priority over port data.
0
O
DIG
Synchronous serial clock output (EUSART2 module). Takes priority
over port data.
1
0
1
1
1
I
O
I
ST
DIG
ST
Synchronous serial clock input (EUSART2 module).
LATG<2> data output.
RG2
PORTG<2> data input.
RX2
DT2
I
ST
Asynchronous serial receive data input (EUSART2 module).
O
DIG
Synchronous serial data output (EUSART2 module). Takes priority
over port data. User must configure as an input.
1
I
ST
Synchronous serial data input (EUSART2 module). User must
configure as an input.
RG3
0
1
0
O
I
DIG
ST
LATG<3> data output.
PORTG<3> data input.
CCP4
O
DIG
CCP4 compare and PWM output; takes priority over port data and
P3D function.
1
0
I
ST
CCP4 capture input.
P3D
O
DIG
ECCP3 Enhanced PWM output, channel D. May be configured for
tri-state during Enhanced PWM shutdown events. Takes priority over
port data.
RG4/CCP5/P1D
RG4
0
1
0
O
I
DIG
ST
LATG<4> data output.
PORTG<4> data input.
CCP5
O
DIG
CCP5 compare and PWM output. Takes priority over port data and
P1D function.
1
0
I
ST
CCP5 capture input.
P1D
O
DIG
ECCP1 Enhanced PWM output, channel B. May be configured for
tri-state during Enhanced PWM shutdown events. Takes priority over
port data.
(1)
RG5/MCLR/VPP
RG5
MCLR
VPP
—
I
I
I
ST
ST
PORTG<5> data input; enabled when MCLRE Configuration bit
is clear.
—
—
External Master Clear input; enabled when MCLRE Configuration
bit is set.
ANA
High-voltage detection; used for ICSP™ mode entry detection.
Always available regardless of pin mode.
Legend:
PWR = Power Supply, O = Output, I = Input, ANA = Analog Signal, DIG = Digital Output, ST = Schmitt Buffer Input,
TTL = TTL Buffer Input, x= Don’t care (TRIS bit does not affect port direction or is overridden for this option).
Note 1: RG5 does not have a corresponding TRISG bit.
DS39646C-page 152
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
TABLE 11-14: SUMMARY OF REGISTERS ASSOCIATED WITH PORTG
Reset
Values on
page
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
PORTG
LATG
—
—
—
—
—
—
RG5(1)
LATG5(1)
—
RG4
RG3
RG2
RG1
RG0
60
60
60
LATG4
TRISG4
LATG3
LATG2
LATG1
LATG0
TRISG
TRISG3 TRISG2 TRISG1 TRISG0
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by PORTG.
Note 1: RG5 and LATG5 are only available when MCLR is disabled (MCLRE Configuration bit = 0; otherwise, RG5
and LATG5 read as ‘0’.
© 2008 Microchip Technology Inc.
DS39646C-page 153
PIC18F8722 FAMILY
When the external memory interface is enabled, four of
the PORTH pins function as the high-order address
lines for the interface. The address output from the
interface takes priority over other digital I/O. The
corresponding TRISH bits are also overridden.
11.8 PORTH, LATH and
TRISH Registers
Note: PORTH
is
available
only
on
PIC18F8527/8622/8627/8722 devices.
PORTH is an 8-bit wide, bidirectional I/O port. The
corresponding Data Direction register is TRISH. Set-
ting a TRISH bit (= 1) will make the corresponding
PORTH pin an input (i.e., put the corresponding output
driver in a high-impedance mode). Clearing a TRISH
bit (= 0) will make the corresponding PORTH pin an
output (i.e., put the contents of the output latch on the
selected pin).
EXAMPLE 11-8:
INITIALIZING PORTH
CLRF
PORTH
; Initialize PORTH by
; clearing output
; data latches
; Alternate method
; to clear output
; data latches
; Value used to
; initialize data
; direction
CLRF
LATH
MOVLW
MOVWF
0CFh
The Data Latch register (LATH) is also memory
mapped. Read-modify-write operations on the LATH
register, read and write the latched output value for
PORTH.
TRISH
; Set RH3:RH0 as inputs
; RH5:RH4 as outputs
; RH7:RH6 as inputs
All pins on PORTH are implemented with Schmitt
Trigger input buffers. Each pin is individually
configurable as an input or output.
Note: On a Power-on Reset, these pins are
configured as digital inputs.
DS39646C-page 154
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
TABLE 11-15: PORTH FUNCTIONS
TRIS
Setting
I/O
Type
Pin Name
Function
I/O
Description
RH0/A16
RH0
0
1
x
0
1
x
0
1
x
0
1
x
0
1
1
0
O
I
DIG
ST
LATH<0> data output.
PORTH<0> data input.
A16
O
O
I
DIG
DIG
ST
External memory interface, address line 16. Takes priority over port data.
LATH<1> data output.
RH1/A17
RH2/A18
RH3/A19
RH1
PORTH<1> data input.
A17
O
O
I
DIG
DIG
ST
External memory interface, address line 17. Takes priority over port data.
LATH<2> data output.
RH2
PORTH<2> data input.
A18
O
O
I
DIG
DIG
ST
External memory interface, address line 18. Takes priority over port data.
LATH<3> data output.
RH3
PORTH<3> data input.
A19
O
O
I
DIG
DIG
ST
External memory interface, address line 19. Takes priority over port data.
LATH<4> data output.
RH4/AN12/
P3C
RH4
PORTH<4> data input.
AN12
I
ANA A/D input channel 12. Default configuration on POR.
(1)
P3C
O
DIG
ECCP3 Enhanced PWM output, channel C. May be configured for tri-state
during Enhanced PWM shutdown events. Takes priority over port data.
RH5/AN13/
P3B
RH5
0
1
1
0
O
I
DIG
ST
LATH<5> data output.
PORTH<5> data input.
AN13
I
ANA A/D input channel 13. Default configuration on POR.
(1)
P3B
O
DIG
ECCP3 Enhanced PWM output, channel B. May be configured for tri-state
during Enhanced PWM shutdown events. Takes priority over port data.
RH6/AN14/
P1C
RH6
0
1
1
0
O
I
DIG
ST
LATH<6> data output.
PORTH<6> data input.
AN14
I
ANA A/D input channel 14. Default configuration on POR.
(1)
P1C
O
DIG
ECCP1 Enhanced PWM output, channel C. May be configured for tri-state
during Enhanced PWM shutdown events. Takes priority over port data.
RH7/AN15/
P1B
RH7
0
1
1
0
O
I
DIG
ST
LATH<7> data output.
PORTH<7> data input.
AN15
I
ANA A/D input channel 15. Default configuration on POR.
(1)
P1B
O
DIG
ECCP1 Enhanced PWM output, channel B. May be configured for tri-state
during Enhanced PWM shutdown events. Takes priority over port data.
Legend:
PWR = Power Supply, O = Output, I = Input, ANA = Analog Signal, DIG = Digital Output, ST = Schmitt Buffer Input,
TTL = TTL Buffer Input, x= Don’t care (TRIS bit does not affect port direction or is overridden for this option).
Note 1: Alternate assignment for P1B/P1C/P3B/P3C (ECCPMX is clear).
TABLE 11-16: SUMMARY OF REGISTERS ASSOCIATED WITH PORTH
Reset
Values
on page
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
TRISH
TRISH7
RH7
TRISH6
RH6
TRISH5
RH5
TRISH4
RH4
TRISH3
RH3
TRISH2 TRISH1 TRISH0
60
60
60
59
PORTH
LATH
RH2
RH1
RH0
LATH7
—
LATH6
—
LATH5
VCFG1
LATH4
VCFG0
LATH3
PCFG3
LATH2
PCFG2
LATH1
LATH0
ADCON1
PCFG1 PCFG0
© 2008 Microchip Technology Inc.
DS39646C-page 155
PIC18F8722 FAMILY
When the external memory interface is enabled, all of
the PORTJ pins function as control outputs for the
interface. This occurs automatically when the interface
is enabled by clearing the EBDIS control bit
(MEMCON<7>). The TRISJ bits are also overridden.
11.9 PORTJ, TRISJ and
LATJ Registers
Note: PORTJ
is
available
only
on
PIC18F8527/8622/8627/8722 devices.
PORTJ is an 8-bit wide, bidirectional port. The corre-
sponding Data Direction register is TRISJ. Setting a
TRISJ bit (= 1) will make the corresponding PORTJ pin
an input (i.e., put the corresponding output driver in a
high-impedance mode). Clearing a TRISJ bit (= 0) will
make the corresponding PORTJ pin an output (i.e., put
the contents of the output latch on the selected pin).
EXAMPLE 11-9:
INITIALIZING PORTJ
CLRF
PORTJ
; Initialize PORTJ by
; clearing output
; data latches
; Alternate method
; to clear output
; data latches
CLRF
LATJ
MOVLW 0xCF
; Value used to
; initialize data
; direction
; Set RJ3:RJ0 as inputs
; RJ5:RJ4 as output
; RJ7:RJ6 as inputs
The Data Latch register (LATJ) is also memory
mapped. Read-modify-write operations on the LATJ
register, read and write the latched output value for
PORTJ.
MOVWF TRISJ
All pins on PORTJ are implemented with Schmitt
Trigger input buffers. Each pin is individually
configurable as an input or output.
Note: On a Power-on Reset, these pins are
configured as digital inputs.
DS39646C-page 156
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
TABLE 11-17: PORTJ FUNCTIONS
TRIS
Setting
I/O
Type
Pin Name
RJ0/ALE
Function
I/O
Description
RJ0
O
I
DIG
ST
LATJ<0> data output.
0
1
x
PORTJ<0> data input.
ALE
RJ1
O
DIG
External memory interface address latch enable control output. Takes
priority over digital I/O.
RJ1/OE
RJ2/WRL
RJ3/WRH
RJ4/BA0
RJ5/CE
RJ6/LB
0
1
x
O
I
DIG
ST
LATJ<1> data output.
PORTJ<1> data input.
OE
O
DIG
External memory interface output enable control output. Takes priority
over digital I/O.
RJ2
0
1
x
O
I
DIG
ST
LATJ<2> data output.
PORTJ<2> data input.
WRL
RJ3
O
DIG
External Memory Bus write low byte control. Takes priority over
digital I/O.
0
1
x
O
I
DIG
ST
LATJ<3> data output.
PORTJ<3> data input.
WRH
RJ4
O
DIG
External memory interface write high byte control output. Takes priority
over digital I/O.
0
1
x
O
I
DIG
ST
LATJ<4> data output.
PORTJ<4> data input.
BA0
RJ5
O
DIG
External memory interface byte address 0 control output. Takes
priority over digital I/O.
0
1
x
O
I
DIG
ST
LATJ<5> data output.
PORTJ<5> data input.
CE
O
DIG
External memory interface chip enable control output. Takes priority
over digital I/O.
RJ6
0
1
x
O
I
DIG
ST
LATJ<6> data output.
PORTJ<6> data input.
LB
O
DIG
External memory interface lower byte enable control output. Takes
priority over digital I/O.
RJ7/UB
Legend:
RJ7
0
1
x
O
I
DIG
ST
LATJ<7> data output.
PORTJ<7> data input.
UB
O
DIG
External memory interface upper byte enable control output. Takes
priority over digital I/O.
PWR = Power Supply, O = Output, I = Input, ANA = Analog Signal, DIG = Digital Output, ST = Schmitt Buffer Input,
TTL = TTL Buffer Input, x= Don’t care (TRIS bit does not affect port direction or is overridden for this option).
TABLE 11-18: SUMMARY OF REGISTERS ASSOCIATED WITH PORTJ
Reset
Values
on page
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
PORTJ
RJ7
RJ6
RJ5
RJ4
RJ3
RJ2
RJ1
RJ0
60
60
60
LATJ
LATJ7
TRISJ7
LATJ6
TRISJ6
LATJ5
TRISJ5
LATJ4
TRISJ4
LATJ3
TRISJ3
LATJ2
TRISJ2
LATJ1
TRISJ1
LATJ0
TRISJ0
TRISJ
© 2008 Microchip Technology Inc.
DS39646C-page 157
PIC18F8722 FAMILY
FIGURE 11-2:
PORTD AND PORTE
BLOCK DIAGRAM
(PARALLEL SLAVE PORT)
11.10 Parallel Slave Port
PORTD can also function as an 8-bit wide Parallel
Slave Port, or microprocessor port, when control bit
PSPMODE (PSPCON<4>) is set. It is asynchronously
readable and writable by the external world through the
RD and WR control input pins.
Data Bus
D
Q
RDx
pin
WR LATD
or
PORTD
CKx
Data Latch
Note: For PIC18F8527/8622/8627/8722 devices,
the Parallel Slave Port is available only in
Microcontroller mode.
TTL
Q
D
The PSP can directly interface to an 8-bit micro-
processor data bus. The external microprocessor can
read or write the PORTD latch as an 8-bit latch. Setting
bit PSPMODE enables port pin RE0/RD to be the RD
input, RE1/WR to be the WR input and RE2/CS to be
the CS (Chip Select) input. For this functionality, the
corresponding data direction bits of the TRISE register
(TRISE<2:0>) must be configured as inputs (set).
RD PORTD
EN
TRIS Latch
RD LATD
A write to the PSP occurs when both the CS and WR
lines are first detected low and ends when either are
detected high. The PSPIF and IBF flag bits are both set
when the write ends.
One bit of PORTD
Set Interrupt Flag
PSPIF (PIR1<7>)
A read from the PSP occurs when both the CS and RD
lines are first detected low. The data in PORTD is read
out and the OBF bit is set. If the user writes new data
to PORTD to set OBF, the data is immediately read out;
however, the OBF bit is not set.
Read
When either the CS or RD lines are detected high, the
PORTD pins return to the input state and the PSPIF bit
is set. User applications should wait for PSPIF to be set
before servicing the PSP; when this happens, the IBF
and OBF bits can be polled and the appropriate action
taken.
RD
CS
TTL
Chip Select
TTL
Write
WR
TTL
The timing for the control signals in Write and Read
modes is shown in Figure 11-3 and Figure 11-4,
respectively.
Note: I/O pin has protection diodes to VDD and VSS.
DS39646C-page 158
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
REGISTER 11-1: PSPCON: PARALLEL SLAVE PORT CONTROL REGISTER
R-0
IBF
R-0
R/W-0
IBOV
R/W-0
U-0
—
U-0
—
U-0
—
U-0
—
OBF
PSPMODE
bit 7
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7
bit 6
bit 5
bit 4
bit 3-0
IBF: Input Buffer Full Status bit
1= A word has been received and is waiting to be read by the CPU
0= No word has been received
OBF: Output Buffer Full Status bit
1= The output buffer still holds a previously written word
0= The output buffer has been read
IBOV: Input Buffer Overflow Detect bit
1= A write occurred when a previously input word has not been read (must be cleared in software)
0= No overflow occurred
PSPMODE: Parallel Slave Port Mode Select bit
1= Parallel Slave Port mode
0= General Purpose I/O mode
Unimplemented: Read as ‘0’
© 2008 Microchip Technology Inc.
DS39646C-page 159
PIC18F8722 FAMILY
FIGURE 11-3:
PARALLEL SLAVE PORT WRITE WAVEFORMS
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
CS
WR
RD
PORTD<7:0>
IBF
OBF
PSPIF
FIGURE 11-4:
PARALLEL SLAVE PORT READ WAVEFORMS
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
CS
WR
RD
PORTD<7:0>
IBF
OBF
PSPIF
TABLE 11-19: REGISTERS ASSOCIATED WITH PARALLEL SLAVE PORT
Reset
Values
on page
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
PORTD
LATD
RD7
LATD7
TRISD7
RE7
RD6
LATD6
TRISD6
RE6
RD5
LATD5
TRISD5
RE5
RD4
LATD4
TRISD4
RE4
RD3
RD2
RD1
RD0
60
60
60
60
60
60
59
57
60
60
60
LATD3
LATD2
LATD1
LATD0
TRISD
PORTE
LATE
TRISD3 TRISD2
TRISD1 TRISD0
RE3
LATE3
TRISE3
—
RE2
LATE2
TRISE2
—
RE1
LATE1
TRISE1
—
RE0
LATE0
TRISE0
—
LATE7
TRISE7
IBF
LATE6
TRISE6
OBF
LATE5
TRISE5
IBOV
LATE4
TRISE4
PSPMODE
INT0IE
TX1IF
TRISE
PSPCON
INTCON
PIR1
GIE/GIEH PEIE/GIEL TMR0IE
RBIE
TMR0IF
INT0IF
RBIF
PSPIF
PSPIE
PSPIP
ADIF
ADIE
ADIP
RC1IF
RC1IE
RC1IP
SSP1IF
SSP1IE
SSP1IP
CCP1IF TMR2IF TMR1IF
CCP1IE TMR2IE TMR1IE
CCP1IP TMR2IP TMR1IP
PIE1
TX1IE
IPR1
TX1IP
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by the Parallel Slave Port.
DS39646C-page 160
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
The T0CON register (Register 12-1) controls all
aspects of the module’s operation, including the
prescale selection. It is both readable and writable.
12.0 TIMER0 MODULE
The Timer0 module incorporates the following features:
• Software selectable operation as a timer or
counter in both 8-bit or 16-bit modes
• Readable and writable registers
• Dedicated 8-bit, software programmable
prescaler
A simplified block diagram of the Timer0 module in 8-bit
mode is shown in Figure 12-1. Figure 12-2 shows a
simplified block diagram of the Timer0 module in 16-bit
mode.
• Selectable clock source (internal or external)
• Edge select for external clock
• Interrupt-on-overflow
REGISTER 12-1: T0CON: TIMER0 CONTROL REGISTER
R/W-1
R/W-1
R/W-1
T0CS
R/W-1
T0SE
R/W-1
PSA
R/W-1
T0PS2
R/W-1
T0PS1
R/W-1
T0PS0
TMR0ON
T08BIT
bit 7
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2-0
TMR0ON: Timer0 On/Off Control bit
1= Enables Timer0
0= Stops Timer0
T08BIT: Timer0 8-bit/16-bit Control bit
1= Timer0 is configured as an 8-bit timer/counter
0= Timer0 is configured as a 16-bit timer/counter
T0CS: Timer0 Clock Source Select bit
1= Transition on T0CKI pin
0= Internal instruction cycle clock (CLKO)
T0SE: Timer0 Source Edge Select bit
1= Increment on high-to-low transition on T0CKI pin
0= Increment on low-to-high transition on T0CKI pin
PSA: Timer0 Prescaler Assignment bit
1= TImer0 prescaler is NOT assigned. Timer0 clock input bypasses prescaler.
0= Timer0 prescaler is assigned. Timer0 clock input comes from prescaler output.
T0PS<2:0>: Timer0 Prescaler Select bits
111= 1:256 Prescale value
110= 1:128 Prescale value
101= 1:64 Prescale value
100= 1:32 Prescale value
011= 1:16 Prescale value
010= 1:8 Prescale value
001= 1:4 Prescale value
000= 1:2 Prescale value
© 2008 Microchip Technology Inc.
DS39646C-page 161
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internal phase clock (TOSC). There is a delay between
synchronization and the onset of incrementing the
timer/counter.
12.1 Timer0 Operation
Timer0 can operate as either a timer or a counter; the
mode is selected with the T0CS bit (T0CON<5>). In
Timer mode (T0CS = 0), the module increments on
every clock by default unless a different prescaler value
is selected (see Section 12.3 “Prescaler”). If the
TMR0 register is written to, the increment is inhibited
for the following two instruction cycles. The user can
work around this by writing an adjusted value to the
TMR0 register.
12.2 Timer0 Reads and Writes in
16-bit Mode
TMR0H is not the actual high byte of Timer0 in 16-bit
mode; it is actually a buffered version of the real high
byte of Timer0 which is not directly readable nor writ-
able (refer to Figure 12-2). TMR0H is updated with the
contents of the high byte of Timer0 during a read of
TMR0L. This provides the ability to read all 16 bits of
Timer0 without having to verify that the read of the high
and low byte were valid, due to a rollover between
successive reads of the high and low byte.
The Counter mode is selected by setting the T0CS bit
(= 1). In this mode, Timer0 increments either on every
rising or falling edge of pin RA4/T0CKI. The increment-
ing edge is determined by the Timer0 Source Edge
Select bit, T0SE (T0CON<4>); clearing this bit selects
the rising edge. Restrictions on the external clock input
are discussed below.
Similarly, a write to the high byte of Timer0 must also
take place through the TMR0H Buffer register. The high
byte is updated with the contents of TMR0H when a
write occurs to TMR0L. This allows all 16 bits of Timer0
to be updated at once.
An external clock source can be used to drive Timer0;
however, it must meet certain requirements to ensure
that the external clock can be synchronized with the
FIGURE 12-1:
TIMER0 BLOCK DIAGRAM (8-BIT MODE)
FOSC/4
0
1
1
0
Set
TMR0IF
on Overflow
Sync with
Internal
Clocks
TMR0L
8
Programmable
Prescaler
T0CKI pin
(2 TCY Delay)
T0SE
T0CS
3
T0PS<2:0>
PSA
8
Internal Data Bus
Note: Upon Reset, Timer0 is enabled in 8-bit mode with clock input from T0CKI max. prescale.
FIGURE 12-2:
TIMER0 BLOCK DIAGRAM (16-BIT MODE)
FOSC/4
0
1
Sync with
Internal
Clocks
Set
TMR0
High Byte
1
TMR0L
TMR0IF
Programmable
Prescaler
on Overflow
T0CKI pin
0
8
(2 TCY Delay)
T0SE
T0CS
3
Read TMR0L
Write TMR0L
T0PS<2:0>
PSA
8
8
TMR0H
8
8
Internal Data Bus
Note: Upon Reset, Timer0 is enabled in 8-bit mode with clock input from T0CKI max. prescale.
DS39646C-page 162
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
12.3.1
SWITCHING PRESCALER
ASSIGNMENT
12.3 Prescaler
An 8-bit counter is available as a prescaler for the Timer0
module. The prescaler is not directly readable or writable;
its value is set by the PSA and T0PS<2:0> bits
(T0CON<3:0>) which determine the prescaler
assignment and prescale ratio.
The prescaler assignment is fully under software
control and can be changed “on-the-fly” during program
execution.
12.4 Timer0 Interrupt
Clearing the PSA bit assigns the prescaler to the
Timer0 module. When it is assigned, prescale values
from 1:2 through 1:256 in power-of-2 increments are
selectable.
The TMR0 interrupt is generated when the TMR0
register overflows from FFh to 00h in 8-bit mode, or
from FFFFh to 0000h in 16-bit mode. This overflow sets
the TMR0IF flag bit. The interrupt can be masked by
clearing the TMR0IE bit (INTCON<5>). Before re-
enabling the interrupt, the TMR0IF bit must be cleared
in software by the Interrupt Service Routine.
When assigned to the Timer0 module, all instructions
writing to the TMR0 register (e.g., CLRF TMR0, MOVWF
TMR0, BSF TMR0, etc.) clear the prescaler count.
Note:
Writing to TMR0 when the prescaler is
assigned to Timer0 will clear the prescaler
count, but will not change the prescaler
assignment.
Since Timer0 is shut down in Sleep mode, the TMR0
interrupt cannot awaken the processor from Sleep.
TABLE 12-1: REGISTERS ASSOCIATED WITH TIMER0
Reset
Values
on page
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
TMR0L
Timer0 Register Low Byte
Timer0 Register High Byte
58
58
57
58
60
TMR0H
INTCON
T0CON
TRISA
GIE/GIEH PEIE/GIEL TMR0IE
TMR0ON T08BIT T0CS
TRISA7(1) TRISA6(1) TRISA5
INT0IE
T0SE
RBIE
PSA
TMR0IF
T0PS2
INT0IF
T0PS1
TRISA1
RBIF
T0PS0
TRISA0
TRISA4
TRISA3
TRISA2
Legend: Shaded cells are not used by Timer0.
Note 1: PORTA<7:6> and their direction bits are individually configured as port pins based on various primary
oscillator modes. When disabled, these bits read as ‘0’.
© 2008 Microchip Technology Inc.
DS39646C-page 163
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NOTES:
DS39646C-page 164
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
A simplified block diagram of the Timer1 module is
shown in Figure 13-1. A block diagram of the module’s
operation in Read/Write mode is shown in Figure 13-2.
13.0 TIMER1 MODULE
The Timer1 timer/counter module incorporates these
features:
The module incorporates its own low-power oscillator
to provide an additional clocking option. The Timer1
oscillator can also be used as a low-power clock source
for the microcontroller in power-managed operation.
• Software selectable operation as a 16-bit timer or
counter
• Readable and writable 8-bit registers (TMR1H
and TMR1L)
• Selectable clock source (internal or external) with
device clock or Timer1 oscillator internal options
• Interrupt-on-overflow
• Reset on CCP Special Event Trigger
• Device clock status flag (T1RUN)
Timer1 can also be used to provide Real-Time Clock
(RTC) functionality to applications with only a minimal
addition of external components and code overhead.
Timer1 is controlled through the T1CON Control
register (Register 13-1). It also contains the Timer1
Oscillator Enable bit (T1OSCEN). Timer1 can be
enabled or disabled by setting or clearing control bit,
TMR1ON (T1CON<0>).
REGISTER 13-1: T1CON: TIMER1 CONTROL REGISTER
R/W-0
RD16
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
T1RUN
T1CKPS1
T1CKPS0
T1OSCEN
T1SYNC
TMR1CS
TMR1ON
bit 7
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7
RD16: 16-Bit Read/Write Mode Enable bit
1= Enables register read/write of Timer1 in one 16-bit operation
0= Enables register read/write of Timer1 in two 8-bit operations
bit 6
T1RUN: Timer1 System Clock Status bit
1= Device clock is derived from Timer1 oscillator
0= Device clock is derived from another source
bit 5-4
T1CKPS<1:0>: Timer1 Input Clock Prescale Select bits
11= 1:8 Prescale value
10= 1:4 Prescale value
01= 1:2 Prescale value
00= 1:1 Prescale value
bit 3
bit 2
T1OSCEN: Timer1 Oscillator Enable bit
1= Timer1 oscillator is enabled
0= Timer1 oscillator is shut off
The oscillator inverter and feedback resistor are turned off to eliminate power drain.
T1SYNC: Timer1 External Clock Input Synchronization Select bit
When TMR1CS = 1:
1= Do not synchronize external clock input
0= Synchronize external clock input
When TMR1CS = 0:
This bit is ignored. Timer1 uses the internal clock when TMR1CS = 0.
bit 1
bit 0
TMR1CS: Timer1 Clock Source Select bit
1= External clock from pin RC0/T1OSO/T13CKI (on the rising edge)
0= Internal clock (FOSC/4)
TMR1ON: Timer1 On bit
1= Enables Timer1
0= Stops Timer1
© 2008 Microchip Technology Inc.
DS39646C-page 165
PIC18F8722 FAMILY
cycle (FOSC/4). When the bit is set, Timer1 increments
on every rising edge of the Timer1 external clock input
or the Timer1 oscillator, if enabled.
13.1 Timer1 Operation
Timer1 can operate in one of these modes:
• Timer
• Synchronous Counter
• Asynchronous Counter
When Timer1 is enabled, the RC1/T1OSI and RC0/
T1OSO/T13CKI pins become inputs. This means the
values of TRISC<1:0> are ignored and the pins are
read as ‘0’.
The operating mode is determined by the clock select
bit, TMR1CS (T1CON<1>). When TMR1CS is cleared
(= 0), Timer1 increments on every internal instruction
FIGURE 13-1:
TIMER1 BLOCK DIAGRAM
Timer1 Oscillator
Timer1 Clock Input
1
0
On/Off
T1OSO/T13CKI
T1OSI
1
Synchronize
Detect
Prescaler
1, 2, 4, 8
FOSC/4
Internal
Clock
0
2
Sleep Input
T1OSCEN(1)
T1CKPS<1:0>
T1SYNC
Timer1
On/Off
TMR1CS
TMR1ON
Set
TMR1
High Byte
Clear TMR1
(CCP Special Event Trigger)
TMR1L
TMR1IF
on Overflow
Note 1: When enable bit, T1OSCEN, is cleared, the inverter and feedback resistor are turned off to eliminate power drain.
FIGURE 13-2:
TIMER1 BLOCK DIAGRAM (16-BIT READ/WRITE MODE)
Timer1 Oscillator
Timer1 Clock Input
1
0
T1OSO/T13CKI
T1OSI
1
0
Synchronize
Detect
Prescaler
1, 2, 4, 8
FOSC/4
Internal
Clock
2
Sleep Input
T1OSCEN(1)
T1CKPS1:T1CKPS0
T1SYNC
Timer1
On/Off
TMR1CS
TMR1ON
Set
TMR1
High Byte
Clear TMR1
(CCP Special Event Trigger)
TMR1L
TMR1IF
on Overflow
8
Read TMR1L
Write TMR1L
8
8
TMR1H
8
8
Internal Data Bus
Note 1: When enable bit, T1OSCEN, is cleared, the inverter and feedback resistor are turned off to eliminate power drain.
DS39646C-page 166
© 2008 Microchip Technology Inc.
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TABLE 13-1: CAPACITOR SELECTION FOR
THETIMEROSCILLATOR(2,3,4)
13.2 Timer1 16-bit Read/Write Mode
Timer1 can be configured for 16-bit reads and writes
(see Figure 13-2). When the RD16 control bit
(T1CON<7>) is set, the address for TMR1H is mapped
to a buffer register for the high byte of Timer1. A read
from TMR1L will load the contents of the high byte of
Timer1 into the Timer1 high byte buffer. This provides
the user with the ability to accurately read all 16 bits of
Timer1 without having to determine whether a read of
the high byte, followed by a read of the low byte, has
become invalid due to a rollover between reads.
Osc Type
Freq
C1
C2
LP
32 kHz
27 pF(1)
27 pF(1)
Note 1: Microchip suggests these values as a
starting point in validating the oscillator
circuit.
2: Higher capacitance increases the stability
of the oscillator but also increases the
start-up time.
A write to the high byte of Timer1 must also take place
through the TMR1H Buffer register. The Timer1 high
byte is updated with the contents of TMR1H when a
write occurs to TMR1L. This allows a user to write all
16 bits to both the high and low bytes of Timer1 at once.
3: Since each resonator/crystal has its own
characteristics, the user should consult
the resonator/crystal manufacturer for
appropriate
values
of
external
components.
The high byte of Timer1 is not directly readable or
writable in this mode. All reads and writes must take
place through the Timer1 High Byte Buffer register.
Writes to TMR1H do not clear the Timer1 prescaler.
The prescaler is only cleared on writes to TMR1L.
4: Capacitor values are for design guidance
only.
13.3.1
USING TIMER1 AS A
CLOCK SOURCE
The Timer1 oscillator is also available as a clock source
in power-managed modes. By setting the clock select
bits, SCS<1:0> (OSCCON<1:0>), to ‘01’, the device
switches to SEC_RUN mode; both the CPU and
peripherals are clocked from the Timer1 oscillator. If the
IDLEN bit (OSCCON<7>) is cleared and a SLEEP
instruction is executed, the device enters SEC_IDLE
mode. Additional details are available in Section 3.0
“Power-Managed Modes”.
13.3 Timer1 Oscillator
An on-chip crystal oscillator circuit is incorporated
between pins T1OSI (input) and T1OSO (amplifier out-
put). It is enabled by setting the Timer1 Oscillator Enable
bit, T1OSCEN (T1CON<3>). The oscillator is a low-
power circuit rated for 32 kHz crystals. It will continue to
run during all power-managed modes. The circuit for a
typical LP oscillator is shown in Figure 13-3. Table 13-1
shows the capacitor selection for the Timer1 oscillator.
Whenever the Timer1 oscillator is providing the clock
source, the Timer1 system clock status flag, T1RUN
(T1CON<6>), is set. This can be used to determine the
controller’s current clocking mode. It can also indicate
the clock source being currently used by the Fail-Safe
Clock Monitor. If the Clock Monitor is enabled and the
Timer1 oscillator fails while providing the clock, polling
the T1RUN bit will indicate whether the clock is being
provided by the Timer1 oscillator or another source.
The user must provide a software time delay to ensure
proper start-up of the Timer1 oscillator.
FIGURE 13-3:
EXTERNAL
COMPONENTS FOR THE
TIMER1 LP OSCILLATOR
C1
27 pF
PIC18FXXXX
T1OSI
13.3.2
LOW-POWER TIMER1 OPTION
The Timer1 oscillator can operate at two distinct levels
of power consumption based on device configuration.
When the LPT1OSC Configuration bit is set, the Timer1
oscillator operates in a low-power mode. When
LPT1OSC is not set, Timer1 operates at a higher power
level. Power consumption for a particular mode is rela-
tively constant, regardless of the device’s operating
mode. The default Timer1 configuration is the higher
power mode.
XTAL
32.768 kHz
T1OSO
C2
27 pF
Note:
See the Notes with Table 13-1 for additional
information about capacitor selection.
As the low-power Timer1 mode tends to be more
sensitive to interference, high noise environments may
cause some oscillator instability. The low-power option
is, therefore, best suited for low noise applications
where power conservation is an important design
consideration.
© 2008 Microchip Technology Inc.
DS39646C-page 167
PIC18F8722 FAMILY
In the event that a write to Timer1 coincides with a
Special Event Trigger, the write operation will take
precedence.
13.3.3
TIMER1 OSCILLATOR LAYOUT
CONSIDERATIONS
The Timer1 oscillator circuit draws very little power
during operation. Due to the low-power nature of the
oscillator, it may also be sensitive to rapidly changing
signals in close proximity.
Note:
The Special Event Triggers from the CCPx
module will not set the TMR1IF interrupt
flag bit (PIR1<0>).
The oscillator circuit, shown in Figure 13-3, should be
located as close as possible to the microcontroller.
There should be no circuits passing within the oscillator
circuit boundaries other than VSS or VDD.
13.6 Using Timer1 as a Real-Time Clock
Adding an external LP oscillator to Timer1 (such as the
one described in Section 13.3 “Timer1 Oscillator”
above) gives users the option to include RTC function-
ality to their applications. This is accomplished with an
inexpensive watch crystal to provide an accurate time
base and several lines of application code to calculate
the time. When operating in Sleep mode and using a
battery or supercapacitor as a power source, it can
completely eliminate the need for a separate RTC
device and battery backup.
If a high-speed circuit must be located near the Timer1
oscillator, a grounded guard ring around the oscillator
circuit may be helpful when used on a single-sided
PCB or in addition to a ground plane.
13.4 Timer1 Interrupt
The TMR1 register pair (TMR1H:TMR1L) increments
from 0000h to FFFFh and rolls over to 0000h. The
Timer1 interrupt, if enabled, is generated on overflow,
which is latched in interrupt flag bit, TMR1IF
(PIR1<0>). This interrupt can be enabled or disabled
by setting or clearing the Timer1 Interrupt Enable bit,
TMR1IE (PIE1<0>).
The application code routine, RTCisr, shown in
Example 13-1, demonstrates a simple method to
increment a counter at one-second intervals using an
Interrupt Service Routine. Incrementing the TMR1
register pair to overflow triggers the interrupt and calls
the routine, which increments the seconds counter by
one; additional counters for minutes and hours are
incremented as the previous counter overflow.
13.5 Resetting Timer1 Using the CCP
Special Event Trigger
Since the register pair is 16 bits wide, counting up to
overflow the register directly from a 32.768 kHz clock
would take 2 seconds. To force the overflow at the
required one-second intervals, it is necessary to pre-
load it; the simplest method is to set the MSb of TMR1H
with a BSFinstruction. Note that the TMR1L register is
never preloaded or altered; doing so may introduce
cumulative error over many cycles.
If any of the CCP modules are configured to use Timer1
and generate a Special Event Trigger in Compare mode
(CCPxM<3:0>, this signal will reset Timer1. The trigger
from the ECCP2 module will also start an A/D conver-
sion if the A/D module is enabled (see Section 17.3.4
“Special Event Trigger” for more information).
The module must be configured as either a timer or a
synchronous counter to take advantage of this feature.
When used this way, the CCPRH:CCPRL register pair
effectively becomes a period register for Timer1.
For this method to be accurate, Timer1 must operate in
Asynchronous mode and the Timer1 overflow interrupt
must be enabled (PIE1<0> = 1), as shown in the
routine, RTCinit. The Timer1 oscillator must also be
enabled and running at all times.
If Timer1 is running in Asynchronous Counter mode,
this Reset operation may not work.
DS39646C-page 168
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
EXAMPLE 13-1:
IMPLEMENTING A REAL-TIME CLOCK USING A TIMER1 INTERRUPT SERVICE
RTCinit
MOVLW
MOVWF
CLRF
80h
TMR1H
TMR1L
; Preload TMR1 register pair
; for 1 second overflow
MOVLW
MOVWF
CLRF
b’00001111’
T1CON
secs
; Configure for external clock,
; Asynchronous operation, external oscillator
; Initialize timekeeping registers
;
CLRF
mins
MOVLW
MOVWF
BSF
.12
hours
PIE1, TMR1IE
; Enable Timer1 interrupt
RETURN
RTCisr
BSF
BCF
INCF
MOVLW
TMR1H, 7
PIR1, TMR1IF
secs, F
.59
; Preload for 1 sec overflow
; Clear interrupt flag
; Increment seconds
; 60 seconds elapsed?
CPFSGT secs
RETURN
; No, done
CLRF
INCF
MOVLW
secs
mins, F
.59
; Clear seconds
; Increment minutes
; 60 minutes elapsed?
CPFSGT mins
RETURN
; No, done
CLRF
INCF
MOVLW
mins
hours, F
.23
; clear minutes
; Increment hours
; 24 hours elapsed?
CPFSGT hours
RETURN
; No, done
; Reset hours
; Done
CLRF
hours
RETURN
TABLE 13-2: REGISTERS ASSOCIATED WITH TIMER1 AS A TIMER/COUNTER
Reset
Values
on page
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
INTCON
PIR1
GIE/GIEH PEIE/GIEL TMR0IE
INT0IE
TX1IF
TX1IE
TX1IP
RBIE
TMR0IF
CCP1IF
CCP1IE
CCP1IP
INT0IF
TMR2IF
TMR2IE
TMR2IP
RBIF
57
60
60
60
58
58
58
PSPIF
PSPIE
PSPIP
ADIF
ADIE
ADIP
RC1IF
RC1IE
RC1IP
SSP1IF
SSP1IE
SSP1IP
TMR1IF
TMR1IE
TMR1IP
PIE1
IPR1
TMR1L
TMR1H
T1CON
Timer1 Register Low Byte
Timer1 Register High Byte
RD16
T1RUN T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON
Legend: Shaded cells are not used by the Timer1 module.
© 2008 Microchip Technology Inc.
DS39646C-page 169
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NOTES:
DS39646C-page 170
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
14.1 Timer2 Operation
14.0 TIMER2 MODULE
In normal operation, TMR2 is incremented from 00h on
each clock (FOSC/4). A 4-bit counter/prescaler on the
clock input gives direct input, divide-by-4 and divide-by-
16 prescale options; these are selected by the prescaler
control bits, T2CKPS<1:0> (T2CON<1:0>). The value of
TMR2 is compared to that of the period register, PR2, on
each clock cycle. When the two values match, the com-
parator generates a match signal as the timer output.
This signal also resets the value of TMR2 to 00h on the
next cycle and drives the output counter/postscaler (see
Section 14.2 “Timer2 Interrupt”).
The Timer2 timer module incorporates the following
features:
• 8-bit Timer and Period registers (TMR2 and PR2,
respectively)
• Readable and writable (both registers)
• Software programmable prescaler
(1:1, 1:4 and 1:16)
• Software programmable postscaler
(1:1 through 1:16)
• Interrupt on TMR2 to PR2 match
• Optional use as the shift clock for the
MSSPx module
The TMR2 and PR2 registers are both directly readable
and writable. The TMR2 register is cleared on any
device Reset, while the PR2 register initializes at FFh.
Both the prescaler and postscaler counters are cleared
on the following events:
The module is controlled through the T2CON register
(Register 14-1), which enables or disables the timer
and configures the prescaler and postscaler. Timer2
can be shut off by clearing control bit, TMR2ON
(T2CON<2>), to minimize power consumption.
• a write to the TMR2 register
• a write to the T2CON register
• any device Reset (Power-on Reset, MCLR Reset,
Watchdog Timer Reset or Brown-out Reset)
A simplified block diagram of the module is shown in
Figure 14-1.
TMR2 is not cleared when T2CON is written.
REGISTER 14-1: T2CON: TIMER2 CONTROL REGISTER
U-0
—
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
T2OUTPS3 T2OUTPS2 T2OUTPS1 T2OUTPS0
TMR2ON
T2CKPS1
T2CKPS0
bit 7
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7
Unimplemented: Read as ‘0’
bit 6-3
T2OUTPS<3:0>: Timer2 Output Postscale Select bits
0000= 1:1 Postscale
0001= 1:2 Postscale
•
•
•
1111= 1:16 Postscale
bit 2
TMR2ON: Timer2 On bit
1= Timer2 is on
0= Timer2 is off
bit 1-0
T2CKPS<1:0>: Timer2 Clock Prescale Select bits
00= Prescaler is 1
01= Prescaler is 4
1x= Prescaler is 16
© 2008 Microchip Technology Inc.
DS39646C-page 171
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14.2 Timer2 Interrupt
14.3 Timer2 Output
Timer2 also can generate an optional device interrupt.
The Timer2 output signal (TMR2 to PR2 match) pro-
vides the input for the 4-bit output counter/postscaler.
This counter generates the TMR2 match interrupt flag
which is latched in TMR2IF (PIR1<1>). The interrupt is
enabled by setting the TMR2 Match Interrupt Enable
bit, TMR2IE (PIE1<1>).
The unscaled output of TMR2 is available primarily to
the CCP modules, where it is used as a time base for
operations in PWM mode.
Timer2 can be optionally used as the shift clock source
for the MSSP module operating in SPI mode. Addi-
tional information is provided in Section 19.0 “Master
Synchronous Serial Port (MSSP) Module”.
A range of 16 postscale options (from 1:1 through 1:16
inclusive) can be selected with the postscaler control
bits, T2OUTPS<3:0> (T2CON<6:3>).
FIGURE 14-1:
TIMER2 BLOCK DIAGRAM
4
1:1 to 1:16
Set TMR2IF
Postscaler
T2OUTPS<3:0>
T2CKPS<1:0>
2
TMR2 Output
(to PWM or MSSP)
TMR2/PR2
Match
Reset
1:1, 1:4, 1:16
Prescaler
PR2
FOSC/4
Comparator
TMR2
8
8
8
Internal Data Bus
TABLE 14-1: REGISTERS ASSOCIATED WITH TIMER2 AS A TIMER/COUNTER
Reset
Values
on page
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
INTCON GIE/GIEH PEIE/GIEL TMR0IE
INT0IE
TX1IF
TX1IE
TX1IP
RBIE
TMR0IF
CCP1IF
CCP1IE
CCP1IP
INT0IF
TMR2IF
TMR2IE
TMR2IP
RBIF
57
60
60
60
58
58
58
PIR1
PSPIF
PSPIE
PSPIP
ADIF
ADIE
ADIP
RC1IF
RC1IE
RC1IP
SSP1IF
SSP1IE
SSP1IP
TMR1IF
TMR1IE
TMR1IP
PIE1
IPR1
TMR2
T2CON
PR2
Timer2 Register
T2OUTPS3 T2OUTPS2 T2OUTPS1 T2OUTPS0 TMR2ON T2CKPS1 T2CKPS0
Timer2 Period Register
—
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by the Timer2 module.
DS39646C-page 172
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
A simplified block diagram of the Timer3 module is
shown in Figure 15-1. A block diagram of the module’s
operation in Read/Write mode is shown in Figure 15-2.
15.0 TIMER3 MODULE
The Timer3 timer/counter module incorporates these
features:
The Timer3 module is controlled through the T3CON
register (Register 15-1). It also selects the clock source
options for the CCP modules (see Section 17.1.1
“CCP Modules and Timer Resources” for more
information).
• Software selectable operation as a 16-bit timer or
counter
• Readable and writable 8-bit registers
(TMR3H and TMR3L)
• Selectable clock source (internal or external) with
device clock or Timer1 oscillator internal options
• Interrupt-on-overflow
• Module Reset on CCP Special Event Trigger
REGISTER 15-1: T3CON: TIMER3 CONTROL REGISTER
R/W-0
RD16
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
T3CCP2
T3CKPS1
T3CKPS0
T3CCP1
T3SYNC
TMR3CS
TMR3ON
bit 7
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7
RD16: 16-Bit Read/Write Mode Enable bit
1= Enables register read/write of Timer3 in one 16-bit operation
0= Enables register read/write of Timer3 in two 8-bit operations
bit 6, 3
T3CCP<2:1>: Timer3 and Timer1 to CCPx Enable bits
11= Timer3 and Timer4 are the clock sources for ECCP1, ECCP2, ECCP3, CCP4 and CCP5
10= Timer3 and Timer4 are the clock sources for ECCP3, CCP4 and CCP5;
Timer1 and Timer2 are the clock sources for ECCP1 and ECCP2
01= Timer3 and Timer4 are the clock sources for ECCP2, ECCP3, CCP4 and CCP5;
Timer1 and Timer2 are the clock sources for ECCP1
00= Timer1 and Timer2 are the clock sources for ECCP1, ECCP2, ECCP3, CCP4 and CCP5
bit 5-4
bit 2
T3CKPS<1:0>: Timer3 Input Clock Prescale Select bits
11= 1:8 Prescale value
10= 1:4 Prescale value
01= 1:2 Prescale value
00= 1:1 Prescale value
T3SYNC: Timer3 External Clock Input Synchronization Control bit
(Not usable if the device clock comes from Timer1/Timer3.)
When TMR3CS = 1:
1= Do not synchronize external clock input
0= Synchronize external clock input
When TMR3CS = 0:
This bit is ignored. Timer3 uses the internal clock when TMR3CS = 0.
bit 1
bit 0
TMR3CS: Timer3 Clock Source Select bit
1= External clock input from Timer1 oscillator or T13CKI (on the rising edge after the first falling edge)
0= Internal clock (FOSC/4)
TMR3ON: Timer3 On bit
1= Enables Timer3
0= Stops Timer3
© 2008 Microchip Technology Inc.
DS39646C-page 173
PIC18F8722 FAMILY
The operating mode is determined by the clock select
bit, TMR3CS (T3CON<1>). When TMR3CS is cleared
(= 0), Timer3 increments on every internal instruction
cycle (FOSC/4). When the bit is set, Timer3 increments
on every rising edge of the Timer1 external clock input
or the Timer1 oscillator, if enabled.
15.1 Timer3 Operation
Timer3 can operate in one of three modes:
• Timer
• Synchronous Counter
• Asynchronous Counter
As with Timer1, the RC1/T1OSI and RC0/T1OSO/
T13CKI pins become inputs when the Timer1 oscillator
is enabled. This means the values of TRISC<1:0> are
ignored and the pins are read as ‘0’.
FIGURE 15-1:
TIMER3 BLOCK DIAGRAM
Timer1 Oscillator
Timer1 Clock Input
1
0
T1OSO/T13CKI
T1OSI
1
0
Synchronize
Detect
Prescaler
1, 2, 4, 8
FOSC/4
Internal
Clock
2
Sleep Input
T1OSCEN(1)
TMR3CS
Timer3
On/Off
T3CKPS<1:0>
T3SYNC
TMR3ON
CCPx Special Event Trigger
Clear TMR3
Set
TMR3
High Byte
TMR3L
TMR3IF
CCPx Select from T3CON<6,3>
on Overflow
Note 1: When enable bit, T1OSCEN, is cleared, the inverter and feedback resistor are turned off to eliminate power drain.
FIGURE 15-2:
TIMER3 BLOCK DIAGRAM (16-BIT READ/WRITE MODE)
Timer1 Oscillator
Timer1 Clock Input
1
0
T13CKI/T1OSO
T1OSI
1
0
Synchronize
Detect
Prescaler
1, 2, 4, 8
FOSC/4
Internal
Clock
2
Sleep Input
T1OSCEN(1)
T3CKPS<1:0>
T3SYNC
Timer3
On/Off
TMR3CS
TMR3ON
CCPx Special Event Trigger
Clear TMR3
Set
TMR3
High Byte
TMR3L
TMR3IF
CCPx Select from T3CON<6,3>
on Overflow
8
Read TMR1L
Write TMR1L
8
8
TMR3H
8
8
Internal Data Bus
Note 1: When enable bit, T1OSCEN, is cleared, the inverter and feedback resistor are turned off to eliminate power drain.
DS39646C-page 174
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
15.2 Timer3 16-bit Read/Write Mode
15.4 Timer3 Interrupt
Timer3 can be configured for 16-bit reads and writes
(see Figure 15-2). When the RD16 control bit
(T3CON<7>) is set, the address for TMR3H is mapped
to a buffer register for the high byte of Timer3. A read
from TMR3L will load the contents of the high byte of
Timer3 into the Timer3 High Byte Buffer register. This
provides the user with the ability to accurately read all
16 bits of Timer3 without having to determine whether
a read of the high byte, followed by a read of the low
byte, has become invalid due to a rollover between
reads.
The TMR3 register pair (TMR3H:TMR3L) increments
from 0000h to FFFFh and overflows to 0000h. The
Timer3 interrupt, if enabled, is generated on overflow
and is latched in interrupt flag bit, TMR3IF (PIR2<1>).
This interrupt can be enabled or disabled by setting or
clearing the Timer3 Interrupt Enable bit, TMR3IE
(PIE2<1>).
15.5 Resetting Timer3 Using the CCP
Special Event Trigger
If any of the CCP modules are configured to use Timer3
and to generate a Special Event Trigger in Compare
mode (CCPxM<3:0> = 1011), this signal will reset
Timer3. ECCP2 can also start an A/D conversion if the
A/D module is enabled (see Section 17.3.4 “Special
Event Trigger” for more information).
A write to the high byte of Timer3 must also take place
through the TMR3H Buffer register. The Timer3 high
byte is updated with the contents of TMR3H when a
write occurs to TMR3L. This allows a user to write all
16 bits to both the high and low bytes of Timer3 at once.
The high byte of Timer3 is not directly readable or
writable in this mode. All reads and writes must take
place through the Timer3 High Byte Buffer register.
The module must be configured as either a timer or
synchronous counter to take advantage of this feature.
When used this way, the CCPRxH:CCPRxL register
pair effectively becomes a period register for Timer3.
Writes to TMR3H do not clear the Timer3 prescaler.
The prescaler is only cleared on writes to TMR3L.
If Timer3 is running in Asynchronous Counter mode,
the Reset operation may not work.
15.3 Using the Timer1 Oscillator as the
Timer3 Clock Source
In the event that a write to Timer3 coincides with a
Special Event Trigger from a CCP module, the write will
take precedence.
The Timer1 internal oscillator may be used as the clock
source for Timer3. The Timer1 oscillator is enabled by
setting the T1OSCEN (T1CON<3>) bit. To use it as the
Timer3 clock source, the TMR3CS bit must also be set.
As previously noted, this also configures Timer3 to
increment on every rising edge of the oscillator source.
Note:
The Special Event Triggers from the CCPx
module will not set the TMR3IF interrupt
flag bit (PIR2<1>).
The Timer1 oscillator is described in Section 13.0
“Timer1 Module”.
TABLE 15-1: REGISTERS ASSOCIATED WITH TIMER3 AS A TIMER/COUNTER
Reset
Values
on page
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
INTCON
PIR2
GIE/GIEH PEIE/GIEL TMR0IE
INT0IE
EEIF
RBIE
TMR0IF
HLVDIF
HLVDIE
HLVDIP
INT0IF
TMR3IF
TMR3IE
TMR3IP
RBIF
57
60
60
60
59
59
58
59
OSCFIF
OSCFIE
OSCFIP
CMIF
CMIE
CMIP
—
—
—
BCL1IF
BCL1IE
BCL1IP
CCP2IF
CCP2IE
CCP2IP
PIE2
EEIE
EEIP
IPR2
TMR3L
TMR3H
T1CON
T3CON
Timer3 Register Low Byte
Timer3 Register High Byte
RD16
RD16
T1RUN T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON
T3CCP2 T3CKPS1 T3CKPS0 T3CCP1 T3SYNC TMR3CS TMR3ON
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by the Timer3 module.
© 2008 Microchip Technology Inc.
DS39646C-page 175
PIC18F8722 FAMILY
NOTES:
DS39646C-page 176
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
16.1 Timer4 Operation
16.0 TIMER4 MODULE
Timer4 can be used as the PWM time base for the
PWM mode of the CCP modules. The TMR4 register is
readable and writable and is cleared on any device
Reset. The input clock (FOSC/4) has a prescale option
of 1:1, 1:4 or 1:16, selected by control bits
T4CKPS<1:0> (T4CON<1:0>). The match output of
TMR4 goes through a 4-bit postscaler (which gives a
1:1 to 1:16 scaling inclusive) to generate a TMR4
interrupt, latched in flag bit, TMR4IF (PIR3<3>).
The Timer4 timer module has the following features:
• 8-bit Timer register (TMR4)
• 8-bit Period register (PR4)
• Readable and writable (both registers)
• Software programmable prescaler (1:1, 1:4, 1:16)
• Software programmable postscaler (1:1 to 1:16)
• Interrupt on TMR4 match of PR4
Timer4 has a control register shown in Register 16-1.
Timer4 can be shut off by clearing control bit, TMR4ON
(T4CON<2>), to minimize power consumption. The
prescaler and postscaler selection of Timer4 are also
controlled by this register. Figure 16-1 is a simplified
block diagram of the Timer4 module.
The prescaler and postscaler counters are cleared
when any of the following occurs:
• a write to the TMR4 register
• a write to the T4CON register
• any device Reset (Power-on Reset, MCLR Reset,
Watchdog Timer Reset or Brown-out Reset)
TMR4 is not cleared when T4CON is written.
REGISTER 16-1: T4CON: TIMER4 CONTROL REGISTER
U-0
—
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
T4OUTPS3 T4OUTPS2 T4OUTPS1 T4OUTPS0
TMR4ON
T4CKPS1
T4CKPS0
bit 7
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7
Unimplemented: Read as ‘0’
bit 6-3
T4OUTPS<3:0>: Timer4 Output Postscale Select bits
0000= 1:1 Postscale
0001= 1:2 Postscale
•
•
•
1111= 1:16 Postscale
bit 2
TMR4ON: Timer4 On bit
1= Timer4 is on
0= Timer4 is off
bit 1-0
T4CKPS<1:0>: Timer4 Clock Prescale Select bits
00= Prescaler is 1
01= Prescaler is 4
1x= Prescaler is 16
© 2008 Microchip Technology Inc.
DS39646C-page 177
PIC18F8722 FAMILY
16.2 Timer4 Interrupt
16.3 Output of TMR4
The Timer4 module has an 8-bit Period register, PR4,
which is both readable and writable. Timer4 increments
from 00h until it matches PR4 and then resets to 00h on
the next increment cycle. The PR4 register is initialized
to FFh upon Reset.
The output of TMR4 (before the postscaler) is used
only as a PWM time base for the CCP modules. It is not
used as a baud rate clock for the MSSP, as is the
Timer2 output.
FIGURE 16-1:
TIMER4 BLOCK DIAGRAM
Sets Flag
TMR4
bit TMR4IF
(1)
Output
Prescaler
Reset
EQ
TMR4
FOSC/4
1:1, 1:4, 1:16
Postscaler
1:1 to 1:16
2
Comparator
PR4
T4CKPS<1:0>
4
T4OUTPS<3:0>
TABLE 16-1: REGISTERS ASSOCIATED WITH TIMER4 AS A TIMER/COUNTER
Reset
Values
on page
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
INTCON GIE/GIEH PEIE/GIEL
TMR0IE
RC2IP
RC2IF
RC2IE
INT0IE
TX2IP
TX2IF
TX2IE
RBIE
TMR0IF
CCP5IP
CCP5IF
CCP5IE
INT0IF
CCP4IP
CCP4IF
CCP4IE
RBIF
57
60
60
60
61
61
61
IPR3
PIR3
PIE3
SSP2IP
SSP2IF
SSP2IE
BCL2IP
BCL2IF
BCL2IE
TMR4IP
TMR4IF
TMR4IE
CCP3IP
CCP3IF
CCP3IE
TMR4
T4CON
PR4
Timer4 Register
T4OUTPS3 T4OUTPS2 T4OUTPS1 T4OUTPS0 TMR4ON T4CKPS1 T4CKPS0
Timer4 Period Register
—
Legend: x= unknown, u= unchanged, — = unimplemented, read as ‘0’. Shaded cells are not used by the Timer4 module.
DS39646C-page 178
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
Capture and Compare operations described in this chap-
ter apply to all standard and Enhanced CCP modules.
The operations of PWM mode described in Section 17.4
“PWM Mode” apply to CCP4 and CCP5 only.
17.0 CAPTURE/COMPARE/PWM
(CCP) MODULES
The PIC18F8722 family of devices all have a total of
five CCP (Capture/Compare/PWM) modules. Two of
these (CCP4 and CCP5) implement standard Capture,
Compare and Pulse-Width Modulation (PWM) modes
and are discussed in this section. The other three
modules (ECCP1, ECCP2, ECCP3) implement
standard Capture and Compare modes, as well as
Enhanced PWM modes. These are discussed in
Section 18.0 “Enhanced Capture/Compare/PWM
(ECCP) Module”.
Note:
Throughout this section and Section 18.0
“Enhanced Capture/Compare/PWM
(ECCP) Module”, references to register
and bit names that may be associated with
a specific CCP module are referred to
generically by the use of ‘x’ or ‘y’ in place of
the specific module number. Thus,
“CCPxCON” might refer to the control
register for CCP4 or CCP5, or ECCP1,
ECCP2 or ECCP3. “CCPxCON” is used
throughout these sections to refer to the
module control register, regardless of
whether the CCP module is a standard or
enhanced implementation.
Each CCP/ECCP module contains a 16-bit register
which can operate as a 16-bit Capture register, a 16-bit
Compare register or a PWM Master/Slave Duty Cycle
register. For the sake of clarity, all CCP module opera-
tions in the following sections are described with
respect to CCP4, but are equally applicable to CCP5.
REGISTER 17-1: CCPxCON: CCPx CONTROL REGISTER (CCP4 AND CCP5 MODULES)
U-0
—
U-0
—
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
DCxB1
DCxB0
CCPxM3
CCPxM2
CCPxM1
CCPxM0
bit 7
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7-6
bit 5-4
Unimplemented: Read as ‘0’
DCxB<1:0>: PWM Duty Cycle bit 1 and bit 0 for CCP Module x
Capture mode:
Unused.
Compare mode:
Unused.
PWM mode:
These bits are the two Least Significant bits (bit 1 and bit 0) of the 10-bit PWM duty cycle. The eight
Most Significant bits (DCx<9:2>) of the duty cycle are found in CCPRxL.
bit 3-0
CCPxM<3:0>: CCP Module x Mode Select bits
0000= Capture/Compare/PWM disabled; resets CCPx module
0001= Reserved
0010= Compare mode, toggle output on match; CCPxIF bit is set
0011= Reserved
0100= Capture mode, every falling edge
0101= Capture mode, every rising edge
0110= Capture mode, every 4th rising edge
0111= Capture mode, every 16th rising edge
1000= Compare mode, initialize CCPx pin low; on compare match, force CCPx pin high; CCPxIF bit is set
1001= Compare mode, initialize CCPx pin high; on compare match, force CCPx pin low; CCPxIF bit is set
1010= Compare mode, generate software interrupt on compare match; CCPxIF bit is set; CCPx pin
reflects I/O state
1011= Compare mode, trigger special event; CCPxIF bit is set, CCPx pin is unaffected (For the effects
of the trigger, see Section 17.3.4 “Special Event Trigger”.)
11xx= PWM mode
© 2008 Microchip Technology Inc.
DS39646C-page 179
PIC18F8722 FAMILY
The assignment of a particular timer to a module is
determined by the Timer to CCP enable bits in the
T3CON register (Register 15-1). Depending on the
configuration selected, up to four timers may be active
at once, with modules in the same configuration
(Capture/Compare or PWM) sharing timer resources.
The possible configurations are shown in Figure 17-1.
17.1 CCP Module Configuration
Each Capture/Compare/PWM module is associated
with a control register (generically, CCPxCON) and a
data register (CCPRx). The data register, in turn, is
comprised of two 8-bit registers: CCPRxL (low byte)
and CCPRxH (high byte). All registers are both
readable and writable.
17.1.2
ECCP2 PIN ASSIGNMENT
17.1.1
CCP MODULES AND TIMER
RESOURCES
The pin assignment for ECCP2 (Capture input,
Compare and PWM output) can change, based on
device configuration. The CCP2MX Configuration bit
determines which pin ECCP2 is multiplexed to. By
default, it is assigned to RC1 (CCP2MX = 1). If the
Configuration bit is cleared, ECCP2 is multiplexed with
RE7 in Microcontroller mode, or RE3 in all other
modes.
The CCP/ECCP modules utilize Timers 1, 2, 3 or 4,
depending on the mode selected. Timer1 and Timer3
are available to modules in Capture or Compare
modes, while Timer2 and Timer4 are available for
modules in PWM mode.
TABLE 17-1: CCP MODE – TIMER
RESOURCE
Changing the pin assignment of ECCP2 does not auto-
matically change any requirements for configuring the
port pin. Users must always verify that the appropriate
TRIS register is configured correctly for ECCP2
operation regardless of where it is located.
CCP Mode
Timer Resource
Capture
Compare
PWM
Timer1 or Timer3
Timer1 or Timer3
Timer2 or Timer4
FIGURE 17-1:
CCP AND TIMER INTERCONNECT CONFIGURATIONS
T3CCP<2:1> = 00
T3CCP<2:1> = 01
T3CCP<2:1> = 10
T3CCP<2:1> = 11
TMR1
TMR3
TMR1
TMR3
TMR1
TMR3
TMR1
TMR3
ECCP1
ECCP2
ECCP3
CCP4
ECCP1
ECCP1
ECCP2
ECCP1
ECCP2
ECCP3
CCP4
ECCP2
ECCP3
CCP4
ECCP3
CCP4
CCP5
CCP5
CCP5
CCP5
TMR2
TMR4
TMR2
TMR4
TMR2
TMR4
TMR2
TMR4
Timer1 is used for all Capture Timer1 and Timer2 are used Timer1 and Timer2 are used
and Compare operations for for Capture and Compare or for Capture and Compare or
Timer3 is used for all Capture
and Compare operations for
all CCP modules. Timer4 is
used for PWM operations for
all CCP modules. Modules
may share either timer
resource as a common time
base.
PWM operations for ECCP1
used for PWM operations for only (depending on selected and ECCP2 only (depending
all CCP modules. Timer2 is PWM operations for ECCP1
all CCP modules. Modules mode).
may share either timer
on the mode selected for each
module). Both modules may
use a timer as a common time
base if they are both in
Capture/Compare or PWM
modes.
All other modules use either
resource as a common time
base.
Timer3 or Timer4. Modules
may share either timer
Timer3 and Timer4 are not resource as a common time
Timer1 and Timer2 are not
available.
available.
base if they are in Capture/
Compare or PWM modes.
The other modules use either
Timer3 or Timer4. Modules
may share either timer
resource as a common time
base if they are in Capture/
Compare or PWM modes.
DS39646C-page 180
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
17.2.3
SOFTWARE INTERRUPT
17.2 Capture Mode
When the Capture mode is changed, a false capture
interrupt may be generated. The user should keep the
CCPxIE interrupt enable bit clear to avoid false inter-
rupts. The interrupt flag bit, CCPxIF, should also be
cleared following any such change in operating mode.
In Capture mode, the CCPRxH:CCPRxL register pair
captures the 16-bit value of the TMR1 or TMR3
registers when an event occurs on the corresponding
CCPx pin. An event is defined as one of the following:
• every falling edge
• every rising edge
17.2.4
CCP PRESCALER
• every 4th rising edge
• every 16th rising edge
There are four prescaler settings in Capture mode; they
are specified as part of the operating mode selected by
the mode select bits (CCPxM<3:0>). Whenever the
CCP module is turned off, or Capture mode is disabled,
the prescaler counter is cleared. This means that any
Reset will clear the prescaler counter.
The event is selected by the mode select bits,
CCPxM<3:0> (CCPxCON<3:0>). When a capture is
made, the interrupt request flag bit, CCPxIF, is set; it
must be cleared in software. If another capture occurs
before the value in the CCPRx registers is read, the old
captured value is overwritten by the new captured value.
Switching from one capture prescaler to another may
generate an interrupt. Also, the prescaler counter will
not be cleared; therefore, the first capture may be from
17.2.1
CCPx PIN CONFIGURATION
a
non-zero prescaler. Example 17-1 shows the
In Capture mode, the appropriate CCPx pin should be
configured as an input by setting the corresponding
TRIS direction bit.
recommended method for switching between capture
prescalers. This example also clears the prescaler
counter and will not generate the “false” interrupt.
Note:
If a CCPx pin is configured as an output, a
write to the port can cause a capture
condition.
EXAMPLE 17-1:
CHANGING BETWEEN
CAPTURE PRESCALERS
(CCP5 SHOWN)
17.2.2
TIMER1/TIMER3 MODE SELECTION
CLRF
CCP5CON
; Turn CCP module off
MOVLW NEW_CAPT_PS ; Load WREG with the
; new prescaler mode
The timers that are to be used with the capture feature
(Timer1 and/or Timer3) must be running in Timer mode or
Synchronized Counter mode. In Asynchronous Counter
mode, the capture operation will not work. The timer to be
used with each CCP module is selected in the T3CON
register (see Section 17.1.1 “CCP Modules and Timer
Resources”).
; value and CCP ON
MOVWF CCP5CON
; Load CCP5CON with
; this value
FIGURE 17-2:
CAPTURE MODE OPERATION BLOCK DIAGRAM
TMR3H
TMR3L
CCPR4L
TMR1L
Set Flag bit CCP4IF
T3CCP2
TMR3
Enable
Prescaler
÷ 1, 4, 16
RG3/CCP4 pin
CCPR4H
TMR1
and
Enable
T3CCP2
Edge Detect
TMR1H
CCP1CON<3:0>
Q’s
© 2008 Microchip Technology Inc.
DS39646C-page 181
PIC18F8722 FAMILY
17.3.3
SOFTWARE INTERRUPT MODE
17.3 Compare Mode
When the Generate Software Interrupt mode is chosen
(CCPxM<3:0> = 1010), the corresponding CCPx pin is
not affected. Only a CCP interrupt is generated, if
enabled and the CCPxIE bit is set.
In Compare mode, the 16-bit value of the CCPRx
registers is constantly compared against either the
TMR1 or TMR3 register pair value. When a match
occurs, the CCPx pin can be:
• driven high
• driven low
17.3.4
SPECIAL EVENT TRIGGER
All CCP modules are equipped with a Special Event
Trigger. This is an internal hardware signal generated
in Compare mode to trigger actions by other modules.
The Special Event Trigger is enabled by selecting
the Compare Special Event Trigger mode
(CCPxM<3:0> = 1011).
• toggled (high-to-low or low-to-high)
• remain unchanged (that is, reflects the state of the
I/O latch)
The action on the pin is based on the value of the mode
select bits (CCPxM<3:0>). At the same time, the
interrupt flag bit, CCPxIF, is set.
For all CCP modules, the Special Event Trigger resets
the timer register pair for whichever timer resource is
currently assigned as the module’s time base. This
allows the CCPRx registers to serve as a programmable
period register for either timer.
17.3.1
CCPx PIN CONFIGURATION
The user must configure the CCPx pin as an output by
clearing the appropriate TRIS bit.
The ECCP2 Special Event Trigger can also start an A/D
conversion. In order to do this, the A/D converter must
already be enabled.
Note:
Clearing the CCPxCON register will force
the compare output latch (depending on
device configuration) to the default low
level. This is not the port I/O data latch.
17.3.2
TIMER1/TIMER3 MODE SELECTION
Timer1 and/or Timer3 must be running in Timer mode
or Synchronized Counter mode if the CCP module is
using the compare feature. In Asynchronous Counter
mode, the compare operation may not work.
FIGURE 17-3:
COMPARE MODE OPERATION BLOCK DIAGRAM
Special Event Trigger
Set Flag bit CCP4IF
CCPR4H CCPR4L
Comparator
Q
S
R
Output
Logic
Match
RG3/CCP4 pin
TRISG<3>
Output Enable
1
0
T3CCP2
CCP4CON<3:0>
Mode Select
TMR1H TMR1L
TMR3H TMR3L
DS39646C-page 182
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
TABLE 17-2: REGISTERS ASSOCIATED WITH CAPTURE, COMPARE, TIMER1 AND TIMER3
Reset
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Values
on page
INTCON
RCON
GIE/GIEH PEIE/GIEL TMR0IE
INT0IE
RI
RBIE
TMR0IF
PD
INT0IF
POR
RBIF
BOR
57
56
60
60
60
60
60
60
60
60
60
60
60
60
60
60
58
58
58
59
59
59
59
59
59
59
59
59
59
61
61
IPEN
PSPIF
SBOREN
ADIF
—
TO
PIR1
RC1IF
RC1IE
RC1IP
—
TX1IF
TX1IE
TX1IP
EEIF
SSP1IF
SSP1IE
SSP1IP
BCL1IF
BCL1IE
BCL1IP
TMR4IF
TMR4IE
TMR4IP
TRISB3
TRISC3
TRISE3
TRISG3
TRISH3
CCP1IF
TMR2IF TMR1IF
PIE1
PSPIE
PSPIP
OSCFIF
OSCFIE
OSCFIP
SSP2IF
SSP2IE
SSP2IP
TRISB7
TRISC7
TRISE7
—
ADIE
CCP1IE TMR2IE TMR1IE
CCP1IP TMR2IP TMR1IP
IPR1
ADIP
PIR2
CMIF
HLVDIF
TMR3IF
CCP2IF
PIE2
CMIE
—
EEIE
HLVDIE TMR3IE CCP2IE
HLVDIP TMR3IP CCP2IP
IPR2
CMIP
—
EEIP
PIR3
BCL2IF
BCL2IE
BCL2IP
TRISB6
TRISC6
TRISE6
—
RC2IF
RC2IE
RC2IP
TRISB5
TRISC5
TRISE5
—
TX2IF
TX2IE
TX2IP
TRISB4
TRISC4
TRISE4
TRISG4
TRISH4
CCP5IF
CCP4IF
CCP3IF
PIE3
CCP5IE CCP4IE CCP3IE
CCP5IP CCP4IP CCP3IP
IPR3
TRISB
TRISB2
TRISC2
TRISE2
TRISB1
TRISC1
TRISE1
TRISB0
TRISC0
TRISE0
TRISC
TRISE
TRISG
TRISH(1)
TMR1L
TMR1H
T1CON
TMR3H
TMR3L
T3CON
CCPR1L
CCPR1H
CCP1CON
CCPR2L
CCPR2H
CCP2CON
CCP3CON
CCP4CON
CCP5CON
TRISG2 TRISG1 TRISG0
TRISH2 TRISH1 TRISH0
TRISH7
TRISH6
TRISH5
Timer1 Register Low Byte
Timer1 Register High Byte
RD16
T1RUN T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON
Timer3 Register High Byte
Timer3 Register Low Byte
RD16
T3CCP2 T3CKPS1 T3CKPS0 T3CCP1 T3SYNC TMR3CS TMR3ON
Enhanced Capture/Compare/PWM Register 1 Low Byte
Enhanced Capture/Compare/PWM Register 1 High Byte
P1M1
P1M0
DC1B1
DC1B0 CCP1M3 CCP1M2 CCP1M1 CCP1M0
Enhanced Capture/Compare/PWM Register 2 Low Byte
Enhanced Capture/Compare/PWM Register 2 High Byte
P2M1
P3M1
—
P2M0
P3M0
—
DC2B1
DC3B1
DC4B1
DC5B1
DC2B0 CCP2M3 CCP2M2 CCP2M1 CCP2M0
DC3B0 CCP3M3 CCP3M2 CCP3M1 CCP3M0
DC4B0 CCP4M3 CCP4M2 CCP4M1 CCP4M0
DC5B0 CCP5M3 CCP5M2 CCP5M1 CCP5M0
—
—
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by Capture/Compare, Timer1 or Timer3.
Note 1: Implemented on 80-pin devices only.
© 2008 Microchip Technology Inc.
DS39646C-page 183
PIC18F8722 FAMILY
17.4.1
PWM PERIOD
17.4 PWM Mode
The PWM period is specified by writing to the PR2
(PR4) register. The PWM period can be calculated
using the following formula:
In Pulse-Width Modulation (PWM) mode, the CCPx pin
produces up to a 10-bit resolution PWM output. Since
the CCP4 and CCP5 pins are multiplexed with a
PORTG data latch, the appropriate TRISG bit must be
cleared to make the CCP4 or CCP5 pin an output.
EQUATION 17-1:
PWM Period = [(PR2) + 1] • 4 • TOSC •
(TMR2 Prescale Value)
Note:
Clearing the CCP4CON or CCP5CON
register will force the RG3 or RG4 output
latch (depending on device configuration)
to the default low level. This is not the
PORTG I/O data latch.
PWM frequency is defined as 1/[PWM period].
When TMR2 (TMR4) is equal to PR2 (PR4), the
following three events occur on the next increment
cycle:
Figure 17-4 shows a simplified block diagram of the
CCP module in PWM mode.
For a step-by-step procedure on how to set up a CCP
module for PWM operation, see Section 17.4.3
“Setup for PWM Operation”.
• TMR2 (TMR4) is cleared
• The CCPx pin is set (exception: if PWM duty
cycle = 0%, the CCPx pin will not be set)
• The PWM duty cycle is latched from CCPRxL into
CCPRxH
FIGURE 17-4:
SIMPLIFIED PWM BLOCK
DIAGRAM
Note:
The Timer2 and Timer 4 postscalers (see
Section 14.0 “Timer2 Module” and
Section 16.0 “Timer4 Module”) are not
used in the determination of the PWM
frequency. The postscaler could be used
to have a servo update rate at a different
frequency than the PWM output.
CCPxCON<5:4>
Duty Cycle Registers
CCPRxL
CCPRxH (Slave)
Comparator
CCPx Output
17.4.2
PWM DUTY CYCLE
Q
R
S
The PWM duty cycle is specified by writing to the
CCPRxL register and to the CCPxCON<5:4> bits. Up
to 10-bit resolution is available. The CCPRxL contains
the eight MSbs and the CCPxCON<5:4> contains the
two LSbs. This 10-bit value is represented by
CCPRxL:CCPxCON<5:4>. The following equation is
used to calculate the PWM duty cycle in time:
(Note 1)
TMR2 (TMR4)
Corresponding
TRIS bit
Comparator
PR2 (PR4)
Clear Timer,
CCPx pin and
latch D.C.
EQUATION 17-2:
Note 1:The 8-bit TMR2 or TMR4 value is concatenated with the
2-bit internal Q clock, or 2 bits of the prescaler, to cre-
ate the 10-bit time base.
PWM Duty Cycle = (CCPRxL:CCPxCON<5:4>) •
TOSC • (TMR2 Prescale Value)
A PWM output (Figure 17-5) has a time base (period)
and a time that the output stays high (duty cycle).
The frequency of the PWM is the inverse of the
period (1/period).
CCPRxL and CCPxCON<5:4> can be written to at any
time, but the duty cycle value is not latched into
CCPRxH until after a match between PR2 (PR4) and
TMR2 (TMR4) occurs (i.e., the period is complete). In
PWM mode, CCPRxH is a read-only register.
FIGURE 17-5:
PWM OUTPUT
Period
Duty Cycle
TMR2 (TMR4) = PR2 (PR4)
TMR2 (TMR4) = Duty Cycle
TMR2 (TMR4) = PR2 (TMR4)
DS39646C-page 184
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
The CCPRxH register and a 2-bit internal latch are
used to double-buffer the PWM duty cycle. This
double-buffering is essential for glitchless PWM
operation.
17.4.3
SETUP FOR PWM OPERATION
The following steps should be taken when configuring
the CCP module for PWM operation:
1. Set the PWM period by writing to the PR2 (PR4)
register.
When the CCPRxH and 2-bit latch match TMR2
(TMR4), concatenated with an internal 2-bit Q clock or
2 bits of the TMR2 (TMR4) prescaler, the CCPx pin is
cleared.
2. Set the PWM duty cycle by writing to the
CCPRxL register and CCPxCON<5:4> bits.
3. Make the CCPx pin an output by clearing the
appropriate TRIS bit.
The maximum PWM resolution (bits) for a given PWM
frequency is given by the equation:
4. Set the TMR2 (TMR4) prescale value, then
enable Timer2 (Timer4) by writing to T2CON
(T4CON).
EQUATION 17-3:
FOSC
⎛
⎞
⎠
5. Configure the CCPx module for PWM operation.
log ---------------
⎝
FPWM
PWM Resolution (max)
= ----------------------------- b i t s
log(2)
Note:
If the PWM duty cycle value is longer than
the PWM period, the CCPx pin will not be
cleared.
TABLE 17-3: EXAMPLE PWM FREQUENCIES AND RESOLUTIONS AT 40 MHz
PWM Frequency
2.44 kHz
9.77 kHz
39.06 kHz 156.25 kHz 312.50 kHz 416.67 kHz
Timer Prescaler (1, 4, 16)
PR2 Value
16
FFh
10
4
1
1
3Fh
8
1
1Fh
7
1
FFh
10
FFh
10
17h
6.58
Maximum Resolution (bits)
© 2008 Microchip Technology Inc.
DS39646C-page 185
PIC18F8722 FAMILY
TABLE 17-4: REGISTERS ASSOCIATED WITH PWM, TIMER2 AND TIMER4
Reset
Values
on page
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
INTCON
RCON
PIR1
GIE/GIEH PEIE/GIEL TMR0IE
INT0IE
RI
RBIE
TO
TMR0IF
PD
INT0IF
POR
RBIF
BOR
57
56
60
60
60
60
60
60
58
58
58
61
61
61
59
59
59
59
61
61
IPEN
PSPIF
PSPIE
PSPIP
SSP2IF
SSP2IE
SSP2IP
SBOREN
ADIF
—
RC1IF
RC1IE
RC1IP
RC2IF
RC2IE
RC2IP
TX1IF
TX1IE
TX1IP
TX2IF
TX2IE
TX2IP
SSP1IF
SSP1IE
SSP1IP
TMR4IF
TMR4IE
TMR4IP
CCP1IF TMR2IF TMR1IF
CCP1IE TMR2IE TMR1IE
CCP1IP TMR2IP TMR1IP
CCP5IF CCP4IF CCP3IF
CCP5IE CCP4IE CCP3IE
CCP5IP CCP4IP CCP3IP
PIE1
ADIE
IPR1
ADIP
PIR3
BCL2IF
BCL2IF
BCL2IP
PIE3
IPR3
TMR2
Timer2 Register
PR2
Timer2 Period Register
T2CON
TMR4
—
T2OUTPS3 T2OUTPS2 T2OUTPS1 T2OUTPS0 TMR2ON T2CKPS1 T2CKPS0
Timer4 Register
PR4
Timer4 Period Register
T4CON
CCPR1L
CCPR1H
CCPR2L
CCPR2H
CCP4CON
CCP5CON
—
T4OUTPS3 T4OUTPS2 T4OUTPS1 T4OUTPS0 TMR4ON T4CKPS1 T4CKPS0
Enhanced Capture/Compare/PWM Register 1 Low Byte
Enhanced Capture/Compare/PWM Register 1 High Byte
Enhanced Capture/Compare/PWM Register 2 Low Byte
Enhanced Capture/Compare/PWM Register 2 High Byte
—
—
—
—
DC4B1
DC5B1
DC4B0
DC5B0
CCP4M3 CCP4M2 CCP4M1 CCP4M0
CCP5M3 CCP5M2 CCP5M1 CCP5M0
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by PWM, Timer2 or Timer4.
DS39646C-page 186
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
The control register for the Enhanced CCP modules is
shown in Register 18-1. It differs from the CCPxCON
registers discussed in Section 17.0 “Capture/
Compare/PWM (CCP) Modules” in that the two Most
Significant bits are implemented to control PWM
functionality. In addition to the expanded range of
modes available through the Enhanced CCPxCON
register, the ECCP modules each have two additional
features associated with Enhanced PWM operation
and auto-shutdown features. They are:
18.0 ENHANCED CAPTURE/
COMPARE/PWM (ECCP)
MODULE
In the PIC18F8722 family of devices, ECCP1, ECCP2
and ECCP3 are implemented as a standard CCP
module with Enhanced PWM capabilities. These
include the provision for 2 or 4 output channels, user
selectable polarity, dead-band control and automatic
shutdown and restart. The enhanced features are
discussed in detail in Section 18.4 “Enhanced PWM
Mode”. Capture, Compare and single-output PWM
functions of the ECCP module are the same as
described for the standard CCP module.
• ECCPxDEL (Dead-Band Delay)
• ECCPxAS (Auto-Shutdown Configuration)
REGISTER 18-1: CCPxCON: ENHANCED CCPx CONTROL REGISTER (ECCP1, ECCP2, ECCP3)
R/W-0
PxM1
R/W-0
PxM0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
DCxB1
DCxB0
CCPxM3
CCPxM2
CCPxM1
CCPxM0
bit 7
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7-6
bit 5-4
bit 3-0
PxM1:PxM0: Enhanced PWM Output Configuration bits
If CCPxM<3:2> = 00, 01, 10:
xx= PxA assigned as Capture/Compare input/output; PxB, PxC, PxD assigned as port pins
If CCPxM<3:2> = 11:
00= Single output: PxA modulated; PxB, PxC, PxD assigned as port pins
01= Full-bridge output forward: P1D modulated; P1A active; P1B, P1C inactive
10= Half-bridge output: P1A, P1B modulated with dead-band control; P1C, P1D assigned as port pins
11= Full-bridge output reverse: P1B modulated; P1C active; P1A, P1D inactive
DCxB<1:0>: PWM Duty Cycle bit 1 and bit 0
Capture mode:
Unused.
Compare mode:
Unused.
PWM mode:
These bits are the two LSbs of the 10-bit PWM duty cycle. The eight MSbs of the duty cycle are found
in CCPRxL.
CCPxM3:CCPxM0: Enhanced CCP Mode Select bits
0000= Capture/Compare/PWM off (resets ECCPx module)
0001= Reserved
0010= Compare mode: toggle output on match
0011= Capture mode
0100= Capture mode: every falling edge
0101= Capture mode: every rising edge
0110= Capture mode: every 4th rising edge
0111= Capture mode: every 16th rising edge
1000= Compare mode: initialize ECCPx pin low; set output on compare match (set CCPxIF)
1001= Compare mode: initialize ECCPx pin high; clear output on compare match (set CCPxIF)
1010= Compare mode: generate software interrupt only; ECCPx pin reverts to I/O state
1011= Compare mode: trigger special event (ECCP resets TMR1 or TMR3, sets CCPxIF bit; ECCP2
trigger starts A/D conversion if A/D module is enabled)
1100= PWM mode: PxA, PxC active-high; PxB, PxD active-high
1101= PWM mode: PxA, PxC active-high; PxB, PxD active-low
1110= PWM mode: PxA, PxC active-low; PxB, PxD active-high
1111= PWM mode: PxA, PxC active-low; PxB, PxD active-low
© 2008 Microchip Technology Inc.
DS39646C-page 187
PIC18F8722 FAMILY
18.1.2
ECCP MODULE OUTPUTS,
18.1 ECCP Outputs and Configuration
PROGRAM MEMORY MODES AND
EMB ADDRESS BUS WIDTH
Each of the Enhanced CCP modules may have up to
four PWM outputs, depending on the selected
operating mode. These outputs, designated PxA
through PxD, are multiplexed with various I/O pins.
Some ECCPx pin assignments are constant, while
others change based on device configuration. For
those pins that do change, the controlling bits are:
For PIC18F8527/8622/8627/8722 devices, the
program memory mode of the device (Section 7.2
“Address and Data Width” and Section 7.4 “Pro-
gram Memory Modes and the External Memory
Bus”) impacts both pin multiplexing and the operation
of the module.
• CCP2MX Configuration bit (CONFIG3H<0>)
• ECCPMX Configuration bit (CONFIG3H<1>)
• Program Memory mode (set by Configuration bits,
CONFIG3L<1:0>)
The ECCP2 input/output (ECCP2/P2A) can be multi-
plexed to one of three pins. By default, this is RC1 for
all devices; in this case, the default is in effect when
CCP2MX is set and the device is operating in Micro-
controller mode. With PIC18F8527/8622/8627/8722
devices, three other options exist. When CCP2MX is
not set (= 0) and the device is in Microcontroller mode,
ECCP2/P2A is multiplexed to RE7; in all other program
memory modes, it is multiplexed to RB3.
The pin assignments for the Enhanced CCP modules
are summarized in Table 18-1, Table 18-2 and
Table 18-3. To configure the I/O pins as PWM outputs,
the proper PWM mode must be selected by setting the
PxMx and CCPxMx bits (CCPxCON<7:6> and <3:0>,
respectively). The appropriate TRIS direction bits for
the corresponding port pins must also be set as
outputs.
Another option is for ECCPMX to be set while the
device is operating in one of the three other program
memory modes. In this case, ECCP1 and ECCP3 oper-
ate as compatible (i.e., single output) CCP modules.
The pins used by their other outputs (PxB through PxD)
are available for other multiplexed functions. ECCP2
continues to operate as an Enhanced CCP module
regardless of the program memory mode.
18.1.1
USE OF CCP4 AND CCP5 WITH
ECCP1 AND ECCP3
Only the ECCP2 module has four dedicated output pins
available for use. Assuming that the I/O ports or other
multiplexed functions on those pins are not needed,
they may be used whenever needed without interfering
with any other CCP module.
The final option is that the ABW<1:0> Configuration
bits can be used to select 8, 12, 16 or 20-bit EMB
addressing. Pins not assigned to EMB address pins are
available for peripheral or port functions.
ECCP1 and ECCP3, on the other hand, only have
three dedicated output pins: ECCPx/P3A, PxB and
PxC. Whenever these modules are configured for
Quad PWM mode, the pin used for CCP4 or CCP5
takes priority over the D output pins for ECCP3 and
ECCP1, respectively.
DS39646C-page 188
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
TABLE 18-1: PIN CONFIGURATIONS FOR ECCP1
CCP1CON
Configuration
ECCP Mode
RC2
RE6
RE5
RG4
RH7
RH6
PIC18F6527/6622/6627/6722 Devices:
Compatible CCP
Dual PWM
00xx 11xx
10xx 11xx
x1xx 11xx
ECCP1
P1A
RE6
P1B
P1B
RE5
RE5
P1C
RG4/CCP5
RG4/CCP5
N/A
N/A
N/A
N/A
N/A
N/A
(1)
Quad PWM
P1A
CCP5/P1D
PIC18F8527/8622/8627/8722 Devices, ECCPMX = 1, Microcontroller mode:
Compatible CCP
Dual PWM
00xx 11xx
10xx 11xx
x1xx 11xx
ECCP1
P1A
RE6
P1B
P1B
RE5
RE5
P1C
RG4/CCP5
RG4/CCP5
RH7/AN15
RH7/AN15
RH7/AN15
RH6/AN14
RH6/AN14
RH6/AN14
(1)
Quad PWM
P1A
CCP5/P1D
PIC18F8527/8622/8627/8722 Devices, ECCPMX = 0, Microcontroller mode:
Compatible CCP
Dual PWM
00xx 11xx
10xx 11xx
x1xx 11xx
ECCP1
P1A
RE6
RE6
RE6
RE5
RE5
RE5
RG4/CCP5
RG4/CCP5
RH7/AN15
P1B
RH6/AN14
RH6/AN14
P1C
(1)
Quad PWM
P1A
CCP5/P1D
P1B
PIC18F8527/8622/8627/8722 Devices, ECCPMX = 1, all other Program Memory modes:
(2)
(2)
Compatible CCP
Dual PWM
00xx 11xx
10xx 11xx
x1xx 11xx
ECCP1
P1A
AD14
AD13
AD13
RG4/CCP5
RH7/AN15
RH7/AN15
RH7/AN15
RH6/AN14
RH6/AN14
RH6/AN14
(2)
(2)
(2)
P1B/AD14
P1B/AD14
RG4/CCP5
(2)
(1)
Quad PWM
P1A
P1C/AD13
CCP5/P1D
PIC18F8527/8622/8627/8722 Devices, ECCPMX = 0, all other Program Memory modes:
(2)
(2)
(2)
(2)
(2)
(2)
Compatible CCP
Dual PWM
ECCP1
P1A
AD14
AD14
AD14
AD13
AD13
AD13
RG4/CCP5
RH7/AN15
P1B
RH6/AN14
RH6/AN14
P1C
00xx 11xx
10xx 11xx
x1xx 11xx
RG4/CCP5
(1)
Quad PWM
P1A
CCP5/P1D
P1B
Legend: x= Don’t care, N/A = Not available. Shaded cells indicate pin assignments not used by ECCP1 in a given mode.
Note 1: With ECCP1 in Quad PWM mode, the CCP5 module’s output overrides P1D.
2: The EMB address bus width will determine whether the pin will perform an EMB or port/peripheral function.
© 2008 Microchip Technology Inc.
DS39646C-page 189
PIC18F8722 FAMILY
TABLE 18-2: PIN CONFIGURATIONS FOR ECCP2
CCP2CON
Configuration
ECCP Mode
RB3
RC1
RE7
RE2
RE1
RE0
PIC18F6527/6622/6627/6722 Devices, CCP2MX = 1:
Compatible CCP
Dual PWM
00xx 11xx
10xx 11xx
x1xx 11xx
RB3/INT3
RB3/INT3
RB3/INT3
ECCP2
P2A
RE7
RE7
RE7
RE2
P2B
P2B
RE1
RE1
P2C
RE0
RE0
P2D
Quad PWM
P2A
PIC18F6527/6622/6627/6722 Devices CCP2MX = 0:
Compatible CCP
Dual PWM
00xx 11xx
10xx 11xx
x1xx 11xx
RB3/INT3
RB3/INT3
RB3/INT3
RC1/T1OSI
RC1/T1OSI
RC1/T1OSI
ECCP2
P2A
RE2
P2B
P2B
RE1
RE1
P2C
RE0
RE0
P2D
Quad PWM
P2A
PIC18F8527/8622/8627/8722 Devices, CCP2MX = 1, Microcontroller mode:
RB3/INT3
RB3/INT3
RB3/INT3
Compatible CCP
Dual PWM
00xx 11xx
10xx 11xx
x1xx 11xx
ECCP2
P2A
RE7
RE7
RE7
RE2
P2B
P2B
RE1
RE1
P2C
RE0
RE0
P2D
Quad PWM
P2A
PIC18F8527/8622/8627/8722 Devices, CCP2MX = 0, Microcontroller mode:
RB3/INT3
RB3/INT3
RB3/INT3
RC1/T1OSI
RC1/T1OSI
RC1/T1OSI
ECCP2
P2A
RE2
P2B
P2B
RE1
RE1
P2C
RE0
RE0
P2D
00xx 11xx
10xx 11xx
x1xx 11xx
Compatible CCP
Dual PWM
Quad PWM
P2A
PIC18F8527/8622/8627/8722 Devices, CCP2MX = 1, all other Program Memory modes:
(1)
(1)
(1)
(1)
(1)
(1)
RB3/INT3
RB3/INT3
RB3/INT3
ECCP2
P2A
AD15
AD15
AD15
AD10
AD9
AD9
AD8
AD8
00xx 11xx
10xx 11xx
x1xx 11xx
Compatible CCP
Dual PWM
(1)
(1)
(1)
(1)
AD10/P2B
AD10/P2B
(1)
(1)
(1)
Quad PWM
P2A
AD9/P2C
P2D/AD8
PIC18F8527/8622/8627/8722 Devices, CCP2MX = 0, all other Program Memory modes:
(1)
(1)
(1)
(1)
(1)
(1)
ECCP2
P2A
RC1/T1OSI
RC1/T1OSI
RC1/T1OSI
AD15
AD15
AD15
AD10
AD9
AD9
AD8
00xx 11xx
10xx 11xx
x1xx 11xx
Compatible CCP
Dual PWM
(1)
(1)
(1)
(1)
AD10/P2B
AD10/P2B
AD8
(1)
Quad PWM
P2A
AD9/P2C
P2D/AD8
Legend: x= Don’t care. Shaded cells indicate pin assignments not used by ECCP2 in a given mode.
Note 1: The EMB address bus width will determine whether the pin will perform an EMB or port/peripheral function.
DS39646C-page 190
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
TABLE 18-3: PIN CONFIGURATIONS FOR ECCP3
CCP3CON
Configuration
ECCP Mode
RG0
RE4
RE3
RG3
RH5
RH4
PIC18F6527/6622/6627/6722 Devices:
Compatible CCP
Dual PWM
00xx 11xx
10xx 11xx
x1xx 11xx
ECCP3
P3A
RE4
P3B
P3B
RE3
RE3
P3C
RG3/CCP4
RG3/CCP4
N/A
N/A
N/A
N/A
N/A
N/A
(1)
Quad PWM
P3A
CCP4/P3D
PIC18F8527/8622/8627/8722 Devices, ECCPMX = 1, Microcontroller mode:
Compatible CCP
Dual PWM
00xx 11xx
10xx 11xx
x1xx 11xx
ECCP3
P3A
RE4
P3B
P3B
RE3
RE3
P3C
RG3/CCP4
RG3/CCP4
RH5/AN13
RH5/AN13
RH5/AN13
RH4/AN12
RH4/AN12
RH4/AN12
(1)
Quad PWM
P3A
CCP4/P3D
PIC18F8527/8622/8627/8722 Devices, ECCPMX = 0, Microcontroller mode:
Compatible CCP
Dual PWM
00xx 11xx
10xx 11xx
x1xx 11xx
ECCP3
P3A
RE4
RE4
RE4
RE3
RE3
RE3
RG3/CCP4
RG3/CCP4
RH5/AN13
P3B
RH4/AN12
RH4/AN12
P3C
(1)
Quad PWM
P3A
CCP4/P3D
P3B
PIC18F8527/8622/8627/8722 Devices, ECCPMX = 1, all other Program Memory modes:
(2)
(2)
Compatible CCP
Dual PWM
00xx 11xx
10xx 11xx
x1xx 11xx
ECCP3
P3A
AD12
AD10
AD10
RG3/CCP4
RG3/CCP4
RH5/AN13
RH5/AN13
RH5/AN13
RH4/AN12
RH4/AN12
RH4/AN12
(2)
(2)
(2)
AD12/P3B
AD12/P3B
(1)
(1)
Quad PWM
P3A
P3C/AD10
CCP4/P3D
PIC18F8527/8622/8627/8722 Devices, ECCPMX = 0, all other Program Memory modes:
(2)
(2)
(2)
(2)
(2)
(2)
Compatible CCP
Dual PWM
00xx 11xx
10xx 11xx
x1xx 11xx
ECCP3
P3A
AD12
AD12
AD12
AD10
AD10
AD10
RG3/CCP4
RG3/CCP4
RH5/AN13
P3B
RH4/AN12
RH4/AN12
P3C
(1)
Quad PWM
P3A
CCP4/P3D
P3B
Legend: x= Don’t care, N/A = Not available. Shaded cells indicate pin assignments not used by ECCP3 in a given mode.
Note 1: With ECCP3 in Quad PWM mode, the CCP4 module’s output overrides P3D.
2: The EMB address bus width will determine whether the pin will perform an EMB or port/peripheral function.
© 2008 Microchip Technology Inc.
DS39646C-page 191
PIC18F8722 FAMILY
For the sake of clarity, Enhanced PWM mode operation
is described generically throughout this section with
respect to ECCP1 and TMR2 modules. Control register
names are presented in terms of ECCP1. All three
Enhanced modules, as well as the two timer resources,
can be used interchangeably and function identically.
TMR2 or TMR4 can be selected for PWM operation by
selecting the proper bits in T3CON.
18.1.3
ECCP MODULES AND TIMER
RESOURCES
Like the standard CCP modules, the ECCP modules
can utilize Timers 1, 2, 3 or 4, depending on the mode
selected. Timer1 and Timer3 are available for modules
in Capture or Compare modes, while Timer2 and
Timer4 are available for modules in PWM mode.
Additional details on timer resources are provided in
Figure 18-1 shows a simplified block diagram of PWM
operation. All control registers are double-buffered and
are loaded at the beginning of a new PWM cycle (the
period boundary when Timer2 resets) in order to
prevent glitches on any of the outputs. The exception is
the PWM Dead-Band Delay register, ECCP1DEL,
which is loaded at either the duty cycle boundary or the
boundary period (whichever comes first). Because of
the buffering, the module waits until the assigned timer
resets instead of starting immediately. This means that
Enhanced PWM waveforms do not exactly match the
standard PWM waveforms, but are instead offset by
one full instruction cycle (4 TOSC).
Section 17.1.1
Resources”.
“CCP
Modules
and
Timer
18.2 Capture and Compare Modes
With the exception of the Special Event Trigger
discussed below, the Capture and Compare modes of
the ECCP modules are identical in operation to that of
CCP4. These are discussed in detail in Section 17.2
“Capture Mode” and Section 17.3 “Compare
Mode”.
18.2.1
SPECIAL EVENT TRIGGER
The Special Event Trigger output of ECCPx resets the
TMR1 or TMR3 register pair, depending on which timer
resource is currently selected. This allows the CCPRx
registers to effectively be 16-bit programmable period
registers for Timer1 or Timer3.
As before, the user must manually configure the
appropriate TRIS bits for output.
18.4.1
PWM PERIOD
The PWM period is specified by writing to the PR2
register. The PWM period can be calculated using the
following equation:
18.3 Standard PWM Mode
When configured in Single Output mode, the ECCP
module functions identically to the standard CCP
module in PWM mode as described in Section 17.4
“PWM Mode”. This is also sometimes referred to as
“Compatible CCP” mode as in Tables 18-1
through 18-3.
EQUATION 18-1:
PWM Period = [(PR2) + 1] • 4 • TOSC •
(TMR2 Prescale Value)
PWM frequency is defined as 1/[PWM period]. When
TMR2 is equal to PR2, the following three events occur
on the next increment cycle:
Note:
When setting up single output PWM
operations, users are free to use either of
the processes described in Section 17.4.3
“Setup for PWM Operation” or
Section 18.4.9 “Setup for PWM Opera-
tion”. The latter is more generic, but will
work for either single or multi-output PWM.
• TMR2 is cleared
• The ECCP1 pin is set (if PWM duty cycle = 0%,
the ECCP1 pin will not be set)
• The PWM duty cycle is copied from CCPR1L into
CCPR1H
Note:
The Timer2 postscaler (see Section 14.0
“Timer2 Module”) is not used in the
determination of the PWM frequency. The
postscaler could be used to have a servo
update rate at a different frequency than
the PWM output.
18.4 Enhanced PWM Mode
The Enhanced PWM mode provides additional PWM
output options for a broader range of control applica-
tions. The module is a backward compatible version of
the standard CCP module and offers up to four outputs,
designated PxA through PxD. Users are also able to
select the polarity of the signal (either active-high or
active-low). The module’s output mode and polarity
are configured by setting the PxM<1:0> and
CCPxM<3:0> bits of the CCPxCON register
(CCPxCON<7:6> and CCPxCON<3:0>, respectively).
DS39646C-page 192
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
FIGURE 18-1:
SIMPLIFIED BLOCK DIAGRAM OF THE ENHANCED PWM MODULE
CCP1CON<5:4>
P1M1<1:0>
CCP1M<3:0>
4
Duty Cycle Registers
2
CCPR1L
ECCP1/P1A
P1B
ECCP1/P1A
P1B
TRISx<x>
TRISx<x>
TRISx<x>
TRISx<x>
CCPR1H (Slave)
Comparator
Output
Controller
R
Q
P1C
P1C
P1D
(Note 1)
TMR2
S
P1D
Comparator
PR2
Clear Timer,
set ECCP1 pin and
latch D.C.
ECCP1DEL
Note: The 8-bit TMR2 register is concatenated with the 2-bit internal Q clock, or 2 bits of the prescaler, to create the 10-bit time base.
The CCPR1H register and a 2-bit internal latch are
used to double-buffer the PWM duty cycle. This
double-buffering is essential for glitchless PWM opera-
tion. When the CCPR1H and 2-bit latch match TMR2,
concatenated with an internal 2-bit Q clock or two bits
of the TMR2 prescaler, the ECCP1 pin is cleared. The
maximum PWM resolution (bits) for a given PWM
frequency is given by the equation:
18.4.2
PWM DUTY CYCLE
The PWM duty cycle is specified by writing to the
CCPR1L register and to the CCP1CON<5:4> bits. Up
to 10-bit resolution is available. The CCPR1L contains
the eight MSbs and the CCP1CON<5:4> contains the
two LSbs. This 10-bit value is represented by
CCPR1L:CCP1CON<5:4>. The PWM duty cycle is
calculated by the equation:
EQUATION 18-3:
EQUATION 18-2:
FOSC
log
PWM Duty Cycle = (CCPR1L:CCP1CON<5:4>) •
TOSC • (TMR2 Prescale Value)
(
)
FPWM
bits
PWM Resolution (max) =
log(2)
CCPR1L and CCP1CON<5:4> can be written to at any
time but the duty cycle value is not copied into
CCPR1H until a match between PR2 and TMR2 occurs
(i.e., the period is complete). In PWM mode, CCPR1H
is a read-only register.
Note:
If the PWM duty cycle value is longer than
the PWM period, the ECCP1 pin will not
be cleared.
TABLE 18-4: EXAMPLE PWM FREQUENCIES AND RESOLUTIONS AT 40 MHz
PWM Frequency
2.44 kHz
9.77 kHz
39.06 kHz 156.25 kHz 312.50 kHz 416.67 kHz
Timer Prescaler (1, 4, 16)
PR2 Value
16
FFh
10
4
1
1
3Fh
8
1
1Fh
7
1
FFh
10
FFh
10
17h
6.58
Maximum Resolution (bits)
© 2008 Microchip Technology Inc.
DS39646C-page 193
PIC18F8722 FAMILY
The Single Output mode is the standard PWM mode
discussed in Section 18.4 “Enhanced PWM Mode”.
The Half-Bridge and Full-Bridge Output modes are
covered in detail in the sections that follow.
18.4.3
PWM OUTPUT CONFIGURATIONS
The P1M1:P1M0 bits in the CCP1CON register allow
one of four configurations:
• Single Output
• Half-Bridge Output
• Full-Bridge Output, Forward mode
• Full-Bridge Output, Reverse mode
The general relationship of the outputs in all
configurations is summarized in Figure 18-2.
FIGURE 18-2:
PWM OUTPUT RELATIONSHIPS (ACTIVE-HIGH STATE)
0
PR2 + 1
Duty
Cycle
SIGNAL
CCP1CON<7:6>
Period
P1A Modulated
P1A Modulated
P1B Modulated
P1A Active
(Single Output)
(Half-Bridge)
00
10
(1)
(1)
Delay
Delay
P1B Inactive
P1C Inactive
P1D Modulated
P1A Inactive
P1B Modulated
P1C Active
(Full-Bridge,
Forward)
01
11
(Full-Bridge,
Reverse)
P1D Inactive
Relationships:
•
•
•
Period = 4 * TOSC * (PR2 + 1) * (TMR2 Prescale Value)
Duty Cycle = TOSC * (CCPR1L<7:0>:CCP1CON<5:4>) * (TMR2 Prescale Value)
Delay = 4 * TOSC * (ECCP1DEL<6:0>)
Note 1: Dead-band delay is programmed using the ECCP1DEL register (Section 18.4.6 “Programmable
Dead-Band Delay”).
DS39646C-page 194
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
FIGURE 18-3:
PWM OUTPUT RELATIONSHIPS (ACTIVE-LOW STATE)
0
PR2 + 1
Duty
Cycle
SIGNAL
CCP1CON<7:6>
Period
P1A Modulated
P1A Modulated
P1B Modulated
P1A Active
(Single Output)
(Half-Bridge)
00
10
(1)
(1)
Delay
Delay
P1B Inactive
P1C Inactive
P1D Modulated
P1A Inactive
P1B Modulated
P1C Active
(Full-Bridge,
Forward)
01
11
(Full-Bridge,
Reverse)
P1D Inactive
Relationships:
•
•
•
Period = 4 * TOSC * (PR2 + 1) * (TMR2 Prescale Value)
Duty Cycle = TOSC * (CCPR1L<7:0>:CCP1CON<5:4>) * (TMR2 Prescale Value)
Delay = 4 * TOSC * (ECCP1DEL<6:0>)
Note 1: Dead-band delay is programmed using the ECCP1DEL register (Section 18.4.6 “Programmable
Dead-Band Delay”).
© 2008 Microchip Technology Inc.
DS39646C-page 195
PIC18F8722 FAMILY
The P1A and P1B outputs are multiplexed with the
PORTC<2> and PORTE<6> data latches. Alternatively,
P1B can be assigned to PORTH<7> by programming
the ECCPMX Configuration bit to ‘0’. See Table 18-1,
Table 18-2 and Table 18-3 for more information. The
associated TRIS bit must be cleared to configure P1A
and P1B as outputs.
18.4.4
HALF-BRIDGE MODE
In the Half-Bridge Output mode, two pins are used as
outputs to drive push-pull loads. The PWM output sig-
nal is output on the P1A pin, while the complementary
PWM output signal is output on the P1B pin
(Figure 18-4). This mode can be used for half-bridge
applications, as shown in Figure 18-5, or for full-bridge
applications, where four power switches are being
modulated with two PWM signals.
FIGURE 18-4:
HALF-BRIDGE PWM
OUTPUT
In Half-Bridge Output mode, the programmable
dead-band delay can be used to prevent shoot-through
current in half-bridge power devices. The value of bits,
P1DC<6:0> sets the number of instruction cycles
before the output is driven active. If the value is greater
than the duty cycle, the corresponding output remains
inactive during the entire cycle. See Section 18.4.6
“Programmable Dead-Band Delay” for more details
on dead-band delay operations.
Period
Period
Duty Cycle
(2)
(2)
P1A
td
td
P1B
(1)
(1)
(1)
td = Dead Band Delay
Note 1: At this time, the TMR2 register is equal to the
PR2 register.
2: Output signals are shown as active-high.
FIGURE 18-5:
EXAMPLES OF HALF-BRIDGE OUTPUT MODE APPLICATIONS
Standard Half-Bridge Circuit (“Push-Pull”)
V+
PIC18F6X27/6X22/8X27/8X22
FET
Driver
+
V
-
P1A
Load
FET
Driver
+
V
-
P1B
V-
Half-Bridge Output Driving a Full-Bridge Circuit
V+
PIC18F6X27/6X22/8X27/8X22
FET
Driver
FET
Driver
P1A
Load
FET
FET
Driver
Driver
P1B
V-
DS39646C-page 196
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
P1A, P1B, P1C and P1D outputs are multiplexed with
the PORTC<2>, PORTE<6:5> and PORTG<4> data
latches. Alternatively, P1B and P1C can be assigned to
PORTH<7> and PORTH<6>, respectively, by program-
ming the ECCPMX Configuration bit to ‘0’. See
Table 18-1, Table 18-2 and Table 18-3 for more infor-
mation. The associated bits must be cleared to make
the P1A, P1B, P1C and P1D pins outputs.
18.4.5
FULL-BRIDGE MODE
In Full-Bridge Output mode, four pins are used as
outputs; however, only two outputs are active at a time.
In the Forward mode, pin P1A is continuously active
and pin P1D is modulated. In the Reverse mode, pin
P1C is continuously active and pin P1B is modulated.
These are illustrated in Figure 18-6.
FIGURE 18-6:
FULL-BRIDGE PWM OUTPUT
Forward Mode
Period
(2)
P1A
Duty Cycle
(2)
(2)
P1B
P1C
(2)
P1D
(1)
(1)
Reverse Mode
Period
Duty Cycle
(2)
P1A
(2)
P1B
(2)
P1C
(2)
P1D
(1)
(1)
Note 1: At this time, the TMR2 register is equal to the PR2 register.
Note 2: Output signal is shown as active-high.
© 2008 Microchip Technology Inc.
DS39646C-page 197
PIC18F8722 FAMILY
FIGURE 18-7:
EXAMPLE OF FULL-BRIDGE APPLICATION
V+
PIC18F6X27/6X22/8X27/8X22
QC
QA
FET
Driver
FET
Driver
P1A
Load
P1B
FET
Driver
FET
Driver
P1C
P1D
QD
QB
V-
Figure 18-9 shows an example where the PWM direc-
tion changes from forward to reverse at a near 100%
duty cycle. At time, t1, the outputs P1A and P1D
become inactive, while output P1C becomes active. In
this example, since the turn-off time of the power
devices is longer than the turn-on time, a shoot-through
current may flow through power devices QC and QD
(see Figure 18-7) for the duration of ‘t’. The same
phenomenon will occur to power devices QA and QB
for PWM direction change from reverse to forward.
18.4.5.1
Direction Change in Full-Bridge Mode
In the Full-Bridge Output mode, the P1M1 bit in the
CCP1CON register allows users to control the forward/
reverse direction. When the application firmware
changes this direction control bit, the module will
assume the new direction on the next PWM cycle.
Just before the end of the current PWM period, the
modulated outputs (P1B and P1D) are placed in their
inactive state, while the unmodulated outputs (P1A and
P1C) are switched to drive in the opposite direction.
This occurs in a time interval of (4 TOSC * (Timer2
Prescale Value)) before the next PWM period begins.
The Timer2 prescaler will be either 1, 4 or 16, depend-
ing on the value of the T2CKPSx bit (T2CON<1:0>).
During the interval from the switch of the unmodulated
outputs to the beginning of the next period, the
modulated outputs (P1B and P1D) remain inactive.
This relationship is shown in Figure 18-8.
If changing PWM direction at high duty cycle is required
for an application, one of the following requirements
must be met:
1. Reduce PWM for
changing directions.
a PWM period before
2. Use switch drivers that can drive the switches off
faster than they can drive them on.
Other options to prevent shoot-through current may
exist.
Note that in the Full-Bridge Output mode, the ECCP1
module does not provide any dead-band delay. In gen-
eral, since only one output is modulated at all times,
dead-band delay is not required. However, there is a
situation where a dead-band delay might be required.
This situation occurs when both of the following
conditions are true:
1. The direction of the PWM output changes when
the duty cycle of the output is at or near 100%.
2. The turn-off time of the power switch, including
the power device and driver circuit, is greater
than the turn-on time.
DS39646C-page 198
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
FIGURE 18-8:
PWM DIRECTION CHANGE
(1)
Period
Period
SIGNAL
P1A (Active-High)
P1B (Active-High)
DC
P1C (Active-High)
P1D (Active-High)
(Note 2)
DC
Note 1: The direction bit in the ECCP1 Control register (CCP1CON<7>) is written any time during the PWM cycle.
2: When changing directions, the P1A and P1C signals switch before the end of the current PWM cycle at intervals
of 4 TOSC, 16 TOSC or 64 TOSC, depending on the Timer2 prescaler value. The modulated P1B and P1D signals
are inactive at this time.
FIGURE 18-9:
PWM DIRECTION CHANGE AT NEAR 100% DUTY CYCLE(1)
Forward Period
Reverse Period
t1
P1A
P1B
DC
P1C
P1D
DC
(2)
t
ON
External Switch C
External Switch D
(3)
t
OFF
Potential
Shoot-Through
Current
t = t
– t
ON
OFF
Note 1: All signals are shown as active-high.
2:
3:
t
t
is the turn-on delay of power switch QC and its driver.
ON
is the turn-off delay of power switch QD and its driver.
OFF
© 2008 Microchip Technology Inc.
DS39646C-page 199
PIC18F8722 FAMILY
A shutdown event can be caused by either of the two
comparator modules or the FLT0 pin (or any combina-
tion of these three sources). The comparators may be
used to monitor a voltage input proportional to a current
being monitored in the bridge circuit. If the voltage
exceeds a threshold, the comparator switches state and
triggers a shutdown. Alternatively, a digital signal on the
18.4.6
PROGRAMMABLE DEAD-BAND
DELAY
In half-bridge applications where all power switches are
modulated at the PWM frequency at all times, the
power switches normally require more time to turn off
than to turn on. If both the upper and lower power
switches are switched at the same time (one turned on
and the other turned off), both switches may be on for
a short period of time until one switch completely turns
off. During this brief interval, a very high current
(shoot-through current) may flow through both power
switches, shorting the bridge supply. To avoid this
potentially destructive shoot-through current from flow-
ing during switching, turning on either of the power
switches is normally delayed to allow the other switch
to completely turn off.
FLT0 pin can also trigger
a
shutdown. The
auto-shutdown feature can be disabled by not selecting
any auto-shutdown sources. The auto-shutdown
sources to be used are selected using the
ECCP1AS<2:0> bits (ECCP1AS<6:4>).
When a shutdown occurs, the output pins are
asynchronously placed in their shutdown states,
specified by the PSS1AC<1:0> and PSS1BD<1:0> bits
(ECCP1AS<3:0>). Each pin pair (P1A/P1C and P1B/
P1D) may be set to drive high, drive low or be tri-stated
(not driving). The ECCP1ASE bit (ECCP1AS<7>) is
also set to hold the Enhanced PWM outputs in their
shutdown states.
In the Half-Bridge Output mode, a digitally program-
mable dead-band delay is available to avoid
shoot-through current from destroying the bridge
power switches. The delay occurs at the signal transi-
tion from the non-active state to the active state. See
Figure 18-4 for illustration. The lower seven bits of the
ECCP1DEL register (Register 18-2) set the delay
period in terms of microcontroller instruction cycles
(TCY or 4 TOSC).
The ECCP1ASE bit is set by hardware when a shut-
down event occurs. If automatic restarts are not
enabled, the ECCP1ASE bit is cleared by firmware
when the cause of the shutdown clears. If automatic
restarts are enabled, the ECCP1ASE bit is auto-
matically cleared when the cause of the auto-shutdown
has cleared.
18.4.7
ENHANCED PWM
AUTO-SHUTDOWN
If the ECCP1ASE bit is set when a PWM period begins,
the PWM outputs remain in their shutdown state for that
entire PWM period. When the ECCP1ASE bit is cleared,
the PWM outputs will return to normal operation at the
beginning of the next PWM period.
When the ECCP is programmed for any of the
Enhanced PWM modes, the active output pins may be
configured for auto-shutdown. Auto-shutdown immedi-
ately places the Enhanced PWM output pins into a
defined shutdown state when a shutdown event
occurs.
Note:
Writing to the ECCP1ASE bit is disabled
while a shutdown condition is active.
REGISTER 18-2: ECCPxDEL: ENHANCED PWM DEAD-BAND DELAY REGISTER
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
PxRSEN
PxDC6
PxDC5
PxDC4
PxDC3
PxDC2
PxDC1
PxDC0
bit 7
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7
PxRSEN: PWM Restart Enable bit
1= Upon auto-shutdown, the ECCPxASE bit clears automatically once the shutdown event goes
away; the PWM restarts automatically
0= Upon auto-shutdown, the ECCPxASE bit must be cleared in software to restart the PWM
bit 6-0
PxDC<6:0>: PWM Delay Count bits
Delay time, in number of FOSC/4 (4 * TOSC) cycles, between the scheduled and actual time for a PWM
signal to transition to active.
DS39646C-page 200
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
REGISTER 18-3: ECCPxAS: ENHANCED CCP AUTO-SHUTDOWN CONFIGURATION REGISTER
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
ECCPxASE
ECCPxAS2 ECCPxAS1 ECCPxAS0 PSSxAC1
PSSxAC0
PSSxBD1
PSSxBD0
bit 7
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7
ECCPxASE: ECCP Auto-Shutdown Event Status bit
0= ECCP outputs are operating
1= A shutdown event has occurred; ECCP outputs are in shutdown state
bit 6-4
ECCPxAS<2:0>: ECCP Auto-Shutdown Source Select bits
000= Auto-shutdown is disabled
001= Comparator 1 output
010= Comparator 2 output
011= Either Comparator 1 or 2
100= FLT0
101= FLT0 or Comparator 1
110= FLT0 or Comparator 2
111= FLT0 or Comparator 1 or Comparator 2
bit 3-2
bit 1-0
PSSxAC<1:0>: Pins A and C Shutdown State Control bits
00= Drive pins A and C to ‘0’
01= Drive pins A and C to ‘1’
1x= Pins A and C tri-state
PSSxBD<1:0>: Pins B and D Shutdown State Control bits
00= Drive pins B and D to ‘0’
01= Drive pins B and D to ‘1’
1x= Pins B and D tri-state
© 2008 Microchip Technology Inc.
DS39646C-page 201
PIC18F8722 FAMILY
18.4.7.1
Auto-Shutdown and Automatic
Restart
18.4.8
START-UP CONSIDERATIONS
When the ECCP module is used in the PWM mode, the
application hardware must use the proper external
pull-up and/or pull-down resistors on the PWM output
pins. When the microcontroller is released from Reset,
all of the I/O pins are in the high-impedance state. The
external circuits must keep the power switch devices in
the OFF state until the microcontroller drives the I/O
pins with the proper signal levels or activates the PWM
output(s).
The Auto-Shutdown feature can be configured to allow
automatic restarts of the module following a shutdown
event. This is enabled by setting the P1RSEN bit of the
ECCP1DEL register (ECCP1DEL<7>).
In Shutdown mode with P1RSEN = 1 (Figure 18-10),
the ECCP1ASE bit will remain set for as long as the
cause of the shutdown continues. When the shutdown
condition clears, the ECCP1ASE bit is cleared. If
P1RSEN = 0 (Figure 18-11), once a shutdown condi-
tion occurs, the ECCP1ASE bit will remain set until it is
cleared by firmware. Once ECCP1ASE is cleared, the
Enhanced PWM will resume at the beginning of the
next PWM period.
The CCP1M<1:0> bits (CCP1CON<1:0>) allow the
user to choose whether the PWM output signals are
active-high or active-low for each pair of PWM output
pins (P1A/P1C and P1B/P1D). The PWM output
polarities must be selected before the PWM pins are
configured as outputs. Changing the polarity configura-
tion while the PWM pins are configured as outputs is
not recommended since it may result in damage to the
application circuits.
Note:
Writing to the ECCP1ASE bit is disabled
while a shutdown condition is active.
Independent of the P1RSEN bit setting, if the
auto-shutdown source is one of the comparators, the
shutdown condition is a level. The ECCP1ASE bit can-
not be cleared as long as the cause of the shutdown
persists.
The P1A, P1B, P1C and P1D output latches may not be
in the proper states when the PWM module is initialized.
Enabling the PWM pins for output at the same time as
the ECCP1 module may cause damage to the applica-
tion circuit. The ECCP1 module must be enabled in the
proper output mode and complete a full PWM cycle
before configuring the PWM pins as outputs. The com-
pletion of a full PWM cycle is indicated by the TMR2IF
bit being set as the second PWM period begins.
The Auto-Shutdown mode can be forced by writing a ‘1’
to the ECCP1ASE bit.
FIGURE 18-10:
PWM AUTO-SHUTDOWN (P1RSEN = 1, AUTO-RESTART ENABLED)
PWM Period
Shutdown Event
ECCP1ASE bit
PWM Activity
Normal PWM
Start of
PWM Period
Shutdown
Event Occurs Event Clears
Shutdown
PWM
Resumes
FIGURE 18-11:
PWM AUTO-SHUTDOWN (P1RSEN = 0, AUTO-RESTART DISABLED)
PWM Period
Shutdown Event
ECCP1ASE bit
PWM Activity
Normal PWM
ECCP1ASE
Cleared by
Firmware
Start of
PWM Period
Shutdown
Event Occurs Event Clears
Shutdown
PWM
Resumes
DS39646C-page 202
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
18.4.9
SETUP FOR PWM OPERATION
18.4.10 OPERATION IN POWER-MANAGED
MODES
The following steps should be taken when configuring
the ECCP1 module for PWM operation using Timer2:
In Sleep mode, all clock sources are disabled. Timer2 or
Timer4 will not increment and the state of the module will
not change. If the ECCP1 pin is driving a value, it will
continue to drive that value. When the device wakes up,
it will continue from this state. If Two-Speed Start-ups are
enabled, the initial start-up frequency from INTOSC and
the postscaler may not be stable immediately.
1. Configure the PWM pins, P1A and P1B (and
P1C and P1D, if used), as inputs by setting the
corresponding TRIS bits.
2. Set the PWM period by loading the PR2 register.
3. If auto-shutdown is required do the following:
• Disable auto-shutdown (ECCP1AS = 0)
In PRI_IDLE mode, the primary clock will continue to
clock the ECCP1 module without change. In all other
power-managed modes, the selected power-managed
mode clock will clock Timer2 or Timer4. Other
power-managed mode clocks will most likely be
different than the primary clock frequency.
• Configure source (FLT0, Comparator 1 or
Comparator 2)
• Wait for non-shutdown condition
4. Configure the ECCP1 module for the desired
PWM mode and configuration by loading the
CCP1CON register with the appropriate values:
18.4.10.1 Operation with Fail-Safe
Clock Monitor
• Select one of the available output
configurations and direction with the
P1M<1:0> bits.
If the Fail-Safe Clock Monitor is enabled, a clock failure
will force the device into the power-managed RC_RUN
mode and the OSCFIF bit (PIR2<7>) will be set. The
ECCP1 will then be clocked from the internal oscillator
clock source, which may have a different clock
frequency than the primary clock.
• Select the polarities of the PWM output
signals with the CCP1M<3:0> bits.
5. Set the PWM duty cycle by loading the CCPR1L
register and CCP1CON<5:4> bits.
6. For Half-Bridge Output mode, set the
dead-band delay by loading ECCP1DEL<6:0>
with the appropriate value.
See the previous section for additional details.
18.4.11 EFFECTS OF A RESET
7. If auto-shutdown operation is required, load the
ECCP1AS register:
Both Power-on Reset and subsequent Resets will force
all ports to Input mode and the CCP registers to their
Reset states.
• Select the auto-shutdown sources using the
ECCP1AS<2:0> bits.
• Select the shutdown states of the PWM
output pins using the PSS1AC<1:0> and
PSS1BD<1:0> bits.
This forces the Enhanced CCP module to reset to a
state compatible with the standard CCP module.
• Set the ECCP1ASE bit (ECCP1AS<7>).
• Configure the comparators using the CMCON
register.
• Configure the comparator inputs as analog
inputs.
8. If auto-restart operation is required, set the
P1RSEN bit (ECCP1DEL<7>).
9. Configure and start TMR2:
• Clear the TMR2 interrupt flag bit by clearing
the TMR2IF bit (PIR1<1>).
• Set the TMR2 prescale value by loading the
T2CKPS bits (T2CON<1:0>).
• Enable Timer2 by setting the TMR2ON bit
(T2CON<2>).
10. Enable PWM outputs after a new PWM cycle
has started:
• Wait until TMRx overflows (TMRxIF bit is set).
• Enable the ECCP1/P1A, P1B, P1C and/or
P1D pin outputs by clearing the respective
TRIS bits.
• Clear the ECCP1ASE bit (ECCP1AS<7>).
© 2008 Microchip Technology Inc.
DS39646C-page 203
PIC18F8722 FAMILY
TABLE 18-5: REGISTERS ASSOCIATED WITH ECCP MODULES AND TIMER1 TO TIMER4
Reset
Values
on page
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
INTCON
RCON
PIR1
GIE/GIEH PEIE/GIEL TMR0IE
INT0IE
RI
RBIE
TMR0IF
PD
INT0IF
POR
RBIF
BOR
57
58
IPEN
PSPIF
SBOREN
ADIF
—
TO
RC1IF
RC1IE
RC1IP
—
TX1IF
TX1IE
TX1IP
EEIF
SSP1IF
SSP1IE
SSP1IP
BCL1IF
BCL1IE
BCL1IP
TMR4IF
TMR4IE
TMR4IP
TRISB3
TRISC3
TRISE3
TRISG3
TRISH3
CCP1IF TMR2IF TMR1IF
CCP1IE TMR2IE TMR1IE
CCP1IP TMR2IP TMR1IP
HLVDIF TMR3IF CCP2IF
HLVDIE TMR3IE CCP2IE
HLVDIP TMR3IP CCP2IP
CCP5IF CCP4IF CCP3IF
CCP5IE CCP4IE CCP3IE
CCP5IP CCP4IP CCP3IP
TRISB2 TRISB1 TRISB0
TRISC2 TRISC1 TRISC0
TRISE2 TRISE1 TRISE0
TRISG2 TRISG1 TRISG0
TRISH2 TRISH1 TRISH0
60
PIE1
PSPIE
PSPIP
OSCFIF
OSCFIE
OSCFIP
SSP2IF
SSP2IE
SSP2IP
TRISB7
TRISC7
TRISE7
—
ADIE
60
IPR1
ADIP
60
PIR2
CMIF
60
PIE2
CMIE
—
EEIE
60
IPR2
CMIP
—
EEIP
60
PIR3
BCL2IF
BCL2IE
BCL2IP
TRISB6
TRISC6
TRISE6
—
RC2IF
RC2IE
RC2IP
TRISB5
TRISC5
TRISE5
—
TX2IF
TX2IE
TX2IP
TRISB4
TRISC4
TRISE4
TRISG4
TRISH4
60
PIE3
60
IPR3
60
TRISB
TRISC
TRISE
TRISG
60
60
60
60
(2)
TRISH
TRISH7
TRISH6
TRISH5
60
TMR1L
TMR1H
T1CON
TMR2
Timer1 Register Low Byte
Timer1 Register High Byte
58
58
RD16
Timer2 Register
T2OUTPS3 T2OUTPS2 T2OUTPS1 T2OUTPS0 TMR2ON T2CKPS1 T2CKPS0
T1RUN
T1CKPS1 T1CKPS0 T1OSCEN T1SYNC TMR1CS TMR1ON
58
58
T2CON
PR2
—
58
Timer2 Period Register
Timer3 Register Low Byte
Timer3 Register High Byte
58
TMR3L
TMR3H
T3CON
TMR4
59
59
RD16
Timer4 Register
T4OUTPS3 T4OUTPS2 T4OUTPS1 T4OUTPS0 TMR4ON T4CKPS1 T4CKPS0
T3CCP2
T3CKPS1 T3CKPS0
T3CCP1 T3SYNC TMR3CS TMR3ON
59
61
T4CON
PR4
—
61
Timer4 Period Register
61
(1)
CCPRxL
CCPRxH
Enhanced Capture/Compare/PWM Register x Low Byte
Enhanced Capture/Compare/PWM Register x High Byte
59, 61
59, 61
59
(1)
(1)
CCPxCON
PxM1
PxM0
DCxB1
DCxB0
CCPxM3 CCPxM2 CCPxM1 CCPxM0
(1)
ECCPxAS
ECCPxASE ECCPxAS2 ECCPxAS1 ECCPxAS0 PSSxAC1 PSSxAC0 PSSxBD1 PSSxBD0
59, 61
61
(1)
ECCPxDEL
PxRSEN
PxDC6
PxDC5
PxDC4
PxDC3
PxDC2
PxDC1
PxDC0
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used during ECCP operation.
Note 1: Generic term for all of the identical registers of this name for all Enhanced CCP modules, where ‘x’ identifies the
individual module (ECCP1, ECCP2 or ECCP3). Bit assignments and Reset values for all registers of the same
generic name are identical.
2: This register is not implemented on PIC18F6527/6622/6627/6722 devices.
DS39646C-page 204
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
19.3 SPI Mode
19.0 MASTER SYNCHRONOUS
SERIAL PORT (MSSP)
MODULE
The SPI mode allows 8 bits of data to be synchronously
transmitted and received simultaneously. All four
modes of SPI are supported. To accomplish
communication, typically three pins are used:
19.1 Master SSP (MSSP) Module
Overview
• Serial Data Out (SDOx) – RC5/SDO1 or
RD4/SDO2
The Master Synchronous Serial Port (MSSP) module is
a serial interface, useful for communicating with other
peripheral or microcontroller devices. These peripheral
devices may be serial EEPROMs, shift registers,
display drivers, A/D converters, etc. The MSSP module
can operate in one of two modes:
• Serial Data In (SDIx) – RC4/SDI1/SDA1 or
RD5/SDI2/SDA2
• Serial Clock (SCKx) – RC3/SCK1/SCL1 or
RD6/SCK2/SCL2
Additionally, a fourth pin may be used when in a Slave
mode of operation:
• Serial Peripheral Interface (SPI)
• Inter-Integrated Circuit (I2C™)
- Full Master mode
• Slave Select (SSx) – RF7/SS1 or RD7/SS2
Figure 19-1 shows the block diagram of the MSSP
module when operating in SPI mode.
- Slave mode (with general address call)
The I2C interface supports the following modes in
hardware:
FIGURE 19-1:
MSSP BLOCK DIAGRAM
(SPI MODE)
• Master mode
• Multi-Master mode
• Slave mode
Internal
Data Bus
Read
Write
All members of the PIC18F8722 family have two MSSP
modules, designated as MSSP1 and MSSP2. Each
module operates independently of the other.
SSPxBUF reg
SSPxSR reg
Note:
Throughout this section, generic refer-
ences to an MSSP module in any of its
operating modes may be interpreted as
being equally applicable to MSSP1 or
MSSP2. Register names and module I/O
signals use the generic designator ‘x’ to
indicate the use of a numeral to distinguish
a particular module when required. Control
bit names are not individuated.
RC4 or RD5
RC5 or RD4
Shift
Clock
bit 0
RF7 or RD7
Control
Enable
SSx
19.2 Control Registers
Edge
Select
Each MSSP module has three associated control regis-
ters. These include a status register (SSPxSTAT) and
two control registers (SSPxCON1 and SSPxCON2). The
use of these registers and their individual Configuration
bits differ significantly depending on whether the MSSP
module is operated in SPI or I2C mode.
2
Clock Select
SSPM<3:0>
SMP:CKE
2
4
TMR2 Output
(
)
Additional details are provided under the individual
sections.
2
RC3 or RD6
Edge
Select
TOSC
Prescaler
4, 16, 64
Note:
In devices with more than one MSSP
module, it is very important to pay close
attention to SSPCON register names.
SSP1CON1 and SSP1CON2 control
different operational aspects of the same
Data to TXx/RXx in SSPxSR
TRIS bit
Note: Only port I/O names are used in this diagram for
the sake of brevity. Refer to the text for a full list of
multiplexed functions.
module,
while
SSP1CON1
and
SSP2CON1 control the same features for
two different modules.
© 2008 Microchip Technology Inc.
DS39646C-page 205
PIC18F8722 FAMILY
SSPxSR is the shift register used for shifting data in or
out. SSPxBUF is the buffer register to which data
bytes are written to or read from.
19.3.1
REGISTERS
Each MSSP module has four registers for SPI mode
operation. These are:
In receive operations, SSPxSR and SSPxBUF
together create a double-buffered receiver. When
SSPxSR receives a complete byte, it is transferred to
SSPxBUF and the SSPxIF interrupt is set.
• MSSP Control Register 1 (SSPxCON1)
• MSSP Status Register (SSPxSTAT)
• Serial Receive/Transmit Buffer Register
(SSPxBUF)
• MSSP Shift Register (SSPxSR) – Not directly
accessible
During transmission, the SSPxBUF is not
double-buffered. A write to SSPxBUF will write to both
SSPxBUF and SSPxSR.
SSPxCON1 and SSPxSTAT are the control and status
registers in SPI mode operation. The SSPxCON1
register is readable and writable. The lower 6 bits of
the SSPxSTAT are read-only. The upper two bits of the
SSPxSTAT are read/write.
REGISTER 19-1: SSPxSTAT: MSSPx STATUS REGISTER (SPI MODE)
R/W-0
SMP
R/W-0
CKE
R-0
D/A
R-0
P
R-0
S
R-0
R-0
UA
R-0
BF
R/W
bit 7
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7
bit 6
SMP: Sample bit
SPI Master mode:
1= Input data sampled at end of data output time
0= Input data sampled at middle of data output time
SPI Slave mode:
SMP must be cleared when SPI is used in Slave mode.
CKE: SPI Clock Select bit
1= Transmit occurs on transition from active to Idle clock state
0= Transmit occurs on transition from Idle to active clock state
Note:
Polarity of clock state is set by the CKP bit (SSPxCON1<4>).
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
D/A: Data/Address bit
Used in I2C mode only.
P: Stop bit
Used in I2C mode only. This bit is cleared when the MSSP module is disabled, SSPEN is cleared.
S: Start bit
Used in I2C mode only.
R/W: Read/Write Information bit
Used in I2C mode only.
UA: Update Address bit
Used in I2C mode only.
BF: Buffer Full Status bit (Receive mode only)
1= Receive complete, SSPxBUF is full
0= Receive not complete, SSPxBUF is empty
DS39646C-page 206
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
REGISTER 19-2: SSPxCON1: MSSPx CONTROL REGISTER 1 (SPI MODE)
R/W-0
WCOL
R/W-0
SSPOV(1)
R/W-0
SSPEN(2)
R/W-0
CKP
R/W-0
SSPM3(3)
R/W-0
SSPM2(3)
R/W-0
SSPM1(3)
R/W-0
SSPM0(3)
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
-n = Value at POR
bit 7
bit 6
WCOL: Write Collision Detect bit
1= The SSPxBUF register is written while it is still transmitting the previous word
(must be cleared in software)
0= No collision
SSPOV: Receive Overflow Indicator bit(1)
SPI Slave mode:
1= A new byte is received while the SSPxBUF register is still holding the previous data. In case of
overflow, the data in SSPxSR is lost. Overflow can only occur in Slave mode. The user must read
the SSPxBUF, even if only transmitting data, to avoid setting overflow (must be cleared in soft-
ware).
0= No overflow
bit 5
SSPEN: Synchronous Serial Port Enable bit(2)
1= Enables serial port and configures SCKx, SDOx, SDIx and SSx as serial port pins
0= Disables serial port and configures these pins as I/O port pins
bit 4
CKP: Clock Polarity Select bit
1= Idle state for clock is a high level
0= Idle state for clock is a low level
bit 3-0
SSPM<3:0>: Synchronous Serial Port Mode Select bits(3)
0101= SPI Slave mode, clock = SCKx pin, SSx pin control disabled, SSx can be used as I/O pin
0100= SPI Slave mode, clock = SCKx pin, SSx pin control enabled
0011= SPI Master mode, clock = TMR2 output/2
0010= SPI Master mode, clock = FOSC/64
0001= SPI Master mode, clock = FOSC/16
0000= SPI Master mode, clock = FOSC/4
Note 1: In Master mode, the overflow bit is not set since each new reception (and transmission) is initiated by
writing to the SSPxBUF register.
2: When enabled, these pins must be properly configured as input or output.
3: Bit combinations not specifically listed here are either reserved or implemented in I2C™ mode only.
© 2008 Microchip Technology Inc.
DS39646C-page 207
PIC18F8722 FAMILY
before reading the data that was just received. Any
write to the SSPxBUF register during transmis-
sion/reception of data will be ignored and the Write
Collision Detect bit, WCOL (SSPxCON1<7>), will be
set. User software must clear the WCOL bit so that it
can be determined if the following write(s) to the
SSPxBUF register completed successfully.
19.3.2
OPERATION
When initializing the SPI, several options need to be
specified. This is done by programming the appropriate
control bits (SSPxCON1<5:0> and SSPxSTAT<7:6>).
These control bits allow the following to be specified:
• Master mode (SCKx is the clock output)
• Slave mode (SCKx is the clock input)
• Clock Polarity (Idle state of SCKx)
• Data Input Sample Phase (middle or end of data
output time)
• Clock Edge (output data on rising/falling edge of
SCKx)
• Clock Rate (Master mode only)
• Slave Select mode (Slave mode only)
When the application software is expecting to receive
valid data, the SSPxBUF should be read before the
next byte of data to transfer is written to the SSPxBUF.
The Buffer Full bit, BF (SSPxSTAT<0>), indicates when
SSPxBUF has been loaded with the received data
(transmission is complete). When the SSPxBUF is
read, the BF bit is cleared. This data may be irrelevant
if the SPI is only a transmitter. Generally, the MSSP
interrupt is used to determine when the transmis-
sion/reception has completed. If the interrupt method is
not going to be used, then software polling can be done
to ensure that a write collision does not occur.
Example 19-1 shows the loading of the SSPxBUF
(SSPxSR) for data transmission.
Each MSSP module consists of a transmit/receive shift
register (SSPxSR) and a buffer register (SSPxBUF).
The SSPxSR shifts the data in and out of the device,
MSb first. The SSPxBUF holds the data that was
written to the SSPxSR until the received data is ready.
Once the 8 bits of data have been received, that byte is
moved to the SSPxBUF register. Then, the Buffer Full
detect bit, BF (SSPxSTAT<0>) and the interrupt flag bit,
SSPxIF, are set. This double-buffering of the received
data (SSPxBUF) allows the next byte to start reception
The SSPxSR is not directly readable or writable and
can only be accessed by addressing the SSPxBUF
register. Additionally, the SSPxSTAT register indicates
the various status conditions.
EXAMPLE 19-1:
LOADING THE SSP1BUF (SSP1SR) REGISTER
LOOP
BTFSS
BRA
SSP1STAT, BF
LOOP
;Has data been received (transmit complete)?
;No
MOVF
SSP1BUF, W
;WREG reg = contents of SSP1BUF
MOVWF
RXDATA
;Save in user RAM, if data is meaningful
MOVF
MOVWF
TXDATA, W
SSP1BUF
;W reg = contents of TXDATA
;New data to xmit
DS39646C-page 208
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Any serial port function that is not desired may be
overridden by programming the corresponding data
direction (TRIS) register to the opposite value.
19.3.3
ENABLING SPI I/O
To enable the serial port, SSP Enable bit, SSPEN
(SSPxCON1<5>), must be set. To reset or reconfigure
SPI mode, clear the SSPEN bit, reinitialize the
SSPxCON registers and then set the SSPEN bit. This
configures the SDIx, SDOx, SCKx and SSx pins as
serial port pins. For the pins to behave as the serial port
function, some must have their data direction bits (in
the TRIS register) appropriately programmed as
follows:
19.3.4
TYPICAL CONNECTION
Figure 19-2 shows a typical connection between two
microcontrollers. The master controller (Processor 1)
initiates the data transfer by sending the SCKx signal.
Data is shifted out of both shift registers on their pro-
grammed clock edge and latched on the opposite edge
of the clock. Both processors should be programmed to
the same Clock Polarity (CKP), then both controllers
would send and receive data at the same time.
Whether the data is meaningful (or dummy data)
depends on the application software. This leads to
three scenarios for data transmission:
• SDIx is automatically controlled by the
SPI module
• SDOx must have the TRISC<5> or TRISD<4> bit
cleared
• SCKx (Master mode) must have the TRISC<3> or
TRISD<6>bit cleared
• SCKx (Slave mode) must have the TRISC<3> or
TRISD<6> bit set
• Master sends data – Slave sends dummy data
• Master sends data – Slave sends data
• Master sends dummy data – Slave sends data
• SSx must have the TRISF<7> or TRISD<7> bit
set
FIGURE 19-2:
SPI MASTER/SLAVE CONNECTION
SPI Master SSPM<3:0> = 00xxb
SPI Slave SSPM<3:0> = 010xb
SDOx
SDIx
Serial Input Buffer
(SSPxBUF)
Serial Input Buffer
(SSPxBUF)
SDIx
SDOx
Shift Register
(SSPxSR)
Shift Register
(SSPxSR)
LSb
MSb
MSb
LSb
Serial Clock
SCKx
SCKx
PROCESSOR 1
PROCESSOR 2
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shown in Figure 19-3, Figure 19-5 and Figure 19-6,
where the MSB is transmitted first. In Master mode, the
SPI clock rate (bit rate) is user programmable to be one
of the following:
19.3.5
MASTER MODE
The master can initiate the data transfer at any time
because it controls the SCKx. The master determines
when the slave (Processor 1, Figure 19-2) is to
broadcast data by the software protocol.
• FOSC/4 (or TCY)
• FOSC/16 (or 4 • TCY)
• FOSC/64 (or 16 • TCY)
• Timer2 output/2
In Master mode, the data is transmitted/received as
soon as the SSPxBUF register is written to. If the SPI
is only going to receive, the SDOx output could be dis-
abled (programmed as an input). The SSPxSR register
will continue to shift in the signal present on the SDIx
pin at the programmed clock rate. As each byte is
received, it will be loaded into the SSPxBUF register as
if a normal received byte (interrupts and status bits
appropriately set). This could be useful in receiver
applications as a “Line Activity Monitor” mode.
This allows a maximum data rate (at 40 MHz) of
10.00 Mbps.
Figure 19-3 shows the waveforms for Master mode.
When the CKE bit is set, the SDOx data is valid before
there is a clock edge on SCKx. The change of the input
sample is shown based on the state of the SMP bit. The
time when the SSPxBUF is loaded with the received
data is shown.
The clock polarity is selected by appropriately
programming the CKP bit (SSPxCON1<4>). This then,
would give waveforms for SPI communication as
FIGURE 19-3:
SPI MODE WAVEFORM (MASTER MODE)
Write to
SSPxBUF
SCKx
(CKP = 0
CKE = 0)
SCKx
(CKP = 1
CKE = 0)
4 Clock
Modes
SCKx
(CKP = 0
CKE = 1)
SCKx
(CKP = 1
CKE = 1)
bit 6
bit 6
bit 2
bit 2
bit 5
bit 5
bit 4
bit 4
bit 1
bit 1
bit 0
bit 0
SDOx
(CKE = 0)
bit 7
bit 7
bit 3
bit 3
SDOx
(CKE = 1)
SDIx
(SMP = 0)
bit 0
bit 7
Input
Sample
(SMP = 0)
SDIx
(SMP = 1)
bit 0
bit 7
Input
Sample
(SMP = 1)
SSPxIF
Next Q4 Cycle
after Q2↓
SSPxSR to
SSPxBUF
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transmitted byte and becomes a floating output. Exter-
nal pull-up/pull-down resistors may be desirable
depending on the application.
19.3.6
SLAVE MODE
In Slave mode, the data is transmitted and received as
the external clock pulses appear on SCKx. When the
last bit is latched, the SSPxIF interrupt flag bit is set.
Note 1: When the SPI is in Slave mode
with
SSx pin
control
enabled
While in Slave mode, the external clock is supplied by
the external clock source on the SCKx pin. This exter-
nal clock must meet the minimum high and low times
as specified in the electrical specifications.
(SSPxCON1<3:0> = 0100), the SPI
module will reset if the SSx pin is set to VDD.
2: If the SPI is used in Slave mode with CKE
set, then the SSx pin control must be
enabled.
While in Sleep mode, the slave can transmit/receive
data. When a byte is received, the device can be
configured to wake-up from Sleep.
When the SPI module resets, the bit counter is forced
to ‘0’. This can be done by either forcing the SSx pin to
a high level or clearing the SSPEN bit.
19.3.7
SLAVE SELECT
SYNCHRONIZATION
To emulate two-wire communication, the SDOx pin can
be connected to the SDIx pin. When the SPI needs to
operate as a receiver, the SDOx pin can be configured
as an input. This disables transmissions from the
SDOx. The SDIx can always be left as an input (SDI
function) since it cannot create a bus conflict.
The SSx pin allows a Synchronous Slave mode. The
SPI must be in Slave mode with the SSx pin control
enabled (SSPxCON1<3:0> = 04h). When the SSx pin
is low, transmission and reception are enabled and the
SDOx pin is driven. When the SSx pin goes high, the
SDOx pin is no longer driven, even if in the middle of a
FIGURE 19-4:
SLAVE SYNCHRONIZATION WAVEFORM
SSx
SCKx
(CKP = 0
CKE = 0)
SCKx
(CKP = 1
CKE = 0)
Write to
SSPxBUF
bit 6
bit 7
bit 7
bit 0
SDOx
bit 7
SDIx
(SMP = 0)
bit 0
bit 7
Input
Sample
(SMP = 0)
SSPxIF
Interrupt
Flag
Next Q4 Cycle
after Q2
↓
SSPxSR to
SSPxBUF
© 2008 Microchip Technology Inc.
DS39646C-page 211
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FIGURE 19-5:
SPI MODE WAVEFORM (SLAVE MODE WITH CKE = 0)
SSx
Optional
SCKx
(CKP = 0
CKE = 0)
SCKx
(CKP = 1
CKE = 0)
Write to
SSPxBUF
bit 6
bit 2
bit 5
bit 4
bit 3
bit 1
bit 0
SDOx
bit 7
SDIx
(SMP = 0)
bit 0
bit 7
Input
Sample
(SMP = 0)
SSPxIF
Interrupt
Flag
Next Q4 Cycle
after Q2↓
SSPxSR to
SSPxBUF
FIGURE 19-6:
SPI MODE WAVEFORM (SLAVE MODE WITH CKE = 1)
SSx
Not Optional
SCKx
(CKP = 0
CKE = 1)
SCKx
(CKP = 1
CKE = 1)
Write to
SSPxBUF
bit 6
bit 3
bit 2
bit 5
bit 4
bit 1
bit 0
SDOx
bit 7
bit 7
SDIx
(SMP = 0)
bit 0
Input
Sample
(SMP = 0)
SSPxIF
Interrupt
Flag
Next Q4 Cycle
after Q2↓
SSPxSR to
SSPxBUF
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19.3.8
OPERATION IN POWER-MANAGED
MODES
19.3.10 BUS MODE COMPATIBILITY
Table 19-1 shows the compatibility between the
standard SPI modes and the states of the CKP and
CKE control bits.
In SPI Master mode, module clocks may be operating
at a different speed than when in full power mode; in
the case of the Sleep mode, all clocks are halted.
TABLE 19-1: SPI BUS MODES
In Idle modes, a clock is provided to the peripherals.
That clock can be from the primary clock source, the
secondary clock (Timer1 oscillator) or the INTOSC
source. See Section 2.7 “Clock Sources and
Oscillator Switching” for additional information.
Control Bits State
Standard SPI Mode
Terminology
CKP
CKE
0, 0
0, 1
1, 0
1, 1
0
0
1
1
1
0
1
0
In most cases, the speed that the master clocks SPI
data is not important; however, this should be
evaluated for each system.
If MSSP interrupts are enabled, they can wake the con-
troller from Sleep mode, or one of the Idle modes, when
the master completes sending data. If an exit from
Sleep or Idle mode is not desired, MSSP interrupts
should be disabled.
There is also an SMP bit which controls when the data
is sampled.
19.3.11 SPI CLOCK SPEED AND MODULE
INTERACTIONS
If the Sleep mode is selected, all module clocks are
halted and the transmission/reception will remain in
that state until the devices wakes. After the device
returns to Run mode, the module will resume
transmitting and receiving data.
Because MSSP1 and MSSP2 are independent
modules, they can operate simultaneously at different
data rates. Setting the SSPM3:SSPM0 bits of the
SSPxCON register determines the rate for the
corresponding module.
In SPI Slave mode, the SPI Transmit/Receive Shift
register operates asynchronously to the device. This
allows the device to be placed in any power-managed
mode and data to be shifted into the SPI Trans-
mit/Receive Shift register. When all 8 bits have been
received, the MSSP interrupt flag bit will be set and if
enabled, will wake the device.
An exception is when both modules use Timer2 as a
time base in Master mode. In this instance, any
changes to the Timer2 module’s operation will affect
both MSSP modules equally. If different bit rates are
required for each module, the user should select one of
the other three time base options for one of the
modules.
19.3.9
EFFECTS OF A RESET
A Reset disables the MSSP module and terminates the
current transfer.
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TABLE 19-2: REGISTERS ASSOCIATED WITH SPI OPERATION
Reset
Values
on page
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
INTCON
PIR1
GIE/GIEH PEIE/GIEL TMR0IE
INT0IE
TX1IF
RBIE
TMR0IF
CCP1IF
CCP1IE
CCP1IP
CCP5IF
CCP5IE
CCP5IP
TRISC2
TRISD2
TRISF2
INT0IF
RBIF
57
60
60
60
60
60
60
60
60
60
58
58
58
58
58
61
61
61
PSPIF
PSPIE
ADIF
ADIE
RC1IF
RC1IE
RC1IP
RC2IF
RC2IE
RC2IP
TRISC5
TRISD5
TRISF5
SSP1IF
SSP1IE
SSP1IP
TMR4IF
TMR4IE
TMR4IP
TRISC3
TRISD3
TRISF3
TMR2IF
TMR1IF
PIE1
TX1IE
TX1IP
TX2IF
TMR2IE TMR1IE
TMR2IP TMR1IP
IPR1
PSPIP
ADIP
PIR3
SSP2IF
SSP2IE
SSP2IP
TRISC7
TRISD7
TRISF7
BCL2IF
BCL2IE
BCL2IP
TRISC6
TRISD6
TRISF6
CCP4IF
CCP4IE
CCP4IP
TRISC1
TRISD1
TRISF1
CCP3IF
CCP3IE
CCP3IP
TRISC0
TRISD0
TRISF0
PIE3
TX2IE
TX2IP
TRISC4
TRISD4
TRISF4
IPR3
TRISC
TRISD
TRISF
TMR2
PR2
Timer2 Register
Timer2 Period Register
SSP1BUF MSSP1 Receive Buffer/Transmit Register
SSP1CON1 WCOL
SSP1STAT SMP
SSPOV
CKE
SSPEN
D/A
CKP
P
SSPM3
S
SSPM2
R/W
SSPM1
UA
SSPM0
BF
SSP2BUF MSSP2 Receive Buffer/Transmit Register
SSP2CON1 WCOL
SSP2STAT SMP
SSPOV
CKE
SSPEN
D/A
CKP
P
SSPM3
S
SSPM2
R/W
SSPM1
UA
SSPM0
BF
Legend: Shaded cells are not used by the MSSP module in SPI mode.
DS39646C-page 214
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2
FIGURE 19-7:
MSSP BLOCK DIAGRAM
(I2C™ MODE)
19.4 I C Mode
The MSSP module in I2C mode fully implements all
master and slave functions (including general call
support) and provides interrupts on Start and Stop bits
in hardware to determine a free bus (multi-master
function). The MSSP module implements the standard
mode specifications, as well as 7-bit and 10-bit
addressing.
Internal
Data Bus
Read
Write
RC3 or
RD6
SSPxBUF reg
Two pins are used for data transfer:
Shift
Clock
• Serial clock (SCLx) – RC3/SCK1/SCL1 or
RD6/SCK2/SCL2
SSPxSR reg
LSb
RC4 or
RD5
• Serial data (SDAx) – RC4/SDI1/SDA1 or
RD5/SDI2/SDA2
MSb
Match Detect
SSPxADD reg
The user must configure these pins as inputs by setting
the associated TRIS bits.
Addr Match
Set, Reset
Start and
Stop bit Detect
S, P bits
(SSPxSTAT reg)
Note: Only port I/O names are used in this diagram for
the sake of brevity. Refer to the text for a full list of
multiplexed functions.
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REGISTER 19-3: SSPxSTAT: MSSPx STATUS REGISTER (I2C™ MODE)
R/W-0
SMP
R/W-0
CKE
R-0
D/A
R-0
P(1)
R-0
S(1)
R-0
R/W(2,3)
R-0
UA
R-0
BF
bit 7
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7
bit 6
bit 5
SMP: Slew Rate Control bit
In Master or Slave mode:
1 = Slew rate control disabled for Standard Speed mode (100 kHz and 1 MHz)
0 = Slew rate control enabled for High-Speed mode (400 kHz)
CKE: SMBus Select bit
In Master or Slave mode:
1= Enable SMBus specific inputs
0= Disable SMBus specific inputs
D/A: Data/Address bit
In Master mode:
Reserved.
In Slave mode:
1= Indicates that the last byte received or transmitted was data
0= Indicates that the last byte received or transmitted was address
bit 4
bit 3
bit 2
P: Stop bit(1)
1= Indicates that a Stop bit has been detected last
0= Stop bit was not detected last
S: Start bit(1)
1= Indicates that a Start bit has been detected last
0= Start bit was not detected last
R/W: Read/Write Information bit(2,3)
In Slave mode:
1= Read
0= Write
In Master mode:
1= Transmit is in progress
0= Transmit is not in progress
bit 1
bit 0
UA: Update Address bit (10-bit Slave mode only)
1= Indicates that the user needs to update the address in the SSPxADD register
0= Address does not need to be updated
BF: Buffer Full Status bit
In Transmit mode:
1= SSPxBUF is full
0= SSPxBUF is empty
In Receive mode:
1= SSPxBUF is full (does not include the ACK and Stop bits)
0= SSPxBUF is empty (does not include the ACK and Stop bits)
Note 1: This bit is cleared on Reset and when SSPEN is cleared.
2: This bit holds the R/W bit information following the last address match. This bit is only valid from the
address match to the next Start bit, Stop bit or not ACK bit.
3: ORing this bit with SEN, RSEN, PEN, RCEN or ACKEN will indicate if the MSSP is in Active mode.
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REGISTER 19-4: SSPxCON1: MSSPx CONTROL REGISTER 1 (I2C™ MODE)
R/W-0
WCOL
R/W-0
R/W-0
SSPEN(1)
R/W-0
CKP
R/W-0
R/W-0
R/W-0
R/W-0
SSPOV
SSPM3
SSPM2
SSPM1
SSPM0
bit 7
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7
WCOL: Write Collision Detect bit
In Master Transmit mode:
1= A write to the SSPxBUF register was attempted while the I2C™ conditions were not valid for a
transmission to be started (must be cleared in software)
0= No collision
In Slave Transmit mode:
1= The SSPxBUF register is written while it is still transmitting the previous word (must be cleared in
software)
0= No collision
In Receive mode (Master or Slave modes):
This is a “don’t care” bit.
bit 6
SSPOV: Receive Overflow Indicator bit
In Receive mode:
1= A byte is received while the SSPxBUF register is still holding the previous byte (must be cleared
in software)
0= No overflow
In Transmit mode:
This is a “don’t care” bit in Transmit mode.
bit 5
bit 4
SSPEN: Synchronous Serial Port Enable bit(1)
1= Enables the serial port and configures the SDAx and SCLx pins as the serial port pins
0= Disables serial port and configures these pins as I/O port pins
CKP: SCKx Release Control bit
In Slave mode:
1= Release clock
0= Holds clock low (clock stretch), used to ensure data setup time
In Master mode:
Unused in this mode.
bit 3-0
SSPM<3:0>: Synchronous Serial Port Mode Select bits
1111= I2C Slave mode, 10-bit address with Start and Stop bit interrupts enabled
1110= I2C Slave mode, 7-bit address with Start and Stop bit interrupts enabled
1011= I2C Firmware Controlled Master mode (Slave Idle)
1000= I2C Master mode, clock = FOSC/(4 * (SSPxADD + 1))
0111= I2C Slave mode, 10-bit address
0110= I2C Slave mode, 7-bit address
Bit combinations not specifically listed here are either reserved or implemented in SPI mode only.
Note 1: When enabled, the SDAx and SCLx pins must be configured as input.
© 2008 Microchip Technology Inc.
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REGISTER 19-5: SSPxCON2: MSSPx CONTROL REGISTER 2 (I2C™ MODE)
R/W-0
GCEN
R/W-0
R/W-0
ACKDT(1)
R/W-0
ACKEN(2)
R/W-0
RCEN(2)
R/W-0
PEN(2)
R/W-0
RSEN(2)
R/W-0
SEN(2)
ACKSTAT
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
-n = Value at POR
bit 7
bit 6
bit 5
bit 4
GCEN: General Call Enable bit (Slave mode only)
1= Enable interrupt when a general call address (0000h) is received in the SSPxSR
0= General call address disabled
ACKSTAT: Acknowledge Status bit (Master Transmit mode only)
1= Acknowledge was not received from slave
0= Acknowledge was received from slave
ACKDT: Acknowledge Data bit (Master Receive mode only)(1)
1= Not Acknowledge
0= Acknowledge
ACKEN: Acknowledge Sequence Enable bit (Master Receive mode only)(2)
1= Initiate Acknowledge sequence on SDAx and SCLx pins and transmit ACKDT data bit.
Automatically cleared by hardware.
0= Acknowledge sequence Idle
bit 3
bit 2
bit 1
bit 0
RCEN: Receive Enable bit (Master mode only)(2)
1= Enables Receive mode for I2C
0= Receive Idle
PEN: Stop Condition Enable bit (Master mode only)(2)
1= Initiate Stop condition on SDAx and SCLx pins. Automatically cleared by hardware.
0= Stop condition Idle
RSEN: Repeated Start Condition Enable bit (Master mode only)(2)
1= Initiate Repeated Start condition on SDAx and SCLx pins. Automatically cleared by hardware.
0= Repeated Start condition Idle
SEN: Start Condition Enable/Stretch Enable bit(2)
In Master mode:
1= Initiate Start condition on SDAx and SCLx pins. Automatically cleared by hardware.
0= Start condition Idle
In Slave mode:
1= Clock stretching is enabled for both slave transmit and slave receive (stretch enabled)
0= Clock stretching is disabled
Note 1: Value that will be transmitted when the user initiates an Acknowledge sequence at the end of a receive.
2: For bits ACKEN, RCEN, PEN, RSEN, SEN: If the I2C™ module is active, these bits may not be set (no
spooling) and the SSPxBUF may not be written (or writes to the SSPxBUF are disabled).
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19.4.2
OPERATION
19.4.3.1
Addressing
The MSSP module functions are enabled by setting
MSSP Enable bit, SSPEN (SSPxCON1<5>).
The SSPxCON1 register allows control of the I2C
operation. Four mode selection bits (SSPxCON1<3:0>)
allow one of the following I2C modes to be selected:
Once the MSSP module has been enabled, it waits for
a Start condition to occur. Following the Start condition,
the 8 bits are shifted into the SSPxSR register. All
incoming bits are sampled with the rising edge of the
clock (SCLx) line. The value of register SSPxSR<7:1>
is compared to the value of the SSPxADD register. The
address is compared on the falling edge of the eighth
clock (SCLx) pulse. If the addresses match and the BF
and SSPOV bits are clear, the following events occur:
• I2C Master mode, clock
• I2C Slave mode (7-bit address)
• I2C Slave mode (10-bit address)
• I2C Slave mode (7-bit address) with Start and
Stop bit interrupts enabled
1. The SSPxSR register value is loaded into the
SSPxBUF register.
• I2C Slave mode (10-bit address) with Start and
Stop bit interrupts enabled
• I2C Firmware Controlled Master mode, slave is
Idle
Selection of any I2C mode with the SSPEN bit set
forces the SCLx and SDAx pins to be open-drain,
provided these pins are programmed as inputs by
setting the appropriate TRISC or TRISD bits. To ensure
proper operation of the module, pull-up resistors must
be provided externally to the SCLx and SDAx pins.
2. The Buffer Full bit, BF, is set.
3. An ACK pulse is generated.
4. The MSSP Interrupt Flag bit, SSPxIF, is set (and
interrupt is generated, if enabled) on the falling
edge of the ninth SCLx pulse.
In 10-Bit Addressing mode, two address bytes need to
be received by the slave. The five Most Significant bits
(MSbs) of the first address byte specify if this is a 10-bit
address. Bit R/W (SSPxSTAT<2>) must specify a write
so the slave device will receive the second address byte.
For a 10-bit address, the first byte would equal ‘11110
A9 A8 0’, where ‘A9’ and ‘A8’ are the two MSbs of the
address. The sequence of events for 10-bit address is as
follows, with steps 7 through 9 for the slave-transmitter:
19.4.3
SLAVE MODE
In Slave mode, the SCLx and SDAx pins must be
configured as inputs (TRISC<4:3> set). The MSSP
module will override the input state with the output data
when required (slave-transmitter).
The I2C Slave mode hardware will always generate an
interrupt on an address match. Through the mode
select bits, the user can also choose to interrupt on
Start and Stop bits
1. Receive first (high) byte of address (bits SSPxIF,
BF and UA (SSPxSTAT<1>) are set on address
match).
2. Update the SSPxADD register with second (low)
byte of address (clears bit UA and releases the
SCLx line).
When an address is matched, or the data transfer after
an address match is received, the hardware auto-
matically will generate the Acknowledge (ACK) pulse
and load the SSPxBUF register with the received value
currently in the SSPxSR register.
3. Read the SSPxBUF register (clears bit BF) and
clear flag bit SSPxIF.
4. Receive second (low) byte of address (bits
SSPxIF, BF and UA are set).
5. Update the SSPxADD register with the first
(high) byte of address. If match releases SCLx
line, this will clear bit UA.
Any combination of the following conditions will cause
the MSSP module not to give this ACK pulse:
• The Buffer Full bit, BF (SSPxSTAT<0>), was set
before the transfer was received.
• The overflow bit, SSPOV (SSPxCON1<6>), was
set before the transfer was received.
6. Read the SSPxBUF register (clears bit BF) and
clear flag bit SSPxIF.
7. Receive Repeated Start condition.
8. Receive first (high) byte of address (bits SSPxIF
and BF are set).
In this case, the SSPxSR register value is not loaded
into the SSPxBUF, but bit SSPxIF is set. The BF bit is
cleared by reading the SSPxBUF register, while bit
SSPOV is cleared through software.
9. Read the SSPxBUF register (clears bit BF) and
clear flag bit SSPxIF.
The SCLx clock input must have a minimum high and
low for proper operation. The high and low times of the
I2C specification, as well as the requirement of the
MSSP module, are shown in timing parameter 100 and
parameter 101.
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19.4.3.2
Reception
19.4.3.3
Transmission
When the R/W bit of the address byte is clear and an
address match occurs, the R/W bit of the SSPxSTAT
register is cleared. The received address is loaded into
the SSPxBUF register and the SDAx line is held low
(ACK).
When the R/W bit of the incoming address byte is set
and an address match occurs, the R/W bit of the
SSPxSTAT register is set. The received address is
loaded into the SSPxBUF register. The ACK pulse will
be sent on the ninth bit and pin SCLx is held low regard-
less of SEN (see Section 19.4.4 “Clock Stretching”
for more detail). By stretching the clock, the master will
be unable to assert another clock pulse until the slave
is done preparing the transmit data. The transmit data
must be loaded into the SSPxBUF register which also
loads the SSPxSR register. Then pin SCLx should be
enabled by setting bit, CKP (SSPxCON1<4>). The
eight data bits are shifted out on the falling edge of the
SCLx input. This ensures that the SDAx signal is valid
during the SCLx high time (Figure 19-9).
When the address byte overflow condition exists, then
the no Acknowledge (ACK) pulse is given. An overflow
condition is defined as either bit BF (SSPxSTAT<0>) is
set, or bit SSPOV (SSPxCON1<6>) is set.
An MSSP interrupt is generated for each data transfer
byte. The interrupt flag bit, SSPxIF, must be cleared in
software. The SSPxSTAT register is used to determine
the status of the byte.
If SEN is enabled (SSPxCON2<0> = 1), SCLx will be
held low (clock stretch) following each data transfer. The
clock must be released by setting bit, CKP
The ACK pulse from the master-receiver is latched on
the rising edge of the ninth SCLx input pulse. If the
SDAx line is high (not ACK), then the data transfer is
complete. In this case, when the ACK is latched by the
slave, the slave logic is reset (resets SSPxSTAT
register) and the slave monitors for another occurrence
of the Start bit. If the SDAx line was low (ACK), the next
transmit data must be loaded into the SSPxBUF
register. Again, pin SCLx must be enabled by setting bit
CKP.
(SSPxCON1<4>).
See
Section 19.4.4
“Clock
Stretching” for more detail.
An MSSP interrupt is generated for each data transfer
byte. The SSPxIF bit must be cleared in software and
the SSPxSTAT register is used to determine the status
of the byte. The SSPxIF bit is set on the falling edge of
the ninth clock pulse.
DS39646C-page 220
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2
FIGURE 19-8:
I C™ SLAVE MODE TIMING WITH SEN = 0 (RECEPTION, 7-BIT ADDRESS)
© 2008 Microchip Technology Inc.
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2
FIGURE 19-9:
I C™ SLAVE MODE TIMING (TRANSMISSION, 7-BIT ADDRESS)
DS39646C-page 222
© 2008 Microchip Technology Inc.
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FIGURE 19-10:
I2C™ SLAVE MODE TIMING WITH SEN = 0 (RECEPTION, 10-BIT ADDRESS)
© 2008 Microchip Technology Inc.
DS39646C-page 223
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2
FIGURE 19-11:
I C™ SLAVE MODE TIMING (TRANSMISSION, 10-BIT ADDRESS)
DS39646C-page 224
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19.4.4
CLOCK STRETCHING
19.4.4.3
Clock Stretching for 7-Bit Slave
Transmit Mode
Both 7-Bit and 10-Bit Slave modes implement
automatic clock stretching during a transmit sequence.
The 7-Bit Slave Transmit mode implements clock
stretching by clearing the CKP bit after the falling edge
of the ninth clock if the BF bit is clear. This occurs
regardless of the state of the SEN bit.
The SEN bit (SSPxCON2<0>) allows clock stretching
to be enabled during receives. Setting SEN will cause
the SCLx pin to be held low at the end of each data
receive sequence.
The user’s ISR must set the CKP bit before transmis-
sion is allowed to continue. By holding the SCLx line
low, the user has time to service the ISR and load the
contents of the SSPxBUF before the master device
can initiate another transmit sequence (see
Figure 19-9).
19.4.4.1
Clock Stretching for 7-Bit Slave
Receive Mode (SEN = 1)
In 7-Bit Slave Receive mode, on the falling edge of the
ninth clock at the end of the ACK sequence, if the BF
bit is set, the CKP bit in the SSPxCON1 register is
automatically cleared, forcing the SCLx output to be
held low. The CKP being cleared to ‘0’ will assert the
SCLx line low. The CKP bit must be set in the user’s
ISR before reception is allowed to continue. By holding
the SCLx line low, the user has time to service the ISR
and read the contents of the SSPxBUF before the
master device can initiate another receive sequence.
This will prevent buffer overruns from occurring (see
Figure 19-13).
Note 1: If the user loads the contents of
SSPxBUF, setting the BF bit before the
falling edge of the ninth clock, the CKP bit
will not be cleared and clock stretching
will not occur.
2: The CKP bit can be set in software
regardless of the state of the BF bit.
19.4.4.4
Clock Stretching for 10-Bit Slave
Transmit Mode
Note 1: If the user reads the contents of the
SSPxBUF before the falling edge of the
ninth clock, thus clearing the BF bit, the
CKP bit will not be cleared and clock
stretching will not occur.
In 10-Bit Slave Transmit mode, clock stretching is
controlled during the first two address sequences by
the state of the UA bit, just as it is in 10-Bit Slave
Receive mode. The first two addresses are followed
by a third address sequence which contains the
high-order bits of the 10-bit address and the R/W bit
set to ‘1’. After the third address sequence is
performed, the UA bit is not set, the module is now
configured in Transmit mode and clock stretching is
controlled by the BF flag as in 7-Bit Slave Transmit
mode (see Figure 19-11).
2: The CKP bit can be set in software
regardless of the state of the BF bit. The
user should be careful to clear the BF bit
in the ISR before the next receive
sequence in order to prevent an overflow
condition.
19.4.4.2
Clock Stretching for 10-Bit Slave
Receive Mode (SEN = 1)
In 10-Bit Slave Receive mode during the address
sequence, clock stretching automatically takes place
but CKP is not cleared. During this time, if the UA bit is
set after the ninth clock, clock stretching is initiated.
The UA bit is set after receiving the upper byte of the
10-bit address and following the receive of the second
byte of the 10-bit address with the R/W bit cleared to
‘0’. The release of the clock line occurs upon updating
SSPxADD. Clock stretching will occur on each data
receive sequence as described in 7-bit mode.
Note:
If the user polls the UA bit and clears it by
updating the SSPxADD register before the
falling edge of the ninth clock occurs and if
the user hasn’t cleared the BF bit by read-
ing the SSPxBUF register before that time,
then the CKP bit will still NOT be asserted
low. Clock stretching on the basis of the
state of the BF bit only occurs during a
data sequence, not an address sequence.
© 2008 Microchip Technology Inc.
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already asserted the SCLx line. The SCLx output will
remain low until the CKP bit is set and all other
devices on the I2C bus have deasserted SCLx. This
ensures that a write to the CKP bit will not violate the
minimum high time requirement for SCLx (see
Figure 19-12).
19.4.4.5
Clock Synchronization and
the CKP bit
When the CKP bit is cleared, the SCLx output is forced
to ‘0’. However, clearing the CKP bit will not assert the
SCLx output low until the SCLx output is already
sampled low. Therefore, the CKP bit will not assert the
SCLx line until an external I2C master device has
FIGURE 19-12:
CLOCK SYNCHRONIZATION TIMING
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
SDAx
SCLx
DX – 1
DX
Master device
asserts clock
CKP
Master device
deasserts clock
WR
SSPxCON1
DS39646C-page 226
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FIGURE 19-13:
I C™ SLAVE MODE TIMING WITH SEN = 1 (RECEPTION, 7-BIT ADDRESS)
© 2008 Microchip Technology Inc.
DS39646C-page 227
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FIGURE 19-14:
I2C™ SLAVE MODE TIMING WITH SEN = 1 (RECEPTION, 10-BIT ADDRESS)
DS39646C-page 228
© 2008 Microchip Technology Inc.
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If the general call address matches, the SSPxSR is
transferred to the SSPxBUF, the BF flag bit is set
(eighth bit) and on the falling edge of the ninth bit (ACK
bit), the SSPxIF interrupt flag bit is set.
19.4.5
GENERAL CALL ADDRESS
SUPPORT
The addressing procedure for the I2C bus is such that
the first byte after the Start condition usually
determines which device will be the slave addressed by
the master. The exception is the general call address
which can address all devices. When this address is
used, all devices should, in theory, respond with an
Acknowledge.
When the interrupt is serviced, the source for the
interrupt can be checked by reading the contents of the
SSPxBUF. The value can be used to determine if the
address was device specific or a general call address.
In 10-bit mode, the SSPxADD is required to be updated
for the second half of the address to match and the UA
bit is set (SSPxSTAT<1>). If the general call address is
sampled when the GCEN bit is set, while the slave is
configured in 10-Bit Addressing mode, then the second
half of the address is not necessary, the UA bit will not
be set and the slave will begin receiving data after the
Acknowledge (Figure 19-15).
The general call address is one of eight addresses
reserved for specific purposes by the I2C protocol. It
consists of all ‘0’s with R/W = 0.
The general call address is recognized when the
General Call Enable bit, GCEN, is enabled
(SSPxCON2<7> set). Following a Start bit detect, 8 bits
are shifted into the SSPxSR and the address is
compared against the SSPxADD. It is also compared to
the general call address and fixed in hardware.
FIGURE 19-15:
SLAVE MODE GENERAL CALL ADDRESS SEQUENCE
(7 OR 10-BIT ADDRESS MODE)
Address is compared to General Call Address
after ACK, set interrupt
Receiving Data
ACK
R/W = 0
ACK D7 D6
General Call Address
SDAx
SCLx
D5 D4 D3 D2 D1 D0
1
2
3
4
5
6
7
8
9
1
2
3
4
5
6
7
8
9
S
SSPxIF
BF (SSPxSTAT<0>)
Cleared in software
SSPxBUF is read
SSPOV (SSPxCON1<6>)
GCEN (SSPxCON2<7>)
‘0’
‘1’
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19.4.6
MASTER MODE
Note:
The MSSP module, when configured in
I2C Master mode, does not allow queueing
of events. For instance, the user is not
allowed to initiate a Start condition and
immediately write the SSPxBUF register to
initiate transmission before the Start condi-
tion is complete. In this case, the
SSPxBUF will not be written to and the
WCOL bit will be set, indicating that a write
to the SSPxBUF did not occur.
Master mode is enabled by setting and clearing the
appropriate SSPM bits in SSPxCON1 and by setting
the SSPEN bit. In Master mode, the SCLx and SDAx
lines are manipulated by the MSSP hardware if the
TRIS bits are set.
Master mode of operation is supported by interrupt
generation on the detection of the Start and Stop con-
ditions. The Stop (P) and Start (S) bits are cleared from
a Reset or when the MSSP module is disabled. Control
of the I2C bus may be taken when the P bit is set, or the
bus is Idle, with both the S and P bits clear.
The following events will cause the SSP Interrupt Flag
bit, SSPxIF, to be set (and SSP interrupt, if enabled):
In Firmware Controlled Master mode, user code
conducts all I2C bus operations based on Start and
Stop bit conditions.
• Start condition
• Stop condition
• Data transfer byte transmitted/received
• Acknowledge transmit
• Repeated Start
Once Master mode is enabled, the user has six
options.
1. Assert a Start condition on SDAx and SCLx.
2. Assert a Repeated Start condition on SDAx and
SCLx.
3. Write to the SSPxBUF register initiating
transmission of data/address.
4. Configure the I2C port to receive data.
5. Generate an Acknowledge condition at the end
of a received byte of data.
6. Generate a Stop condition on SDAx and SCLx.
2
FIGURE 19-16:
MSSP BLOCK DIAGRAM (I C™ MASTER MODE)
Internal
Data Bus
SSPM<3:0>
SSPxADD<6:0>
Read
Write
SSPxBUF
SSPxSR
Baud
Rate
Generator
SDAx
Shift
Clock
SDAx In
MSb
LSb
Start bit, Stop bit,
Acknowledge
Generate
SCLx
Start bit Detect
Stop bit Detect
Write Collision Detect
Clock Arbitration
State Counter for
end of XMIT/RCV
SCLx In
Bus Collision
Set/Reset S, P (SSPxSTAT), WCOL (SSPxCON1)
Set SSPxIF, BCLxIF
Reset ACKSTAT, PEN (SSPxCON2)
DS39646C-page 230
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I2C Master Mode Operation
A typical transmit sequence would go as follows:
19.4.6.1
1. The user generates a Start condition by setting
the Start Enable bit, SEN (SSPxCON2<0>).
The master device generates all of the serial clock
pulses and the Start and Stop conditions. A transfer is
ended with a Stop condition or with a Repeated Start
condition. Since the Repeated Start condition is also
the beginning of the next serial transfer, the I2C bus will
not be released.
2. SSPxIF is set. The MSSP module will wait the
required start time before any other operation
takes place.
3. The user loads the SSPxBUF with the slave
address to transmit.
In Master Transmitter mode, serial data is output
through SDAx, while SCLx outputs the serial clock. The
first byte transmitted contains the slave address of the
receiving device (7 bits) and the Read/Write (R/W) bit.
In this case, the R/W bit will be logic ‘0’. Serial data is
transmitted 8 bits at a time. After each byte is transmit-
ted, an Acknowledge bit is received. Start and Stop
conditions are output to indicate the beginning and the
end of a serial transfer.
4. Address is shifted out the SDAx pin until all 8 bits
are transmitted.
5. The MSSP module shifts in the ACK bit from the
slave device and writes its value into the
SSPxCON2 register (SSPxCON2<6>).
6. The MSSP module generates an interrupt at the
end of the ninth clock cycle by setting the
SSPxIF bit.
In Master Receive mode, the first byte transmitted
contains the slave address of the transmitting device
(7 bits) and the R/W bit. In this case, the R/W bit will be
logic ‘1’. Thus, the first byte transmitted is a 7-bit slave
address, followed by a ‘1’ to indicate the receive bit.
Serial data is received via SDAx, while SCLx outputs
the serial clock. Serial data is received 8 bits at a time.
After each byte is received, an Acknowledge bit is
transmitted. Start and Stop conditions indicate the
beginning and end of transmission.
7. The user loads the SSPxBUF with eight bits of
data.
8. Data is shifted out the SDAx pin until all 8 bits
are transmitted.
9. The MSSP module shifts in the ACK bit from the
slave device and writes its value into the
SSPxCON2 register (SSPxCON2<6>).
10. The MSSP module generates an interrupt at the
end of the ninth clock cycle by setting the
SSPxIF bit.
The Baud Rate Generator used for the SPI mode
operation is used to set the SCLx clock frequency for
either 100 kHz, 400 kHz or 1 MHz I2C operation. See
Section 19.4.7 “Baud Rate” for more detail.
11. The user generates a Stop condition by setting
the Stop Enable bit, PEN (SSPxCON2<2>).
12. Interrupt is generated once the Stop condition is
complete.
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19.4.7
BAUD RATE
19.4.7.1
Baud Rate and Module
Interdependence
In I2C Master mode, the Baud Rate Generator (BRG)
reload value is placed in the lower 7 bits of the
SSPxADD register (Figure 19-17). When a write
occurs to SSPxBUF, the Baud Rate Generator will
automatically begin counting. The BRG counts down to
‘0’ and stops until another reload has taken place. The
BRG count is decremented twice per instruction cycle
(TCY) on the Q2 and Q4 clocks. In I2C Master mode, the
BRG is reloaded automatically.
Because MSSP1 and MSSP2 are independent, they
can operate simultaneously in I2C Master mode at
different baud rates. This is done by using different
BRG reload values for each module.
Because this mode derives its basic clock source from
the system clock, any changes to the clock will affect
both modules in the same proportion. It may be
possible to change one or both baud rates back to a
previous value by changing the BRG reload value.
Once the given operation is complete (i.e., transmis-
sion of the last data bit is followed by ACK), the internal
clock will automatically stop counting and the SCLx pin
will remain in its last state.
Table 19-3 demonstrates clock rates based on
instruction cycles and the BRG value loaded into
SSPxADD.
FIGURE 19-17:
BAUD RATE GENERATOR BLOCK DIAGRAM
SSPM<3:0>
SSPxADD<6:0>
SSPM<3:0>
SCLx
Reload
Control
Reload
BRG Down Counter
CLKO
FOSC/4
TABLE 19-3: I2C™ CLOCK RATE w/BRG
FSCL
FOSC
FCY
FCY*2
BRG Value
(2 Rollovers of BRG)
40 MHz
40 MHz
40 MHz
16 MHz
16 MHz
16 MHz
4 MHz
10 MHz
10 MHz
10 MHz
4 MHz
4 MHz
4 MHz
1 MHz
1 MHz
1 MHz
20 MHz
20 MHz
20 MHz
8 MHz
8 MHz
8 MHz
2 MHz
2 MHz
2 MHz
18h
1Fh
63h
09h
0Ch
27h
02h
09h
00h
400 kHz(1)
312.5 kHz
100 kHz
400 kHz(1)
308 kHz
100 kHz
333 kHz(1)
4 MHz
100 kHz
1 MHz(1)
4 MHz
Note 1: The I2C interface does not conform to the 400 kHz I2C specification (which applies to rates greater than
100 kHz) in all details, but may be used with care where higher rates are required by the application.
DS39646C-page 232
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SCLx pin is sampled high, the Baud Rate Generator is
reloaded with the contents of SSPxADD<6:0> and
begins counting. This ensures that the SCLx high time
will always be at least one BRG rollover count in the
event that the clock is held low by an external device
(Figure 19-18).
19.4.7.2
Clock Arbitration
Clock arbitration occurs when the master, during any
receive, transmit or Repeated Start/Stop condition,
deasserts the SCLx pin (SCLx allowed to float high).
When the SCLx pin is allowed to float high, the Baud
Rate Generator (BRG) is suspended from counting
until the SCLx pin is actually sampled high. When the
FIGURE 19-18:
BAUD RATE GENERATOR TIMING WITH CLOCK ARBITRATION
SDAx
DX
DX – 1
SCLx allowed to transition high
SCLx deasserted but slave holds
SCLx low (clock arbitration)
SCLx
BRG decrements on
Q2 and Q4 cycles
BRG
Value
03h
02h
01h
00h (hold off)
03h
02h
SCLx is sampled high, reload takes
place and BRG starts its count
BRG
Reload
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19.4.8
I2C MASTER MODE START
CONDITION TIMING
Note:
If at the beginning of the Start condition,
the SDAx and SCLx pins are already sam-
pled low, or if during the Start condition, the
SCLx line is sampled low before the SDAx
line is driven low, a bus collision occurs,
the Bus Collision Interrupt Flag, BCLxIF, is
set, the Start condition is aborted and the
I2C module is reset into its Idle state.
To initiate a Start condition, the user sets the Start
Enable bit, SEN (SSPxCON2<0>). If the SDAx and
SCLx pins are sampled high, the Baud Rate Generator
is reloaded with the contents of SSPxADD<6:0> and
starts its count. If SCLx and SDAx are both sampled
high when the Baud Rate Generator times out (TBRG),
the SDAx pin is driven low. The action of the SDAx
being driven low while SCLx is high is the Start condi-
tion and causes the S bit (SSPxSTAT<3>) to be set.
Following this, the Baud Rate Generator is reloaded
with the contents of SSPxADD<6:0> and resumes its
count. When the Baud Rate Generator times out
(TBRG), the SEN bit (SSPxCON2<0>) will be auto-
matically cleared by hardware; the Baud Rate Generator
is suspended, leaving the SDAx line held low and the
Start condition is complete.
19.4.8.1
WCOL Status Flag
If the user writes the SSPxBUF when a Start sequence
is in progress, the WCOL bit is set and the contents of
the buffer are unchanged (the write doesn’t occur).
Note:
Because queueing of events is not
allowed, writing to the lower 5 bits of
SSPxCON2 is disabled until the Start
condition is complete.
FIGURE 19-19:
FIRST START BIT TIMING
Set S bit (SSPxSTAT<3>)
Write to SEN bit occurs here
SDAx = 1,
At completion of Start bit,
hardware clears SEN bit
and sets SSPxIF bit
SCLx = 1
TBRG
TBRG
Write to SSPxBUF occurs here
2nd bit
1st bit
SDAx
TBRG
SCLx
TBRG
S
DS39646C-page 234
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19.4.9
I2C MASTER MODE REPEATED
START CONDITION TIMING
Note 1: If RSEN is programmed while any other
event is in progress, it will not take effect.
A Repeated Start condition occurs when the RSEN bit
(SSPxCON2<1>) is programmed high and the I2C logic
module is in the Idle state. When the RSEN bit is set,
the SCLx pin is asserted low. When the SCLx pin is
sampled low, the Baud Rate Generator is loaded with
the contents of SSPxADD<5:0> and begins counting.
The SDAx pin is released (brought high) for one Baud
Rate Generator count (TBRG). When the Baud Rate
Generator times out, if SDAx is sampled high, the SCLx
pin will be deasserted (brought high). When SCLx is
sampled high, the Baud Rate Generator is reloaded
with the contents of SSPxADD<6:0> and begins count-
ing. SDAx and SCLx must be sampled high for one
TBRG. This action is then followed by assertion of the
SDAx pin (SDAx = 0) for one TBRG while SCLx is high.
Following this, the RSEN bit (SSPxCON2<1>) will be
automatically cleared and the Baud Rate Generator will
not be reloaded, leaving the SDAx pin held low. As
soon as a Start condition is detected on the SDAx and
SCLx pins, the S bit (SSPxSTAT<3>) will be set. The
SSPxIF bit will not be set until the Baud Rate Generator
has timed out.
2: A bus collision during the Repeated Start
condition occurs if:
• SDAx is sampled low when SCLx
goes from low-to-high.
• SCLx goes low before SDAx is
asserted low. This may indicate that
another master is attempting to
transmit a data ‘1’.
Immediately following the SSPxIF bit getting set, the
user may write the SSPxBUF with the 7-bit address in
7-bit mode or the default first address in 10-bit mode.
After the first eight bits are transmitted and an ACK is
received, the user may then transmit an additional eight
bits of address (10-bit mode) or eight bits of data (7-bit
mode).
19.4.9.1
WCOL Status Flag
If the user writes the SSPxBUF when a Repeated Start
sequence is in progress, the WCOL is set and the
contents of the buffer are unchanged (the write doesn’t
occur).
Note:
Because queueing of events is not
allowed, writing of the lower 5 bits of
SSPxCON2 is disabled until the Repeated
Start condition is complete.
FIGURE 19-20:
REPEATED START CONDITION WAVEFORM
S bit set by hardware
SDAx = 1,
SCLx = 1
At completion of Start bit,
hardware clears RSEN bit
and sets SSPxIF
Write to SSPxCON2 occurs here:
SDAx = 1,
SCLx (no change).
TBRG TBRG
TBRG
1st bit
SDAx
RSEN bit set by hardware
on falling edge of ninth clock,
end of Xmit
Write to SSPxBUF occurs here
TBRG
SCLx
TBRG
Sr = Repeated Start
© 2008 Microchip Technology Inc.
DS39646C-page 235
PIC18F8722 FAMILY
19.4.10 I2C MASTER MODE TRANSMISSION
The user should verify that the WCOL bit is clear after
each write to SSPxBUF to ensure the transfer is correct.
In all cases, WCOL must be cleared in software.
Transmission of a data byte, a 7-bit address, or the
other half of a 10-bit address, is accomplished by sim-
ply writing a value to the SSPxBUF register. This action
will set the Buffer Full flag bit, BF and allow the Baud
Rate Generator to begin counting and start the next
transmission. Each bit of address/data will be shifted
out onto the SDAx pin after the falling edge of SCLx is
asserted (see data hold time specification
parameter 106). SCLx is held low for one Baud Rate
Generator rollover count (TBRG). Data should be valid
before SCLx is released high (see data setup time
specification parameter 107). When the SCLx pin is
released high, it is held that way for TBRG. The data on
the SDAx pin must remain stable for that duration and
some hold time after the next falling edge of SCLx.
After the eighth bit is shifted out (the falling edge of the
eighth clock), the BF flag is cleared and the master
releases SDAx. This allows the slave device being
addressed to respond with an ACK bit during the ninth
bit time if an address match occurred, or if data was
received properly. The status of ACK is written into the
ACKDT bit on the falling edge of the ninth clock. If the
master receives an Acknowledge, the Acknowledge
Status bit, ACKSTAT, is cleared. If not, the bit is set.
After the ninth clock, the SSPxIF bit is set and the
master clock (Baud Rate Generator) is suspended until
the next data byte is loaded into the SSPxBUF, leaving
SCLx low and SDAx unchanged (Figure 19-21).
19.4.10.3 ACKSTAT Status Flag
In Transmit mode, the ACKSTAT bit (SSPxCON2<6>)
is cleared when the slave has sent an Acknowledge
(ACK = 0) and is set when the slave does not Acknowl-
edge (ACK = 1). A slave sends an Acknowledge when
it has recognized its address (including a general call),
or when the slave has properly received its data.
19.4.11 I2C MASTER MODE RECEPTION
Master mode reception is enabled by programming the
Receive Enable bit, RCEN (SSPxCON2<3>).
Note:
The MSSP module must be in an inactive
state before the RCEN bit is set or the
RCEN bit will be disregarded.
The Baud Rate Generator begins counting and on each
rollover, the state of the SCLx pin changes
(high-to-low/low-to-high) and data is shifted into the
SSPxSR. After the falling edge of the eighth clock, the
receive enable flag is automatically cleared, the con-
tents of the SSPxSR are loaded into the SSPxBUF, the
BF flag bit is set, the SSPxIF flag bit is set and the Baud
Rate Generator is suspended from counting, holding
SCLx low. The MSSP is now in Idle state awaiting the
next command. When the buffer is read by the CPU,
the BF flag bit is automatically cleared. The user can
then send an Acknowledge bit at the end of reception
by setting the Acknowledge Sequence Enable bit,
ACKEN (SSPxCON2<4>).
After the write to the SSPxBUF, each bit of the address
will be shifted out on the falling edge of SCLx until all
seven address bits and the R/W bit are completed. On
the falling edge of the eighth clock, the master will
deassert the SDAx pin, allowing the slave to respond
with an Acknowledge. On the falling edge of the ninth
clock, the master will sample the SDAx pin to see if the
address was recognized by a slave. The status of the
ACK bit is loaded into the ACKSTAT status bit
(SSPxCON2<6>). Following the falling edge of the
ninth clock transmission of the address, the SSPxIF is
set, the BF flag is cleared and the Baud Rate Generator
is turned off until another write to the SSPxBUF takes
place, holding SCLx low and allowing SDAx to float.
19.4.11.1 BF Status Flag
In receive operation, the BF bit is set when an address
or data byte is loaded into SSPxBUF from SSPxSR. It
is cleared when the SSPxBUF register is read.
19.4.11.2 SSPOV Status Flag
In receive operation, the SSPOV bit is set when 8 bits
are received into the SSPxSR and the BF flag bit is
already set from a previous reception.
19.4.10.1 BF Status Flag
19.4.11.3 WCOL Status Flag
In Transmit mode, the BF bit (SSPxSTAT<0>) is set
when the CPU writes to SSPxBUF and is cleared when
all 8 bits are shifted out.
If the user writes the SSPxBUF when a receive is
already in progress (i.e., SSPxSR is still shifting in a
data byte), the WCOL bit is set and the contents of the
buffer are unchanged (the write doesn’t occur).
19.4.10.2 WCOL Status Flag
If the user writes the SSPxBUF when a transmit is
already in progress (i.e., SSPxSR is still shifting out a
data byte), the WCOL bit is set and the contents of the
buffer are unchanged (the write doesn’t occur) after
2 TCY after the SSPxBUF write. If SSPxBUF is rewritten
within 2 TCY, the WCOL bit is set and SSPxBUF is
updated. This may result in a corrupted transfer.
DS39646C-page 236
© 2008 Microchip Technology Inc.
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2
FIGURE 19-21:
I C™ MASTER MODE WAVEFORM (TRANSMISSION, 7 OR 10-BIT ADDRESS)
© 2008 Microchip Technology Inc.
DS39646C-page 237
PIC18F8722 FAMILY
2
FIGURE 19-22:
I C™ MASTER MODE WAVEFORM (RECEPTION, 7-BIT ADDRESS)
DS39646C-page 238
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
19.4.12 ACKNOWLEDGE SEQUENCE
TIMING
19.4.13 STOP CONDITION TIMING
A Stop bit is asserted on the SDAx pin at the end of a
receive/transmit by setting the Stop Sequence Enable
bit, PEN (SSPxCON2<2>). At the end of
An Acknowledge sequence is enabled by setting the
Acknowledge Sequence Enable bit, ACKEN
(SSPxCON2<4>). When this bit is set, the SCLx pin is
pulled low and the contents of the Acknowledge data bit
are presented on the SDAx pin. If the user wishes to
generate an Acknowledge, then the ACKDT bit should
be cleared. If not, the user should set the ACKDT bit
before starting an Acknowledge sequence. The Baud
Rate Generator then counts for one rollover period
(TBRG) and the SCLx pin is deasserted (pulled high).
When the SCLx pin is sampled high (clock arbitration),
the Baud Rate Generator counts for TBRG. The SCLx pin
is then pulled low. Following this, the ACKEN bit is auto-
matically cleared, the Baud Rate Generator is turned off
and the MSSP module then goes into an inactive state
(Figure 19-23).
a
receive/transmit, the SCLx line is held low after the
falling edge of the ninth clock. When the PEN bit is set,
the master will assert the SDAx line low. When the
SDAx line is sampled low, the Baud Rate Generator is
reloaded and counts down to ‘0’. When the Baud Rate
Generator times out, the SCLx pin will be brought high
and one TBRG (Baud Rate Generator rollover count)
later, the SDAx pin will be deasserted. When the SDAx
pin is sampled high while SCLx is high, the P bit
(SSPxSTAT<4>) is set. A TBRG later, the PEN bit is
cleared and the SSPxIF bit is set (Figure 19-24).
19.4.13.1 WCOL Status Flag
If the user writes the SSPxBUF when a Stop sequence
is in progress, then the WCOL bit is set and the
contents of the buffer are unchanged (the write doesn’t
occur).
19.4.12.1 WCOL Status Flag
If the user writes the SSPxBUF when an Acknowledge
sequence is in progress, then WCOL is set and the
contents of the buffer are unchanged (the write doesn’t
occur).
FIGURE 19-23:
ACKNOWLEDGE SEQUENCE WAVEFORM
Acknowledge sequence starts here,
write to SSPxCON2,
ACKEN automatically cleared
ACKEN = 1, ACKDT = 0
TBRG
ACK
TBRG
SDAx
SCLx
D0
8
9
SSPxIF
Cleared in
software
SSPxIF set at the end
of Acknowledge sequence
SSPxIF set at
the end of receive
Cleared in
software
Note: TBRG = one Baud Rate Generator period.
FIGURE 19-24:
STOP CONDITION RECEIVE OR TRANSMIT MODE
SCLx = 1for TBRG, followed by SDAx = 1for TBRG
after SDAx sampled high. P bit (SSPxSTAT<4>) is set.
Write to SSPxCON2,
set PEN
PEN bit (SSPxCON2<2>) is cleared by
hardware and the SSPxIF bit is set
Falling edge of
9th clock
TBRG
SCLx
SDAx
ACK
P
TBRG
TBRG
TBRG
SCLx brought high after TBRG
SDAx asserted low before rising edge of clock
to setup Stop condition
Note: TBRG = one Baud Rate Generator period.
© 2008 Microchip Technology Inc.
DS39646C-page 239
PIC18F8722 FAMILY
19.4.14 SLEEP OPERATION
19.4.17 MULTI -MASTER COMMUNICATION,
BUS COLLISION AND BUS
While in Sleep mode, the I2C module can receive
addresses or data and when an address match or
complete byte transfer occurs, wake the processor
from Sleep (if the MSSP interrupt is enabled).
ARBITRATION
Multi-Master mode support is achieved by bus arbitra-
tion. When the master outputs address/data bits onto
the SDAx pin, arbitration takes place when the master
outputs a ‘1’ on SDAx, by letting SDAx float high and
another master asserts a ‘0’. When the SCLx pin floats
high, data should be stable. If the expected data on
SDAx is a ‘1’ and the data sampled on the SDAx
pin = 0, then a bus collision has taken place. The
master will set the Bus Collision Interrupt Flag, BCLxIF
and reset the I2C port to its Idle state (Figure 19-25).
19.4.15 EFFECTS OF A RESET
A Reset disables the MSSP module and terminates the
current transfer.
19.4.16 MULTI-MASTER MODE
In Multi-Master mode, the interrupt generation on the
detection of the Start and Stop conditions allows the
determination of when the bus is free. The Stop (P) and
Start (S) bits are cleared from a Reset or when the
MSSP module is disabled. Control of the I2C bus may
be taken when the P bit (SSPxSTAT<4>) is set, or the
bus is Idle, with both the S and P bits clear. When the
bus is busy, enabling the MSSP interrupt will generate
the interrupt when the Stop condition occurs.
If a transmit was in progress when the bus collision
occurred, the transmission is halted, the BF flag is
cleared, the SDAx and SCLx lines are deasserted and
the SSPxBUF can be written to. When the user services
the bus collision Interrupt Service Routine and if the I2C
bus is free, the user can resume communication by
asserting a Start condition.
In multi-master operation, the SDAx line must be
monitored for arbitration to see if the signal level is the
expected output level. This check is performed in
hardware with the result placed in the BCLxIF bit.
If a Start, Repeated Start, Stop or Acknowledge condition
was in progress when the bus collision occurred, the con-
dition is aborted, the SDAx and SCLx lines are
deasserted and the respective control bits in the
SSPxCON2 register are cleared. When the user services
the bus collision Interrupt Service Routine and if the I2C
bus is free, the user can resume communication by
asserting a Start condition.
The states where arbitration can be lost are:
• Address Transfer
• Data Transfer
• A Start Condition
• A Repeated Start Condition
• An Acknowledge Condition
The master will continue to monitor the SDAx and SCLx
pins. If a Stop condition occurs, the SSPxIF bit will be set.
A write to the SSPxBUF will start the transmission of
data at the first data bit regardless of where the
transmitter left off when the bus collision occurred.
In Multi-Master mode, the interrupt generation on the
detection of Start and Stop conditions allows the deter-
mination of when the bus is free. Control of the I2C bus
can be taken when the P bit is set in the SSPxSTAT
register, or the bus is Idle and the S and P bits are
cleared.
FIGURE 19-25:
BUS COLLISION TIMING FOR TRANSMIT AND ACKNOWLEDGE
Sample SDAx. While SCLx is high,
data doesn’t match what is driven
by the master.
Data changes
while SCLx = 0
SDAx line pulled low
by another source
Bus collision has occurred.
SDAx released
by master
SDAx
SCLx
Set bus collision
interrupt (BCLxIF)
BCLxIF
DS39646C-page 240
© 2008 Microchip Technology Inc.
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If the SDAx pin is sampled low during this count, the
BRG is reset and the SDAx line is asserted early
(Figure 19-28). If, however, a ‘1’ is sampled on the
SDAx pin, the SDAx pin is asserted low at the end of
the BRG count. The Baud Rate Generator is then
reloaded and counts down to ‘0’. If the SCLx pin is
sampled as ‘0’ during this time, a bus collision does not
occur. At the end of the BRG count, the SCLx pin is
asserted low.
19.4.17.1 Bus Collision During a Start
Condition
During a Start condition, a bus collision occurs if:
a) SDAx or SCLx are sampled low at the beginning
of the Start condition (Figure 19-26).
b) SCLx is sampled low before SDAx is asserted
low (Figure 19-27).
During a Start condition, both the SDAx and the SCLx
pins are monitored.
Note:
The reason that bus collision is not a factor
during a Start condition is that no two bus
masters can assert a Start condition at the
exact same time. Therefore, one master
will always assert SDAx before the other.
This condition does not cause a bus colli-
sion because the two masters must be
allowed to arbitrate the first address
following the Start condition. If the address
is the same, arbitration must be allowed to
continue into the data portion, Repeated
Start or Stop conditions.
If the SDAx pin is already low, or the SCLx pin is
already low, then all of the following occur:
• the Start condition is aborted,
• the BCLxIF flag is set and
• the MSSP module is reset to its inactive state
(Figure 19-26).
The Start condition begins with the SDAx and SCLx
pins deasserted. When the SDAx pin is sampled high,
the Baud Rate Generator is loaded from
SSPxADD<6:0> and counts down to ‘0’. If the SCLx pin
is sampled low while SDAx is high, a bus collision
occurs because it is assumed that another master is
attempting to drive a data ‘1’ during the Start condition.
FIGURE 19-26:
BUS COLLISION DURING START CONDITION (SDAx ONLY)
SDAx goes low before the SEN bit is set.
Set BCLxIF,
S bit and SSPxIF set because
SDAx = 0, SCLx = 1.
SDAx
SCLx
SEN
Set SEN, enable Start
condition if SDAx = 1, SCLx = 1
SEN cleared automatically because of bus collision.
MSSP module reset into Idle state.
SDAx sampled low before
Start condition. Set BCLxIF.
S bit and SSPxIF set because
SDAx = 0, SCLx = 1.
BCLxIF
SSPxIF and BCLxIF are
cleared in software
S
SSPxIF
SSPxIF and BCLxIF are
cleared in software
© 2008 Microchip Technology Inc.
DS39646C-page 241
PIC18F8722 FAMILY
FIGURE 19-27:
BUS COLLISION DURING START CONDITION (SCLx = 0)
SDAx = 0, SCLx = 1
TBRG
TBRG
SDAx
Set SEN, enable Start
sequence if SDAx = 1, SCLx = 1
SCLx
SEN
SCLx = 0before SDAx = 0,
bus collision occurs. Set BCLxIF.
SCLx = 0before BRG time-out,
bus collision occurs. Set BCLxIF.
BCLxIF
Interrupt cleared
in software
S
‘0’
‘0’
‘0’
‘0’
SSPxIF
FIGURE 19-28:
BRG RESET DUE TO SDAx ARBITRATION DURING START CONDITION
SDAx = 0, SCLx = 1
Set S
Set SSPxIF
Less than TBRG
TBRG
SDAx pulled low by other master.
Reset BRG and assert SDAx.
SDAx
SCLx
S
SCLx pulled low after BRG
time-out
SEN
Set SEN, enable START
sequence if SDAx = 1, SCLx = 1
‘0’
BCLxIF
S
SSPxIF
Interrupts cleared
in software
SDAx = 0, SCLx = 1,
set SSPxIF
DS39646C-page 242
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
If SDAx is low, a bus collision has occurred (i.e., another
master is attempting to transmit a data ‘0’, Figure 19-29).
If SDAx is sampled high, the BRG is reloaded and
begins counting. If SDAx goes from high-to-low before
the BRG times out, no bus collision occurs because no
two masters can assert SDAx at exactly the same time.
19.4.17.2 Bus Collision During a Repeated
Start Condition
During a Repeated Start condition, a bus collision
occurs if:
a) A low level is sampled on SDAx when SCLx
goes from low level to high level.
If SCLx goes from high-to-low before the BRG times
out and SDAx has not already been asserted, a bus
collision occurs. In this case, another master is
attempting to transmit a data ‘1’ during the Repeated
Start condition (see Figure 19-30).
b) SCLx goes low before SDAx is asserted low,
indicating that another master is attempting to
transmit a data ‘1’.
When the user deasserts SDAx and the pin is allowed
to float high, the BRG is loaded with SSPxADD<6:0>
and counts down to ‘0’. The SCLx pin is then
deasserted and when sampled high, the SDAx pin is
sampled.
If, at the end of the BRG time-out, both SCLx and SDAx
are still high, the SDAx pin is driven low and the BRG is
reloaded and begins counting. At the end of the count,
regardless of the status of the SCLx pin, the SCLx pin is
driven low and the Repeated Start condition is complete.
FIGURE 19-29:
BUS COLLISION DURING A REPEATED START CONDITION (CASE 1)
SDAx
SCLx
Sample SDAx when SCLx goes high.
If SDAx = 0, set BCLxIF and release SDAx and SCLx.
RSEN
BCLxIF
Cleared in software
‘0’
S
‘0’
SSPxIF
FIGURE 19-30:
BUS COLLISION DURING REPEATED START CONDITION (CASE 2)
TBRG
TBRG
SDAx
SCLx
SCLx goes low before SDAx,
set BCLxIF. Release SDAx and SCLx.
BCLxIF
RSEN
Interrupt cleared
in software
‘0’
S
SSPxIF
© 2008 Microchip Technology Inc.
DS39646C-page 243
PIC18F8722 FAMILY
The Stop condition begins with SDAx asserted low.
When SDAx is sampled low, the SCLx pin is allowed to
float. When the pin is sampled high (clock arbitration),
the Baud Rate Generator is loaded with
SSPxADD<6:0> and counts down to ‘0’. After the BRG
times out, SDAx is sampled. If SDAx is sampled low, a
bus collision has occurred. This is due to another
master attempting to drive a data ‘0’ (Figure 19-31). If
the SCLx pin is sampled low before SDAx is allowed to
float high, a bus collision occurs. This is another case
of another master attempting to drive a data ‘0’
(Figure 19-32).
19.4.17.3 Bus Collision During a Stop
Condition
Bus collision occurs during a Stop condition if:
a) After the SDAx pin has been deasserted and
allowed to float high, SDAx is sampled low after
the BRG has timed out.
b) After the SCLx pin is deasserted, SCLx is
sampled low before SDAx goes high.
FIGURE 19-31:
BUS COLLISION DURING A STOP CONDITION (CASE 1)
SDAx sampled
low after TBRG,
set BCLxIF
TBRG
TBRG
TBRG
SDAx
SDAx asserted low
SCLx
PEN
BCLxIF
P
‘0’
‘0’
SSPxIF
FIGURE 19-32:
BUS COLLISION DURING A STOP CONDITION (CASE 2)
TBRG
TBRG
TBRG
SDAx
SCLx goes low before SDAx goes high,
set BCLxIF
Assert SDAx
SCLx
PEN
BCLxIF
P
‘0’
‘0’
SSPxIF
DS39646C-page 244
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TABLE 19-4: REGISTERS ASSOCIATED WITH I2C™ OPERATION
Reset
Values
on page
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
INTCON
PIR1
GIE/GIEH PEIE/GIEL TMR0IE
INT0IE
TX1IF
TX1IE
TX1IP
EEIF
RBIE
TMR0IF
CCP1IF
CCP1IE
CCP1IP
HLVDIF
HLVDIE
HLVDIP
CCP5IF
CCP5IE
CCP5IP
TRISC2
TRISD2
INT0IF
RBIF
57
60
60
60
60
60
60
60
60
60
60
60
58
61
58
PSPIF
PSPIE
ADIF
ADIE
RC1IF
RC1IE
RC1IP
—
SSP1IF
SSP1IE
SSP1IP
BCL1IF
BCL1IE
BCL1IP
TMR4IF
TMR4IE
TMR4IP
TRISC3
TRISD3
TMR2IF
TMR1IF
PIE1
TMR2IE TMR1IE
TMR2IP TMR1IP
IPR1
PSPIP
ADIP
PIR2
OSCFIF
OSCFIE
OSCFIP
SSP2IF
SSP2IE
SSP2IP
TRISC7
TRISD7
CMIF
TMR3IF
TMR3IE
TMR3IP
CCP4IF
CCP4IE
CCP4IP
TRISC1
TRISD1
CCP2IF
CCP2IE
CCP2IP
CCP3IF
CCP3IE
CCP3IP
TRISC0
TRISD0
PIE2
CMIE
—
EEIE
IPR2
CMIP
—
EEIP
PIR3
BCL2IF
BCL2IE
BCL2IP
TRISC6
TRISD6
RC2IF
RC2IE
RC2IP
TRISC5
TRISD5
TX2IF
TX2IE
TX2IP
TRISC4
TRISD4
PIE3
IPR3
TRISC
TRISD
SSP1BUF MSSP1 Receive Buffer/Transmit Register
SSP2BUF MSSP2 Receive Buffer/Transmit Register
SSP1ADD MSSP1 Address Register in I2C™ Slave mode. MSSP1 Baud Rate Reload Register in I2C
Master mode.
SSP2ADD MSSP2 Address Register in I2C Slave mode. MSSP2 Baud Rate Reload Register in I2C
61
Master mode.
TMR2
PR2
Timer2 Register
58
58
58
58
58
61
61
61
Timer2 Period Register
SSP1CON1 WCOL
SSP1CON2 GCEN
SSPOV
SSPEN
CKP
ACKEN
P
SSPM3
RCEN
S
SSPM2
PEN
SSPM1
RSEN
UA
SSPM0
SEN
BF
ACKSTAT ACKDT
SSP1STAT
SMP
CKE
D/A
R/W
SSP2CON1 WCOL
SSP2CON2 GCEN
SSPOV
SSPEN
CKP
ACKEN
P
SSPM3
RCEN
S
SSPM2
PEN
SSPM1
RSEN
UA
SSPM0
SEN
BF
ACKSTAT ACKDT
SSP2STAT
SMP
CKE D/A
R/W
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by the MSSP module in I2C mode.
© 2008 Microchip Technology Inc.
DS39646C-page 245
PIC18F8722 FAMILY
NOTES:
DS39646C-page 246
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
The pins of EUSART1 and EUSART2 are multiplexed
with the functions of PORTC (RC6/TX1/CK1 and RC7/
RX1/DT1) and PORTG (RG1/TX2/CK2 and RG2/RX2/
DT2), respectively. In order to configure these pins as
an EUSART:
20.0 ENHANCED UNIVERSAL
SYNCHRONOUS RECEIVER
TRANSMITTER (EUSART)
The Enhanced Universal Synchronous Asynchronous
Receiver Transmitter (EUSART) module is one of two
serial I/O modules. (Generically, the USART is also
known as a Serial Communications Interface or SCI.)
The EUSART can be configured as a full-duplex
asynchronous system that can communicate with
peripheral devices, such as CRT terminals and
personal computers. It can also be configured as a half-
duplex synchronous system that can communicate
with peripheral devices, such as A/D or D/A integrated
circuits, serial EEPROMs, etc.
• For EUSART1:
- bit SPEN (RCSTA1<7>) must be set (= 1)
- bit TRISC<7> must be set (= 1)
- bit TRISC<6> must be cleared (= 0) for
Asynchronous and Synchronous Master
modes
- bit TRISC<6> must be set (= 1) for
Synchronous Slave mode
• For EUSART2:
- bit SPEN (RCSTA2<7>) must be set (= 1)
- bit TRISG<2> must be set (= 1)
- bit TRISG<1> must be cleared (= 0) for
Asynchronous and Synchronous Master
modes
The Enhanced USART module implements additional
features, including automatic baud rate detection and
calibration, automatic wake-up on Sync Break recep-
tion and 12-bit Break Character transmit. These make
it ideally suited for use in Local Interconnect Network
bus (LIN bus) systems.
- bit TRISC<6> must be set (= 1) for
Synchronous Slave mode
The EUSART can be configured in the following
modes:
Note:
The EUSART control will automatically
reconfigure the pin from input to output as
needed.
• Asynchronous (full duplex) with:
- Auto-Wake-up on Character Reception
- Auto-Baud Calibration
The operation of each Enhanced USART module is
controlled through three registers:
- 12-bit Break Character Transmission
• Synchronous – Master (half duplex) with
Selectable Clock Polarity
• Synchronous – Slave (half duplex) with
Selectable Clock Polarity
• Transmit Status and Control (TXSTAx)
• Receive Status and Control (RCSTAx)
• Baud Rate Control (BAUDCONx)
These are detailed on the following pages in
Register 20-1, Register 20-2 and Register 20-3,
respectively.
Note:
Throughout this section, references to
register and bit names that may be associ-
ated with a specific EUSART module are
referred to generically by the use of ‘x’ in
place of the specific module number.
Thus, “RCSTAx” might refer to the
Receive Status register for either
EUSART1 or EUSART2
© 2008 Microchip Technology Inc.
DS39646C-page 247
PIC18F8722 FAMILY
REGISTER 20-1: TXSTAx: TRANSMIT STATUS AND CONTROL REGISTER
R/W-0
CSRC
R/W-0
TX9
R/W-0
TXEN
R/W-0
SYNC
R/W-0
R/W-0
BRGH
R-1
R/W-0
TX9D
SENDB
TRMT
bit 7
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7
CSRC: Clock Source Select bit
Asynchronous mode:
Don’t care.
Synchronous mode:
1= Master mode (clock generated internally from BRG)
0= Slave mode (clock from external source)
bit 6
bit 5
TX9: 9-bit Transmit Enable bit
1= Selects 9-bit transmission
0= Selects 8-bit transmission
TXEN: Transmit Enable bit
1= Transmit enabled
0= Transmit disabled
Note:
SREN/CREN overrides TXEN in Sync mode.
bit 4
bit 3
SYNC: EUSART Mode Select bit
1= Synchronous mode
0= Asynchronous mode
SENDB: Send Break Character bit
Asynchronous mode:
1= Send Sync Break on next transmission (cleared by hardware upon completion)
0= Sync Break transmission completed
Synchronous mode:
Don’t care.
bit 2
BRGH: High Baud Rate Select bit
Asynchronous mode:
1= High speed
0= Low speed
Synchronous mode:
Unused in this mode.
bit 1
bit 0
TRMT: Transmit Shift Register Status bit
1= TSRx empty
0= TSRx full
TX9D: Ninth bit of Transmit Data
Can be address/data bit or a parity bit.
DS39646C-page 248
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
REGISTER 20-2: RCSTAx: RECEIVE STATUS AND CONTROL REGISTER
R/W-0
SPEN
R/W-0
RX9
R/W-0
SREN
R/W-0
CREN
R/W-0
R-0
R-0
R-x
ADDEN
FERR
OERR
RX9D
bit 7
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7
bit 6
bit 5
SPEN: Serial Port Enable bit
1= Serial port enabled (configures RXx/DTx and TXx/CKx pins as serial port pins)
0= Serial port disabled (held in Reset)
RX9: 9-bit Receive Enable bit
1= Selects 9-bit reception
0= Selects 8-bit reception
SREN: Single Receive Enable bit
Asynchronous mode:
Don’t care.
Synchronous mode – Master:
1= Enables single receive
0= Disables single receive
This bit is cleared after reception is complete.
Synchronous mode – Slave:
Don’t care.
bit 4
CREN: Continuous Receive Enable bit
Asynchronous mode:
1= Enables receiver
0= Disables receiver
Synchronous mode:
1= Enables continuous receive until enable bit CREN is cleared (CREN overrides SREN)
0= Disables continuous receive
bit 3
ADDEN: Address Detect Enable bit
Asynchronous mode 9-bit (RX9 = 1):
1= Enables address detection, enables interrupt and loads the receive buffer when RSRx<8> is set
0= Disables address detection, all bytes are received and ninth bit can be used as parity bit
Asynchronous mode 9-bit (RX9 = 0):
Don’t care.
bit 2
bit 1
bit 0
FERR: Framing Error bit
1= Framing error (can be updated by reading RCREGx register and receiving next valid byte)
0= No framing error
OERR: Overrun Error bit
1= Overrun error (can be cleared by clearing bit CREN)
0= No overrun error
RX9D: 9th bit of Received Data
This can be address/data bit or a parity bit and must be calculated by user firmware.
© 2008 Microchip Technology Inc.
DS39646C-page 249
PIC18F8722 FAMILY
REGISTER 20-3: BAUDCONx: BAUD RATE CONTROL REGISTER
R/W-0
R-1
U-0
—
R/W-0
SCKP
R/W-0
U-0
—
R/W-0
WUE
R/W-0
ABDOVF
RCIDL
BRG16
ABDEN
bit 7
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7
bit 6
ABDOVF: Auto-Baud Acquisition Rollover Status bit
1= A BRG rollover has occurred during Auto-Baud Rate Detect mode (must be cleared in software)
0= No BRG rollover has occurred
RCIDL: Receive Operation Idle Status bit
1= Receive operation is inactive
0= Receive operation is active
bit 5
bit 4
Unimplemented: Read as ‘0’
SCKP: Synchronous Clock Polarity Select bit
Asynchronous mode:
Unused in this mode.
Synchronous mode:
1= Idle state for clock (CKx) is a high level
0= Idle state for clock (CKx) is a low level
bit 3
BRG16: 16-bit Baud Rate Register Enable bit
1= 16-bit Baud Rate Generator – SPBRGHx and SPBRGx
0= 8-bit Baud Rate Generator – SPBRGx only (Compatible mode), SPBRGHx value ignored
bit 2
bit 1
Unimplemented: Read as ‘0’
WUE: Wake-up Enable bit
Asynchronous mode:
1= EUSART will continue to sample the RXx pin – interrupt generated on falling edge; bit cleared in
hardware on following rising edge
0= RXx pin not monitored or rising edge detected
Synchronous mode:
Unused in this mode.
bit 0
ABDEN: Auto-Baud Detect Enable bit
Asynchronous mode:
1= Enable baud rate measurement on the next character. Requires reception of a Sync field (55h);
cleared in hardware upon completion.
0= Baud rate measurement disabled or completed
Synchronous mode:
Unused in this mode.
DS39646C-page 250
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
advantageous to use the high baud rate (BRGH = 1) or
the 16-bit BRG to reduce the baud rate error, or
achieve a slow baud rate for a fast oscillator frequency.
20.1
Baud Rate Generator (BRG)
The BRG is a dedicated 8-bit or 16-bit generator that
supports both the Asynchronous and Synchronous
modes of the EUSART. By default, the BRG operates
in 8-bit mode; setting the BRG16 bit (BAUDCONx<3>)
selects 16-bit mode.
Writing a new value to the SPBRGHx:SPBRGx regis-
ters causes the BRG timer to be reset (or cleared). This
ensures the BRG does not wait for a timer overflow
before outputting the new baud rate.
The SPBRGHx:SPBRGx register pair controls the
period of a free running timer. In Asynchronous mode,
bits
(BAUDCONx<3>) also control the baud rate. In
Synchronous mode, BRGH is ignored. Table 20-1
shows the formula for computation of the baud rate for
different EUSART modes which only apply in Master
mode (internally generated clock).
20.1.1
OPERATION IN POWER-MANAGED
MODES
BRGH
(TXSTAx<2>)
and
BRG16
The device clock is used to generate the desired baud
rate. When one of the power-managed modes is
entered, the new clock source may be operating at a
different frequency. This may require an adjustment to
the value in the SPBRGx register pair.
Given the desired baud rate and FOSC, the nearest
integer value for the SPBRGHx:SPBRGx registers can
be calculated using the formulas in Table 20-1. From
this, the error in baud rate can be determined. An
example calculation is shown in Example 20-1. Typical
baud rates and error values for the various Asynchro-
nous modes are shown in Table 20-2. It may be
20.1.2
SAMPLING
The data on the RXx pin (either RC7/RX1/DT1 or RG2/
RX2/DT2) is sampled three times by a majority detect
circuit to determine if a high or a low level is present at
the RXx pin.
TABLE 20-1: BAUD RATE FORMULAS
Configuration Bits
BRG/EUSART Mode
Baud Rate Formula
SYNC
BRG16
BRGH
0
0
0
0
1
1
0
0
1
1
0
1
0
1
0
1
x
x
8-bit/Asynchronous
8-bit/Asynchronous
16-bit/Asynchronous
16-bit/Asynchronous
8-bit/Synchronous
16-bit/Synchronous
FOSC/[64 (n + 1)]
FOSC/[16 (n + 1)]
FOSC/[4 (n + 1)]
Legend: x= Don’t care, n = value of SPBRGHx:SPBRGx register pair
© 2008 Microchip Technology Inc.
DS39646C-page 251
PIC18F8722 FAMILY
EXAMPLE 20-1:
CALCULATING BAUD RATE ERROR
For a device with FOSC of 16 MHz, desired baud rate of 9600, Asynchronous mode, 8-bit BRG:
Desired Baud Rate = FOSC/(64 ([SPBRGHx:SPBRGx] + 1))
Solving for SPBRGHx:SPBRGx:
X
=
=
=
((FOSC/Desired Baud Rate)/64) – 1
((16000000/9600)/64) – 1
[25.042] = 25
Calculated Baud Rate= 16000000/(64 (25 + 1))
=
=
=
9615
Error
(Calculated Baud Rate – Desired Baud Rate)/Desired Baud Rate
(9615 – 9600)/9600 = 0.16%
TABLE 20-2: REGISTERS ASSOCIATED WITH BAUD RATE GENERATOR
Reset
Values
on page
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
TXSTAx
CSRC
SPEN
TX9
RX9
TXEN
SREN
—
SYNC
CREN
SCKP
SENDB
ADDEN
BRG16
BRGH
FERR
—
TRMT
OERR
WUE
TX9D
RX9D
59
59
61
59
59
RCSTAx
BAUDCONx
SPBRGHx
SPBRGx
ABDOVF RCIDL
ABDEN
EUSARTx Baud Rate Generator Register High Byte
EUSARTx Baud Rate Generator Register Low Byte
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by the BRG.
DS39646C-page 252
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
TABLE 20-3: BAUD RATES FOR ASYNCHRONOUS MODES
SYNC = 0, BRGH = 0, BRG16 = 0
BAUD
RATE
(K)
FOSC = 40.000 MHz
FOSC = 20.000 MHz FOSC = 10.000 MHz
FOSC = 8.000 MHz
Actual
Rate
(K)
SPBRG Actual
value
SPBRG Actual
SPBRG Actual
value
(decimal)
SPBRG
value
(decimal)
%
%
Error
%
Error
%
Error
Rate
(K)
value
Rate
(K)
Rate
(K)
Error
(decimal)
(decimal)
0.3
1.2
—
—
—
—
—
—
—
255
129
31
15
4
—
—
—
129
64
15
7
—
1.201
2.403
9.615
—
—
-0.16
-0.16
-0.16
—
—
103
51
12
—
—
—
1.221
1.73
0.16
1.73
1.73
8.51
-9.58
1.202
2.404
9.766
19.531
52.083
78.125
0.16
0.16
1.73
1.73
-9.58
-32.18
2.4
2.441
9.615
19.531
56.818
125.000
1.73
0.16
1.73
-1.36
8.51
255
64
31
10
4
2.404
9.6
9.766
19.2
57.6
115.2
19.531
62.500
104.167
2
—
—
—
2
1
—
—
—
SYNC = 0, BRGH = 0, BRG16 = 0
BAUD
RATE
(K)
FOSC = 4.000 MHz
FOSC = 2.000 MHz
FOSC = 1.000 MHz
Actual
Rate
(K)
SPBRG Actual
value
SPBRG Actual
value
(decimal)
SPBRG
value
(decimal)
%
%
Error
%
Error
Rate
(K)
Rate
(K)
Error
(decimal)
0.3
1.2
0.300
1.202
0.16
0.16
207
51
25
6
0.300
1.201
2.403
—
-0.16
-0.16
-0.16
—
103
25
12
—
0.300
1.201
—
-0.16
-0.16
—
51
12
—
—
—
—
—
2.4
2.404
0.16
9.6
8.929
-6.99
8.51
—
—
19.2
57.6
115.2
20.833
62.500
62.500
2
—
—
—
—
—
8.51
0
—
—
—
—
—
-45.75
0
—
—
—
—
—
SYNC = 0, BRGH = 1, BRG16 = 0
BAUD
RATE
(K)
FOSC = 40.000 MHz
FOSC = 20.000 MHz
FOSC = 10.000 MHz
FOSC = 8.000 MHz
Actual
Rate
(K)
SPBRG Actual
value
(decimal)
SPBRG Actual
value
(decimal)
SPBRG Actual
value
(decimal)
SPBRG
value
%
Error
%
Error
%
Error
%
Error
Rate
(K)
Rate
(K)
Rate
(K)
(decimal)
0.3
1.2
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
2.4
—
—
—
—
—
—
2.441
9.615
19.531
56.818
125.000
1.73
0.16
1.73
-1.36
8.51
255
64
31
10
4
2.403
9.615
19.230
55.555
—
-0.16
-0.16
-0.16
3.55
—
207
51
25
8
9.6
9.766
19.231
58.140
113.636
1.73
0.16
0.94
-1.36
255
129
42
9.615
19.231
56.818
113.636
0.16
0.16
-1.36
-1.36
129
64
21
10
19.2
57.6
115.2
21
—
SYNC = 0, BRGH = 1, BRG16 = 0
BAUD
RATE
(K)
FOSC = 4.000 MHz
FOSC = 2.000 MHz
FOSC = 1.000 MHz
Actual
Rate
(K)
SPBRG Actual
value
SPBRG Actual
value
(decimal)
SPBRG
value
(decimal)
%
%
Error
%
Error
Rate
(K)
Rate
(K)
Error
(decimal)
0.3
1.2
—
—
—
207
103
25
12
3
—
1.201
2.403
9.615
—
—
-0.16
-0.16
-0.16
—
—
103
51
12
—
0.300
1.201
2.403
—
-0.16
-0.16
-0.16
—
207
51
25
—
1.202
0.16
0.16
0.16
0.16
8.51
8.51
2.4
2.404
9.6
9.615
19.2
57.6
115.2
19.231
62.500
125.000
—
—
—
—
—
—
—
—
—
1
—
—
—
—
—
—
© 2008 Microchip Technology Inc.
DS39646C-page 253
PIC18F8722 FAMILY
TABLE 20-3: BAUD RATES FOR ASYNCHRONOUS MODES (CONTINUED)
SYNC = 0, BRGH = 0, BRG16 = 1
BAUD
RATE
(K)
FOSC = 40.000 MHz
FOSC = 20.000 MHz
FOSC = 10.000 MHz
FOSC = 8.000 MHz
Actual
Rate
(K)
SPBRG Actual
value
SPBRG Actual
value
(decimal)
SPBRG Actual
value
(decimal)
SPBRG
value
(decimal)
%
%
Error
%
Error
%
Error
Rate
(K)
Rate
(K)
Rate
(K)
Error
(decimal)
0.3
1.2
0.300
1.200
0.00
0.02
0.06
0.16
0.16
0.94
-1.36
8332
2082
1040
259
129
42
0.300
1.200
0.02
-0.03
-0.03
0.16
4165
1041
520
129
64
0.300
1.200
0.02
-0.03
0.16
0.16
1.73
-1.36
8.51
2082
520
259
64
0.300
1.201
2.403
9.615
19.230
55.555
—
-0.04
-0.16
-0.16
-0.16
-0.16
3.55
—
1665
415
207
51
2.4
2.402
2.399
2.404
9.6
9.615
9.615
9.615
19.2
57.6
115.2
19.231
58.140
113.636
19.231
56.818
113.636
0.16
19.531
56.818
125.000
31
25
-1.36
-1.36
21
10
8
21
10
4
—
SYNC = 0, BRGH = 0, BRG16 = 1
BAUD
RATE
(K)
FOSC = 4.000 MHz
FOSC = 2.000 MHz
FOSC = 1.000 MHz
Actual
Rate
(K)
SPBRG Actual
value
SPBRG Actual
value
(decimal)
SPBRG
value
(decimal)
%
%
Error
%
Error
Rate
(K)
Rate
(K)
Error
(decimal)
0.3
1.2
0.300
1.202
0.04
0.16
0.16
0.16
0.16
8.51
8.51
832
207
103
25
12
3
0.300
1.201
2.403
9.615
—
-0.16
-0.16
-0.16
-0.16
—
415
103
51
12
—
0.300
1.201
2.403
—
-0.16
-0.16
-0.16
—
207
51
25
—
2.4
2.404
9.6
9.615
19.2
57.6
115.2
19.231
62.500
125.000
—
—
—
—
—
—
—
—
—
1
—
—
—
—
—
—
SYNC = 0, BRGH = 1, BRG16 = 1 or SYNC = 1, BRG16 = 1
FOSC = 20.000 MHz FOSC = 10.000 MHz
BAUD
RATE
(K)
FOSC = 40.000 MHz
FOSC = 8.000 MHz
Actual
Rate
(K)
SPBRG Actual
SPBRG Actual
SPBRG Actual
value
SPBRG
value
(decimal)
%
Error
%
%
%
Error
value
(decimal)
Rate
(K)
value
Rate
(K)
Rate
(K)
Error
Error
(decimal)
(decimal)
0.3
1.2
0.300
1.200
0.00
0.00
0.02
0.06
-0.03
0.35
-0.22
33332
8332
4165
1040
520
0.300
1.200
0.00
0.02
0.02
-0.03
0.16
-0.22
0.94
16665
4165
2082
520
259
86
0.300
1.200
0.00
0.02
0.06
0.16
0.16
0.94
-1.36
8332
2082
1040
259
129
42
0.300
1.200
-0.01
-0.04
-0.04
-0.16
-0.16
0.79
6665
1665
832
207
103
34
2.4
2.400
2.400
2.402
2.400
9.6
9.606
9.596
9.615
9.615
19.2
57.6
115.2
19.193
57.803
114.943
19.231
57.471
116.279
19.231
58.140
113.636
19.230
57.142
11.7647
172
86
42
21
-2.12
16
SYNC = 0, BRGH = 1, BRG16 = 1 or SYNC = 1, BRG16 = 1
FOSC = 4.000 MHz FOSC = 2.000 MHz FOSC = 1.000 MHz
BAUD
RATE
(K)
Actual
Rate
(K)
SPBRG Actual
SPBRG Actual
SPBRG
value
(decimal)
%
Error
%
Error
%
Error
value
Rate
(K)
value
Rate
(K)
(decimal)
(decimal)
0.3
1.2
0.300
1.200
0.01
0.04
0.16
0.16
0.16
2.12
-3.55
3332
832
415
103
51
0.300
1.201
2.403
9.615
19.230
55.555
—
-0.04
-0.16
-0.16
-0.16
-0.16
3.55
—
1665
415
207
51
0.300
1.201
2.403
9.615
19.230
—
-0.04
-0.16
-0.16
-0.16
-0.16
—
832
207
103
25
2.4
2.404
9.6
9.615
19.2
57.6
115.2
19.231
58.824
111.111
25
12
16
8
—
8
—
—
—
—
DS39646C-page 254
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
20.1.3
AUTO-BAUD RATE DETECT
Note 1: If the WUE bit is set with the ABDEN bit,
Auto-Baud Rate Detection will occur on
the byte following the Break character.
The Enhanced USART module supports the automatic
detection and calibration of baud rate. This feature is
active only in Asynchronous mode and while the WUE
bit is clear.
2: It is up to the user to determine that the
incoming character baud rate is within the
range of the selected BRG clock source.
Some combinations of oscillator frequency
and EUSART baud rates are not possible
due to bit error rates. Overall system
timing and communication baud rates
must be taken into consideration when
using the Auto-Baud Rate Detection
feature.
The automatic baud rate measurement sequence
(Figure 20-1) begins whenever a Start bit is received
and the ABDEN bit is set. The calculation is
self-averaging.
In the Auto-Baud Rate Detect (ABD) mode, the clock to
the BRG is reversed. Rather than the BRG clocking the
incoming RXx signal, the RXx signal is timing the BRG.
In ABD mode, the internal Baud Rate Generator is
used as a counter to time the bit period of the incoming
serial byte stream.
TABLE 20-4: BRG COUNTER
CLOCK RATES
Once the ABDEN bit is set, the state machine will clear
the BRG and look for a Start bit. The Auto-Baud Rate
Detect must receive a byte with the value 55h (ASCII
“U”, which is also the LIN bus Sync character) in order to
calculate the proper bit rate. The measurement is taken
over both a low and a high bit time in order to minimize
any effects caused by asymmetry of the incoming signal.
After a Start bit, the SPBRGx begins counting up, using
the preselected clock source on the first rising edge of
RXx. After eight bits on the RXx pin or the fifth rising
edge, an accumulated value totalling the proper BRG
period is left in the SPBRGHx:SPBRGx register pair.
Once the 5th edge is seen (this should correspond to the
Stop bit), the ABDEN bit is automatically cleared.
BRG16 BRGH
BRG Counter Clock
0
0
1
1
0
1
0
1
FOSC/512
FOSC/128
FOSC/128
FOSC/32
Note: During the ABD sequence, SPBRGx and
SPBRGHx are both used as a 16-bit counter,
independent of BRG16 setting.
20.1.3.1
ABD and EUSART Transmission
Since the BRG clock is reversed during ABD acquisi-
tion, the EUSART transmitter cannot be used during
ABD. This means that whenever the ABDEN bit is set,
TXREGx cannot be written to. Users should also
ensure that ABDEN does not become set during a
transmit sequence. Failing to do this may result in
unpredictable EUSART operation.
If a rollover of the BRG occurs (an overflow from FFFFh
to 0000h), the event is trapped by the ABDOVF status
bit (BAUDCONx<7>). It is set in hardware by BRG roll-
overs and can be set or cleared by the user in software.
ABD mode remains active after rollover events and the
ABDEN bit remains set (Figure 20-2).
While calibrating the baud rate period, the BRG regis-
ters are clocked at 1/8th the preconfigured clock rate.
Note that the BRG clock will be configured by the
BRG16 and BRGH bits. Independent of the BRG16 bit
setting, both the SPBRGx and SPBRGHx will be used
as a 16-bit counter. This allows the user to verify that
no carry occurred for 8-bit modes by checking for 00h
in the SPBRGHx register. Refer to Table 20-4 for
counter clock rates to the BRG.
While the ABD sequence takes place, the EUSART
state machine is held in Idle. The RCxIF interrupt is set
once the fifth rising edge on RXx is detected. The value
in the RCREGx needs to be read to clear the RCxIF
interrupt. The contents of RCREGx should be
discarded.
© 2008 Microchip Technology Inc.
DS39646C-page 255
PIC18F8722 FAMILY
FIGURE 20-1:
AUTOMATIC BAUD RATE CALCULATION
BRG Value
RXx pin
XXXXh
0000h
001Ch
Edge #5
Stop Bit
Edge #2
Bit 3
Edge #3
Bit 5
Edge #4
Bit 7
Bit 6
Edge #1
Bit 1
Start
Bit 0
Bit 2
Bit 4
BRG Clock
Auto-Cleared
Set by User
ABDEN bit
RCxIF bit
(Interrupt)
Read
RCREGx
XXXXh
XXXXh
1Ch
00h
SPBRGx
SPBRGHx
Note: The ABD sequence requires the EUSART module to be configured in Asynchronous mode and WUE = 0.
FIGURE 20-2:
BRG OVERFLOW SEQUENCE
BRG Clock
ABDEN bit
RXx pin
Start
Bit 0
ABDOVF bit
BRG Value
FFFFh
XXXXh
0000h
0000h
DS39646C-page 256
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
Once the TXREGx register transfers the data to the
TSRx register (occurs in one TCY), the TXREGx register
is empty and the TXxIF flag bit (PIR1<4>) is set. This
interrupt can be enabled or disabled by setting or clearing
the interrupt enable bit, TXxIE (PIE1<4>). TXxIF will be
set regardless of the state of TXxIE; it cannot be cleared
in software. TXxIF is also not cleared immediately upon
loading TXREGx, but becomes valid in the second
instruction cycle following the load instruction. Polling
TXxIF immediately following a load of TXREGx will return
invalid results.
20.2 EUSART Asynchronous Mode
The Asynchronous mode of operation is selected by
clearing the SYNC bit (TXSTAx<4>). In this mode, the
EUSART uses standard Non-Return-to-Zero (NRZ)
format (one Start bit, eight or nine data bits and one Stop
bit). The most common data format is 8 bits. An on-chip
dedicated 8-bit/16-bit Baud Rate Generator can be used
to derive standard baud rate frequencies from the
oscillator.
The EUSART transmits and receives the LSb first. The
EUSART’s transmitter and receiver are functionally
independent, but use the same data format and baud
rate. The Baud Rate Generator produces a clock, either
x16 or x64 of the bit shift rate depending on the BRGH
and BRG16 bits (TXSTAx<2> and BAUDCONx<3>).
Parity is not supported by the hardware, but can be
implemented in software and stored as the 9th data bit.
While TXxIF indicates the status of the TXREGx regis-
ter, another bit, TRMT (TXSTAx<1>), shows the status
of the TSRx register. TRMT is a read-only bit which is
set when the TSRx register is empty. No interrupt logic
is tied to this bit so the user has to poll this bit in order
to determine if the TSRx register is empty.
When operating in Asynchronous mode, the EUSART
module consists of the following important elements:
Note 1: The TSRx register is not mapped in data
memory so it is not available to the user.
• Baud Rate Generator
• Sampling Circuit
2: Flag bit, TXxIF, is set when enable bit
TXEN is set.
• Asynchronous Transmitter
• Asynchronous Receiver
• Auto-Wake-up on Sync Break Character
• 12-bit Break Character Transmit
• Auto-Baud Rate Detection
To set up an Asynchronous Transmission:
1. Initialize the SPBRGHx:SPBRGx registers for
the appropriate baud rate. Set or clear the
BRGH and BRG16 bits, as required, to achieve
the desired baud rate.
2. Enable the asynchronous serial port by clearing
bit, SYNC, and setting bit, SPEN.
20.2.1
EUSART ASYNCHRONOUS
TRANSMITTER
3. If interrupts are desired, set enable bit, TXxIE.
The EUSART transmitter block diagram is shown in
Figure 20-3. The heart of the transmitter is the Transmit
(Serial) Shift Register (TSRx). The Shift register
obtains its data from the Read/Write Transmit Buffer
register, TXREGx. The TXREGx register is loaded with
data in software. The TSRx register is not loaded until
the Stop bit has been transmitted from the previous
load. As soon as the Stop bit is transmitted, the TSRx
is loaded with new data from the TXREGx register (if
available).
4. If 9-bit transmission is desired, set transmit bit,
TX9. Can be used as address/data bit.
5. Enable the transmission by setting bit, TXEN,
which will also set bit, TXxIF.
6. If 9-bit transmission is selected, the ninth bit
should be loaded in bit, TX9D.
7. Load data to the TXREGx register (starts
transmission).
8. If using interrupts, ensure that the GIE and PEIE
bits in the INTCON register (INTCON<7:6>) are
set.
© 2008 Microchip Technology Inc.
DS39646C-page 257
PIC18F8722 FAMILY
FIGURE 20-3:
EUSART TRANSMIT BLOCK DIAGRAM
Data Bus
TXxIF
TXREGx Register
8
TXxIE
MSb
(8)
LSb
0
Pin Buffer
and Control
•
• •
TSRx Register
TXx pin
Interrupt
Baud Rate CLK
TXEN
TRMT
SPEN
BRG16
SPBRGHx SPBRGx
Baud Rate Generator
TX9
TX9D
FIGURE 20-4:
ASYNCHRONOUS TRANSMISSION
Write to TXREGx
Word 1
BRG Output
(Shift Clock)
TXx (pin)
Start bit
bit 0
bit 1
Word 1
bit 7/8
Stop bit
TXxIF bit
(Transmit Buffer
Reg. Empty Flag)
1 TCY
Word 1
Transmit Shift Reg
TRMT bit
(Transmit Shift
Reg. Empty Flag)
FIGURE 20-5:
ASYNCHRONOUS TRANSMISSION (BACK TO BACK)
Write to TXREGx
Word 2
Start bit
Word 1
BRG Output
(Shift Clock)
TXx (pin)
Start bit
Word 2
bit 0
bit 1
bit 7/8
bit 0
Stop bit
1 TCY
Word 1
TXxIF bit
(Interrupt Reg. Flag)
1 TCY
Word 1
Transmit Shift Reg.
Word 2
Transmit Shift Reg.
TRMT bit
(Transmit Shift
Reg. Empty Flag)
Note: This timing diagram shows two consecutive transmissions.
DS39646C-page 258
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
TABLE 20-5: REGISTERS ASSOCIATED WITH ASYNCHRONOUS TRANSMISSION
Reset
Values
on page
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
INTCON
PIR1
GIE/GIEH PEIE/GIEL TMR0IE
INT0IE
TX1IF
RBIE
TMR0IF
CCP1IF
INT0IF
RBIF
57
60
60
60
60
60
59
59
59
61
61
59
PSPIF
PSPIE
PSPIP
TRISC7
—
ADIF
ADIE
ADIP
TRISC6
—
RC1IF
RC1IE
RC1IP
TRISC5
—
SSP1IF
SSP1IE
SSP1IP
TRISC3
TRISG3
ADDEN
TMR2IF
TMR1IF
PIE1
TX1IE
CCP1IE TMR2IE TMR1IE
CCP1IP TMR2IP TMR1IP
IPR1
TX1IP
TRISC
TRISG
RCSTAx
TXREGx
TXSTAx
TRISC4
TRISG4
CREN
TRISC2
TRISG2
FERR
TRISC1
TRISG1
OERR
TRISC0
TRISG0
RX9D
SPEN
RX9
SREN
EUSARTx Transmit Register
CSRC
TX9
TXEN
—
SYNC
SCKP
SENDB
BRG16
BRGH
—
TRMT
WUE
TX9D
BAUDCONx ABDOVF
RCIDL
ABDEN
SPBRGHx
SPBRGx
EUSARTx Baud Rate Generator Register High Byte
EUSARTx Baud Rate Generator Register Low Byte
Legend: — = unimplemented locations read as ‘0’. Shaded cells are not used for asynchronous transmission.
© 2008 Microchip Technology Inc.
DS39646C-page 259
PIC18F8722 FAMILY
20.2.2
EUSART ASYNCHRONOUS
RECEIVER
20.2.3
SETTING UP 9-BIT MODE WITH
ADDRESS DETECT
The receiver block diagram is shown in Figure 20-6.
The data is received on the RXx pin and drives the data
recovery block. The data recovery block is actually a
high-speed shifter operating at x16 times the baud rate,
whereas the main receive serial shifter operates at the
bit rate or at FOSC. This mode would typically be used
in RS-232 systems.
This mode would typically be used in RS-485 systems.
To set up an Asynchronous Reception with Address
Detect Enable:
1. Initialize the SPBRGHx:SPBRGx registers for
the appropriate baud rate. Set or clear the
BRGH and BRG16 bits, as required, to achieve
the desired baud rate.
To set up an Asynchronous Reception:
2. Enable the asynchronous serial port by clearing
the SYNC bit and setting the SPEN bit.
1. Initialize the SPBRGHx:SPBRGx registers for
the appropriate baud rate. Set or clear the
BRGH and BRG16 bits, as required, to achieve
the desired baud rate.
3. If interrupts are required, set the RCEN bit and
select the desired priority level with the RCxIP
bit.
2. Enable the asynchronous serial port by clearing
bit, SYNC, and setting bit, SPEN.
4. Set the RX9 bit to enable 9-bit reception.
5. Set the ADDEN bit to enable address detect.
6. Enable reception by setting the CREN bit.
3. If interrupts are desired, set enable bit, RCxIE.
4. If 9-bit reception is desired, set bit, RX9.
5. Enable the reception by setting bit, CREN.
7. The RCxIF bit will be set when reception is
complete. The interrupt will be Acknowledged if
the RCxIE and GIE bits are set.
6. Flag bit, RCxIF, will be set when reception is
complete and an interrupt will be generated if
enable bit, RCxIE, was set.
8. Read the RCSTAx register to determine if any
error occurred during reception, as well as read
bit 9 of data (if applicable).
7. Read the RCSTAx register to get the 9th bit (if
enabled) and determine if any error occurred
during reception.
9. Read RCREGx to determine if the device is
being addressed.
8. Read the 8-bit received data by reading the
RCREGx register.
10. If any error occurred, clear the CREN bit.
11. If the device has been addressed, clear the
ADDEN bit to allow all received data into the
receive buffer and interrupt the CPU.
9. If any error occurred, clear the error by clearing
enable bit, CREN.
10. If using interrupts, ensure that the GIE and PEIE
bits in the INTCON register (INTCON<7:6>) are
set.
FIGURE 20-6:
EUSART RECEIVE BLOCK DIAGRAM
CREN
OERR
FERR
x64 Baud Rate CLK
÷ 64
RSRx Register
• • •
0
MSb
Stop
LSb
Start
BRG16
SPBRGHx SPBRGx
or
÷ 16
(8)
7
1
or
Baud Rate Generator
÷ 4
RX9
Pin Buffer
and Control
Data
Recovery
RXx
RX9D
RCREGx Register
FIFO
SPEN
8
Interrupt
RCxIF
RCxIE
Data Bus
DS39646C-page 260
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
FIGURE 20-7:
ASYNCHRONOUS RECEPTION
Start
bit
Start
bit
Start
bit
RXx (pin)
Stop
bit
Stop
bit
Stop
bit
bit 0 bit 1
bit 7/8
bit 0
bit 7/8
bit 7/8
Rcv Shift Reg
Rcv Buffer Reg
Word 2
RCREGx
Word 1
RCREGx
Read Rcv
Buffer Reg
RCREGx
RCxIF
(Interrupt Flag)
OERR bit
CREN
Note: This timing diagram shows three words appearing on the RXx input. The RCREGx (receive buffer) is read after the third word
causing the OERR (Overrun) bit to be set.
TABLE 20-6: REGISTERS ASSOCIATED WITH ASYNCHRONOUS RECEPTION
Reset
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Values
on page
INTCON
PIR1
GIE/GIEH PEIE/GIEL TMR0IE
INT0IE
TX1IF
RBIE
TMR0IF
INT0IF
RBIF
57
60
60
60
60
60
59
59
59
61
61
59
PSPIF
PSPIE
PSPIP
TRISC7
—
ADIF
ADIE
ADIP
TRISC6
—
RC1IF
RC1IE
RC1IP
TRISC5
—
SSP1IF
SSP1IE
SSP1IP
TRISC3
CCP1IF TMR2IF TMR1IF
CCP1IE TMR2IE TMR1IE
CCP1IP TMR2IP TMR1IP
PIE1
TX1IE
TX1IP
TRISC4
IPR1
TRISC
TRISG
RCSTAx
RCREGx
TXSTAx
TRISC2
TRISC1 TRISC0
TRISG4 TRISG3 TRISG2 TRISG1 TRISG0
SPEN
RX9
SREN
CREN
ADDEN
FERR
OERR
RX9D
EUSARTx Receive Register
CSRC
TX9
TXEN
—
SYNC
SCKP
SENDB
BRG16
BRGH
—
TRMT
WUE
TX9D
BAUDCONx ABDOVF
RCIDL
ABDEN
SPBRGHx
SPBRGx
EUSARTx Baud Rate Generator Register High Byte
EUSARTx Baud Rate Generator Register Low Byte
Legend: — = unimplemented locations read as ‘0’. Shaded cells are not used for asynchronous reception.
© 2008 Microchip Technology Inc.
DS39646C-page 261
PIC18F8722 FAMILY
character and cause data or framing errors. To work
properly, therefore, the initial character in the transmis-
sion must be all ‘0’s. This can be 00h (8 bytes) for
standard RS-232 devices or 000h (12 bits) for LIN bus.
20.2.4
AUTO-WAKE-UP ON SYNC BREAK
CHARACTER
During Sleep mode, all clocks to the EUSART are
suspended. Because of this, the Baud Rate Generator is
inactive and a proper byte reception cannot be
performed. The auto-wake-up feature allows the
controller to wake-up due to activity on the RXx/DTx line,
while the EUSART is operating in Asynchronous mode.
Oscillator start-up time must also be considered,
especially in applications using oscillators with longer
start-up intervals (i.e., XT or HS mode). The Sync
Break (or Wake-up Signal) character must be of
sufficient length and be followed by a sufficient interval
to allow enough time for the selected oscillator to start
and provide proper initialization of the EUSART.
The auto-wake-up feature is enabled by setting the
WUE bit (BAUDCONx<1>). Once set, the typical receive
sequence on RXx/DTx is disabled and the EUSART
remains in an Idle state, monitoring for a wake-up event
independent of the CPU mode. A wake-up event
consists of a high-to-low transition on the RXx/DTx line.
(This coincides with the start of a Sync Break or a
Wake-up Signal character for the LIN protocol.)
20.2.4.2
Special Considerations Using
the WUE Bit
The timing of WUE and RCxIF events may cause
some confusion when it comes to determining the
validity of received data. As noted, setting the WUE bit
places the EUSART in an inactive state. The wake-up
event causes a receive interrupt by setting the RCxIF
bit. The WUE bit is cleared after this when a rising
edge is seen on RXx/DTx. The interrupt condition is
then cleared by reading the RCREGx register.
Ordinarily, the data in RCREGx will be dummy data
and should be discarded.
Following a wake-up event, the module generates an
RCxIF interrupt. The interrupt is generated synchro-
nously to the Q clocks in normal operating modes
(Figure 20-8) and asynchronously, if the device is in
Sleep mode (Figure 20-9). The interrupt condition is
cleared by reading the RCREGx register.
The WUE bit is automatically cleared once a low-to-
high transition is observed on the RXx line following the
wake-up event. At this point, the EUSART module is
inactive and returns to normal operation. This signals to
the user that the Sync Break event is over.
The fact that the WUE bit has been cleared (or is still
set) and the RCxIF flag is set should not be used as an
indicator of the integrity of the data in RCREGx. Users
should consider implementing a parallel method in
firmware to verify received data integrity.
20.2.4.1
Special Considerations Using
Auto-Wake-up
To assure that no actual data is lost, check the RCIDL
bit to verify that a receive operation is not in process. If
a receive operation is not occurring, the WUE bit may
then be set just prior to entering the Sleep mode.
Since auto-wake-up functions by sensing rising edge
transitions on RXx/DTx, information with any state
changes before the Stop bit may signal a false end-of-
FIGURE 20-8:
AUTO-WAKE-UP BIT (WUE) TIMINGS DURING NORMAL OPERATION
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
OSC1
WUE bit(1)
RXx/DTx Line
RCxIF
Bit set by user
Auto-Cleared
Cleared due to user read of RCREGx
Note 1:The EUSART remains inactive while the WUE bit is set.
FIGURE 20-9:
AUTO-WAKE-UP BIT (WUE) TIMINGS DURING SLEEP
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q1
Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
OSC1
WUE bit(2)
RXx/DTx Line
RCxIF
Bit set by user
Auto-Cleared
Note 1
Cleared due to user read of RCREGx
Sleep Ends
Sleep Command Executed
Note 1: If the wake-up event requires long oscillator warm-up time, the auto-clear of the WUE bit can occur before the oscillator is ready. This
sequence should not depend on the presence of Q clocks.
2: The EUSART remains inactive while the WUE bit is set.
DS39646C-page 262
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
1. Configure the EUSART for the desired mode.
20.2.5
BREAK CHARACTER SEQUENCE
2. Set the TXEN and SENDB bits to set up the
Break character.
The EUSART module has the capability of sending the
special Break character sequences that are required by
the LIN bus standard. The Break character transmit
consists of a Start bit, followed by twelve ‘0’ bits and a
Stop bit. The frame Break character is sent whenever
the SENDB and TXEN bits (TXSTAx<3> and
TXSTAx<5>) are set while the Transmit Shift register is
loaded with data. Note that the value of data written to
TXREGx will be ignored and all ‘0’s will be transmitted.
3. Load the TXREGx with a dummy character to
initiate transmission (the value is ignored).
4. Write ‘55h’ to TXREGx to load the Sync
character into the transmit FIFO buffer.
5. After the Break has been sent, the SENDB bit is
reset by hardware. The Sync character now
transmits in the preconfigured mode.
The SENDB bit is automatically reset by hardware after
the corresponding Stop bit is sent. This allows the user
to preload the transmit FIFO with the next transmit byte
following the Break character (typically, the Sync
character in the LIN specification).
When the TXREGx becomes empty, as indicated by
the TXxIF, the next data byte can be written to
TXREGx.
20.2.6
RECEIVING A BREAK CHARACTER
Note that the data value written to the TXREGx for the
Break character is ignored. The write simply serves the
purpose of initiating the proper sequence.
The Enhanced USART module can receive a Break
character in two ways.
The first method forces configuration of the baud rate
at a frequency of 9/13 the typical speed. This allows for
the Stop bit transition to be at the correct sampling loca-
tion (13 bits for Break versus Start bit and 8 data bits for
typical data).
The TRMT bit indicates when the transmit operation is
active or Idle, just as it does during normal transmis-
sion. See Figure 20-10 for the timing of the Break
character sequence.
The second method uses the auto-wake-up feature
described in Section 20.2.4 “Auto-Wake-up on Sync
Break Character”. By enabling this feature, the
EUSART will sample the next two transitions on RXx/
DTx, cause an RCxIF interrupt and receive the next
data byte followed by another interrupt.
20.2.5.1
Break and Sync Transmit Sequence
The following sequence will send a message frame
header made up of a Break, followed by an Auto-Baud
Sync byte. This sequence is typical of a LIN bus
master.
Note that following a Break character, the user will
typically want to enable the Auto-Baud Rate Detect
feature. For both methods, the user can set the ABD bit
once the TXxIF interrupt is observed.
FIGURE 20-10:
SEND BREAK CHARACTER SEQUENCE
Write to TXREGx
Dummy Write
BRG Output
(Shift Clock)
TXx (pin)
Start Bit
Bit 0
Bit 1
Break
Bit 11
Stop Bit
TXxIF bit
(Transmit Buffer
Reg. Empty Flag)
TRMT bit
(Transmit Shift
Reg. Empty Flag)
SENDB sampled here
Auto-Cleared
SENDB
(Transmit Shift
Reg. Empty Flag)
© 2008 Microchip Technology Inc.
DS39646C-page 263
PIC18F8722 FAMILY
Once the TXREGx register transfers the data to the
TSRx register (occurs in one TCY), the TXREGx is
empty and the TXxIF flag bit is set. The interrupt can be
enabled or disabled by setting or clearing the interrupt
enable bit, TXxIE. TXxIF is set regardless of the state
of enable bit TXxIE; it cannot be cleared in software. It
will reset only when new data is loaded into the
TXREGx register.
20.3 EUSART Synchronous
Master Mode
The Synchronous Master mode is entered by setting
the CSRC bit (TXSTAx<7>). In this mode, the data is
transmitted in a half-duplex manner (i.e., transmission
and reception do not occur at the same time). When
transmitting data, the reception is inhibited and vice
versa. Synchronous mode is entered by setting bit
SYNC (TXSTAx<4>). In addition, enable bit SPEN
(RCSTAx<7>) is set in order to configure the TXx and
RXx pins to CKx (clock) and DTx (data) lines,
respectively.
While flag bit TXxIF indicates the status of the TXREGx
register, another bit, TRMT (TXSTAx<1>), shows the
status of the TSRx register. TRMT is a read-only bit
which is set when the TSRx is empty. No interrupt logic
is tied to this bit, so the user must poll this bit in order to
determine if the TSRx register is empty. The TSRx is not
mapped in data memory so it is not available to the user.
The Master mode indicates that the processor trans-
mits the master clock on the CKx line. Clock polarity is
selected with the SCKP bit (BAUDCONx<4>); setting
SCKP sets the Idle state on CKx as high, while clearing
the bit sets the Idle state as low. This option is provided
to support Microwire devices with this module.
To set up a Synchronous Master Transmission:
1. Initialize the SPBRGHx:SPBRGx registers for the
appropriate baud rate. Set or clear the BRG16
bit, as required, to achieve the desired baud rate.
20.3.1
EUSART SYNCHRONOUS MASTER
TRANSMISSION
2. Enable the synchronous master serial port by
setting bits SYNC, SPEN and CSRC.
3. If interrupts are desired, set enable bit TXxIE.
4. If 9-bit transmission is desired, set bit TX9.
5. Enable the transmission by setting bit TXEN.
The EUSART transmitter block diagram is shown in
Figure 20-3. The heart of the transmitter is the Transmit
(Serial) Shift Register (TSRx). The Shift register
obtains its data from the Read/Write Transmit Buffer
register, TXREGx. The TXREGx register is loaded with
data in software. The TSRx register is not loaded until
the last bit has been transmitted from the previous load.
As soon as the last bit is transmitted, the TSRx is
loaded with new data from the TXREGx (if available).
6. If 9-bit transmission is selected, the ninth bit
should be loaded in bit TX9D.
7. Start transmission by loading data to the
TXREGx register.
8. If using interrupts, ensure that the GIE and PEIE
bits in the INTCON register (INTCON<7:6>) are
set.
FIGURE 20-11:
SYNCHRONOUS TRANSMISSION
Q1 Q2 Q3Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1Q2 Q3 Q4 Q1 Q2 Q3 Q4
Q3 Q4 Q1 Q2 Q3Q4 Q1Q2 Q3Q4 Q1 Q2Q3Q4 Q1 Q2Q3 Q4Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
DTx
bit 0
bit 1
bit 2
bit 7
bit 0
bit 1
bit 7
Word 2
Word 1
CKx pin
(SCKP = 0)
CKx pin
(SCKP = 1)
Write to
TXREGx Reg
Write Word 1
Write Word 2
TXxIF bit
(Interrupt Flag)
TRMT bit
‘1’
‘1’
TXEN bit
Note: Sync Master mode, SPBRGx = 0, continuous transmission of two 8-bit words.
DS39646C-page 264
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
FIGURE 20-12:
SYNCHRONOUS TRANSMISSION (THROUGH TXEN)
DTx pin
bit 0
bit 2
bit 1
bit 6
bit 7
CKx pin
Write to
TXREGx reg
TXxIF bit
TRMT bit
TXEN bit
TABLE 20-7: REGISTERS ASSOCIATED WITH SYNCHRONOUS MASTER TRANSMISSION
Reset
Values
on page
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
INTCON
PIR1
GIE/GIEH PEIE/GIEL TMR0IE
INT0IE
TX1IF
RBIE
TMR0IF
INT0IF
RBIF
57
60
60
60
60
60
59
59
59
61
61
59
PSPIF
PSPIE
PSPIP
TRISC7
—
ADIF
ADIE
ADIP
TRISC6
—
RC1IF
RC1IE
RC1IP
TRISC5
—
SSP1IF
SSP1IE
SSP1IP
TRISC3
CCP1IF TMR2IF TMR1IF
CCP1IE TMR2IE TMR1IE
CCP1IP TMR2IP TMR1IP
PIE1
TX1IE
TX1IP
TRISC4
IPR1
TRISC
TRISG
RCSTAx
TXREGx
TXSTAx
TRISC2
TRISC1
TRISC0
TRISG4 TRISG3 TRISG2 TRISG1 TRISG0
SPEN
RX9
SREN
CREN
ADDEN
FERR
OERR
RX9D
EUSARTx Transmit Register
CSRC
TX9
TXEN
—
SYNC
SCKP
SENDB
BRG16
BRGH
—
TRMT
WUE
TX9D
BAUDCONx ABDOVF
RCIDL
ABDEN
SPBRGHx EUSARTx Baud Rate Generator Register High Byte
SPBRGx EUSARTx Baud Rate Generator Register Low Byte
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used for synchronous master transmission.
© 2008 Microchip Technology Inc.
DS39646C-page 265
PIC18F8722 FAMILY
3. Ensure bits, CREN and SREN, are clear.
4. If interrupts are desired, set enable bit, RCxIE.
5. If 9-bit reception is desired, set bit, RX9.
20.3.2
EUSART SYNCHRONOUS
MASTER RECEPTION
Once Synchronous mode is selected, reception is
enabled by setting either the Single Receive Enable bit,
SREN (RCSTAx<5>), or the Continuous Receive
Enable bit, CREN (RCSTAx<4>). Data is sampled on
the RXx pin on the falling edge of the clock.
6. If a single reception is required, set bit, SREN.
For continuous reception, set bit, CREN.
7. Interrupt flag bit, RCxIF, will be set when recep-
tion is complete and an interrupt will be generated
if the enable bit, RCxIE, was set.
If enable bit SREN is set, only a single word is received.
If enable bit CREN is set, the reception is continuous
until CREN is cleared. If both bits are set, then CREN
takes precedence.
8. Read the RCSTAx register to get the 9th bit (if
enabled) and determine if any error occurred
during reception.
9. Read the 8-bit received data by reading the
RCREGx register.
To set up a Synchronous Master Reception:
1. Initialize the SPBRGHx:SPBRGx registers for the
appropriate baud rate. Set or clear the BRG16
bit, as required, to achieve the desired baud rate.
10. If any error occurred, clear the error by clearing
bit, CREN.
11. If using interrupts, ensure that the GIE and PEIE bits
in the INTCON register (INTCON<7:6>) are set.
2. Enable the synchronous master serial port by
setting bits, SYNC, SPEN and CSRC.
FIGURE 20-13:
SYNCHRONOUS RECEPTION (MASTER MODE, SREN)
Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1Q2 Q3 Q4 Q1 Q2Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
DTx pin
bit 0
bit 1
bit 2
bit 3
bit 4
bit 5
bit 6
bit 7
CKx pin
(SCKP = 0)
CKx pin
(SCKP = 1)
Write to
bit SREN
SREN bit
CREN bit
‘0’
‘0’
RCxIF bit
(Interrupt)
Read
RCREGx
Note: Timing diagram demonstrates Sync Master mode with bit SREN = 1and bit BRGH = 0.
DS39646C-page 266
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
TABLE 20-8: REGISTERS ASSOCIATED WITH SYNCHRONOUS MASTER RECEPTION
Reset
Values
on page
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
INTCON
PIR1
GIE/GIEH PEIE/GIEL TMR0IE
INT0IE
TX1IF
RBIE
TMR0IF
CCP1IF
CCP1IE
CCP1IP
TRISC2
TRISG2
FERR
INT0IF
TMR2IF
TMR2IE
TMR2IP
TRISC1
TRISG1
OERR
RBIF
57
60
60
60
60
60
59
59
59
61
61
59
PSPIF
PSPIE
PSPIP
TRISC7
—
ADIF
ADIE
ADIP
TRISC6
—
RC1IF
RC1IE
RC1IP
TRISC5
—
SSP1IF
SSP1IE
SSP1IP
TRISC3
TRISG3
ADDEN
TMR1IF
TMR1IE
TMR1IP
TRISC0
TRISG0
RX9D
PIE1
TX1IE
IPR1
TX1IP
TRISC
TRISG
RCSTAx
RCREGx
TXSTAx
TRISC4
TRISG4
CREN
SPEN
RX9
SREN
EUSARTx Receive Register
CSRC
TX9
TXEN
—
SYNC
SCKP
SENDB
BRG16
BRGH
—
TRMT
WUE
TX9D
BAUDCONx ABDOVF
RCIDL
ABDEN
SPBRGHx EUSARTx Baud Rate Generator Register High Byte
SPBRGx EUSARTx Baud Rate Generator Register Low Byte
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used for synchronous master reception.
© 2008 Microchip Technology Inc.
DS39646C-page 267
PIC18F8722 FAMILY
To set up a Synchronous Slave Transmission:
20.4 EUSART Synchronous
Slave Mode
1. Enable the synchronous slave serial port by
setting bits, SYNC and SPEN, and clearing bit,
CSRC.
Synchronous Slave mode is entered by clearing bit,
CSRC (TXSTAx<7>). This mode differs from the
Synchronous Master mode in that the shift clock is
supplied externally at the CKx pin (instead of being
supplied internally in Master mode). This allows the
device to transfer or receive data while in any low-power
mode.
2. Clear bits, CREN and SREN.
3. If interrupts are desired, set enable bit, TXxIE.
4. If 9-bit transmission is desired, set bit, TX9.
5. Enable the transmission by setting enable bit,
TXEN.
6. If 9-bit transmission is selected, the ninth bit
should be loaded in bit, TX9D.
20.4.1
EUSART SYNCHRONOUS
SLAVE TRANSMISSION
7. Start transmission by loading data to the
TXREGx register.
The operation of the Synchronous Master and Slave
modes is identical, except in the case of Sleep mode.
8. If using interrupts, ensure that the GIE and PEIE
bits in the INTCON register (INTCON<7:6>) are
set.
If two words are written to the TXREGx and then the
SLEEPinstruction is executed, the following will occur:
a) The first word will immediately transfer to the
TSRx register and transmit.
b) The second word will remain in the TXREGx
register.
c) Flag bit, TXxIF, will not be set.
d) When the first word has been shifted out of
TSRx, the TXREGx register will transfer the
second word to the TSRx and flag bit, TXxIF, will
now be set.
e) If enable bit, TXxIE, is set, the interrupt will wake
the chip from Sleep. If the global interrupt is
enabled, the program will branch to the interrupt
vector.
TABLE 20-9: REGISTERS ASSOCIATED WITH SYNCHRONOUS SLAVE TRANSMISSION
Reset
Values
on page
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
INTCON
PIR1
GIE/GIEH PEIE/GIEL TMR0IE
INT0IE
TX1IF
TX1IE
TX1IP
RBIE
TMR0IF
CCP1IF
INT0IF
RBIF
57
60
60
60
60
60
59
59
59
61
61
59
PSPIF
PSPIE
PSPIP
TRISC7
—
ADIF
ADIE
ADIP
TRISC6
—
RC1IF
RC1IE
RC1IP
SSP1IF
SSP1IE
SSP1IP
TRISC3
TMR2IF TMR1IF
PIE1
CCP1IE TMR2IE TMR1IE
CCP1IP TMR2IP TMR1IP
IPR1
TRISC
TRISG
RCSTAx
TXREGx
TXSTAx
TRISC5 TRISC4
TRISC2
TRISC1
TRISC0
—
TRISG4
CREN
TRISG3 TRISG2 TRISG1 TRISG0
SPEN
RX9
SREN
ADDEN
FERR
OERR
RX9D
EUSARTx Transmit Register
CSRC
TX9
TXEN
—
SYNC
SCKP
SENDB
BRG16
BRGH
—
TRMT
WUE
TX9D
BAUDCONx ABDOVF
RCIDL
ABDEN
SPBRGHx EUSARTx Baud Rate Generator Register High Byte
SPBRGx EUSARTx Baud Rate Generator Register Low Byte
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used for synchronous slave transmission.
DS39646C-page 268
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
To set up a Synchronous Slave Reception:
20.4.2
EUSART SYNCHRONOUS SLAVE
RECEPTION
1. Enable the synchronous master serial port by
setting bits, SYNC and SPEN, and clearing bit,
CSRC.
The operation of the Synchronous Master and Slave
modes is identical, except in the case of Sleep, or any
Idle mode and bit SREN, which is a “don’t care” in
Slave mode.
2. If interrupts are desired, set enable bit, RCxIE.
3. If 9-bit reception is desired, set bit, RX9.
4. To enable reception, set enable bit, CREN.
If receive is enabled by setting the CREN bit prior to
entering Sleep or any Idle mode, then a word may be
received while in this low-power mode. Once the word
is received, the RSRx register will transfer the data to
the RCREGx register; if the RCxIE enable bit is set, the
interrupt generated will wake the chip from the low-
power mode. If the global interrupt is enabled, the
program will branch to the interrupt vector.
5. Flag bit, RCxIF, will be set when reception is
complete. An interrupt will be generated if
enable bit, RCxIE, was set.
6. Read the RCSTAx register to get the 9th bit (if
enabled) and determine if any error occurred
during reception.
7. Read the 8-bit received data by reading the
RCREGx register.
8. If any error occurred, clear the error by clearing
bit, CREN.
9. If using interrupts, ensure that the GIE and PEIE
bits in the INTCON register (INTCON<7:6>) are
set.
TABLE 20-10: REGISTERS ASSOCIATED WITH SYNCHRONOUS SLAVE RECEPTION
Reset
Values
on page
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
INTCON
PIR1
GIE/GIEH PEIE/GIEL TMR0IE
INT0IE
TX1IF
RBIE
TMR0IF
CCP1IF
INT0IF
RBIF
57
60
60
60
60
60
59
59
59
61
61
59
PSPIF
PSPIE
PSPIP
TRISC7
—
ADIF
ADIE
ADIP
TRISC6
—
RC1IF
RC1IE
RC1IP
TRISC5
—
SSP1IF
SSP1IE
SSP1IP
TRISC3
TMR2IF TMR1IF
PIE1
TX1IE
TX1IP
TRISC4
CCP1IE TMR2IE TMR1IE
CCP1IP TMR2IP TMR1IP
IPR1
TRISC
TRISG
RCSTAx
RCREGx
TXSTAx
TRISC2
TRISC1
TRISC0
TRISG4 TRISG3
TRISG2 TRISG1 TRISG0
SPEN
RX9
SREN
CREN
ADDEN
FERR
OERR
RX9D
EUSARTx Receive Register
CSRC
TX9
TXEN
—
SYNC
SCKP
SENDB
BRG16
BRGH
—
TRMT
WUE
TX9D
BAUDCONx ABDOVF
RCIDL
ABDEN
SPBRGHx EUSARTx Baud Rate Generator Register High Byte
SPBRGx EUSARTx Baud Rate Generator Register Low Byte
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used for synchronous slave reception.
© 2008 Microchip Technology Inc.
DS39646C-page 269
PIC18F8722 FAMILY
NOTES:
DS39646C-page 270
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
The ADCON0 register, shown in Register 21-1,
controls the operation of the A/D module. The
ADCON1 register, shown in Register 21-2, configures
the functions of the port pins. The ADCON2 register,
shown in Register 21-3, configures the A/D clock
source, programmed acquisition time and justification.
21.0 10-BIT ANALOG-TO-DIGITAL
CONVERTER (A/D) MODULE
The Analog-to-Digital (A/D) converter module has
12 inputs for the 64-pin devices and 16 for the 80-pin
devices. This module allows conversion of an analog
input signal to a corresponding 10-bit digital number.
The module has five registers:
• A/D Result High Register (ADRESH)
• A/D Result Low Register (ADRESL)
• A/D Control Register 0 (ADCON0)
• A/D Control Register 1 (ADCON1)
• A/D Control Register 2 (ADCON2)
REGISTER 21-1: ADCON0: A/D CONTROL REGISTER
U-0
—
U-0
—
R/W-0
CHS3(1)
R/W-0
CHS2(1)
R/W-0
CHS1(1)
R/W-0
CHS0(1)
R/W-0
R/W-0
ADON
GO/DONE
bit 7
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7-6
bit 5-2
Unimplemented: Read as ‘0’
CHS<3:0> Analog Channel Select bits(1)
0000= Channel 0 (AN0)
0001= Channel 1 (AN1)
0010= Channel 2 (AN2)
0011= Channel 3 (AN3)
0100= Channel 4 (AN4)
0101= Channel 5 (AN5)
0110= Channel 6 (AN6)
0111= Channel 7 (AN7)
1000= Channel 8 (AN8)
1001= Channel 9 (AN9)
1010= Channel 10 (AN10)
1011= Channel 11 (AN11)
1100= Channel 12 (AN12)(1)
1101= Channel 13 (AN13)(1)
1110= Channel 14 (AN14)(1)
1111= Channel 15 (AN15)(1)
bit 1
bit 0
GO/DONE: A/D Conversion Status bit
When ADON = 1:
1= A/D conversion in progress
0= A/D Idle
ADON: A/D On bit
1= A/D converter module is enabled
0= A/D converter module is disabled
Note 1: These channels are not implemented on 64-pin devices.
© 2008 Microchip Technology Inc.
DS39646C-page 271
PIC18F8722 FAMILY
REGISTER 21-2: ADCON1: A/D CONTROL REGISTER 1
U-0
—
U-0
—
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
VCFG1
VCFG0
PCFG3
PCFG2
PCFG1
PCFG0
bit 7
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7-6
bit 5-4
Unimplemented: Read as ‘0’
VCFG<1:0>: Voltage Reference Configuration bits
A/D VREF+
A/D VREF-
00
01
10
11
AVDD
AVSS
External VREF+
AVDD
AVSS
External VREF-
External VREF-
External VREF+
bit 3-0
PCFG<3:0>: A/D Port Configuration Control bits:
PCFG<3:0>
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
1100
1101
1110
1111
A
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
A
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
A
A
D
D
D
D
D
D
D
D
D
D
D
D
D
D
A
A
A
D
D
D
D
D
D
D
D
D
D
D
D
D
A
A
A
A
D
D
D
D
D
D
D
D
D
D
D
D
A
A
A
A
A
D
D
D
D
D
D
D
D
D
D
D
A
A
A
A
A
A
D
D
D
D
D
D
D
D
D
D
A
A
A
A
A
A
A
D
D
D
D
D
D
D
D
D
A
A
A
A
A
A
A
A
D
D
D
D
D
D
D
D
A
A
A
A
A
A
A
A
A
D
D
D
D
D
D
D
A
A
A
A
A
A
A
A
A
A
D
D
D
D
D
D
A
A
A
A
A
A
A
A
A
A
A
D
D
D
D
D
A
A
A
A
A
A
A
A
A
A
A
A
D
D
D
D
A
A
A
A
A
A
A
A
A
A
A
A
A
D
D
D
A
A
A
A
A
A
A
A
A
A
A
A
A
A
D
D
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
D
A = Analog input
D = Digital I/O
Note 1: AN15 through AN12 are available only on 80-pin devices.
DS39646C-page 272
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
REGISTER 21-3: ADCON2: A/D CONTROL REGISTER 2
R/W-0
ADFM
U-0
—
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
ACQT2
ACQT1
ACQT0
ADCS2
ADCS1
ADCS0
bit 7
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7
ADFM: A/D Result Format Select bit
1= Right justified
0= Left justified
bit 6
Unimplemented: Read as ‘0’
bit 5-3
ACQT<2:0>: A/D Acquisition Time Select bits
111= 20 TAD
110= 16 TAD
101= 12 TAD
100= 8 TAD
011= 6 TAD
010= 4 TAD
001= 2 TAD
(1)
000= 0 TAD
bit 2-0
ADCS<2:0>: A/D Conversion Clock Select bits
111= FRC (clock derived from A/D RC oscillator)(1)
110= FOSC/64
101= FOSC/16
100= FOSC/4
011= FRC (clock derived from A/D RC oscillator)(1)
010= FOSC/32
001= FOSC/8
000= FOSC/2
Note 1: If the A/D FRC clock source is selected, a delay of one TCY (instruction cycle) is added before the A/D
clock starts. This allows the SLEEPinstruction to be executed before starting a conversion.
© 2008 Microchip Technology Inc.
DS39646C-page 273
PIC18F8722 FAMILY
The analog reference voltage is software selectable to
either the device’s positive and negative supply voltage
(VDD and VSS), or the voltage level on the RA3/AN3/
VREF+ and RA2/AN2/VREF- pins.
A device Reset forces all registers to their Reset state.
This forces the A/D module to be turned off and any
conversion in progress is aborted.
Each port pin associated with the A/D converter can be
configured as an analog input, or as a digital I/O. The
ADRESH and ADRESL registers contain the result of
the A/D conversion. When the A/D conversion is com-
plete, the result is loaded into the ADRESH:ADRESL
register pair, the GO/DONE bit (ADCON0 register) is
cleared and A/D Interrupt Flag bit, ADIF (PIR1<6>), is
set. The block diagram of the A/D module is shown in
Figure 21-1.
The A/D converter has a unique feature of being able
to operate while the device is in Sleep mode. To oper-
ate in Sleep, the A/D conversion clock must be derived
from the A/D’s internal RC oscillator.
The output of the sample and hold is the input into the
converter, which generates the result via successive
approximation.
FIGURE 21-1:
A/D BLOCK DIAGRAM
CHS<3:0>
1111
AN15(1)
1110
AN14(1)
1101
AN13(1)
1100
AN12(1)
1011
AN11
1010
AN10
1001
AN9
1000
AN8
0111
AN7
0110
AN6
0101
AN5
0100
AN4
VAIN
0011
(Input Voltage)
10-Bit
A/D
Converter
AN3
0010
AN2
0001
VCFG<1:0>
AN1
0000
AVDD
X0
AN0
VREF+
VREF-
X1
1X
0X
Reference
Voltage
AVSS
Note 1: Channels AN12 through AN15 are not available on 64-pin devices.
2: I/O pins have diode protection to VDD and VSS.
DS39646C-page 274
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
The value in the ADRESH:ADRESL registers is not
modified for a Power-on Reset. The ADRESH:ADRESL
registers will contain unknown data after a Power-on
Reset.
5. Wait for A/D conversion to complete, by either:
• Polling for the GO/DONE bit to be cleared
OR
• Waiting for the A/D interrupt
After the A/D module has been configured as desired,
the selected channel must be acquired before the
conversion is started. The analog input channels must
have their corresponding TRIS bits selected as an
input. To determine acquisition time, see Section 21.1
“A/D Acquisition Requirements”. After this acquisi-
tion time has elapsed, the A/D conversion can be
started. An acquisition time can be programmed to
occur between setting the GO/DONE bit and the actual
start of the conversion.
6. Read A/D Result registers (ADRESH:ADRESL);
clear bit ADIF, if required.
7. For next conversion, go to step 1 or step 2, as
required. The A/D conversion time per bit is
defined as TAD. A minimum wait of 2 TAD is
required before the next acquisition starts.
FIGURE 21-2:
A/D TRANSFER FUNCTION
The following steps should be followed to perform an A/D
conversion:
3FFh
3FEh
1. Configure the A/D module:
• Configure analog pins, voltage reference and
digital I/O (ADCON1)
• Select A/D input channel (ADCON0)
• Select A/D acquisition time (ADCON2)
• Select A/D conversion clock (ADCON2)
• Turn on A/D module (ADCON0)
2. Configure A/D interrupt (if desired):
• Clear ADIF bit
003h
002h
001h
000h
• Set ADIE bit
• Set GIE bit
3. Wait the required acquisition time (if required).
4. Start conversion:
Analog Input Voltage
• Set GO/DONE bit (ADCON0 register)
FIGURE 21-3:
ANALOG INPUT MODEL
VDD
Sampling
Switch
VT = 0.6V
ANx
SS
RIC ≤ 1k
RSS
Rs
CPIN
VAIN
ILEAKAGE
± 100 nA
CHOLD = 25 pF
VT = 0.6V
5 pF
VSS
Legend: CPIN
= Input Capacitance
= Threshold Voltage
VT
6V
5V
4V
3V
2V
ILEAKAGE = Leakage Current at the pin due to
various junctions
VDD
RIC
= Interconnect Resistance
SS
= Sampling Switch
CHOLD
RSS
= Sample/Hold Capacitance (from DAC)
= Sampling Switch Resistance
1
2
3
4
(kΩ)
Sampling Switch
© 2008 Microchip Technology Inc.
DS39646C-page 275
PIC18F8722 FAMILY
To calculate the minimum acquisition time,
Equation 21-1 may be used. This equation assumes
that 1/2 LSb error is used (1024 steps for the A/D). The
1/2 LSb error is the maximum error allowed for the A/D
to meet its specified resolution.
21.1 A/D Acquisition Requirements
For the A/D converter to meet its specified accuracy,
the charge holding capacitor (CHOLD) must be allowed
to fully charge to the input channel voltage level. The
analog input model is shown in Figure 21-3. The
source impedance (RS) and the internal sampling
switch (RSS) impedance directly affect the time
required to charge the capacitor CHOLD. The sampling
switch (RSS) impedance varies over the device voltage
(VDD). The source impedance affects the offset voltage
at the analog input (due to pin leakage current). The
maximum recommended impedance for analog
sources is 2.5 kΩ. After the analog input channel is
selected (changed), the channel must be sampled for
at least the minimum acquisition time before starting a
conversion.
Example 21-3 shows the calculation of the minimum
required acquisition time TACQ. This calculation is
based on the following application system
assumptions:
CHOLD
Rs
Conversion Error
VDD
Temperature
=
=
≤
=
=
25 pF
2.5 kΩ
1/2 LSb
5V → Rss = 2 kΩ
85°C (system max.)
Note:
When the conversion is started, the
holding capacitor is disconnected from the
input pin.
EQUATION 21-1: ACQUISITION TIME
TACQ
=
=
Amplifier Settling Time + Holding Capacitor Charging Time + Temperature Coefficient
TAMP + TC + TCOFF
EQUATION 21-2: A/D MINIMUM CHARGING TIME
VHOLD
or
TC
=
=
(VREF – (VREF/2048)) • (1 – e(-TC/CHOLD(RIC + RSS + RS))
)
-(CHOLD)(RIC + RSS + RS) ln(1/2048)
EQUATION 21-3: CALCULATING THE MINIMUM REQUIRED ACQUISITION TIME
TACQ
TAMP
TCOFF
=
=
=
TAMP + TC + TCOFF
0.2 μs
(Temp – 25°C)(0.02 μs/°C)
(85°C – 25°C)(0.02 μs/°C)
1.2 μs
Temperature coefficient is only required for temperatures > 25°C. Below 25°C, TCOFF = 0 ms.
TC
=
-(CHOLD)(RIC + RSS + RS) ln(1/2047) μs
-(25 pF) (1 kΩ + 2 kΩ + 2.5 kΩ) ln(0.0004883) μs
1.05 μs
TACQ
=
0.2 μs + 1 μs + 1.2 μs
2.4 μs
DS39646C-page 276
© 2008 Microchip Technology Inc.
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21.2 Selecting and Configuring
Acquisition Time
21.3 Selecting the A/D Conversion
Clock
The ADCON2 register allows the user to select an
acquisition time that occurs each time the GO/DONE
bit is set. It also gives users the option to use an
automatically determined acquisition time.
The A/D conversion time per bit is defined as TAD. The
A/D conversion requires 11 TAD per 10-bit conversion.
The source of the A/D conversion clock is software
selectable. There are seven possible options for TAD:
Acquisition time may be set with the ACQT<2:0> bits
(ADCON2<5:3>) which provides a range of 2 to 20 TAD.
When the GO/DONE bit is set, the A/D module
continues to sample the input for the selected acquisi-
tion time, then automatically begins a conversion.
Since the acquisition time is programmed, there may
be no need to wait for an acquisition time between
selecting a channel and setting the GO/DONE bit.
• 2 TOSC
• 4 TOSC
• 8 TOSC
• 16 TOSC
• 32 TOSC
• 64 TOSC
• Internal RC Oscillator
For correct A/D conversions, the A/D conversion clock
(TAD) must be as short as possible, but greater than the
minimum TAD (see parameter 130, Table 28-27 for
more information).
Manual
acquisition
is
selected
when
ACQT<2:0> = 000. When the GO/DONE bit is set,
sampling is stopped and a conversion begins. The user
is responsible for ensuring the required acquisition time
has passed between selecting the desired input
channel and setting the GO/DONE bit. This option is
also the default Reset state of the ACQT<2:0> bits and
is compatible with devices that do not offer
programmable acquisition times.
Table 21-1 shows the resultant TAD times derived from
the device operating frequencies and the A/D clock
source selected.
In either case, when the conversion is completed, the
GO/DONE bit is cleared, the ADIF flag is set and the
A/D begins sampling the currently selected channel
again. If an acquisition time is programmed, there is
nothing to indicate if the acquisition time has ended or
if the conversion has begun.
TABLE 21-1: TAD vs. DEVICE OPERATING FREQUENCIES
Maximum Device Frequency
AD Clock Source (TAD)
Operation ADCS<2:0>
PIC18FXXXX
PIC18LFXXXX(4)
2 TOSC
4 TOSC
8 TOSC
16 TOSC
32 TOSC
64 TOSC
RC(3)
000
100
001
101
010
110
x11
2.86 MHz
5.71 MHz
11.43 MHz
22.86 MHz
40.0 MHz
40.0 MHz
1.00 MHz(1)
1.43 kHz
2.86 MHz
5.72 MHz
11.43 MHz
22.86 MHz
22.86 MHz
1.00 MHz(2)
Note 1: The RC source has a typical TAD time of 1.2 μs.
2: The RC source has a typical TAD time of 2.5 μs.
3: For device frequencies above 1 MHz, the device must be in Sleep for the entire conversion or the A/D
accuracy may be out of specification.
4: Low-power (PIC18LFXXXX) devices only.
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21.4 Operation in Power-Managed
Modes
21.5 Configuring Analog Port Pins
The ADCON1, TRISA, TRISF and TRISH registers all
configure the A/D port pins. The port pins needed as
analog inputs must have their corresponding TRIS bits
set (input). If the TRIS bit is cleared (output), the digital
output level (VOH or VOL) will be converted.
The selection of the automatic acquisition time and A/D
conversion clock is determined in part by the clock
source and frequency while in a power-managed mode.
If the A/D is expected to operate while the device is in
The A/D operation is independent of the state of the
CHS<3:0> bits and the TRIS bits.
a
power-managed mode, the ACQT<2:0> and
ADCS<2:0> bits in ADCON2 should be updated in
accordance with the clock source to be used in that
mode. After entering the mode, an A/D acquisition or
conversion may be started. Once started, the device
should continue to be clocked by the same clock
source until the conversion has been completed.
Note 1: When reading the Port register, all pins
configured as analog input channels will
read as cleared (a low level). Pins con-
figured as digital inputs will convert as
analog inputs. Analog levels on a digitally
configured input will be accurately
converted.
If desired, the device may be placed into the
corresponding Idle mode during the conversion. If the
device clock frequency is less than 1 MHz, the A/D RC
clock source should be selected.
2: Analog levels on any pin defined as a
digital input may cause the digital input
buffer to consume current out of the
device’s specification limits.
Operation in the Sleep mode requires the A/D FRC
clock to be selected. If bits ACQT<2:0> are set to ‘000’
and a conversion is started, the conversion will be
delayed one instruction cycle to allow execution of the
SLEEPinstruction and entry to Sleep mode. The IDLEN
bit (OSCCON<7>) must have already been cleared
prior to starting the conversion.
DS39646C-page 278
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After the A/D conversion is completed or aborted, a
2 TAD wait is required before the next acquisition can
be started. After this wait, acquisition on the selected
channel is automatically started.
21.6 A/D Conversions
Figure 21-4 shows the operation of the A/D converter
after the GO/DONE bit has been set and the
ACQT<2:0> bits are cleared. A conversion is started
after the following instruction to allow entry into Sleep
mode before the conversion begins.
Note:
The GO/DONE bit should NOT be set in
the same instruction that turns on the A/D.
Figure 21-5 shows the operation of the A/D converter
after the GO/DONE bit has been set, the ACQT<2:0>
bits are set to ‘010’ and a 4 TAD acquisition time is
selected before the conversion starts.
21.7 Discharge
The discharge phase is used to initialize the value of
the capacitor array. The array is discharged before
every sample. This feature helps to optimize the unity-
gain amplifier, as the circuit always needs to charge the
capacitor array, rather than charge/discharge based on
previous measure values.
Clearing the GO/DONE bit during a conversion will abort
the current conversion. The A/D Result register pair will
NOT be updated with the partially completed A/D
conversion sample. This means the ADRESH:ADRESL
registers will continue to contain the value of the last
completed conversion (or the last value written to the
ADRESH:ADRESL registers).
FIGURE 21-4:
A/D CONVERSION TAD CYCLES (ACQT<2:0> = 000, TACQ = 0)
TCY - TAD
TAD6 TAD7 TAD8 TAD9 TAD10 TAD11 TAD1
TAD1 TAD2 TAD3 TAD4 TAD5
b7
b6
b4
b1
b0
b9
b8
b5
b3
b2
Conversion starts
Discharge
Holding capacitor is disconnected from analog input (typically 100 ns)
Set GO/DONE bit
On the following cycle:
ADRESH:ADRESL are loaded, GO/DONE bit is cleared,
ADIF bit is set, holding capacitor is connected to analog input.
FIGURE 21-5:
A/D CONVERSION TAD CYCLES (ACQT<2:0> = 010, TACQ = 4 TAD)
TAD Cycles
TACQT Cycles
7
8
9
10
b1
11 TAD1
b0
1
2
3
4
1
2
3
4
5
6
b7
b6
b3
b2
b8
b5
b4
b9
Automatic
Acquisition
Time
Discharge
Conversion starts
(Holding capacitor is disconnected)
Set GO/DONE bit
(Holding capacitor continues
acquiring input)
On the following cycle:
ADRESH:ADRESL are loaded, GO/DONE bit is cleared,
ADIF bit is set, holding capacitor is connected to analog input.
© 2008 Microchip Technology Inc.
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(moving ADRESH:ADRESL to the desired location).
The appropriate analog input channel must be selected
and the minimum acquisition period is either timed by
the user, or an appropriate TACQ time selected before
the Special Event Trigger sets the GO/DONE bit (starts
a conversion).
21.8 Use of the ECCP2 Trigger
An A/D conversion can be started by the Special Event
Trigger of the ECCP2 module. This requires that the
CCP2M<3:0> bits (CCP2CON<3:0>) be programmed
as ‘1011’ and that the A/D module is enabled (ADON
bit is set). When the trigger occurs, the GO/DONE bit
will be set, starting the A/D acquisition and conversion
and the Timer1 (or Timer3) counter will be reset to zero.
Timer1 (or Timer3) is reset to automatically repeat the
A/D acquisition period with minimal software overhead
If the A/D module is not enabled (ADON is cleared), the
Special Event Trigger will be ignored by the A/D module
but will still reset the Timer1 (or Timer3) counter.
TABLE 21-2: REGISTERS ASSOCIATED WITH A/D OPERATION
Reset
Values
on page
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
INTCON
PIR1
PIE1
GIE/GIEH PEIE/GIEL TMR0IE
INT0IE
TX1IF
TX1IE
TX1IP
EEIF
RBIE
TMR0IF
CCP1IF
CCP1IE
CCP1IP
HLVDIF
HLVDIE
HLVDIP
INT0IF
TMR2IF
TMR2IE
TMR2IP
TMR3IF
TMR3IE
TMR3IP
RBIF
57
60
60
60
60
60
60
59
59
59
59
59
60
60
60
PSPIF
PSPIE
ADIF
ADIE
ADIP
CMIF
CMIE
CMIP
RC1IF
RC1IE
RC1IP
—
SSP1IF
SSP1IE
SSP1IP
BCL1IF
BCL1IE
BCL1IP
TMR1IF
TMR1IE
TMR1IP
CCP2IF
CCP2IE
CCP2IP
IPR1
PIR2
PIE2
PSPIP
OSCFIF
OSCFIE
OSCFIP
—
EEIE
IPR2
—
EEIP
ADRESH A/D Result Register High Byte
ADRESL A/D Result Register Low Byte
ADCON0
ADCON1
ADCON2
TRISA
—
—
—
—
—
CHS3
VCFG1
ACQT2
CHS2
VCFG0
ACQT1
TRISA4
TRISF4
TRISH4
CHS1
PCFG3
ACQT0
TRISA3
TRISF3
TRISH3
CHS0 GO/DONE ADON
PCFG2
ADCS2
TRISA2
TRISF2
TRISH2
PCFG1
ADCS1
TRISA1
TRISF1
TRISH1
PCFG0
ADCS0
TRISA0
TRISF0
TRISH0
ADFM
TRISA7(1) TRISA6(1) TRISA5
TRISF
TRISH(2)
TRISF7
TRISH7
TRISF6
TRISH6
TRISF5
TRISH5
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used for A/D conversion.
Note 1: PORTA<7:6> and their direction bits are individually configured as port pins based on various primary
oscillator modes. When disabled, these bits read as ‘0’.
2: These registers are not implemented on 64-pin devices.
DS39646C-page 280
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The CMCON register (Register 22-1) selects the
comparator input and output configuration. Block
diagrams of the various comparator configurations are
shown in Figure 22-1.
22.0 COMPARATOR MODULE
The analog comparator module contains two
comparators that can be configured in a variety of
ways. The inputs can be selected from the analog
inputs multiplexed with pins RF3 through RF6, as well
as the on-chip voltage reference (see Section 23.0
“Comparator Voltage Reference Module”). The
digital outputs (normal or inverted) are available on
RF1 and RF2 and can also be read through the control
register.
REGISTER 22-1: CMCON: COMPARATOR MODULE CONTROL REGISTER
R-0
R-0
R/W-0
C2INV
R/W-0
C1INV
R/W-0
CIS
R/W-1
CM2
R/W-1
CM1
R/W-1
CM0
C2OUT
C1OUT
bit 7
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7
C2OUT: Comparator 2 Output bit
When C2INV = 0:
1= C2 VIN+ > C2 VIN-
0= C2 VIN+ < C2 VIN-
When C2INV = 1:
1= C2 VIN+ < C2 VIN-
0= C2 VIN+ > C2 VIN-
bit 6
C1OUT: Comparator 1 Output bit
When C1INV = 0:
1= C1 VIN+ > C1 VIN-
0= C1 VIN+ < C1 VIN-
When C1INV = 1:
1= C1 VIN+ < C1 VIN-
0= C1 VIN+ > C1 VIN-
bit 5
bit 4
bit 3
C2INV: Comparator 2 Output Inversion bit
1= C2 output inverted
0= C2 output not inverted
C1INV: Comparator 1 Output Inversion bit
1= C1 output inverted
0= C1 output not inverted
CIS: Comparator Input Switch bit
When CM2:CM0 = 110:
1= C1 VIN- connects to RF5/AN10/CVREF
C2 VIN- connects to RF3/AN8
0= C1 VIN- connects to RF6/AN11
C2 VIN- connects to RF4/AN9
bit 2-0
CM<2:0>: Comparator mode bits
Figure 22-1 shows the Comparator modes and the CM2:CM0 bit settings.
© 2008 Microchip Technology Inc.
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mode is changed, the comparator output level may not
be valid for the specified mode change delay shown in
Section 28.0 “Electrical Characteristics”.
22.1 Comparator Configuration
There are eight modes of operation for the compara-
tors, shown in Figure 22-1. Bits CM<2:0> of the
CMCON register are used to select these modes. The
TRISF register controls the data direction of the
comparator pins for each mode. If the Comparator
Note:
Comparator interrupts should be disabled
during Comparator mode change;
otherwise, a false interrupt may occur.
a
FIGURE 22-1:
COMPARATOR I/O OPERATING MODES
Comparators Reset
CM<2:0> = 000
Comparators Off (POR Default Value)
CM<2:0> = 111
RF6/AN11
A
D
VIN-
VIN-
RF6/AN11
Off (Read as ‘0’)
Off (Read as ‘0’)
Off (Read as ‘0’)
Off (Read as ‘0’)
C1
C2
C1
VIN+
VIN+
A
D
RF5/AN10/
CVREF
RF5/AN10/
CVREF
RF4/AN9
RF3/AN8
A
D
D
VIN-
VIN-
RF4/AN9
C2
VIN+
VIN+
A
RF3/AN8
Two Independent Comparators
Two Independent Comparators with Outputs
CM<2:0> = 010
CM<2:0> = 011
A
A
VIN-
VIN-
RF6/AN11
RF6/AN11
RF5/AN10
C1OUT
C2OUT
C1OUT
C2OUT
C1
C2
C1
C2
VIN+
VIN+
A
A
RF5/AN10/
CVREF
RF2/AN7/C1OUT*
A
A
RF4/AN9
RF3/AN8
VIN-
A
VIN-
RF4/AN9
VIN+
VIN+
A
RF3/AN8
RF1/AN6/C2OUT*
Two Common Reference Comparators
Two Common Reference Comparators with Outputs
CM<2:0> = 100
CM<2:0> = 101
RF6/AN11
A
A
RF6/AN11
VIN-
VIN-
C1OUT
C2OUT
C1OUT
C1
C2
C1
C2
VIN+
VIN+
A
A
RF5/AN10/
CVREF
RF5/AN10/
CVREF
RF2/AN7/
C1OUT*
RF4/AN9
RF3/AN8
A
D
VIN-
A
D
VIN-
RF4/AN9
RF3/AN8
VIN+
C2OUT
VIN+
RF1/AN6/C2OUT*
Four Inputs Multiplexed to Two Comparators
One Independent Comparator with Output
CM<2:0> = 110
CM<2:0> = 001
RF6/AN11
A
RF6/AN11
A
A
VIN-
CIS = 0
CIS = 1
VIN-
A
C1OUT
C1
VIN+
RF5/AN10/
CVREF
RF5/AN10/
CVREF
C1OUT
C2OUT
C1
C2
VIN+
A
A
RF4/AN9
RF3/AN8
RF2/AN7/
C1OUT*
VIN-
CIS = 0
CIS = 1
VIN+
D
D
VIN-
RF4/AN9
RF3/AN8
Off (Read as ‘0’)
C2
VIN+
CVREF
From VREF Module
A = Analog Input, port reads zeros always
D = Digital Input
CIS (CMCON<3>) is the Comparator Input Switch
* Setting the TRISF<2:1> bits will disable the comparator outputs by configuring the pins as inputs.
DS39646C-page 282
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22.3.2
INTERNAL REFERENCE SIGNAL
22.2 Comparator Operation
The comparator module also allows the selection of an
internally generated voltage reference from the
comparator voltage reference module. This module is
described in more detail in Section 23.0 “Comparator
Voltage Reference Module”.
A single comparator is shown in Figure 22-2, along with
the relationship between the analog input levels and
the digital output. When the analog input at VIN+ is less
than the analog input VIN-, the output of the comparator
is a digital low level. When the analog input at VIN+ is
greater than the analog input VIN-, the output of the
comparator is a digital high level. The shaded areas of
the output of the comparator in Figure 22-2 represent
the uncertainty, due to input offsets and response time.
The internal reference is only available in the mode
where four inputs are multiplexed to two comparators
(CM<2:0> = 110). In this mode, the internal voltage
reference is applied to the VIN+ pin of both
comparators.
22.3 Comparator Reference
22.4 Comparator Response Time
Depending on the comparator operating mode, either
an external or internal voltage reference may be used.
The analog signal present at VIN- is compared to the
signal at VIN+ and the digital output of the comparator
is adjusted accordingly (Figure 22-2).
Response time is the minimum time, after selecting a
new reference voltage or input source, before the
comparator output has a valid level. If the internal
reference is changed, the maximum delay of the
internal voltage reference must be considered when
using the comparator outputs. Otherwise, the
maximum delay of the comparators should be used
(see Section 28.0 “Electrical Characteristics”).
FIGURE 22-2:
SINGLE COMPARATOR
VIN+
VIN-
+
22.5 Comparator Outputs
Output
–
The comparator outputs are read through the CMCON
register. These bits are read-only. The comparator
outputs may also be directly output to the RF1 and RF2
I/O pins. When enabled, multiplexors in the output path
of the RF1 and RF2 pins will switch and the output of
each pin will be the unsynchronized output of the
comparator. The uncertainty of each of the
comparators is related to the input offset voltage and
the response time given in the specifications.
Figure 22-3 shows the comparator output block
diagram.
VIN-
VIN+
Output
The TRISF bits will still function as an output enable/
disable for the RF1 and RF2 pins while in this mode.
The polarity of the comparator outputs can be changed
using the C2INV and C1INV bits (CMCON<5:4>).
22.3.1
EXTERNAL REFERENCE SIGNAL
Note 1: When reading the PORT register, all pins
configured as analog inputs will read as a
‘0’. Pins configured as digital inputs will
convert an analog input according to the
Schmitt Trigger input specification.
When external voltage references are used, the
comparator module can be configured to have the com-
parators operate from the same or different reference
sources. However, threshold detector applications may
require the same reference. The reference signal must
be between VSS and VDD and can be applied to either
pin of the comparator(s).
2: Analog levels on any pin defined as a
digital input may cause the input buffer to
consume more current than is specified.
© 2008 Microchip Technology Inc.
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FIGURE 22-3:
COMPARATOR OUTPUT BLOCK DIAGRAM
Port pins
CxOUT
D
Q
Bus
Data
CxINV
EN
Read CMCON
D
Q
Set
CMIF
bit
EN
CL
From
Other
Comparator
Reset
22.6 Comparator Interrupts
22.7 Comparator Operation
During Sleep
The comparator interrupt flag is set whenever there is
a change in the output value of either comparator.
Software will need to maintain information about the
status of the output bits, as read from CMCON<7:6>, to
determine the actual change that occurred. The CMIF
bit (PIR2<6>) is the Comparator Interrupt Flag. The
CMIF bit must be reset by clearing it. Since it is also
possible to write a ‘1’ to this register, a simulated
interrupt may be initiated.
When a comparator is active and the device is placed
in Sleep mode, the comparator remains active and the
interrupt is functional if enabled. This interrupt will
wake-up the device from Sleep mode, when enabled.
Each operational comparator will consume additional
current, as shown in the comparator specifications. To
minimize power consumption while in Sleep mode, turn
off the comparators (CM<2:0> = 111) before entering
Sleep. If the device wakes up from Sleep, the contents
of the CMCON register are not affected.
Both the CMIE bit (PIE2<6>) and the PEIE bit
(INTCON<6>) must be set to enable the interrupt. In
addition, the GIE bit (INTCON<7>) must also be set. If
any of these bits are clear, the interrupt is not enabled,
though the CMIF bit will still be set if an interrupt
condition occurs.
22.8 Effects of a Reset
A device Reset forces the CMCON register to its Reset
state, causing the comparator modules to be turned off
(CM<2:0> = 111). However, the input pins (RF3
through RF6) are configured as analog inputs by
default on device Reset. The I/O configuration for these
pins is also determined by the setting of the
PCFG<3:0> bits (ADCON1<3:0>). Therefore, device
current is minimized when analog inputs are present at
Reset time.
Note:
If a change in the CMCON register
(C1OUT or C2OUT) should occur when a
read operation is being executed (start of
the Q2 cycle), then the CMIF (PIR2
register) interrupt flag may not get set.
The user, in the Interrupt Service Routine, can clear the
interrupt in the following manner:
a) Any read or write of CMCON will end the
mismatch condition.
b) Clear flag bit, CMIF.
A mismatch condition will continue to set flag bit, CMIF.
Reading CMCON will end the mismatch condition and
allow flag bit, CMIF, to be cleared.
DS39646C-page 284
© 2008 Microchip Technology Inc.
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range by more than 0.6V in either direction, one of the
diodes is forward biased and a latch-up condition may
occur. A maximum source impedance of 10 kΩ is
recommended for the analog sources. Any external
component connected to an analog input pin, such as
a capacitor or a Zener diode, should have very little
leakage current.
22.9 Analog Input Connection
Considerations
A simplified circuit for an analog input is shown in
Figure 22-4. Since the analog pins are connected to a
digital output, they have reverse biased diodes to VDD
and VSS. The analog input, therefore, must be between
VSS and VDD. If the input voltage deviates from this
FIGURE 22-4:
COMPARATOR ANALOG INPUT MODEL
VDD
VT = 0.6V
RIC
RS < 10k
AIN
Comparator
Input
ILEAKAGE
±500 nA
CPIN
5 pF
VA
VT = 0.6V
VSS
Legend: CPIN
=
=
Input Capacitance
Threshold Voltage
VT
ILEAKAGE = Leakage Current at the pin due to various junctions
RIC
RS
VA
=
=
=
Interconnect Resistance
Source Impedance
Analog Voltage
TABLE 22-1: REGISTERS ASSOCIATED WITH COMPARATOR MODULE
Reset
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Values
on page
CMCON
CVRCON
INTCON
PIR2
C2OUT
CVREN
C1OUT
CVROE
C2INV
CVRR
C1INV
CVRSS
INT0IE
EEIF
CIS
CM2
CM1
CVR1
INT0IF
CM0
CVR0
RBIF
59
59
60
60
60
60
60
CVR3
CVR2
GIE/GIEH PEIE/GIEL TMR0IE
RBIE
TMR0IF
HLVDIF
OSCFIF
OSCFIE
OSCFIP
TRISF7
CMIF
CMIE
—
—
BCL1IF
BCL1IE
BCL1IP
TRISF3
TMR3IF CCP2IF
PIE2
EEIE
HLVDIE TMR3IE CCP2IE
HLVDIP TMR3IP CCP2IP
IPR2
CMIP
—
EEIP
TRISF
TRISF6
TRISF5
TRISF4
TRISF2
TRISF1
TRISF0
Legend: — = unimplemented, read as ‘0’. Shaded cells are unused by the comparator module.
© 2008 Microchip Technology Inc.
DS39646C-page 285
PIC18F8722 FAMILY
NOTES:
DS39646C-page 286
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
primary difference between the ranges is the size of the
steps selected by the CVREF Selection bits
(CVR<3:0>), with one range offering finer resolution.
The equations used to calculate the output of the
comparator voltage reference are as follows:
23.0 COMPARATOR VOLTAGE
REFERENCE MODULE
The comparator voltage reference is a 16-tap resistor
ladder network that provides a selectable reference
voltage. Although its primary purpose is to provide a
reference for the analog comparators, it may also be
used independently of them.
If CVRR = 1:
CVREF = ((CVR3:CVR0)/24) x (CVRSRC)
If CVRR = 0:
A block diagram of the module is shown in Figure 23-1.
The resistor ladder is segmented to provide two ranges
of CVREF values and has a power-down function to
conserve power when the reference is not being used.
The module’s supply reference can be provided from
either device VDD/VSS or an external voltage reference.
CVREF = (CVRSRC/4) + ((CVR3:CVR0)/32) x
(CVRSRC)
The comparator reference supply voltage can come
from either VDD and VSS, or the external VREF+ and
VREF- that are multiplexed with RA2 and RA3. The
voltage source is selected by the CVRSS bit
(CVRCON<4>).
23.1 Configuring the Comparator
Voltage Reference
The settling time of the comparator voltage reference
must be considered when changing the CVREF
output (see Table 28-3 in Section 28.0 “Electrical
Characteristics”).
The voltage reference module is controlled through the
CVRCON register (Register 23-1). The comparator
voltage reference provides two ranges of output
voltage, each with 16 distinct levels. The range to be
used is selected by the CVRR bit (CVRCON<5>). The
REGISTER 23-1: CVRCON: COMPARATOR VOLTAGE REFERENCE CONTROL REGISTER
R/W-0
R/W-0
CVROE(1)
R/W-0
CVRR
R/W-0
R/W-0
CVR3
R/W-0
CVR2
R/W-0
CVR1
R/W-0
CVR0
CVREN
CVRSS
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
-n = Value at POR
bit 7
bit 6
bit 5
bit 4
bit 3-0
CVREN: Comparator Voltage Reference Enable bit
1= CVREF circuit powered on
0= CVREF circuit powered down
CVROE: Comparator VREF Output Enable bit(1)
1= CVREF voltage level is also output on the RF5/AN10/CVREF pin
0= CVREF voltage is disconnected from the RF5/AN10/CVREF pin
CVRR: Comparator VREF Range Selection bit
1= 0 to 0.667 CVRSRC, with CVRSRC/24 step size (low range)
0= 0.25 CVRSRC to 0.75 CVRSRC, with CVRSRC/32 step size (high range)
CVRSS: Comparator VREF Source Selection bit
1= Comparator reference source, CVRSRC = (VREF+) – (VREF-)
0= Comparator reference source, CVRSRC = AVDD – AVSS
CVR<3:0>: Comparator VREF Value Selection bits (0 ≤ (CVR<3:0>) ≤ 15)
When CVRR = 1:
CVREF = ((CVR<3:0>)/24) x (CVRSRC)
When CVRR = 0:
CVREF = (CVRSRC/4) + ((CVR<3:0>)/32) x (CVRSRC)
Note 1: CVROE overrides the TRISF<5> bit setting.
© 2008 Microchip Technology Inc.
DS39646C-page 287
PIC18F8722 FAMILY
FIGURE 23-1:
COMPARATOR VOLTAGE REFERENCE BLOCK DIAGRAM
CVRSS = 1
CVRSS = 0
VREF+
AVDD
8R
CVR<3:0>
R
CVREN
R
R
R
16 Steps
CVREF
R
R
R
CVRR
VREF-
8R
CVRSS = 1
CVRSS = 0
AVSS
23.2 Voltage Reference Accuracy/Error
23.4 Effects of a Reset
The full range of voltage reference cannot be realized
due to the construction of the module. The transistors
on the top and bottom of the resistor ladder network
(Figure 23-1) keep CVREF from approaching the refer-
ence source rails. The voltage reference is derived
from the reference source; therefore, the CVREF output
changes with fluctuations in that source. The tested
absolute accuracy of the voltage reference can be
found in Section 28.0 “Electrical Characteristics”.
A device Reset disables the voltage reference by
clearing bit, CVREN (CVRCON<7>). This Reset also
disconnects the reference from the RF5 pin by clearing
bit, CVROE (CVRCON<6>), and selects the high-
voltage range by clearing bit, CVRR (CVRCON<5>).
The CVR value select bits are also cleared.
23.5 Connection Considerations
The voltage reference module operates independently
of the comparator module. The output of the reference
generator may be connected to the RF5 pin if the
CVROE bit is set. Enabling the voltage reference out-
put onto RF5 when it is configured as a digital input will
increase current consumption. Connecting RF5 as a
digital output with CVRSS enabled will also increase
current consumption.
23.3 Operation During Sleep
When the device wakes up from Sleep through an
interrupt or a Watchdog Timer time-out, the contents of
the CVRCON register are not affected. To minimize
current consumption in Sleep mode, the voltage
reference should be disabled.
The RF5 pin can be used as a simple D/A output with
limited drive capability. Due to the limited current drive
capability, a buffer must be used on the voltage
reference output for external connections to VREF.
Figure 23-2 shows an example buffering technique.
DS39646C-page 288
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
FIGURE 23-2:
COMPARATOR VOLTAGE REFERENCE OUTPUT BUFFER EXAMPLE
PIC18FXXXX
CVREF
Module
(1)
R
+
–
CVREF Output
RF5
Voltage
Reference
Output
Impedance
Note 1: R is dependent upon the voltage reference Configuration bits, CVRCON<3:0> and CVRCON<5>.
TABLE 23-1: REGISTERS ASSOCIATED WITH COMPARATOR VOLTAGE REFERENCE
Reset
Values
on page
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
CVRCON
CMCON
TRISF
CVREN
C2OUT
TRISF7
CVROE
C1OUT
TRISF6
CVRR
C2INV
CVRSS
C1INV
CVR3
CIS
CVR2
CM2
CVR1
CM1
CVR0
CM0
59
59
60
TRISF5 TRISF4
TRISF3
TRISF2
TRISF1
TRISF0
Legend: Shaded cells are not used with the comparator voltage reference.
© 2008 Microchip Technology Inc.
DS39646C-page 289
PIC18F8722 FAMILY
NOTES:
DS39646C-page 290
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
The High/Low-Voltage Detect Control register
(Register 24-1) completely controls the operation of the
HLVD module. This allows the circuitry to be “turned
off” by the user under software control, which
minimizes the current consumption for the device.
24.0 HIGH/LOW-VOLTAGE DETECT
(HLVD)
The PIC18F8722 family of devices have
a
High/Low-Voltage Detect module (HLVD). This is a pro-
grammable circuit that allows the user to specify both a
device voltage trip point and the direction of change from
that point. If the device experiences an excursion past
the trip point in that direction, an interrupt flag is set. If the
interrupt is enabled, the program execution will branch to
the interrupt vector address and the software can then
respond to the interrupt.
The block diagram for the HLVD module is shown in
Figure 24-1.
REGISTER 24-1: HLVDCON: HIGH/LOW-VOLTAGE DETECT CONTROL REGISTER
R/W-0
U-0
—
R-0
R/W-0
R/W-0
HLVDL3(1)
R/W-1
HLVDL2(1)
R/W-0
HLVDL1(1)
R/W-1
HLVDL0(1)
VDIRMAG
IRVST
HLVDEN
bit 7
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7
VDIRMAG: Voltage Direction Magnitude Select bit
1= Event occurs when voltage equals or exceeds trip point (HLVDL<3:0>)
0= Event occurs when voltage equals or falls below trip point (HLVDL<3:0>)
bit 6
bit 5
Unimplemented: Read as ‘0’
IRVST: Internal Reference Voltage Stable Flag bit
1= Indicates that the voltage detect logic will generate the interrupt flag at the specified voltage range
0= Indicates that the voltage detect logic will not generate the interrupt flag at the specified voltage
range and the HLVD interrupt should not be enabled
bit 4
HLVDEN: High/Low-Voltage Detect Power Enable bit
1= HLVD enabled
0= HLVD disabled
bit 3-0
HLVDL<3:0>: Voltage Detection Limit bits(1)
1111= External analog input is used (input comes from the HLVDIN pin)
1110= Maximum setting
.
.
.
0000= Minimum setting
Note 1: See Table 28-4 for specifications.
© 2008 Microchip Technology Inc.
DS39646C-page 291
PIC18F8722 FAMILY
The module is enabled by setting the HLVDEN bit.
Each time that the HLVD module is enabled, the
circuitry requires some time to stabilize. The IRVST bit
is a read-only bit and is used to indicate when the circuit
is stable. The module can only generate an interrupt
after the circuit is stable and IRVST is set.
event, depending on the configuration of the module.
When the supply voltage is equal to the trip point, the
voltage tapped off of the resistor array is equal to the
internal reference voltage generated by the voltage
reference module. The comparator then generates an
interrupt signal by setting the HLVDIF bit.
The VDIRMAG bit determines the overall operation of
the module. When VDIRMAG is cleared, the module
monitors for drops in VDD below a predetermined set
point. When the bit is set, the module monitors for rises
in VDD above the set point.
The trip point voltage is software programmable to any one
of 16 values. The trip point is selected by programming the
HLVDL<3:0> bits (HLVDCON<3:0>).
The HLVD module has an additional feature that allows
the user to supply the trip voltage to the module from an
external source. This mode is enabled when bits
HLVDL<3:0> are set to ‘1111’. In this state, the
comparator input is multiplexed from the external input
pin, HLVDIN. This gives users flexibility because it
allows them to configure the High/Low-Voltage Detect
interrupt to occur at any voltage in the valid operating
range.
24.1 Operation
When the HLVD module is enabled, a comparator uses
an internally generated reference voltage as the set
point. The set point is compared with the trip point,
where each node in the resistor divider represents a
trip point voltage. The “trip point” voltage is the voltage
level at which the device detects a high or low-voltage
FIGURE 24-1:
HLVD MODULE BLOCK DIAGRAM (WITH EXTERNAL INPUT)
Externally Generated
Trip Point
VDD
VDD
HLVDL<3:0>
HLVDCON
Register
VDIRMAG
HLVDEN
HLVDIN
Set
HLVDIF
HLVDEN
BOREN
Internal Voltage
Reference
1.2V Typical
DS39646C-page 292
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
Depending on the application, the HLVD module does
not need to be operating constantly. To decrease the
current requirements, the HLVD circuitry may only
need to be enabled for short periods where the voltage
is checked. After doing the check, the HLVD module
may be disabled.
24.2 HLVD Setup
The following steps are needed to set up the HLVD
module:
1. Write the value to the HLVDL<3:0> bits that
selects the desired HLVD trip point.
2. Set the VDIRMAG bit to detect high voltage
24.4 HLVD Start-up Time
(VDIRMAG = 1) or low voltage (VDIRMAG = 0).
3. Enable the HLVD module by setting the
HLVDEN bit.
The internal reference voltage of the HLVD module,
specified in electrical specification parameter D420
(Section 28.2 “DC Characteristics”), may be used
by other internal circuitry, such as the Programmable
Brown-out Reset. If the HLVD or other circuits using the
voltage reference are disabled to lower the device’s
current consumption, the reference voltage circuit will
require time to become stable before a low or
high-voltage condition can be reliably detected. This
start-up time, TIRVST, is an interval that is independent
of device clock speed. It is specified in electrical
specification parameter 36 (Table 28-12).
4. Clear the HLVD interrupt flag (PIR2<2>), which
may have been set from a previous interrupt.
5. Enable the HLVD interrupt if interrupts are
desired by setting the HLVDIE and GIE bits
(PIE2<2> and INTCON<7>). An interrupt will not
be generated until the IRVST bit is set.
24.3 Current Consumption
When the module is enabled, the HLVD comparator
and voltage divider are enabled and will consume static
current. The total current consumption, when enabled,
is specified in electrical specification parameter D022B
(Section 28.2 “DC Characteristics”).
The HLVD interrupt flag is not enabled until TIRVST has
expired and a stable reference voltage is reached. For
this reason, brief excursions beyond the set point may
not be detected during this interval. Refer to
Figure 24-2 or Figure 24-3.
FIGURE 24-2:
LOW-VOLTAGE DETECT OPERATION (VDIRMAG = 0)
CASE 1:
HLVDIF may not be set
VDD
VHLVD
HLVDIF
Enable HLVD
IRVST
TIRVST
HLVDIF cleared in software
Internal Reference is stable
CASE 2:
VDD
VHLVD
HLVDIF
Enable HLVD
TIRVST
IRVST
Internal Reference is stable
HLVDIF cleared in software
HLVDIF cleared in software,
HLVDIF remains set since HLVD condition still exists
© 2008 Microchip Technology Inc.
DS39646C-page 293
PIC18F8722 FAMILY
FIGURE 24-3:
HIGH-VOLTAGE DETECT OPERATION (VDIRMAG = 1)
CASE 1:
HLVDIF may not be set
VHLVD
VDD
HLVDIF
Enable HLVD
IRVST
TIRVST
HLVDIF cleared in software
Internal Reference is stable
CASE 2:
VHLVD
VDD
HLVDIF
Enable HLVD
TIRVST
IRVST
Internal Reference is stable
HLVDIF cleared in software
HLVDIF cleared in software,
HLVDIF remains set since HLVD condition still exists
FIGURE 24-4:
TYPICAL LOW-VOLTAGE
DETECT APPLICATION
24.5 Applications
In many applications, the ability to detect a drop below
or rise above a particular threshold is desirable. For
example, the HLVD module could be periodically
enabled to detect Universal Serial Bus (USB) attach or
detach. This assumes the device is powered by a lower
voltage source than the USB when detached. An attach
would indicate a high-voltage detect from, for example,
3.3V to 5V (the voltage on USB) and vice versa for a
detach. This feature could save a design a few extra
components and an attach signal (input pin).
VA
VB
For general battery applications, Figure 24-4 shows a
possible voltage curve. Over time, the device voltage
decreases. When the device voltage reaches voltage
VA, the HLVD logic generates an interrupt at time TA.
The interrupt could cause the execution of an ISR,
which would allow the application to perform “house-
keeping tasks” and perform a controlled shutdown
before the device voltage exits the valid operating
range at TB. The HLVD, thus, would give the applica-
tion a time window, represented by the difference
between TA and TB, to safely exit.
TB
VA = HLVD trip point
VB = Minimum valid device
operating voltage
TA
Time
Legend:
DS39646C-page 294
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
24.6 Operation During Sleep
24.7 Effects of a Reset
When enabled, the HLVD circuitry continues to operate
during Sleep. If the device voltage crosses the trip
point, the HLVDIF bit will be set and the device will
wake-up from Sleep. Device execution will continue
from the interrupt vector address if interrupts have
been globally enabled.
A device Reset forces all registers to their Reset state.
This forces the HLVD module to be turned off.
TABLE 24-1: REGISTERS ASSOCIATED WITH HIGH/LOW-VOLTAGE DETECT MODULE
Reset
Values
on page
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
HLVDCON VDIRMAG
—
IRVST
HLVDEN HLVDL3 HLVDL2 HLVDL1 HLVDL0
58
57
60
60
60
60
INTCON
PIR2
GIE/GIEH PEIE/GIEL TMR0IE
INT0IE
EEIF
RBIE
TMR0IF
HLVDIF
INT0IF
RBIF
OSCFIF
OSCFIE
OSCFIP
CMIF
CMIE
CMIP
—
—
—
BCL1IF
BCL1IE
BCL1IP
TRISA3
TMR3IF CCP2IF
PIE2
EEIE
HLVDIE TMR3IE CCP2IE
HLVDIP TMR3IP CCP2IP
IPR2
EEIP
TRISA
TRISA7(1) TRISA6(1) TRISA5
TRISA4
TRISA2
TRISA1
TRISA0
Legend: — = unimplemented, read as ‘0’. Shaded cells are unused by the HLVD module.
Note 1: PORTA<7:6> and their direction bits are individually configured as port pins based on various primary
oscillator modes. When disabled, these bits read as ‘0’.
© 2008 Microchip Technology Inc.
DS39646C-page 295
PIC18F8722 FAMILY
NOTES:
DS39646C-page 296
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
25.1 Configuration Bits
25.0 SPECIAL FEATURES OF THE
CPU
The Configuration bits can be programmed (read as
‘0’) or left unprogrammed (read as ‘1’) to select various
device Configurations. These bits are mapped starting
at program memory location 300000h.
The PIC18F8722 family of devices include several fea-
tures intended to maximize reliability and minimize cost
through elimination of external components. These are:
The user will note that address 300000h is beyond the
user program memory space. In fact, it belongs to the
configuration memory space (300000h-3FFFFFh),
which can only be accessed using table reads and
table writes.
• Oscillator Selection
• Resets:
- Power-on Reset (POR)
- Power-up Timer (PWRT)
- Oscillator Start-up Timer (OST)
- Brown-out Reset (BOR)
• Interrupts
• Watchdog Timer (WDT)
• Fail-Safe Clock Monitor
• Two-Speed Start-up
• Code Protection
Programming the Configuration registers is done in a
manner similar to programming the Flash memory. The
WR bit in the EECON1 register starts a self-timed write
to the Configuration register. In normal operation mode,
a TBLWT instruction with the TBLPTR pointing to the
Configuration register sets up the address and the data
for the Configuration register write. Setting the WR bit
starts a long write to the Configuration register. The
Configuration registers are written a byte at a time. To
write or erase a configuration cell, a TBLWTinstruction
can write a ‘1’ or a ‘0’ into the cell. For additional details
on Flash programming, refer to Section 6.5 “Writing
to Flash Program Memory”.
• ID Locations
• In-Circuit Serial Programming
The oscillator can be configured for the application
depending on frequency, power, accuracy and cost. All
of the options are discussed in detail in Section 2.0
“Oscillator Configurations”.
A complete discussion of device Resets and interrupts
is available in previous sections of this data sheet.
In addition to their Power-up and Oscillator Start-up
Timers provided for Resets, the PIC18F8722 family of
devices has a Watchdog Timer, which is either perma-
nently enabled via the Configuration bits or software
controlled (if configured as disabled).
The inclusion of an internal RC oscillator also provides
the additional benefits of a Fail-Safe Clock Monitor
(FSCM) and Two-Speed Start-up. FSCM provides for
background monitoring of the peripheral clock and
automatic switchover in the event of its failure. Two-
Speed Start-up enables code to be executed almost
immediately on start-up, while the primary clock source
completes its start-up delays.
All of these features are enabled and configured by
setting the appropriate Configuration register bits.
© 2008 Microchip Technology Inc.
DS39646C-page 297
PIC18F8722 FAMILY
TABLE 25-1: CONFIGURATION BITS AND DEVICE IDs
Default/
Unprogrammed
Value
File Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
300001h CONFIG1H
300002h CONFIG2L
300003h CONFIG2H
IESO
—
FCMEN
—
—
—
—
FOSC3
BORV0
FOSC2
FOSC1
FOSC0
00-- 0111
---1 1111
---1 1111
1111 --11
1--- -011
1000 -1-1
1111 1111
11-- ----
1111 1111
111- ----
1111 1111
-1-- ----
xxxx xxxx
xxxx xxxx
BORV1
BOREN1 BOREN0 PWRTEN
—
—
—
WDTPS3 WDTPS2 WDTPS1 WDTPS0
WDTEN
PM0
(5)
300004h CONFIG3L
300005h CONFIG3H
300006h CONFIG4L
300008h CONFIG5L
300009h CONFIG5H
30000Ah CONFIG6L
30000Bh CONFIG6H
30000Ch CONFIG7L
30000Dh CONFIG7H
WAIT
MCLRE
DEBUG
BW
ABW1
—
ABW0
—
—
—
—
PM1
(5)
—
LPT1OSC ECCPMX
CCP2MX
STVREN
CP0
XINST
BBSIZ1 BBSIZ0
—
LVP
CP2
—
—
CP1
—
(1)
(1)
(2)
(2)
(3)
CP7
CP6
CP5
—
CP4
—
CP3
—
CPD
CPB
—
(1)
(1)
(2)
(2)
(2)
(3)
(3)
WRT7
WRT6
WRT5
WRTC
WRT4
—
WRT3
—
WRT2
—
WRT1
—
WRT0
—
WRTD
WRTB
(1)
(1)
(2)
EBRT7
EBRT6
EBTR5
—
EBTR4
—
EBTR3
—
EBTR2
—
EBTR1
—
EBTR0
—
—
EBTRB
DEV1
DEV9
(4)
3FFFFEh DEVID1
DEV2
DEV10
DEV0
DEV8
REV4
DEV7
REV3
DEV6
REV2
DEV5
REV1
DEV4
REV0
DEV3
(4)
3FFFFFh DEVID2
Legend:
x= unknown, u= unchanged, -= unimplemented, q= value depends on condition.
Shaded cells are unimplemented, read as ‘0’.
Note 1: Unimplemented in PIC18F6527/6622/6627/8527/8622/8627 devices.
2: Unimplemented in PIC18F6527/6622/8527/8622 devices.
3: Unimplemented in PIC18F6527/8527 devices.
4: See Register 25-13 for DEVID1 values. DEVID registers are read-only and cannot be programmed by the user.
5: Unimplemented in PIC18F6527/6622/6627/6722 devices.
DS39646C-page 298
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
REGISTER 25-1: CONFIG1H: CONFIGURATION REGISTER 1 HIGH (BYTE ADDRESS 300001h)
R/P-0
IESO
R/P-0
U-0
—
U-0
—
R/P-0
R/P-1
R/P-1
R/P-1
FCMEN
FOSC3
FOSC2
FOSC1
FOSC0
bit 7
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7
bit 6
IESO: Internal/External Oscillator Switchover bit
1= Two-Speed Start-up enabled
0= Two-Speed Start-up disabled
FCMEN: Fail-Safe Clock Monitor Enable bit
1= Fail-Safe Clock Monitor enabled
0= Fail-Safe Clock Monitor disabled
bit 5-4
bit 3-0
Unimplemented: Read as ‘0’
FOSC<3:0>: Oscillator Selection bits
11xx= External RC oscillator, CLKO function on RA6
101x= External RC oscillator, CLKO function on RA6
1001= Internal oscillator block, CLKO function on RA6, port function on RA7
1000= Internal oscillator block, port function on RA6 and RA7
0111= External RC oscillator, port function on RA6
0110= HS oscillator, PLL enabled (Clock Frequency = 4 x FOSC1)
0101= EC oscillator, port function on RA6
0100= EC oscillator, CLKO function on RA6
0011= External RC oscillator, CLKO function on RA6
0010= HS oscillator
0001= XT oscillator
0000= LP oscillator
© 2008 Microchip Technology Inc.
DS39646C-page 299
PIC18F8722 FAMILY
REGISTER 25-2: CONFIG2L: CONFIGURATION REGISTER 2 LOW (BYTE ADDRESS 300002h)
U-0
—
U-0
—
U-0
—
R/P-1
BORV1(1)
R/P-1
BORV0(1)
R/P-1
BOREN1(2)
R/P-1
R/P-1
BOREN0(2) PWRTEN(2)
bit 7
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7-5
bit 4-3
Unimplemented: Read as ‘0’
BORV<1:0>: Brown-out Reset Voltage bits(1)
11= Minimum setting
.
.
.
00= Maximum setting
bit 2-1
bit 0
BOREN<1:0>: Brown-out Reset Enable bits(2)
11= Brown-out Reset enabled in hardware only (SBOREN is disabled)
10= Brown-out Reset enabled in hardware only and disabled in Sleep mode (SBOREN is disabled)
01= Brown-out Reset enabled and controlled by software (SBOREN is enabled)
00= Brown-out Reset disabled in hardware and software
PWRTEN: Power-up Timer Enable bit(2)
1= PWRT disabled
0= PWRT enabled
Note 1: See Section 28.1 “DC Characteristics: Supply Voltage” for specifications.
2: The Power-up Timer is decoupled from Brown-out Reset, allowing these features to be independently con-
trolled.
DS39646C-page 300
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
REGISTER 25-3: CONFIG2H: CONFIGURATION REGISTER 2 HIGH (BYTE ADDRESS 300003h)
U-0
—
U-0
—
U-0
—
R/P-1
R/P-1
R/P-1
R/P-1
R/P-1
WDTPS3
WDTPS2
WDTPS1
WDTPS0
WDTEN
bit 7
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7-5
bit 4-1
Unimplemented: Read as ‘0’
WDTPS<3:0>: Watchdog Timer Postscale Select bits
1111= 1:32,768
1110= 1:16,384
1101= 1:8,192
1100= 1:4,096
1011= 1:2,048
1010= 1:1,024
1001= 1:512
1000= 1:256
0111= 1:128
0110= 1:64
0101= 1:32
0100= 1:16
0011= 1:8
0010= 1:4
0001= 1:2
0000= 1:1
bit 0
WDTEN: Watchdog Timer Enable bit
1= WDT enabled
0= WDT disabled (control is placed on the SWDTEN bit)
© 2008 Microchip Technology Inc.
DS39646C-page 301
PIC18F8722 FAMILY
REGISTER 25-4: CONFIG3L: CONFIGURATION REGISTER 3 LOW (BYTE ADDRESS 300004h)(1)
R/P-1
WAIT
R/P-1
BW
R/P-1
R/P-1
U-0
—
U-0
—
R/P-1
PM1
R/P-1
PM0
ABW1
ABW0
bit 7
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7
WAIT: External Bus Data Wait Enable bit
1= Wait selections are unavailable for table reads and table writes
0= Wait selections for table reads and table writes are determined by the WAIT<1:0> bits
bit 6
BW: Data Bus Width Select bit
1= 16-bit External Bus mode
0= 8-bit External Bus mode
bit 5-4
ABW<1:0>: Address Bus Width Select bits
11= 20-bit address bus
10= 16-bit address bus
01= 12-bit address bus
00= 8-bit address bus
bit 3-2
bit 1-0
Unimplemented: Read as ‘0’
PM<1:0>: Processor Data Memory Mode Select bits
11= Microcontroller mode
10= Microprocessor mode
01= Microprocessor with Boot Block mode
00= Extended Microcontroller mode
Note 1: This register is unimplemented in PIC18F6527/6622/6627/6722 devices.
DS39646C-page 302
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
REGISTER 25-5: CONFIG3H: CONFIGURATION REGISTER 3 HIGH (BYTE ADDRESS 300005h)
R/P-1
U-0
—
U-0
—
U-0
—
U-0
—
R/P-0
R/P-1
ECCPMX(1)
R/P-1
MCLRE
LPT1OSC
CCP2MX
bit 7
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7
MCLRE: MCLR Pin Enable bit
1= MCLR pin enabled; RG5 input pin disabled
0= RG5 input pin enabled; MCLR disabled
bit 6-3
bit 2
Unimplemented: Read as ‘0’
LPT1OSC: Low-Power Timer1 Oscillator Enable bit
1= Timer1 configured for low-power operation
0= Timer1 configured for higher power operation
bit 1
bit 0
ECCPMX: ECCP MUX bit(1)
1= ECCP1/3 (P1B/P1C/P3B/P3C) are multiplexed onto RE6, RE5, RE4 and RE3 respectively
0= ECCP1/3 (P1B/P1C/P3B/P3C) are multiplexed onto RH7, RH6, RH5 and RH4 respectively
CCP2MX: CCP2 MUX bit
1= ECCP2 input/output is multiplexed with RC1
0= ECCP2 input/output is multiplexed with RB3 in Extended Microcontroller, Microprocessor or
Microprocessor with Boot Block mode(1). ECCP2 is multiplexed with RE7 in Microcontroller mode.
Note 1: This feature is only available on PIC18F8527/8622/8627/8722 devices.
© 2008 Microchip Technology Inc.
DS39646C-page 303
PIC18F8722 FAMILY
REGISTER 25-6: CONFIG4L: CONFIGURATION REGISTER 4 LOW (BYTE ADDRESS 300006h)
R/P-1
R/P-0
R/P-0
R/P-0
U-0
—
R/P-1
LVP
U-0
—
R/P-1
DEBUG
XINST
BBSIZ1
BBSIZ0
STVREN
bit 7
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7
DEBUG: Background Debugger Enable bit
1= Background debugger disabled, RB6 and RB7 configured as general purpose I/O pins
0= Background debugger enabled, RB6 and RB7 are dedicated to In-Circuit Debug
bit 6
XINST: Extended Instruction Set Enable bit
1= Instruction set extension and Indexed Addressing mode enabled
0= Instruction set extension and Indexed Addressing mode disabled (Legacy mode)
bit 5-4
BBSIZ<1:0>: Boot Block Size Select bits
11= 4K words (8 Kbytes) boot block size
10= 4K words (8 Kbytes) boot block size
01= 2K words (4 Kbytes) boot block size
00= 1K word (2 Kbytes) boot block size
bit 3
bit 2
Unimplemented: Read as ‘0’
LVP: Single-Supply ICSP™ Enable bit
1= Single-Supply ICSP enabled
0= Single-Supply ICSP disabled
bit 1
bit 0
Unimplemented: Read as ‘0’
STVREN: Stack Full/Underflow Reset Enable bit
1= Stack full/underflow will cause Reset
0= Stack full/underflow will not cause Reset
DS39646C-page 304
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
REGISTER 25-7: CONFIG5L: CONFIGURATION REGISTER 5 LOW (BYTE ADDRESS 300008h)
R/C-1
CP7(1)
R/C-1
CP6(1)
R/C-1
CP5(2)
R/C-1
CP5(2)
R/C-1
CP3(3)
R/C-1
CP2
R/C-1
CP1
R/C-1
CP0
bit 7
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
CP7: Code Protection bit(1)
1= Block 7 (01C000-01FFFFh) not code-protected
0= Block 7 (01C000-01FFFFh) code-protected
CP6: Code Protection bit(1)
1= Block 6 (01BFFF-018000h) not code-protected
0= Block 6 (01BFFF-018000h) code-protected
CP5: Code Protection bit(2)
1= Block 5 (014000-017FFFh) not code-protected
0= Block 5 (014000-017FFFh) code-protected
CP4: Code Protection bit(2)
1= Block 4 (010000-013FFFh) not code-protected
0= Block 4 (010000-013FFFh) code-protected
CP3: Code Protection bit(3)
1= Block 3 (00C000-00FFFFh) not code-protected
0= Block 3 (00C000-00FFFFh) code-protected
CP2: Code Protection bit
1= Block 2 (008000-00BFFFh) not code-protected
0= Block 2 (008000-00BFFFh) code-protected
CP1: Code Protection bit
1= Block 1 (004000-007FFFh) not code-protected
0= Block 1 (004000-007FFFh) code-protected
CP0: Code Protection bit
1= Block 0 (000800, 001000 or 002000(4)-003FFFh) not code-protected
0= Block 0 (000800, 001000 or 002000(4)-003FFFh) code-protected
Note 1: Unimplemented in PIC18F6527/6622/6627/8527/8622/8627 devices; maintain this bit set.
2: Unimplemented in PIC18F6527/6622/8527/8622 devices; maintain this bit set.
3: Unimplemented in PIC18F6527/8527 devices; maintain this bit set.
4: Boot block size is determined by the BBSIZ<1:0> bits in CONFIG4L.
© 2008 Microchip Technology Inc.
DS39646C-page 305
PIC18F8722 FAMILY
REGISTER 25-8: CONFIG5H: CONFIGURATION REGISTER 5 HIGH (BYTE ADDRESS 300009h)
R/C-1
CPD
R/C-1
CPB
U-0
—
U-0
—
U-0
—
U-0
—
U-0
—
U-0
—
bit 7
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7
CPD: Data EEPROM Code Protection bit
1= Data EEPROM not code-protected
0= Data EEPROM code-protected
bit 6
CPB: Boot Block Code Protection bit
1= Boot block (000000-0007FFh) not code-protected
0= Boot block (000000-0007FFh) code-protected
bit 5-0
Unimplemented: Read as ‘0’
DS39646C-page 306
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
REGISTER 25-9: CONFIG6L: CONFIGURATION REGISTER 6 LOW (BYTE ADDRESS 30000Ah)
R/C-1
WRT7(1)
R/C-1
WRT6(1)
R/C-1
WRT5(2)
R/C-1
WRT4(2)
R/C-1
WRT3(3)
R/C-1
WRT2
R/C-1
WRT1
R/C-1
WRT0
bit 7
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
WRT7: Write Protection bit(1)
1= Block 7 (01C000-01FFFFh) not write-protected
0= Block 7 (01C000-01FFFFh) write-protected
WRT6: Write Protection bit(1)
1= Block 6 (01BFFF-018000h) not write-protected
0= Block 6 (01BFFF-018000h) write-protected
WRT5: Write Protection bit(2)
1= Block 5 (014000-017FFFh) not write-protected
0= Block 5 (014000-017FFFh) write-protected
WRT4: Write Protection bit(2)
1= Block 4 (010000-013FFFh) not write-protected
0= Block 4 (010000-013FFFh) write-protected
WRT3: Write Protection bit(3)
1= Block 3 (00C000-00FFFFh) not write-protected
0= Block 3 (00C000-00FFFFh) write-protected
WRT2: Write Protection bit
1= Block 2 (008000-00BFFFh) not write-protected
0= Block 2 (008000-00BFFFh) write-protected
WRT1: Write Protection bit
1= Block 1 (004000-007FFFh) not write-protected
0= Block 1 (004000-007FFFh) write-protected
WRT0: Write Protection bit
1= Block 0 (000800, 001000 or 002000(4)-003FFFh) not write-protected
0= Block 0 (000800, 001000 or 002000(4)-003FFFh) write-protected
Note 1: Unimplemented in PIC18F6527/6622/6627/8527/8622/8627 devices; maintain this bit set.
2: Unimplemented in PIC18F6527/6622/8527/8622 devices; maintain this bit set.
3: Unimplemented in PIC18F6527/8527 devices; maintain this bit set.
4: Boot block size is determined by the BBSIZ<1:0> bits in CONFIG4L.
© 2008 Microchip Technology Inc.
DS39646C-page 307
PIC18F8722 FAMILY
REGISTER 25-10: CONFIG6H: CONFIGURATION REGISTER 6 HIGH (BYTE ADDRESS 30000Bh)
R/C-1
R/C-1
R-1
WRTC(2)
U-0
—
U-0
—
U-0
—
U-0
—
U-0
—
WRTD
WRTB
bit 7
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7
bit 6
bit 5
WRTD: Data EEPROM Write Protection bit
1= Data EEPROM not write-protected
0= Data EEPROM write-protected
WRTB: Boot Block Write Protection bit
1= Boot block (000000-007FFF, 000FFF or 001FFFh(1)) not write-protected
0= Boot block (000000-007FFF, 000FFF or 001FFFh(1)) write-protected
WRTC: Configuration Register Write Protection bit(2)
1= Configuration registers (300000-3000FFh) not write-protected
0= Configuration registers (300000-3000FFh) write-protected
bit 4-0
Unimplemented: Read as ‘0’
Note 1: Boot block size is determined by the BBSIZ<1:0> bits in CONFIG4L.
2: This bit is read-only in normal execution mode; it can be written only in Program mode.
DS39646C-page 308
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
REGISTER 25-11: CONFIG7L: CONFIGURATION REGISTER 7 LOW (BYTE ADDRESS 30000Ch)
R/C-1
R/C-1
R/C-1
R/C-1
R/C-1
R/C-1
R/C-1
R/C-1
EBTR7(1)
EBTR6(1)
EBTR5(2)
EBTR4(2)
EBTR3(3)
EBTR2
EBTR1
EBTR0
bit 7
bit 0
Legend:
R = Readable bit
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
-n = Value at POR
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
EBTR7: Table Read Protection bit(1)
1= Block 7 (01C000-01FFFFh) not protected from table reads executed in other blocks
0= Block 7 (01C000-01FFFFh) protected from table reads executed in other blocks
EBTR6: Table Read Protection bit(1)
1= Block 6 (018000-01BFFFh) not protected from table reads executed in other blocks
0= Block 6 (018000-01BFFFh) protected from table reads executed in other blocks
EBTR5: Table Read Protection bit(2)
1= Block 5 (014000-017FFFh) not protected from table reads executed in other blocks
0= Block 5 (014000-017FFFh) protected from table reads executed in other blocks
EBTR4: Table Read Protection bit(2)
1= Block 4 (010000-013FFFh) not protected from table reads executed in other blocks
0= Block 4 (010000-013FFFh) protected from table reads executed in other blocks
EBTR3: Table Read Protection bit(3)
1= Block 3 (00C000-00FFFFh) not protected from table reads executed in other blocks
0= Block 3 (00C000-00FFFFh) protected from table reads executed in other blocks
EBTR2: Table Read Protection bit
1= Block 2 (008000-00BFFFh) not protected from table reads executed in other blocks
0= Block 2 (008000-00BFFFh) protected from table reads executed in other blocks
EBTR1: Table Read Protection bit
1= Block 1 (004000-007FFFh) not protected from table reads executed in other blocks
0= Block 1 (004000-007FFFh) protected from table reads executed in other blocks
EBTR0: Table Read Protection bit
1= Block 0 (000800, 001000 or 002000(4)-003FFFh) not protected from table reads executed in other
blocks
0= Block 0 (000800, 001000 or 002000(4)-003FFFh) protected from table reads executed in other
blocks
Note 1: Unimplemented in PIC18F6527/6622/6627/8527/8622/8627 devices; maintain this bit set.
2: Unimplemented in PIC18F6527/6622/8527/8622 devices; maintain this bit set.
3: Unimplemented in PIC18F6527/8527 devices; maintain this bit set.
4: Unimplemented in PIC18F6527/8527 devices; maintain this bit set.
© 2008 Microchip Technology Inc.
DS39646C-page 309
PIC18F8722 FAMILY
REGISTER 25-12: CONFIG7H: CONFIGURATION REGISTER 7 HIGH (BYTE ADDRESS 30000Dh)
U-0
—
R/C-1
U-0
—
U-0
—
U-0
—
U-0
—
U-0
—
U-0
—
EBTRB
bit 7
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7
bit 6
Unimplemented: Read as ‘0’
EBTRB: Boot Block Table Read Protection bit
1= Boot block (000000-007FFF, 000FFF or 001FFFh(1)) not protected from table reads executed in
other blocks
0= Boot block (000000-007FFF, 000FFF or 001FFFh(1)) protected from table reads executed in other
blocks
bit 5-0
Unimplemented: Read as ‘0’
Note 1: Boot block size is determined by the BBSIZ<1:0> bits in CONFIG4L.
DS39646C-page 310
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
REGISTER 25-13: DEVID1: DEVICE ID REGISTER 1 FOR THE PIC18F8722 FAMILY
R
R
R
R
R
R
R
R
DEV2
DEV1
DEV0
REV4
REV3
REV2
REV1
REV0
bit 7
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7-5
DEV<2:0>: Device ID bits
001= PIC18F8722
111= PIC18F8627
101= PIC18F8622
011= PIC18F8527
000= PIC18F6722
110= PIC18F6627
100= PIC18F6622
010= PIC18F6527
bit 4-0
REV<4:0>: Revision ID bits
These bits are used to indicate the device revision.
REGISTER 25-14: DEVID2: DEVICE ID REGISTER 2 FOR THE PIC18F8722 FAMILY
R
R
R
R
R
R
R
R
DEV10(1)
DEV9(1)
DEV8(1)
DEV7(1)
DEV6(1)
DEV5(1)
DEV4(1)
DEV3(1)
bit 7
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7-0
DEV<10:3>: Device ID bits(1)
These bits are used with the DEV<2:0> bits in the Device ID Register 1 to identify the part number.
0001 0100= PIC18F6722/8722 devices
0001 0011= PIC18F6527/6622/6627/8527/8622/8627 devices
Note 1: These values for DEV<10:3> may be shared with other devices. The specific device is always identified by
using the entire DEV<10:0> bit sequence.
© 2008 Microchip Technology Inc.
DS39646C-page 311
PIC18F8722 FAMILY
25.2 Watchdog Timer (WDT)
Note 1: The CLRWDT and SLEEP instructions
clear the WDT and postscaler counts
when executed.
For the PIC18F8722 family of devices, the WDT is
driven by the INTRC source. When the WDT is
enabled, the clock source is also enabled. The nominal
WDT period is 4 ms and has the same stability as the
INTRC oscillator.
2: Changing the setting of the IRCF bits
(OSCCON<6:4>) clears the WDT and
postscaler counts.
The 4 ms period of the WDT is multiplied by a 16-bit
postscaler. Any output of the WDT postscaler is
selected by a multiplexor, controlled by bits in
Configuration Register 2H. Available periods range
from 4 ms to 131.072 seconds (2.18 minutes). The
WDT and postscaler are cleared when any of the
following events occur: a SLEEPor CLRWDTinstruction
is executed, the IRCF bits (OSCCON<6:4>) are
changed or a clock failure has occurred.
3: When a CLRWDT instruction is executed,
the postscaler count will be cleared.
25.2.1
CONTROL REGISTER
Register 25-15 shows the WDTCON register. This is a
readable and writable register which contains a control
bit that allows software to override the WDT enable
Configuration bit, but only if the Configuration bit has
disabled the WDT.
FIGURE 25-1:
WDT BLOCK DIAGRAM
Enable WDT
SWDTEN
WDTEN
WDT Counter
Wake-up from
Power-Managed
Modes
÷128
INTRC Source
Change on IRCF bits
CLRWDT
WDT
Reset
Reset
Programmable Postscaler
1:1 to 1:32,768
All Device Resets
4
WDTPS<4:1>
Sleep
DS39646C-page 312
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
REGISTER 25-15: WDTCON: WATCHDOG TIMER CONTROL REGISTER
U-0
—
U-0
—
U-0
—
U-0
—
U-0
—
U-0
—
U-0
—
R/W-0
SWDTEN(1)
bit 0
bit 7
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7-1
bit 0
Unimplemented: Read as ‘0’
SWDTEN: Software Controlled Watchdog Timer Enable bit(1)
1= Watchdog Timer is on
0= Watchdog Timer is off
Note 1: This bit has no effect if the Configuration bit, WDTEN, is enabled.
TABLE 25-2: SUMMARY OF WATCHDOG TIMER REGISTERS
Reset
Values
on page
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
RCON
WDTCON
IPEN
—
SBOREN
—
—
—
RI
—
TO
—
PD
—
POR
—
BOR
56
SWDTEN
58
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by the Watchdog Timer.
© 2008 Microchip Technology Inc.
DS39646C-page 313
PIC18F8722 FAMILY
In all other power-managed modes, Two-Speed Start-
up is not used. The device will be clocked by the
currently selected clock source until the primary clock
source becomes available. The setting of the IESO bit
is ignored.
25.3 Two-Speed Start-up
The Two-Speed Start-up feature helps to minimize the
latency period from oscillator start-up to code execution
by allowing the microcontroller to use the INTOSC
oscillator as a clock source until the primary clock
source is available. It is enabled by setting the IESO
Configuration bit.
25.3.1
SPECIAL CONSIDERATIONS FOR
USING TWO-SPEED START-UP
Two-Speed Start-up should be enabled only if the
primary oscillator mode is LP, XT, HS or HSPLL
(crystal-based modes). Other sources do not require
an OST start-up delay; for these, Two-Speed Start-up
should be disabled.
While using the INTOSC oscillator in Two-Speed Start-
up, the device still obeys the normal command
sequences for entering power-managed modes,
including multiple SLEEP instructions (refer to
Section 3.1.4 “Multiple Sleep Commands”). In
practice, this means that user code can change the
SCS<1:0> bit settings or issue SLEEP instructions
before the OST times out. This would allow an
application to briefly wake-up, perform routine
“housekeeping” tasks and return to Sleep before the
device starts to operate from the primary oscillator.
When enabled, Resets and wake-ups from Sleep mode
cause the device to configure itself to run from the
internal oscillator block as the clock source, following
the time-out of the Power-up Timer after a Power-on
Reset is enabled. This allows almost immediate code
execution while the primary oscillator starts and the
OST is running. Once the OST times out, the device
automatically switches to PRI_RUN mode.
User code can also check if the primary clock source is
currently providing the device clocking by checking the
status of the OSTS bit (OSCCON<3>). If the bit is set,
the primary oscillator is providing the clock. Otherwise,
the internal oscillator block is providing the clock during
wake-up from Reset or Sleep mode.
To use a higher clock speed on wake-up, the INTOSC
or postscaler clock sources can be selected to provide
a higher clock speed by setting bits IRCF<2:0>
immediately after Reset. For wake-ups from Sleep, the
INTOSC or postscaler clock sources can be selected
by setting the IRCF2:0> bits prior to entering Sleep
mode.
FIGURE 25-2:
TIMING TRANSITION FOR TWO-SPEED START-UP (INTOSC TO HSPLL)
Q3
Q4
Q1
Q2 Q3 Q4 Q1 Q2 Q3
Q1
Q2
INTOSC
Multiplexor
OSC1
(1)
TOST
(1)
TPLL
1
2
n-1
n
PLL Clock
Output
Clock
Transition(2)
CPU Clock
Peripheral
Clock
Program
Counter
PC
PC + 2
PC + 4
PC + 6
OSTS bit Set
Wake from Interrupt Event
Note 1: TOST = 1024 TOSC; TPLL = 2 ms (approx). These intervals are not shown to scale.
2: Clock transition typically occurs within 2-4 TOSC.
DS39646C-page 314
© 2008 Microchip Technology Inc.
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To use a higher clock speed on wake-up, the INTOSC
or postscaler clock sources can be selected to provide
a higher clock speed by setting bits, IRCF<2:0>,
immediately after Reset. For wake-ups from Sleep, the
INTOSC or postscaler clock sources can be selected
by setting the IRCF<2:0> bits prior to entering Sleep
mode.
25.4 Fail-Safe Clock Monitor
The Fail-Safe Clock Monitor (FSCM) allows the
microcontroller to continue operation in the event of an
external oscillator failure by automatically switching the
device clock to the internal oscillator block. The FSCM
function is enabled by setting the FCMEN Configuration
bit.
The FSCM will detect failures of the primary or second-
ary clock sources only. If the internal oscillator block
fails, no failure would be detected, nor would any action
be possible.
When FSCM is enabled, the INTRC oscillator runs at
all times to monitor clocks to peripherals and provide a
backup clock in the event of a clock failure. Clock
monitoring (shown in Figure 25-3) is accomplished by
creating a sample clock signal, which is the INTRC out-
put divided by 64. This allows ample time between
FSCM sample clocks for a peripheral clock edge to
occur. The peripheral device clock and the sample
clock are presented as inputs to the Clock Monitor latch
(CM). The CM is set on the falling edge of the device
clock source, but cleared on the rising edge of the
sample clock.
25.4.1
FSCM AND THE WATCHDOG TIMER
Both the FSCM and the WDT are clocked by the
INTRC oscillator. Since the WDT operates with a
separate divider and counter, disabling the WDT has
no effect on the operation of the INTRC oscillator when
the FSCM is enabled.
As already noted, the clock source is switched to the
INTOSC clock when a clock failure is detected.
Depending on the frequency selected by the
IRCF<2:0> bits, this may mean a substantial change in
the speed of code execution. If the WDT is enabled
with a small prescale value, a decrease in clock speed
allows a WDT time-out to occur and a subsequent
device Reset. For this reason, fail-safe clock events
also reset the WDT and postscaler, allowing it to start
timing from when execution speed was changed and
decreasing the likelihood of an erroneous time-out.
FIGURE 25-3:
FSCM BLOCK DIAGRAM
Clock Monitor
Latch (CM)
(edge-triggered)
Peripheral
Clock
S
Q
Q
INTRC
Source
C
÷ 64
25.4.2
EXITING FAIL-SAFE OPERATION
(32 μs)
488 Hz
(2.048 ms)
The fail-safe condition is terminated by either a device
Reset or by entering a power-managed mode. On
Reset, the controller starts the primary clock source
specified in Configuration Register 1H (with any
required start-up delays that are required for the
oscillator mode, such as OST or PLL timer). The
INTOSC multiplexor provides the device clock until the
primary clock source becomes ready (similar to a Two-
Speed Start-up). The clock source is then switched to
the primary clock (indicated by the OSTS bit in the
OSCCON register becoming set). The Fail-Safe Clock
Monitor then resumes monitoring the peripheral clock.
Clock
Failure
Detected
Clock failure is tested for on the falling edge of the
sample clock. If a sample clock falling edge occurs
while CM is still set, a clock failure has been detected
(Figure 25-4). This causes the following:
• the FSCM generates an oscillator fail interrupt by
setting bit, OSCFIF (PIR2<7>);
• the device clock source is switched to the internal
oscillator block (OSCCON is not updated to show
the current clock source – this is the fail-safe
condition) and
The primary clock source may never become ready
during start-up. In this case, operation is clocked by the
INTOSC multiplexor. The OSCCON register will remain
in its Reset state until a power-managed mode is
entered.
• the WDT is reset.
During switchover, the postscaler frequency from the
internal oscillator block may not be sufficiently stable for
timing sensitive applications. In these cases, it may be
desirable to select another clock configuration and enter
an alternate power-managed mode. This can be done to
attempt a partial recovery or execute a controlled shut-
down. See Section 3.1.4 “Multiple Sleep Commands”
and Section 25.3.1 “Special Considerations for
Using Two-Speed Start-up” for more details.
© 2008 Microchip Technology Inc.
DS39646C-page 315
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FIGURE 25-4:
FSCM TIMING DIAGRAM
Sample Clock
Oscillator
Failure
Device
Clock
Output
CM Output
(Q)
Failure
Detected
OSCFIF
CM Test
CM Test
CM Test
Note:
The device clock is normally at a much higher frequency than the sample clock. The relative frequencies in this
example have been chosen for clarity.
For oscillator modes involving a crystal or resonator
(HS, HSPLL, LP or XT), the situation is somewhat
different. Since the oscillator may require a start-up
time considerably longer than the FCSM sample clock
time, a false clock failure may be detected. To prevent
this, the internal oscillator block is automatically config-
ured as the device clock and functions until the primary
clock is stable (the OST and PLL timers have timed
out). This is identical to Two-Speed Start-up mode.
Once the primary clock is stable, the INTRC returns to
its role as the FSCM source.
25.4.3
FSCM INTERRUPTS IN
POWER-MANAGED MODES
By entering a power-managed mode, the clock
multiplexor selects the clock source selected by the
OSCCON register. Fail-Safe Monitoring of the power-
managed clock source resumes in the power-managed
mode.
If an oscillator failure occurs during power-managed
operation, the subsequent events depend on whether
or not the oscillator failure interrupt is enabled. If
enabled (OSCFIF = 1), code execution will be clocked
by the INTOSC multiplexer. An automatic transition
back to the failed clock source will not occur.
Note:
The same logic that prevents false oscilla-
tor failure interrupts on POR, or wake from
Sleep, will also prevent the detection of
the oscillator’s failure to start at all follow-
ing these events. This can be avoided by
monitoring the OSTS bit and using a
timing routine to determine if the oscillator
is taking too long to start. Even so, no
oscillator failure interrupt will be flagged.
If the interrupt is disabled, subsequent interrupts while
in Idle mode will cause the CPU to begin executing
instructions while being clocked by the INTOSC
source.
25.4.4
POR OR WAKE FROM SLEEP
The FSCM is designed to detect oscillator failure at any
point after the device has exited Power-on Reset
(POR) or low-power Sleep mode. When the primary
device clock is EC, RC or INTRC modes, monitoring
can begin immediately following these events.
As noted in Section 25.3.1 “Special Considerations
for Using Two-Speed Start-up”, it is also possible to
select another clock configuration and enter an
alternate power-managed mode while waiting for the
primary clock to become stable. When the new power-
managed mode is selected, the primary clock is
disabled.
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Each of the blocks has three code protection bits
associated with them. They are:
25.5 Program Verification and
Code Protection
• Code-Protect bit (CPn)
• Write-Protect bit (WRTn)
• External Block Table Read bit (EBTRn)
The user program memory is divided into four blocks
for PIC18F6527/8527 devices, five blocks for
PIC18F6622/8622 devices, six blocks for PIC18F6627/
8627 devices and eight blocks for PIC18F6722/8722
devices. One of these is a boot block of 2, 4 or
8 Kbytes. The remainder of the memory is divided into
blocks on binary boundaries.
Figure 25-5 shows the program memory organization for
48, 64, 96 and 128-Kbyte devices and the specific code
protection bit associated with each block. The actual
locations of the bits are summarized in Table 25-3.
FIGURE 25-5:
CODE-PROTECTED PROGRAM MEMORY FOR THE PIC18F8722 FAMILY
000000h
MEMORY SIZE/DEVICE
Code Memory
01FFFFh
128 Kbytes
96 Kbytes
64 Kbytes
48 Kbytes
(PIC18FX527)
Address
Range
(PIC18FX722)
(PIC18FX627)
(PIC18FX622)
000000h
0007FFh* or
000FFFh* or
001FFFh*
Boot Block
Block 0
Boot Block
Boot Block
Block 0
Boot Block
Block 0
Unimplemented
Read as ‘0’
000800h* or
001000h* or
002000h*
Block 0
Block 1
003FFFh
004000h
Block 1
Block 1
Block 1
007FFFh
008000h
200000h
Block 2
Block 3
Block 4
Block 5
Block 6
Block 7
Block 2
Block 3
Block 4
Block 5
Block 2
Block 3
Block 2
00BFFFh
00C000h
Configuration
and ID
Space
00FFFFh
010000h
013FFFh
014000h
Unimplemented
Read ‘0’s
017FFFh
018000h
3FFFFFh
Unimplemented
Read ‘0’s
01BFFFh
01C000h
Unimplemented
Read ‘0’s
01FFFFh
Note: Sizes of memory areas are not to scale.
Boot block size is determined by the BBSIZ<1:0> bits in CONFIG4L.
*
© 2008 Microchip Technology Inc.
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PIC18F8722 FAMILY
TABLE 25-3: SUMMARY OF CODE PROTECTION REGISTERS
File Name
300008h CONFIG5L CP7(1)
300009h CONFIG5H CPD
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
CP6(1)
CP5(2)
CP4(2)
CP3(3)
CP2
—
CP1
—
CP0
—
CPB
—
—
—
30000Ah CONFIG6L WRT7(1) WRT6(1) WRT5(2) WRT4(2)
WRT3(3)
—
WRT2
—
WRT1
—
WRT0
—
30000Bh CONFIG6H WRTD WRTB WRTC
—
30000Ch CONFIG7L EBRT7(1) EBRT6(1) EBTR5(2) EBTR4(2) EBTR3(3)
30000Dh CONFIG7H EBTRB
Legend: Shaded cells are unimplemented.
EBTR2
—
EBTR1
—
EBTR0
—
—
—
—
—
Note 1: Unimplemented in PIC18F6527/6622/6627/8527/8622/8627 devices; maintain this bit set.
2: Unimplemented in PIC18F6527/6622/8527/8622 devices; maintain this bit set.
3: Unimplemented in PIC18F6527/8527 devices; maintain this bit set.
not allowed to read and will result in reading ‘0’s.
Figures 25-6 through 25-8 illustrate table write and table
read protection.
25.5.1
PROGRAM MEMORY
CODE PROTECTION
The program memory may be read to or written from
any location using the table read and table write
instructions. The device ID may be read with table
reads. The Configuration registers may be read and
written with the table read and table write instructions.
Note:
Code protection bits may only be written to
a ‘0’ from a ‘1’ state. It is not possible to
write a ‘1’ to a bit in the ‘0’ state. Code
protection bits are only set to ‘1’ by a full
chip erase or block erase function. The full
chip erase and block erase functions can
only be initiated via ICSP or an external
programmer. Refer to the device
programming specification for more
information.
In normal execution mode, the CPn bits have no direct
effect. CPn bits inhibit external reads and writes. A block
of user memory may be protected from table writes if the
WRTn Configuration bit is ‘0’. The EBTRn bits control
table reads. For a block of user memory with the EBTRn
bit set to ‘0’, a table read instruction that executes from
within that block is allowed to read. A table read instruc-
tion that executes from a location outside of that block is
FIGURE 25-6:
TABLE WRITE (WRTn) DISALLOWED
Register Values
Program Memory
Configuration Bit Settings
000000h
0007FFh
WRTB, EBTRB = 11
000800h
TBLPTR = 0008FFh
PC = 003FFEh
WRT0, EBTR0 = 01
TBLWT*
TBLWT*
003FFFh
004000h
WRT1, EBTR1 = 11
WRT2, EBTR2 = 11
WRT3, EBTR3 = 11
007FFFh
008000h
PC = 00BFFEh
00BFFFh
00C000h
00FFFFh
Results: All table writes disabled to Blockn whenever WRTn = 0.
DS39646C-page 318
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
FIGURE 25-7:
EXTERNAL BLOCK TABLE READ (EBTRn) DISALLOWED
Register Values
Program Memory
Configuration Bit Settings
000000h
WRTB, EBTRB = 11
0007FFh
000800h
TBLPTR = 0008FFh
PC = 007FFEh
WRT0, EBTR0 = 10
003FFFh
004000h
TBLRD*
WRT1, EBTR1 = 11
WRT2, EBTR2 = 11
007FFFh
008000h
00BFFFh
00C000h
WRT3, EBTR3 = 11
00FFFFh
Results: All table reads from external blocks to Blockn are disabled whenever EBTRn = 0.
TABLAT register returns a value of ‘0’.
FIGURE 25-8:
EXTERNAL BLOCK TABLE READ (EBTRn) ALLOWED
Register Values
Program Memory
Configuration Bit Settings
000000h
WRTB, EBTRB = 11
WRT0, EBTR0 = 10
0007FFh
000800h
TBLPTR = 0008FFh
PC = 003FFEh
TBLRD*
003FFFh
004000h
WRT1, EBTR1 = 11
WRT2, EBTR2 = 11
WRT3, EBTR3 = 11
007FFFh
008000h
00BFFFh
00C000h
00FFFFh
Results: Table reads permitted within Blockn, even when EBTRBn = 0.
TABLAT register returns the value of the data at the location TBLPTR.
© 2008 Microchip Technology Inc.
DS39646C-page 319
PIC18F8722 FAMILY
To use the In-Circuit Debugger function of the micro-
controller, the design must implement In-Circuit Serial
Programming connections to RG5/MCLR/VPP, VDD,
VSS, RB7 and RB6. This will interface to the In-Circuit
Debugger module available from Microchip or one of
the third party development tool companies.
25.5.2
DATA EEPROM
CODE PROTECTION
The entire data EEPROM is protected from external
reads and writes by two bits: CPD and WRTD. CPD
inhibits external reads and writes of data EEPROM.
WRTD inhibits internal and external writes to data
EEPROM. The CPU can always read data EEPROM
under normal operation, regardless of the protection bit
settings.
25.9 Single-Supply ICSP Programming
The LVP Configuration bit enables Single-Supply ICSP
Programming (formerly known as Low-Voltage ICSP
Programming or LVP). When Single-Supply Program-
ming is enabled, the microcontroller can be programmed
without requiring high voltage being applied to the
RG5/MCLR/VPP pin, but the RB5/KBI1/PGM pin is then
dedicated to controlling Program mode entry and is not
available as a general purpose I/O pin.
25.5.3
CONFIGURATION REGISTER
PROTECTION
The Configuration registers can be write-protected.
The WRTC bit controls protection of the Configuration
registers. In normal execution mode, the WRTC bit is
readable only. WRTC can only be written via ICSP or
an external programmer.
While programming, using single-supply programming
mode, VDD is applied to the RG5/MCLR/VPP pin as in
normal execution mode. To enter Programming mode,
VDD is applied to the PGM pin.
25.6 ID Locations
Eight memory locations (200000h-200007h) are
designated as ID locations, where the user can store
checksum or other code identification numbers. These
locations are both readable and writable during normal
execution through the TBLRD and TBLWT instructions
or during program/verify. The ID locations can be read
when the device is code-protected.
Note 1: High-voltage programming is always
available, regardless of the state of the
LVP bit or the PGM pin, by applying VIHH
to the MCLR pin.
2: By default, Single-Supply ICSP is
enabled in unprogrammed devices (as
supplied from Microchip) and erased
devices.
25.7
In-Circuit Serial Programming
3: When Single-Supply Programming is
enabled, the RB5 pin can no longer be
used as a general purpose I/O pin.
The PIC18F8722 family of devices can be serially
programmed while in the end application circuit. This is
simply done with two lines for clock and data and three
other lines for power, ground and the programming
voltage. This allows customers to manufacture boards
with unprogrammed devices and then program the
microcontroller just before shipping the product. This
also allows the most recent firmware or a custom
firmware to be programmed.
4: When LVP is enabled, externally pull the
PGM pin to VSS to allow normal program
execution.
If Single-Supply ICSP Programming mode will not be
used, the LVP bit can be cleared. RB5/KBI1/PGM then
becomes available as the digital I/O pin, RB5. The LVP
bit may be set or cleared only when using standard
high-voltage programming (VIHH applied to the RG5/
MCLR/VPP pin). Once LVP has been disabled, only the
standard high-voltage programming is available and
must be used to program the device.
25.8 In-Circuit Debugger
When the DEBUG Configuration bit is programmed to
a ‘0’, the In-Circuit Debugger functionality is enabled.
This function allows simple debugging functions when
used with MPLAB® IDE. When the microcontroller has
this feature enabled, some resources are not available
for general use. Table 25-4 shows which resources are
required by the background debugger.
Memory that is not code-protected can be erased using
a block erase, or erased row by row, then written at any
specified VDD. If code-protected memory is to be
erased, a block erase is required. If a block erase is to
be performed when using Low-Voltage Programming,
the device must be supplied with VDD of 4.5V to 5.5V.
TABLE 25-4: DEBUGGER RESOURCES
I/O pins:
RB6, RB7
2 levels
Stack:
Program Memory:
Data Memory:
512 bytes
10 bytes
DS39646C-page 320
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
The literal instructions may use some of the following
operands:
26.0 INSTRUCTION SET SUMMARY
The PIC18F8722 family of devices incorporates the
standard set of 75 PIC18 core instructions, as well as
an extended set of 8 new instructions for the optimiza-
tion of code that is recursive or that utilizes a software
stack. The extended set is discussed later in this
section.
• A literal value to be loaded into a file register
(specified by ‘k’)
• The desired FSR register to load the literal value
into (specified by ‘f’)
• No operand required
(specified by ‘—’)
The control instructions may use some of the following
operands:
26.1 Standard Instruction Set
The standard PIC18 instruction set adds many
enhancements to the previous PIC® MCU instruction
sets, while maintaining an easy migration from these
PIC MCU instruction sets. Most instructions are a
single program memory word (16 bits), but there are
four instructions that require two program memory
locations.
• A program memory address (specified by ‘n’)
• The mode of the CALLor RETURNinstructions
(specified by ‘s’)
• The mode of the table read and table write
instructions (specified by ‘m’)
• No operand required
(specified by ‘—’)
Each single-word instruction is a 16-bit word divided
into an opcode, which specifies the instruction type and
one or more operands, which further specify the
operation of the instruction.
All instructions are a single word, except for four
double-word instructions. These instructions were
made double-word to contain the required information
in 32 bits. In the second word, the 4 MSbs are 1’s. If this
second word is executed as an instruction (by itself), it
will execute as a NOP.
The instruction set is highly orthogonal and is grouped
into four basic categories:
• Byte-oriented operations
• Bit-oriented operations
• Literal operations
All single-word instructions are executed in a single
instruction cycle, unless a conditional test is true or the
program counter is changed as a result of the instruc-
tion. In these cases, the execution takes two instruction
cycles with the additional instruction cycle(s) executed
as a NOP.
• Control operations
The PIC18 instruction set summary in Table 26-2 lists
byte-oriented, bit-oriented, literal and control
operations. Table 26-1 shows the opcode field
descriptions.
The double word instructions execute in two instruction
cycles.
Most byte-oriented instructions have three operands:
One instruction cycle consists of four oscillator periods.
Thus, for an oscillator frequency of 4 MHz, the normal
instruction execution time is 1 μs. If a conditional test is
true, or the program counter is changed as a result of
an instruction, the instruction execution time is 2 μs.
Two-word branch instructions (if true) would take 3 μs.
1. The file register (specified by ‘f’)
2. The destination of the result (specified by ‘d’)
3. The accessed memory (specified by ‘a’)
The file register designator ‘f’ specifies which file regis-
ter is to be used by the instruction. The destination
designator ‘d’ specifies where the result of the
operation is to be placed. If ‘d’ is zero, the result is
placed in the WREG register. If ‘d’ is one, the result is
placed in the file register specified in the instruction.
Figure 26-1 shows the general formats that the instruc-
tions can have. All examples use the convention ‘nnh’
to represent a hexadecimal number.
The Instruction Set Summary, shown in Table 26-2,
lists the standard instructions recognized by the
Microchip MPASMTM Assembler.
All bit-oriented instructions have three operands:
1. The file register (specified by ‘f’)
Section 26.1.1 “Standard Instruction Set” provides
a description of each instruction.
2. The bit in the file register (specified by ‘b’)
3. The accessed memory (specified by ‘a’)
The bit field designator ‘b’ selects the number of the bit
affected by the operation, while the file register
designator ‘f’ represents the number of the file in which
the bit is located.
© 2008 Microchip Technology Inc.
DS39646C-page 321
PIC18F8722 FAMILY
TABLE 26-1: OPCODE FIELD DESCRIPTIONS
Field
Description
a
RAM access bit:
a = 0: RAM location in Access RAM (BSR register is ignored)
a = 1: RAM bank is specified by BSR register
bbb
Bit address within an 8-bit file register (0 to 7).
BSR
Bank Select Register. Used to select the current RAM bank.
ALU status bits: Carry, Digit Carry, Zero, Overflow, Negative.
C, DC, Z, OV, N
d
Destination select bit:
d = 0: store result in WREG
d = 1: store result in file register f
dest
f
Destination: either the WREG register or the specified register file location.
8-bit Register file address (00h to FFh), or 2-bit FSR designator (0h to 3h).
12-bit Register file address (000h to FFFh). This is the source address.
12-bit Register file address (000h to FFFh). This is the destination address.
Global Interrupt Enable bit.
f
f
s
d
GIE
k
Literal field, constant data or label (may be either an 8-bit, 12-bit or a 20-bit value).
Label name.
label
mm
The mode of the TBLPTR register for the table read and table write instructions.
Only used with table read and table write instructions:
No Change to register (such as TBLPTR with table reads and writes)
Post-Increment register (such as TBLPTR with table reads and writes)
Post-Decrement register (such as TBLPTR with table reads and writes)
Pre-Increment register (such as TBLPTR with table reads and writes)
*
*+
*-
+*
n
The relative address (2’s complement number) for relative branch instructions or the direct address for
Call/Branch and Return instructions.
PC
Program Counter.
PCL
Program Counter Low Byte.
Program Counter High Byte.
Program Counter High Byte Latch.
Program Counter Upper Byte Latch.
Power-Down bit.
PCH
PCLATH
PCLATU
PD
PRODH
PRODL
s
Product of Multiply High Byte.
Product of Multiply Low Byte.
Fast Call/Return mode select bit:
s = 0: do not update into/from shadow registers
s = 1: certain registers loaded into/from shadow registers (Fast mode)
TBLPTR
TABLAT
TO
21-bit Table Pointer (points to a Program Memory location).
8-bit Table Latch.
Time-out bit.
TOS
u
Top-of-Stack.
Unused or Unchanged.
Watchdog Timer.
WDT
WREG
x
Working register (accumulator).
Don’t care (‘0’ or ‘1’). The assembler will generate code with x = 0. It is the recommended form of use for
compatibility with all Microchip software tools.
z
z
7-bit offset value for Indirect Addressing of register files (source).
7-bit offset value for Indirect Addressing of register files (destination).
Optional argument.
s
d
{
}
Indicates an indexed address.
[text]
(text)
[expr]<n>
→
The contents of text.
Specifies bit nof the register indicated by the pointer expr.
Assigned to.
< >
Register bit field.
∈
In the set of.
User-defined term (font is Courier).
italics
DS39646C-page 322
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
FIGURE 26-1:
GENERAL FORMAT FOR INSTRUCTIONS
Byte-oriented file register operations
15 10
OPCODE f (FILE #)
Example Instruction
9
8
7
0
ADDWF MYREG, W, B
d
a
d = 0for result destination to be WREG register
d = 1for result destination to be file register (f)
a = 0to force Access Bank
a = 1for BSR to select bank
f = 8-bit file register address
Byte to Byte move operations (2-word)
15
12 11
0
0
OPCODE
f (Source FILE #)
MOVFF MYREG1, MYREG2
15
12 11
1111
f (Destination FILE #)
f = 12-bit file register address
Bit-oriented file register operations
15 12 11 9 8
OPCODE b (BIT #)
7
0
BSF MYREG, bit, B
a
f (FILE #)
b = 3-bit position of bit in file register (f)
a = 0to force Access Bank
a = 1for BSR to select bank
f = 8-bit file register address
Literal operations
15
8
7
0
MOVLW 7Fh
OPCODE
k (literal)
k = 8-bit immediate value
Control operations
CALL, GOTO and Branch operations
15
8 7
0
GOTO Label
OPCODE
12 11
n<7:0> (literal)
15
0
1111
n<19:8> (literal)
n = 20-bit immediate value
15
15
8
7
0
CALL MYFUNC
OPCODE
12 11
n<7:0> (literal)
S
0
1111
n<19:8> (literal)
S = Fast bit
15
11 10
0
0
BRA MYFUNC
BC MYFUNC
OPCODE
n<10:0> (literal)
15
OPCODE
8 7
n<7:0> (literal)
© 2008 Microchip Technology Inc.
DS39646C-page 323
PIC18F8722 FAMILY
TABLE 26-2: PIC18FXXXX INSTRUCTION SET
Mnemonic,
16-Bit Instruction Word
MSb LSb
Status
Affected
Description
Cycles
Notes
Operands
BYTE-ORIENTED OPERATIONS
ADDWF f, d, a Add WREG and f
ADDWFC f, d, a Add WREG and Carry bit to f
1
1
1
1
1
0010 01da ffff ffff C, DC, Z, OV, N 1, 2
0010 00da ffff ffff C, DC, Z, OV, N 1, 2
ANDWF
CLRF
COMF
f, d, a AND WREG with f
f, a Clear f
f, d, a Complement f
0001 01da ffff ffff Z, N
0110 101a ffff ffff Z
0001 11da ffff ffff Z, N
1,2
2
1, 2
4
CPFSEQ
CPFSGT
CPFSLT
DECF
DECFSZ
DCFSNZ
INCF
f, a
f, a
f, a
Compare f with WREG, Skip = 1 (2 or 3) 0110 001a ffff ffff None
Compare f with WREG, Skip > 1 (2 or 3) 0110 010a ffff ffff None
Compare f with WREG, Skip < 1 (2 or 3) 0110 000a ffff ffff None
4
1, 2
f, d, a Decrement f
f, d, a Decrement f, Skip if 0
f, d, a Decrement f, Skip if Not 0
f, d, a Increment f
1
0000 01da ffff ffff C, DC, Z, OV, N 1, 2, 3, 4
1 (2 or 3) 0010 11da ffff ffff None
1 (2 or 3) 0100 11da ffff ffff None
1
1, 2, 3, 4
1, 2
0010 10da ffff ffff C, DC, Z, OV, N 1, 2, 3, 4
INCFSZ
INFSNZ
IORWF
MOVF
f, d, a Increment f, Skip if 0
f, d, a Increment f, Skip if Not 0
f, d, a Inclusive OR WREG with f
f, d, a Move f
fs, fd Move fs (source) to 1st word
fd (destination) 2nd word
1 (2 or 3) 0011 11da ffff ffff None
1 (2 or 3) 0100 10da ffff ffff None
4
1, 2
1, 2
1
1
1
2
0001 00da ffff ffff Z, N
0101 00da ffff ffff Z, N
1100 ffff ffff ffff None
1111 ffff ffff ffff
MOVFF
MOVWF
MULWF
NEGF
RLCF
RLNCF
RRCF
f, a
f, a
f, a
Move WREG to f
Multiply WREG with f
Negate f
1
1
1
1
1
1
1
1
1
0110 111a ffff ffff None
0000 001a ffff ffff None
0110 110a ffff ffff C, DC, Z, OV, N
0011 01da ffff ffff C, Z, N
0100 01da ffff ffff Z, N
0011 00da ffff ffff C, Z, N
0100 00da ffff ffff Z, N
0110 100a ffff ffff None
0101 01da ffff ffff C, DC, Z, OV, N
1, 2
1, 2
f, d, a Rotate Left f through Carry
f, d, a Rotate Left f (No Carry)
f, d, a Rotate Right f through Carry
f, d, a Rotate Right f (No Carry)
RRNCF
SETF
f, a
Set f
1, 2
SUBFWB f, d, a Subtract f from WREG with
Borrow
SUBWF
f, d, a Subtract WREG from f
1
1
0101 11da ffff ffff C, DC, Z, OV, N 1, 2
0101 10da ffff ffff C, DC, Z, OV, N
SUBWFB f, d, a Subtract WREG from f with
Borrow
SWAPF
TSTFSZ
XORWF
f, d, a Swap Nibbles in f
f, a Test f, Skip if 0
f, d, a Exclusive OR WREG with f
1
0011 10da ffff ffff None
4
1, 2
1 (2 or 3) 0110 011a ffff ffff None
0001 10da ffff ffff Z, N
1
Note 1: When a PORT register is modified as a function of itself (e.g., MOVF PORTB, 1, 0), the value used will be that
value present on the pins themselves. For example, if the data latch is ‘1’ for a pin configured as input and is
driven low by an external device, the data will be written back with a ‘0’.
2: If this instruction is executed on the TMR0 register (and where applicable, d = 1), the prescaler will be cleared if
assigned.
3: If Program Counter (PC) is modified or a conditional test is true, the instruction requires two cycles. The second
cycle is executed as a NOP.
4: Some instructions are two-word instructions. The second word of these instructions will be executed as a NOP
unless the first word of the instruction retrieves the information embedded in these 16 bits. This ensures that all
program memory locations have a valid instruction.
DS39646C-page 324
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
TABLE 26-2: PIC18FXXXX INSTRUCTION SET (CONTINUED)
16-Bit Instruction Word
MSb LSb
Mnemonic,
Operands
Status
Affected
Description
Cycles
Notes
BIT-ORIENTED OPERATIONS
BCF
BSF
BTFSC
BTFSS
BTG
f, b, a Bit Clear f
f, b, a Bit Set f
f, b, a Bit Test f, Skip if Clear
f, b, a Bit Test f, Skip if Set
f, b, a Bit Toggle f
1
1
1001 bbba ffff ffff None
1000 bbba ffff ffff None
1, 2
1, 2
3, 4
3, 4
1, 2
1 (2 or 3) 1011 bbba ffff ffff None
1 (2 or 3) 1010 bbba ffff ffff None
1
0111 bbba ffff ffff None
CONTROL OPERATIONS
BC
BN
n
n
n
n
n
n
n
n
Branch if Carry
1 (2)
1 (2)
1 (2)
1 (2)
1 (2)
1 (2)
1 (2)
2
1110 0010 nnnn nnnn None
1110 0110 nnnn nnnn None
1110 0011 nnnn nnnn None
1110 0111 nnnn nnnn None
1110 0101 nnnn nnnn None
1110 0001 nnnn nnnn None
1110 0100 nnnn nnnn None
1101 0nnn nnnn nnnn None
1110 0000 nnnn nnnn None
1110 110s kkkk kkkk None
1111 kkkk kkkk kkkk
Branch if Negative
Branch if Not Carry
Branch if Not Negative
Branch if Not Overflow
Branch if Not Zero
Branch if Overflow
Branch Unconditionally
Branch if Zero
BNC
BNN
BNOV
BNZ
BOV
BRA
BZ
n
n, s
1 (2)
2
CALL
Call Subroutine 1st word
2nd word
CLRWDT
DAW
GOTO
—
—
n
Clear Watchdog Timer
Decimal Adjust WREG
Go to Address 1st word
2nd word
1
1
2
0000 0000 0000 0100 TO, PD
0000 0000 0000 0111 C
1110 1111 kkkk kkkk None
1111 kkkk kkkk kkkk
NOP
NOP
POP
PUSH
RCALL
RESET
RETFIE
—
—
—
—
n
No Operation
No Operation
Pop Top of Return Stack (TOS)
Push Top of Return Stack (TOS) 1
Relative Call
Software Device Reset
Return from Interrupt Enable
1
1
1
0000 0000 0000 0000 None
1111 xxxx xxxx xxxx None
0000 0000 0000 0110 None
0000 0000 0000 0101 None
1101 1nnn nnnn nnnn None
0000 0000 1111 1111 All
0000 0000 0001 000s GIE/GIEH,
PEIE/GIEL
4
2
1
2
s
RETLW
RETURN
SLEEP
k
s
—
Return with Literal in WREG
Return from Subroutine
Go into Standby mode
2
2
1
0000 1100 kkkk kkkk None
0000 0000 0001 001s None
0000 0000 0000 0011 TO, PD
Note 1: When a PORT register is modified as a function of itself (e.g., MOVF PORTB, 1, 0), the value used will be that
value present on the pins themselves. For example, if the data latch is ‘1’ for a pin configured as input and is
driven low by an external device, the data will be written back with a ‘0’.
2: If this instruction is executed on the TMR0 register (and where applicable, d = 1), the prescaler will be cleared if
assigned.
3: If Program Counter (PC) is modified or a conditional test is true, the instruction requires two cycles. The second
cycle is executed as a NOP.
4: Some instructions are two-word instructions. The second word of these instructions will be executed as a NOP
unless the first word of the instruction retrieves the information embedded in these 16 bits. This ensures that all
program memory locations have a valid instruction.
© 2008 Microchip Technology Inc.
DS39646C-page 325
PIC18F8722 FAMILY
TABLE 26-2: PIC18FXXXX INSTRUCTION SET (CONTINUED)
16-Bit Instruction Word
Mnemonic,
Operands
Status
Affected
Description
Cycles
Notes
MSb
LSb
LITERAL OPERATIONS
ADDLW
ANDLW
IORLW
LFSR
k
k
k
f, k
Add Literal and WREG
AND Literal with WREG
Inclusive OR Literal with WREG 1
Move Literal (12-bit) 2nd word
to FSR(f) 1st word
Move Literal to BSR<3:0>
Move Literal to WREG
Multiply Literal with WREG
Return with Literal in WREG
Subtract WREG from Literal
1
1
0000 1111 kkkk
0000 1011 kkkk
0000 1001 kkkk
1110 1110 00ff
1111 0000 kkkk
0000 0001 0000
0000 1110 kkkk
0000 1101 kkkk
0000 1100 kkkk
0000 1000 kkkk
0000 1010 kkkk
kkkk C, DC, Z, OV, N
kkkk Z, N
kkkk Z, N
kkkk None
kkkk
kkkk None
kkkk None
kkkk None
kkkk None
kkkk C, DC, Z, OV, N
kkkk Z, N
2
MOVLB
MOVLW
MULLW
RETLW
SUBLW
XORLW
k
k
k
k
k
k
1
1
1
2
1
Exclusive OR Literal with WREG 1
DATA MEMORY ↔ PROGRAM MEMORY OPERATIONS
TBLRD*
Table Read
2
0000 0000 0000
0000 0000 0000
0000 0000 0000
0000 0000 0000
0000 0000 0000
0000 0000 0000
0000 0000 0000
0000 0000 0000
1000 None
1001 None
1010 None
1011 None
1100 None
1101 None
1110 None
1111 None
TBLRD*+
TBLRD*-
TBLRD+*
TBLWT*
TBLWT*+
TBLWT*-
TBLWT+*
Table Read with Post-Increment
Table Read with Post-Decrement
Table Read with Pre-Increment
Table Write
Table Write with Post-Increment
Table Write with Post-Decrement
Table Write with Pre-Increment
2
5
5
5
5
Note 1: When a PORT register is modified as a function of itself (e.g., MOVF PORTB, 1, 0), the value used will be that
value present on the pins themselves. For example, if the data latch is ‘1’ for a pin configured as input and is
driven low by an external device, the data will be written back with a ‘0’.
2: If this instruction is executed on the TMR0 register (and where applicable, d = 1), the prescaler will be cleared if
assigned.
3: If Program Counter (PC) is modified or a conditional test is true, the instruction requires two cycles. The second
cycle is executed as a NOP.
4: Some instructions are two-word instructions. The second word of these instructions will be executed as a NOP
unless the first word of the instruction retrieves the information embedded in these 16 bits. This ensures that all
program memory locations have a valid instruction.
DS39646C-page 326
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
26.1.1
STANDARD INSTRUCTION SET
ADDLW
ADD Literal to W
ADDWF
ADD W to f
Syntax:
ADDLW
k
Syntax:
ADDWF
f {,d {,a}}
Operands:
Operation:
Status Affected:
Encoding:
Description:
0 ≤ k ≤ 255
Operands:
0 ≤ f ≤ 255
d ∈ [0,1]
a ∈ [0,1]
(W) + k → W
N, OV, C, DC, Z
Operation:
(W) + (f) → dest
0000
1111
kkkk
kkkk
Status Affected:
Encoding:
N, OV, C, DC, Z
The contents of W are added to the
8-bit literal ‘k’ and the result is placed in
W.
0010
01da
ffff
ffff
Description:
Add W to register ‘f’. If ‘d’ is ‘0’, the
result is stored in W. If ‘d’ is ‘1’, the
result is stored back in register ‘f’
(default).
Words:
Cycles:
1
1
Q Cycle Activity:
Q1
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
Q2
Q3
Q4
Decode
Read
literal ‘k’
Process
Data
Write to
W
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 26.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Example:
ADDLW
15h
Before Instruction
10h
After Instruction
25h
W
=
W
=
Words:
Cycles:
1
1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write to
destination
Example:
ADDWF
REG, 0, 0
Before Instruction
W
REG
=
=
17h
0C2h
After Instruction
W
REG
=
=
0D9h
0C2h
Note:
All PIC18 instructions may take an optional label argument preceding the instruction mnemonic for use in
symbolic addressing. If a label is used, the instruction format then becomes: {label} instruction argument(s).
© 2008 Microchip Technology Inc.
DS39646C-page 327
PIC18F8722 FAMILY
ADDWFC
ADD W and Carry bit to f
ANDLW
AND Literal with W
Syntax:
ADDWFC
f {,d {,a}}
Syntax:
ANDLW
k
Operands:
0 ≤ f ≤ 255
d ∈ [0,1]
a ∈ [0,1]
Operands:
Operation:
Status Affected:
Encoding:
Description:
0 ≤ k ≤ 255
(W) .AND. k → W
N, Z
Operation:
(W) + (f) + (C) → dest
0000
1011
kkkk
kkkk
Status Affected:
Encoding:
N,OV, C, DC, Z
The contents of W are ANDed with the
8-bit literal ‘k’. The result is placed in W.
0010
00da
ffff
ffff
Description:
Add W, the Carry flag and data memory
location ‘f’. If ‘d’ is ‘0’, the result is
placed in W. If ‘d’ is ‘1’, the result is
placed in data memory location ‘f’.
Words:
Cycles:
1
1
Q Cycle Activity:
Q1
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
Q2
Q3
Q4
Decode
Read literal
‘k’
Process
Data
Write to
W
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 26.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Example:
ANDLW
05Fh
Before Instruction
W
=
A3h
03h
After Instruction
W
=
Words:
Cycles:
1
1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write to
destination
Example:
ADDWFC
REG, 0, 1
Before Instruction
Carry bit =
1
02h
4Dh
REG
W
=
=
After Instruction
Carry bit =
0
02h
50h
REG
W
=
=
DS39646C-page 328
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
ANDWF
AND W with f
BC
Branch if Carry
BC
Syntax:
ANDWF
f {,d {,a}}
Syntax:
n
Operands:
0 ≤ f ≤ 255
d ∈ [0,1]
a ∈ [0,1]
Operands:
Operation:
-128 ≤ n ≤ 127
if Carry bit is ‘1’
(PC) + 2 + 2n → PC
Operation:
(W) .AND. (f) → dest
Status Affected:
Encoding:
None
Status Affected:
Encoding:
N, Z
1110
0010
nnnn
nnnn
0001
01da
ffff
ffff
Description:
If the Carry bit is ’1’, then the program
Description:
The contents of W are ANDed with
register ‘f’. If ‘d’ is ‘0’, the result is stored
in W. If ‘d’ is ‘1’, the result is stored back
in register ‘f’ (default).
will branch.
The 2’s complement number ‘2n’ is
added to the PC. Since the PC will have
incremented to fetch the next
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
instruction, the new address will be
PC + 2 + 2n. This instruction is then a
two-cycle instruction.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 26.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words:
Cycles:
1
1(2)
Q Cycle Activity:
If Jump:
Q1
Q2
Q3
Q4
Decode
Read literal
‘n’
Process
Data
Write to
PC
Words:
Cycles:
1
1
No
No
No
operation
No
operation
operation
operation
Q Cycle Activity:
Q1
If No Jump:
Q1
Q2
Q3
Q4
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write to
destination
Decode
Read literal
‘n’
Process
Data
No
operation
Example:
ANDWF
REG, 0, 0
Example:
HERE
BC
5
Before Instruction
Before Instruction
W
REG
=
=
17h
C2h
PC
=
address (HERE)
After Instruction
After Instruction
If Carry
PC
If Carry
PC
=
=
=
=
1;
W
REG
=
=
02h
C2h
address (HERE + 12)
0;
address (HERE + 2)
© 2008 Microchip Technology Inc.
DS39646C-page 329
PIC18F8722 FAMILY
BCF
Bit Clear f
BN
Branch if Negative
BN
Syntax:
BCF f, b {,a}
Syntax:
n
Operands:
0 ≤ f ≤ 255
0 ≤ b ≤ 7
a ∈ [0,1]
Operands:
Operation:
-128 ≤ n ≤ 127
if Negative bit is ‘1’
(PC) + 2 + 2n → PC
Operation:
0 → f<b>
Status Affected:
Encoding:
None
Status Affected:
Encoding:
None
1110
0110
nnnn
nnnn
1001
bbba
ffff
ffff
Description:
If the Negative bit is ‘1’, then the
Description:
Bit ‘b’ in register ‘f’ is cleared.
program will branch.
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
The 2’s complement number ‘2n’ is
added to the PC. Since the PC will have
incremented to fetch the next
instruction, the new address will be
PC + 2 + 2n. This instruction is then a
two-cycle instruction.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 26.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words:
Cycles:
1
1(2)
Q Cycle Activity:
If Jump:
Words:
Cycles:
1
1
Q1
Q2
Q3
Q4
Decode
Read literal
‘n’
Process
Data
Write to
PC
Q Cycle Activity:
Q1
Q2
Q3
Q4
No
No
No
No
operation
operation
operation
operation
Decode
Read
register ‘f’
Process
Data
Write
register ‘f’
If No Jump:
Q1
Q2
Q3
Q4
Decode
Read literal
‘n’
Process
Data
No
operation
Example:
BCF
FLAG_REG, 7, 0
Before Instruction
FLAG_REG = C7h
After Instruction
FLAG_REG = 47h
Example:
HERE
BN Jump
Before Instruction
PC
=
address (HERE)
After Instruction
If Negative
PC
If Negative
PC
=
=
=
=
1;
address (Jump)
0;
address (HERE + 2)
DS39646C-page 330
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
BNC
Branch if Not Carry
BNC
BNN
Branch if Not Negative
BNN
Syntax:
n
Syntax:
n
Operands:
Operation:
-128 ≤ n ≤ 127
Operands:
Operation:
-128 ≤ n ≤ 127
if Carry bit is ‘0’
(PC) + 2 + 2n → PC
if Negative bit is ‘0’
(PC) + 2 + 2n → PC
Status Affected:
Encoding:
None
Status Affected:
Encoding:
None
1110
0011
nnnn
nnnn
1110
0111
nnnn
nnnn
Description:
If the Carry bit is ‘0’, then the program
Description:
If the Negative bit is ‘0’, then the
will branch.
program will branch.
The 2’s complement number ‘2n’ is
added to the PC. Since the PC will have
incremented to fetch the next
The 2’s complement number ‘2n’ is
added to the PC. Since the PC will have
incremented to fetch the next
instruction, the new address will be
PC + 2 + 2n. This instruction is then a
two-cycle instruction.
instruction, the new address will be
PC + 2 + 2n. This instruction is then a
two-cycle instruction.
Words:
Cycles:
1
Words:
Cycles:
1
1(2)
1(2)
Q Cycle Activity:
If Jump:
Q Cycle Activity:
If Jump:
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
Decode
Read literal
‘n’
Process
Data
Write to
PC
Decode
Read literal
‘n’
Process
Data
Write to
PC
No
No
No
No
No
No
No
No
operation
operation
operation
operation
operation
operation
operation
operation
If No Jump:
Q1
If No Jump:
Q1
Q2
Q3
Q4
Q2
Q3
Q4
Decode
Read literal
‘n’
Process
Data
No
operation
Decode
Read literal
‘n’
Process
Data
No
operation
Example:
HERE
BNC Jump
Example:
HERE
BNN Jump
Before Instruction
Before Instruction
PC
=
address (HERE)
PC
=
address (HERE)
After Instruction
After Instruction
If Carry
PC
If Carry
PC
=
=
=
=
0;
If Negative
PC
If Negative
PC
=
=
=
=
0;
address (Jump)
address (Jump)
1;
1;
address (HERE + 2)
address (HERE + 2)
© 2008 Microchip Technology Inc.
DS39646C-page 331
PIC18F8722 FAMILY
BNOV
Branch if Not Overflow
BNOV
BNZ
Branch if Not Zero
BNZ
Syntax:
n
Syntax:
n
Operands:
Operation:
-128 ≤ n ≤ 127
Operands:
Operation:
-128 ≤ n ≤ 127
if Overflow bit is ‘0’
(PC) + 2 + 2n → PC
if Zero bit is ‘0’
(PC) + 2 + 2n → PC
Status Affected:
Encoding:
None
Status Affected:
Encoding:
None
1110
0101
nnnn
nnnn
1110
0001
nnnn
nnnn
Description:
If the Overflow bit is ‘0’, then the
Description:
If the Zero bit is ‘0’, then the program
program will branch.
will branch.
The 2’s complement number ‘2n’ is
added to the PC. Since the PC will have
incremented to fetch the next
The 2’s complement number ‘2n’ is
added to the PC. Since the PC will have
incremented to fetch the next
instruction, the new address will be
PC + 2 + 2n. This instruction is then a
two-cycle instruction.
instruction, the new address will be
PC + 2 + 2n. This instruction is then a
two-cycle instruction.
Words:
Cycles:
1
Words:
Cycles:
1
1(2)
1(2)
Q Cycle Activity:
If Jump:
Q Cycle Activity:
If Jump:
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
Decode
Read literal
‘n’
Process
Data
Write to
PC
Decode
Read literal
‘n’
Process
Data
Write to
PC
No
No
No
No
No
No
No
No
operation
operation
operation
operation
operation
operation
operation
operation
If No Jump:
Q1
If No Jump:
Q1
Q2
Q3
Q4
Q2
Q3
Q4
Decode
Read literal
‘n’
Process
Data
No
operation
Decode
Read literal
‘n’
Process
Data
No
operation
Example:
HERE
BNOV Jump
Example:
HERE
BNZ Jump
Before Instruction
Before Instruction
PC
=
address (HERE)
PC
=
address (HERE)
After Instruction
After Instruction
If Overflow
PC
If Overflow
PC
=
=
=
=
0;
If Zero
PC
If Zero
PC
=
=
=
=
0;
address (Jump)
address (Jump)
1;
1;
address (HERE + 2)
address (HERE + 2)
DS39646C-page 332
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
BRA
Unconditional Branch
BRA
BSF
Bit Set f
Syntax:
n
Syntax:
BSF f, b {,a}
Operands:
Operation:
Status Affected:
Encoding:
Description:
-1024 ≤ n ≤ 1023
(PC) + 2 + 2n → PC
None
Operands:
0 ≤ f ≤ 255
0 ≤ b ≤ 7
a ∈ [0,1]
Operation:
1 → f<b>
1101
0nnn
nnnn
nnnn
Status Affected:
Encoding:
None
Add the 2’s complement number ‘2n’ to
the PC. Since the PC will have
incremented to fetch the next
instruction, the new address will be
PC + 2 + 2n. This instruction is a
two-cycle instruction.
1000
bbba
ffff
ffff
Description:
Bit ‘b’ in register ‘f’ is set.
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
Words:
Cycles:
1
2
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 26.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read literal
‘n’
Process
Data
Write to
PC
No
operation
No
operation
No
operation
No
operation
Words:
Cycles:
1
1
Q Cycle Activity:
Q1
Example:
HERE
BRA Jump
Q2
Q3
Q4
Before Instruction
Decode
Read
register ‘f’
Process
Data
Write
register ‘f’
PC
=
=
address (HERE)
address (Jump)
After Instruction
PC
Example:
BSF
FLAG_REG, 7, 1
0Ah
8Ah
Before Instruction
FLAG_REG
After Instruction
FLAG_REG
=
=
© 2008 Microchip Technology Inc.
DS39646C-page 333
PIC18F8722 FAMILY
BTFSC
Bit Test File, Skip if Clear
BTFSS
Bit Test File, Skip if Set
Syntax:
BTFSC f, b {,a}
Syntax:
BTFSS f, b {,a}
Operands:
0 ≤ f ≤ 255
0 ≤ b ≤ 7
a ∈ [0,1]
Operands:
0 ≤ f ≤ 255
0 ≤ b < 7
a ∈ [0,1]
Operation:
skip if (f<b>) = 0
Operation:
skip if (f<b>) = 1
Status Affected:
Encoding:
None
Status Affected:
Encoding:
None
1011
bbba
ffff
ffff
1010
bbba
ffff
ffff
Description:
If bit ‘b’ in register ‘f’ is ‘0’, then the next
instruction is skipped. If bit ‘b’ is ‘0’, then
the next instruction fetched during the
current instruction execution is discarded
and a NOPis executed instead, making
this a two-cycle instruction.
Description:
If bit ‘b’ in register ‘f’ is ‘1’, then the next
instruction is skipped. If bit ‘b’ is ‘1’, then
the next instruction fetched during the
current instruction execution is discarded
and a NOPis executed instead, making
this a two-cycle instruction.
If ‘a’ is ‘0’, the Access Bank is selected. If
‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
If ‘a’ is ‘0’, the Access Bank is selected. If
‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
If ‘a’ is ‘0’ and the extended instruction set
is enabled, this instruction operates in
Indexed Literal Offset Addressing mode
whenever f ≤ 95 (5Fh). See
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates in
Indexed Literal Offset Addressing mode
whenever f ≤ 95 (5Fh). See
Section 26.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Section 26.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words:
Cycles:
1
Words:
Cycles:
1
1(2)
1(2)
Note: 3 cycles if skip and followed
by a 2-word instruction.
Note: 3 cycles if skip and followed
by a 2-word instruction.
Q Cycle Activity:
Q1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
No
operation
Decode
Read
register ‘f’
Process
Data
No
operation
If skip:
Q1
If skip:
Q1
Q2
Q3
Q4
Q2
Q3
Q4
No
No
No
No
No
No
No
No
operation
operation
operation
operation
operation
operation
operation
operation
If skip and followed by 2-word instruction:
If skip and followed by 2-word instruction:
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
No
No
No
No
No
No
No
No
operation
operation
operation
operation
operation
operation
operation
operation
No
No
No
No
No
No
No
No
operation
operation
operation
operation
operation
operation
operation
operation
Example:
HERE
FALSE
TRUE
BTFSC
:
:
FLAG, 1, 0
Example:
HERE
FALSE
TRUE
BTFSS
:
:
FLAG, 1, 0
Before Instruction
PC
Before Instruction
PC
=
address (HERE)
=
address (HERE)
After Instruction
After Instruction
If FLAG<1>
PC
If FLAG<1>
PC
=
=
=
=
0;
If FLAG<1>
PC
If FLAG<1>
PC
=
=
=
=
0;
address (TRUE)
1;
address (FALSE)
1;
address (FALSE)
address (TRUE)
DS39646C-page 334
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
BTG
Bit Toggle f
BOV
Branch if Overflow
BOV
Syntax:
BTG f, b {,a}
Syntax:
n
Operands:
0 ≤ f ≤ 255
0 ≤ b < 7
a ∈ [0,1]
Operands:
Operation:
-128 ≤ n ≤ 127
if Overflow bit is ‘1’
(PC) + 2 + 2n → PC
Operation:
(f<b>) → f<b>
Status Affected:
Encoding:
None
Status Affected:
Encoding:
None
1110
0100
nnnn
nnnn
0111
bbba
ffff
ffff
Description:
If the Overflow bit is ‘1’, then the
Description:
Bit ‘b’ in data memory location ‘f’ is
inverted.
program will branch.
The 2’s complement number ‘2n’ is
added to the PC. Since the PC will have
incremented to fetch the next
instruction, the new address will be
PC + 2 + 2n. This instruction is then a
two-cycle instruction.
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 26.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words:
Cycles:
1
1(2)
Q Cycle Activity:
If Jump:
Q1
Q2
Q3
Q4
Words:
Cycles:
1
1
Decode
Read literal
‘n’
Process
Data
Write to PC
Q Cycle Activity:
Q1
No
operation
No
operation
No
operation
No
operation
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write
register ‘f’
If No Jump:
Q1
Q2
Q3
Q4
Decode
Read literal
‘n’
Process
Data
No
operation
Example:
BTG
PORTC, 4, 0
Before Instruction:
PORTC
After Instruction:
PORTC
=
0111 0101 [75h]
0110 0101 [65h]
Example:
HERE
BOV Jump
Before Instruction
=
PC
=
address (HERE)
After Instruction
If Overflow
PC
If Overflow
PC
=
=
=
=
1;
address (Jump)
0;
address (HERE + 2)
© 2008 Microchip Technology Inc.
DS39646C-page 335
PIC18F8722 FAMILY
BZ
Branch if Zero
BZ
CALL
Subroutine Call
Syntax:
n
Syntax:
CALL k {,s}
Operands:
Operation:
-128 ≤ n ≤ 127
Operands:
0 ≤ k ≤ 1048575
s ∈ [0,1]
if Zero bit is ‘1’
(PC) + 2 + 2n → PC
Operation:
(PC) + 4 → TOS,
k → PC<20:1>,
if s = 1
Status Affected:
Encoding:
None
1110
0000
nnnn
nnnn
(W) → WS,
(STATUS) → STATUSS,
(BSR) → BSRS
Description:
If the Zero bit is ‘1’, then the program
will branch.
Status Affected:
None
The 2’s complement number ‘2n’ is
added to the PC. Since the PC will have
incremented to fetch the next
instruction, the new address will be
PC + 2 + 2n. This instruction is then a
two-cycle instruction.
Encoding:
1st word (k<7:0>)
2nd word(k<19:8>)
1110
110s
k7kkk kkkk0
kkkk8
1111 k19kkk kkkk
Description:
Subroutine call of entire 2-Mbyte
memory range. First, return address
(PC + 4) is pushed onto the return
stack. If ‘s’ = 1, the W, STATUS and
BSR registers are also pushed into their
respective shadow registers, WS,
STATUSS and BSRS. If ‘s’ = 0, no
update occurs (default). Then, the
20-bit value ‘k’ is loaded into PC<20:1>.
CALLis a two-cycle instruction.
Words:
Cycles:
1
1(2)
Q Cycle Activity:
If Jump:
Q1
Q2
Q3
Q4
Decode
Read literal
‘n’
Process
Data
Write to
PC
No
operation
No
operation
No
operation
No
operation
Words:
Cycles:
2
2
If No Jump:
Q1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Q2
Q3
Q4
Decode
Read literal
‘n’
Process
Data
No
operation
Decode
Read literal Push PC to Read literal
‘k’<7:0>,
stack
’k’<19:8>,
Write to PC
Example:
HERE
BZ Jump
No
No
No
No
Before Instruction
operation
operation
operation
operation
PC
=
address (HERE)
After Instruction
Example:
HERE
CALL THERE,1
If Zero
PC
If Zero
PC
=
=
=
=
1;
address (Jump)
Before Instruction
PC
After Instruction
0;
=
address (HERE)
address (HERE + 2)
PC
=
address (THERE)
TOS
WS
=
=
=
address (HERE + 4)
W
BSR
STATUS
BSRS
STATUSS =
DS39646C-page 336
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
CLRF
Clear f
CLRWDT
Clear Watchdog Timer
Syntax:
CLRF f {,a}
Syntax:
CLRWDT
None
Operands:
0 ≤ f ≤ 255
a ∈ [0,1]
Operands:
Operation:
000h → WDT,
000h → WDT postscaler,
1 → TO,
Operation:
000h → f
1 → Z
1 → PD
Status Affected:
Encoding:
Z
Status Affected:
Encoding:
TO, PD
0110
101a
ffff
ffff
0000
0000
0000
0100
Description:
Clears the contents of the specified
register.
Description:
CLRWDTinstruction resets the
Watchdog Timer. It also resets the post-
scaler of the WDT. Status bits, TO and
PD, are set.
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
Words:
Cycles:
1
1
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 26.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
No
Process
Data
No
operation
operation
Words:
Cycles:
1
1
Example:
CLRWDT
Before Instruction
Q Cycle Activity:
Q1
WDT Counter
After Instruction
WDT Counter
WDT Postscaler
TO
=
?
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write
register ‘f’
=
=
=
=
00h
0
1
PD
1
Example:
CLRF
FLAG_REG,1
Before Instruction
FLAG_REG
After Instruction
FLAG_REG
=
=
5Ah
00h
© 2008 Microchip Technology Inc.
DS39646C-page 337
PIC18F8722 FAMILY
CPFSEQ
Compare f with W, Skip if f = W
COMF
Complement f
Syntax:
CPFSEQ f {,a}
Syntax:
COMF f {,d {,a}}
Operands:
0 ≤ f ≤ 255
a ∈ [0,1]
Operands:
0 ≤ f ≤ 255
d ∈ [0,1]
a ∈ [0,1]
Operation:
(f) – (W),
skip if (f) = (W)
(unsigned comparison)
Operation:
(f) → dest
Status Affected:
Encoding:
N, Z
Status Affected:
Encoding:
None
0001
11da
ffff
ffff
0110
001a
ffff
ffff
Description:
The contents of register ‘f’ are
Description:
Compares the contents of data memory
location ‘f’ to the contents of W by
performing an unsigned subtraction.
complemented. If ‘d’ is ‘0’, the result is
stored in W. If ‘d’ is ‘1’, the result is
stored back in register ‘f’ (default).
If ‘f’ = W, then the fetched instruction is
discarded and a NOPis executed
instead, making this a two-cycle
instruction.
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 26.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 26.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words:
Cycles:
1
1
Q Cycle Activity:
Q1
Words:
Cycles:
1
Q2
Q3
Q4
1(2)
Decode
Read
register ‘f’
Process
Data
Write to
destination
Note: 3 cycles if skip and followed
by a 2-word instruction.
Q Cycle Activity:
Q1
Example:
COMF
REG, 0, 0
Q2
Read
register ‘f’
Q3
Process
Data
Q4
No
operation
Before Instruction
Decode
REG
=
13h
After Instruction
If skip:
Q1
REG
W
=
=
13h
ECh
Q2
No
Q3
No
Q4
No
No
operation
operation
operation
operation
If skip and followed by 2-word instruction:
Q1
No
Q2
No
Q3
No
Q4
No
operation
No
operation
No
operation
No
operation
No
operation
operation
operation
operation
Example:
HERE
CPFSEQ REG, 0
NEQUAL
EQUAL
:
:
Before Instruction
PC Address
=
=
=
HERE
?
?
W
REG
After Instruction
If REG
PC
If REG
PC
=
=
≠
=
W;
Address (EQUAL)
W;
Address (NEQUAL)
DS39646C-page 338
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
CPFSGT
Compare f with W, Skip if f > W
CPFSLT
Compare f with W, Skip if f < W
Syntax:
CPFSGT f {,a}
Syntax:
CPFSLT f {,a}
Operands:
0 ≤ f ≤ 255
a ∈ [0,1]
Operands:
0 ≤ f ≤ 255
a ∈ [0,1]
Operation:
(f) – (W),
skip if (f) > (W)
(unsigned comparison)
Operation:
(f) – (W),
skip if (f) < (W)
(unsigned comparison)
Status Affected:
Encoding:
None
Status Affected:
Encoding:
None
0110
010a
ffff
ffff
0110
000a
ffff
ffff
Description:
Compares the contents of data memory
location ‘f’ to the contents of the W by
performing an unsigned subtraction.
Description:
Compares the contents of data memory
location ‘f’ to the contents of W by
performing an unsigned subtraction.
If the contents of ‘f’ are greater than the
contents of WREG, then the fetched
instruction is discarded and a NOPis
executed instead, making this a
two-cycle instruction.
If the contents of ‘f’ are less than the
contents of W, then the fetched
instruction is discarded and a NOPis
executed instead, making this a
two-cycle instruction.
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 26.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words:
Cycles:
1
1(2)
Note: 3 cycles if skip and followed
by a 2-word instruction.
Q Cycle Activity:
Q1
Q2
Q3
Q4
Words:
Cycles:
1
Decode
Read
Process
Data
No
operation
1(2)
register ‘f’
Note: 3 cycles if skip and followed
by a 2-word instruction.
If skip:
Q1
Q2
Q3
Q4
Q Cycle Activity:
Q1
No
operation
No
operation
No
operation
No
operation
Q2
Read
register ‘f’
Q3
Process
Data
Q4
No
operation
Decode
If skip and followed by 2-word instruction:
Q1
Q2
Q3
Q4
If skip:
Q1
No
operation
No
operation
No
operation
No
operation
Q2
No
Q3
No
Q4
No
No
No
No
No
No
operation
operation
operation
operation
operation
operation
operation
operation
If skip and followed by 2-word instruction:
Q1
No
operation
No
Q2
No
operation
No
Q3
No
operation
No
Q4
No
operation
No
Example:
HERE
NLESS
LESS
CPFSLT REG, 1
:
:
operation
operation
operation
operation
Before Instruction
PC
W
=
=
Address (HERE)
?
Example:
HERE
CPFSGT REG, 0
NGREATER
GREATER
:
:
After Instruction
If REG
PC
If REG
PC
<
=
≥
=
W;
Address (LESS)
W;
Before Instruction
PC
W
=
=
Address (HERE)
?
Address (NLESS)
After Instruction
If REG
PC
If REG
PC
>
=
≤
=
W;
Address (GREATER)
W;
Address (NGREATER)
© 2008 Microchip Technology Inc.
DS39646C-page 339
PIC18F8722 FAMILY
DAW
Decimal Adjust W Register
DECF
Decrement f
Syntax:
DAW
None
Syntax:
DECF f {,d {,a}}
Operands:
Operation:
Operands:
0 ≤ f ≤ 255
d ∈ [0,1]
a ∈ [0,1]
If [W<3:0> > 9] or [DC = 1] then
(W<3:0>) + 6 → W<3:0>;
else
Operation:
(f) – 1 → dest
(W<3:0>) → W<3:0>
Status Affected:
Encoding:
C, DC, N, OV, Z
0000
01da
ffff
ffff
If [W<7:4> > 9] or [C = 1] then
(W<7:4>) + 6 → W<7:4>;
C = 1;
Description:
Decrement register ‘f’. If ‘d’ is ‘0’, the
result is stored in W. If ‘d’ is ‘1’, the
result is stored back in register ‘f’
(default).
else
(W<7:4>) → W<7:4>
Status Affected:
Encoding:
C
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
0000
0000
0000
0111
Description:
DAW adjusts the eight-bit value in W,
resulting from the earlier addition of two
variables (each in packed BCD format)
and produces a correct packed BCD
result.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 26.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words:
Cycles:
1
1
Q Cycle Activity:
Q1
Words:
Cycles:
1
1
Q2
Q3
Q4
Decode
Read
register W
Process
Data
Write
W
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write to
destination
Example 1:
DAW
Before Instruction
W
=
A5h
0
Example:
DECF
CNT,
1, 0
C
=
=
DC
0
Before Instruction
After Instruction
CNT
Z
=
01h
0
W
=
=
=
05h
1
0
=
C
After Instruction
DC
CNT
Z
=
=
00h
1
Example 2:
Before Instruction
W
=
=
=
CEh
0
0
C
DC
After Instruction
W
=
=
=
34h
1
0
C
DC
DS39646C-page 340
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
DECFSZ
Decrement f, Skip if 0
DCFSNZ
Decrement f, Skip if not 0
Syntax:
DECFSZ f {,d {,a}}
Syntax:
DCFSNZ f {,d {,a}}
Operands:
0 ≤ f ≤ 255
d ∈ [0,1]
a ∈ [0,1]
Operands:
0 ≤ f ≤ 255
d ∈ [0,1]
a ∈ [0,1]
Operation:
(f) – 1 → dest,
Operation:
(f) – 1 → dest,
skip if result = 0
skip if result ≠ 0
Status Affected:
Encoding:
None
Status Affected:
Encoding:
None
0010
11da
ffff
ffff
0100
11da
ffff
ffff
Description:
The contents of register ‘f’ are
Description:
The contents of register ‘f’ are
decremented. If ‘d’ is ‘0’, the result is
placed in W. If ‘d’ is ‘1’, the result is
placed back in register ‘f’ (default).
decremented. If ‘d’ is ‘0’, the result is
placed in W. If ‘d’ is ‘1’, the result is
placed back in register ‘f’ (default).
If the result is ‘0’, the next instruction
which is already fetched is discarded
and a NOPis executed instead, making
it a two-cycle instruction.
If the result is not ‘0’, the next
instruction which is already fetched is
discarded and a NOPis executed
instead, making it a two-cycle
instruction.
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 26.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 26.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words:
Cycles:
1
Words:
Cycles:
1
1(2)
Note: 3 cycles if skip and followed
by a 2-word instruction.
1(2)
Note: 3 cycles if skip and followed
by a 2-word instruction.
Q Cycle Activity:
Q1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write to
destination
Decode
Read
Process
Data
Write to
destination
register ‘f’
If skip:
Q1
If skip:
Q1
Q2
Q3
Q4
Q2
Q3
Q4
No
No
No
No
operation
operation
operation
operation
No
No
No
No
operation
operation
operation
operation
If skip and followed by 2-word instruction:
If skip and followed by 2-word instruction:
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
No
No
No
No
operation
operation
operation
operation
No
No
No
No
operation
operation
operation
operation
No
No
No
No
operation
operation
operation
operation
No
No
No
No
operation
operation
operation
operation
Example:
HERE
DECFSZ
GOTO
CNT, 1, 1
LOOP
Example:
HERE
ZERO
NZERO
DCFSNZ TEMP, 1, 0
:
:
CONTINUE
Before Instruction
PC
After Instruction
Before Instruction
TEMP
After Instruction
=
Address (HERE)
=
?
CNT
=
CNT – 1
0;
If CNT
=
=
≠
=
TEMP
If TEMP
PC
If TEMP
PC
=
=
=
≠
=
TEMP – 1,
0;
Address (ZERO)
0;
Address (NZERO)
PC
Address (CONTINUE)
0;
If CNT
PC
Address (HERE + 2)
© 2008 Microchip Technology Inc.
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GOTO
Unconditional Branch
GOTO
INCF
Increment f
Syntax:
k
Syntax:
INCF f {,d {,a}}
Operands:
Operation:
Status Affected:
0 ≤ k ≤ 1048575
k → PC<20:1>
None
Operands:
0 ≤ f ≤ 255
d ∈ [0,1]
a ∈ [0,1]
Operation:
(f) + 1 → dest
Encoding:
1st word (k<7:0>)
2nd word(k<19:8>)
Status Affected:
Encoding:
C, DC, N, OV, Z
1110
1111
k7kkk kkkk0
kkkk8
1111 k19kkk kkkk
0010
10da
ffff
ffff
Description:
GOTOallows an unconditional branch
anywhere within entire 2-Mbyte memory
range. The 20-bit value ‘k’ is loaded into
PC<20:1>. GOTOis always a two-cycle
instruction.
Description:
The contents of register ‘f’ are
incremented. If ‘d’ is ‘0’, the result is
placed in W. If ‘d’ is ‘1’, the result is
placed back in register ‘f’ (default).
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
Words:
Cycles:
2
2
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 26.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read literal
‘k’<7:0>,
No
operation
Read literal
‘k’<19:8>,
Write to PC
No
No
No
No
operation
operation
operation
operation
Words:
Cycles:
1
1
Example:
GOTO THERE
Q Cycle Activity:
Q1
After Instruction
Q2
Q3
Q4
PC
=
Address (THERE)
Decode
Read
register ‘f’
Process
Data
Write to
destination
Example:
INCF
CNT, 1, 0
Before Instruction
CNT
Z
=
FFh
0
=
=
=
C
?
DC
?
After Instruction
CNT
Z
=
00h
1
=
=
=
C
1
DC
1
DS39646C-page 342
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
INFSNZ
Increment f, Skip if not 0
INCFSZ
Increment f, Skip if 0
Syntax:
INFSNZ f {,d {,a}}
Syntax:
INCFSZ f {,d {,a}}
Operands:
0 ≤ f ≤ 255
d ∈ [0,1]
a ∈ [0,1]
Operands:
0 ≤ f ≤ 255
d ∈ [0,1]
a ∈ [0,1]
Operation:
(f) + 1 → dest,
skip if result ≠ 0
Operation:
(f) + 1 → dest,
skip if result = 0
Status Affected:
Encoding:
None
Status Affected:
Encoding:
None
0100
10da
ffff
ffff
0011
11da
ffff
ffff
Description:
The contents of register ‘f’ are
Description:
The contents of register ‘f’ are
incremented. If ‘d’ is ‘0’, the result is
placed in W. If ‘d’ is ‘1’, the result is
placed back in register ‘f’ (default).
incremented. If ‘d’ is ‘0’, the result is
placed in W. If ‘d’ is ‘1’, the result is
placed back in register ‘f’. (default)
If the result is not ‘0’, the next
instruction which is already fetched is
discarded and a NOPis executed
instead, making it a two-cycle
instruction.
If the result is ‘0’, the next instruction
which is already fetched is discarded
and a NOPis executed instead, making
it a two-cycle instruction.
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 26.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 26.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words:
Cycles:
1
Words:
Cycles:
1
1(2)
1(2)
Note: 3 cycles if skip and followed
by a 2-word instruction.
Note: 3 cycles if skip and followed
by a 2-word instruction.
Q Cycle Activity:
Q1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write to
destination
Decode
Read
register ‘f’
Process
Data
Write to
destination
If skip:
Q1
If skip:
Q1
Q2
Q3
Q4
Q2
Q3
Q4
No
No
No
No
No
No
No
No
operation
operation
operation
operation
operation
operation
operation
operation
If skip and followed by 2-word instruction:
If skip and followed by 2-word instruction:
Q1
Q2
Q3
Q4
Q1
Q2
Q3
Q4
No
No
No
No
No
No
No
No
operation
operation
operation
operation
operation
operation
operation
operation
No
No
No
No
No
No
No
No
operation
operation
operation
operation
operation
operation
operation
operation
Example:
HERE
NZERO
ZERO
INCFSZ
:
:
CNT, 1, 0
Example:
HERE
ZERO
NZERO
INFSNZ REG, 1, 0
Before Instruction
PC
After Instruction
Before Instruction
PC
After Instruction
=
Address (HERE)
=
Address (HERE)
REG
If REG
PC
If REG
PC
=
REG + 1
CNT
If CNT
PC
If CNT
PC
=
CNT + 1
≠
=
=
=
0;
=
=
≠
=
0;
Address (NZERO)
0;
Address (ZERO)
Address (ZERO)
0;
Address (NZERO)
© 2008 Microchip Technology Inc.
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IORLW
Inclusive OR Literal with W
IORLW
IORWF
Inclusive OR W with f
Syntax:
k
Syntax:
IORWF f {,d {,a}}
Operands:
Operation:
Status Affected:
Encoding:
Description:
0 ≤ k ≤ 255
(W) .OR. k → W
N, Z
Operands:
0 ≤ f ≤ 255
d ∈ [0,1]
a ∈ [0,1]
Operation:
(W) .OR. (f) → dest
0000
1001
kkkk
kkkk
Status Affected:
Encoding:
N, Z
The contents of W are ORed with the
eight-bit literal ‘k’. The result is placed
in W.
0001
00da
ffff
ffff
Description:
Inclusive OR W with register ‘f’. If ‘d’ is
‘0’, the result is placed in W. If ‘d’ is ‘1’,
the result is placed back in register ‘f’
(default).
Words:
Cycles:
1
1
Q Cycle Activity:
Q1
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
Q2
Q3
Q4
Decode
Read
literal ‘k’
Process
Data
Write to
W
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 26.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Example:
IORLW
35h
Before Instruction
W
=
9Ah
BFh
After Instruction
W
=
Words:
Cycles:
1
1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write to
destination
Example:
IORWF RESULT, 0, 1
Before Instruction
RESULT =
13h
91h
W
=
After Instruction
RESULT =
13h
93h
W
=
DS39646C-page 344
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LFSR
Load FSR
MOVF
Move f
Syntax:
LFSR f, k
Syntax:
MOVF f {,d {,a}}
Operands:
0 ≤ f ≤ 2
0 ≤ k ≤ 4095
Operands:
0 ≤ f ≤ 255
d ∈ [0,1]
a ∈ [0,1]
Operation:
k → FSRf
Operation:
f → dest
Status Affected:
Encoding:
None
Status Affected:
Encoding:
N, Z
1110
1111
1110
0000
00ff k11kkk
k7kkk kkkk
0101
00da
ffff
ffff
Description:
The 12-bit literal ‘k’ is loaded into the
file select register pointed to by ‘f’.
Description:
The contents of register ‘f’ are moved to
a destination dependent upon the
status of ‘d’. If ‘d’ is ‘0’, the result is
placed in W. If ‘d’ is ‘1’, the result is
placed back in register ‘f’ (default).
Location ‘f’ can be anywhere in the
256-byte bank.
Words:
Cycles:
2
2
Q Cycle Activity:
Q1
Q2
Q3
Q4
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
Decode
Read literal
‘k’ MSB
Process
Data
Write
literal ‘k’
MSB to
FSRfH
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 26.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Decode
Read literal
‘k’ LSB
Process
Data
Write literal
‘k’ to FSRfL
Example:
LFSR 2, 3ABh
After Instruction
FSR2H
FSR2L
=
=
03h
ABh
Words:
Cycles:
1
1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write
W
Example:
MOVF
REG, 0, 0
Before Instruction
REG
W
=
=
22h
FFh
After Instruction
REG
W
=
=
22h
22h
© 2008 Microchip Technology Inc.
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MOVFF
Move f to f
MOVFF f ,f
MOVLB
Move Literal to Low Nibble in BSR
MOVLW
Syntax:
Syntax:
k
s
d
Operands:
0 ≤ f ≤ 4095
Operands:
Operation:
Status Affected:
Encoding:
Description:
0 ≤ k ≤ 255
k → BSR
None
s
0 ≤ f ≤ 4095
d
Operation:
(f ) → f
s
d
Status Affected:
None
0000
0001
kkkk
kkkk
Encoding:
1st word (source)
2nd word (destin.)
The eight-bit literal ‘k’ is loaded into the
Bank Select Register (BSR). The value
of BSR<7:4> always remains ‘0’
1100
1111
ffff
ffff
ffff
ffff
ffffs
ffffd
Description:
The contents of source register ‘f ’ are
regardless of the value of k :k .
s
7 4
moved to destination register ‘f ’.
d
Words:
Cycles:
1
1
Location of source ‘f ’ can be anywhere
s
in the 4096-byte data space (000h to
FFFh) and location of destination ‘f ’
can also be anywhere from 000h to
FFFh.
d
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
literal ‘k’
Process
Data
Write literal
‘k’ to BSR
Either source or destination can be W
(a useful special situation).
MOVFFis particularly useful for
transferring a data memory location to a
peripheral register (such as the transmit
buffer or an I/O port).
Example:
MOVLB
5
Before Instruction
BSR Register =
After Instruction
BSR Register =
02h
05h
The MOVFFinstruction cannot use the
PCL, TOSU, TOSH or TOSL as the
destination register
Words:
Cycles:
2
2 (3)
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
(src)
Process
Data
No
operation
Decode
No
operation
No
operation
Write
register ‘f’
(dest)
No dummy
read
Example:
MOVFF
REG1, REG2
Before Instruction
REG1
REG2
=
=
33h
11h
After Instruction
REG1
REG2
=
=
33h
33h
DS39646C-page 346
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MOVLW
Move Literal to W
MOVLW
MOVWF
Move W to f
Syntax:
k
Syntax:
MOVWF f {,a}
Operands:
Operation:
Status Affected:
Encoding:
Description:
Words:
0 ≤ k ≤ 255
k → W
None
Operands:
0 ≤ f ≤ 255
a ∈ [0,1]
Operation:
(W) → f
Status Affected:
Encoding:
None
0000
1110
kkkk
kkkk
0110
111a
ffff
ffff
The eight-bit literal ‘k’ is loaded into W.
Description:
Move data from W to register ‘f’.
Location ‘f’ can be anywhere in the
256-byte bank.
1
1
Cycles:
Q Cycle Activity:
Q1
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
Q2
Q3
Q4
Decode
Read
literal ‘k’
Process
Data
Write to
W
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 26.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Example:
MOVLW
5Ah
After Instruction
W
=
5Ah
Words:
Cycles:
1
1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write
register ‘f’
Example:
MOVWF
REG, 0
Before Instruction
W
REG
=
=
4Fh
FFh
After Instruction
W
REG
=
=
4Fh
4Fh
© 2008 Microchip Technology Inc.
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MULLW
Multiply Literal with W
MULWF
Multiply W with f
Syntax:
MULLW
k
Syntax:
MULWF f {,a}
Operands:
Operation:
Status Affected:
Encoding:
Description:
0 ≤ k ≤ 255
Operands:
0 ≤ f ≤ 255
a ∈ [0,1]
(W) x k → PRODH:PRODL
Operation:
(W) x (f) → PRODH:PRODL
None
Status Affected:
Encoding:
None
0000
1101
kkkk
kkkk
0000
001a
ffff
ffff
An unsigned multiplication is carried
out between the contents of W and the
8-bit literal ‘k’. The 16-bit result is
placed in PRODH:PRODL register pair.
PRODH contains the high byte.
Description:
An unsigned multiplication is carried out
between the contents of W and the
register file location ‘f’. The 16-bit result is
stored in the PRODH:PRODL register
pair. PRODH contains the high byte. Both
W and ‘f’ are unchanged.
W is unchanged.
None of the status flags are affected.
None of the status flags are affected.
Note that neither Overflow nor Carry is
possible in this operation. A Zero result
is possible but not detected.
Note that neither Overflow nor Carry is
possible in this operation. A Zero result is
possible but not detected.
Words:
Cycles:
1
1
If ‘a’ is ‘0’, the Access Bank is selected. If
‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
Q Cycle Activity:
Q1
Q2
Q3
Q4
If ‘a’ is ‘0’ and the extended instruction set
is enabled, this instruction operates in
Indexed Literal Offset Addressing mode
whenever f ≤ 95 (5Fh). See
Section 26.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Decode
Read
literal ‘k’
Process
Data
Write
registers
PRODH:
PRODL
Example:
MULLW
0C4h
E2h
Words:
Cycles:
1
1
Before Instruction
W
PRODH
PRODL
=
=
=
?
?
Q Cycle Activity:
Q1
Q2
Q3
Q4
After Instruction
Decode
Read
register ‘f’
Process
Data
Write
W
PRODH
PRODL
=
=
=
E2h
ADh
08h
registers
PRODH:
PRODL
Example:
MULWF
REG, 1
Before Instruction
W
=
=
=
=
C4h
REG
B5h
?
PRODH
PRODL
?
After Instruction
W
=
=
=
=
C4h
B5h
8Ah
94h
REG
PRODH
PRODL
DS39646C-page 348
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
NEGF
Negate f
NOP
No Operation
Syntax:
NEGF f {,a}
Syntax:
NOP
Operands:
0 ≤ f ≤ 255
a ∈ [0,1]
Operands:
Operation:
Status Affected:
Encoding:
None
No operation
None
Operation:
( f ) + 1 → f
Status Affected:
Encoding:
N, OV, C, DC, Z
0000
1111
0000
xxxx
0000
xxxx
0000
xxxx
0110
110a
ffff
ffff
Description:
Location ‘f’ is negated using two’s
complement. The result is placed in the
data memory location ‘f’.
Description:
Words:
No operation.
1
1
Cycles:
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
Q Cycle Activity:
Q1
Q2
Q3
No
operation
Q4
Decode
No
operation
No
operation
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 26.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Example:
None.
Words:
Cycles:
1
1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write
register ‘f’
Example:
NEGF
REG, 1
Before Instruction
REG
After Instruction
REG
=
0011 1010 [3Ah]
1100 0110 [C6h]
=
© 2008 Microchip Technology Inc.
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PIC18F8722 FAMILY
POP
Pop Top of Return Stack
PUSH
Push Top of Return Stack
Syntax:
POP
Syntax:
PUSH
Operands:
Operation:
Status Affected:
Encoding:
Description:
None
Operands:
Operation:
Status Affected:
Encoding:
Description:
None
(TOS) → bit bucket
(PC + 2) → TOS
None
None
0000
0000
0000
0110
0000
0000
0000
0101
The TOS value is pulled off the return
stack and is discarded. The TOS value
then becomes the previous value that
was pushed onto the return stack.
This instruction is provided to enable
the user to properly manage the return
stack to incorporate a software stack.
The PC + 2 is pushed onto the top of
the return stack. The previous TOS
value is pushed down on the stack.
This instruction allows implementing a
software stack by modifying TOS and
then pushing it onto the return stack.
Words:
Cycles:
1
1
Words:
Cycles:
1
1
Q Cycle Activity:
Q1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Q2
Q3
Q4
Decode
PUSH
No
No
Decode
No
operation
POP TOS
value
No
operation
PC + 2 onto
return stack
operation
operation
Example:
POP
Example:
PUSH
GOTO
NEW
Before Instruction
Before Instruction
TOS
Stack (1 level down)
TOS
PC
=
=
345Ah
0124h
=
=
0031A2h
014332h
After Instruction
After Instruction
PC
=
=
=
0126h
0126h
345Ah
TOS
TOS
PC
=
=
014332h
NEW
Stack (1 level down)
DS39646C-page 350
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RCALL
Relative Call
RCALL
RESET
Reset
Syntax:
n
Syntax:
RESET
None
Operands:
Operation:
-1024 ≤ n ≤ 1023
Operands:
Operation:
(PC) + 2 → TOS,
(PC) + 2 + 2n → PC
Reset all registers and flags that are
affected by a MCLR Reset.
Status Affected:
Encoding:
None
Status Affected:
Encoding:
All
1101
1nnn
nnnn
nnnn
0000
0000
1111
1111
Description:
Subroutine call with a jump up to 1K
from the current location. First, return
address (PC + 2) is pushed onto the
stack. Then, add the 2’s complement
number ‘2n’ to the PC. Since the PC will
have incremented to fetch the next
instruction, the new address will be
PC + 2 + 2n. This instruction is a
two-cycle instruction.
Description:
This instruction provides a way to
execute a MCLR Reset in software.
Words:
Cycles:
1
1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Start
reset
No
operation
No
operation
Words:
Cycles:
1
2
Example:
RESET
Q Cycle Activity:
Q1
After Instruction
Registers =
Q2
Q3
Q4
Reset Value
Reset Value
Flags*
=
Decode
Read literal
‘n’
Process
Data
Write to PC
PUSH PC
to stack
No
No
No
No
operation
operation
operation
operation
Example:
HERE
RCALL Jump
Before Instruction
PC
After Instruction
PC
TOS =
=
Address (HERE)
=
Address (Jump)
Address (HERE + 2)
© 2008 Microchip Technology Inc.
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RETFIE
Return from Interrupt
RETLW
Return Literal to W
RETLW
Syntax:
RETFIE {s}
Syntax:
k
Operands:
Operation:
s ∈ [0,1]
Operands:
Operation:
0 ≤ k ≤ 255
(TOS) → PC,
k → W,
1 → GIE/GIEH or PEIE/GIEL,
if s = 1
(TOS) → PC,
PCLATU, PCLATH are unchanged
(WS) → W,
(STATUSS) → STATUS,
(BSRS) → BSR,
Status Affected:
Encoding:
None
0000
1100
kkkk
kkkk
PCLATU, PCLATH are unchanged
Description:
W is loaded with the eight-bit literal ‘k’.
The program counter is loaded from the
top of the stack (the return address).
The high address latch (PCLATH)
remains unchanged.
Status Affected:
Encoding:
GIE/GIEH, PEIE/GIEL.
0000
0000
0001
000s
Description:
Return from interrupt. Stack is popped
and Top-of-Stack (TOS) is loaded into
the PC. Interrupts are enabled by
setting either the high or low-priority
global interrupt enable bit. If ‘s’ = 1, the
contents of the shadow registers WS,
STATUSS and BSRS are loaded into
their corresponding registers W,
Words:
Cycles:
1
2
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
literal ‘k’
Process
Data
POP PC
from stack,
write to W
STATUS and BSR. If ‘s’ = 0, no update
of these registers occurs (default).
No
operation
No
No
No
Words:
Cycles:
1
2
operation
operation
operation
Q Cycle Activity:
Q1
Example:
Q2
Q3
Q4
CALL TABLE ; W contains table
; offset value
Decode
No
operation
No
operation
POP PC
from stack
; W now has
; table value
Set GIEH or
GIEL
:
No
operation
No
operation
No
operation
No
operation
TABLE
ADDWF PCL ; W = offset
RETLW k0
RETLW k1
:
; Begin table
;
Example:
RETFIE
1
After Interrupt
:
PC
=
=
=
=
=
TOS
WS
RETLW kn
; End of table
W
BSR
STATUS
BSRS
STATUSS
1
Before Instruction
GIE/GIEH, PEIE/GIEL
W
=
07h
After Instruction
W
=
value of kn
DS39646C-page 352
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
RETURN
Return from Subroutine
RLCF
Rotate Left f through Carry
Syntax:
RETURN {s}
Syntax:
RLCF f {,d {,a}}
Operands:
Operation:
s ∈ [0,1]
Operands:
0 ≤ f ≤ 255
d ∈ [0,1]
a ∈ [0,1]
(TOS) → PC,
if s = 1
(WS) → W,
Operation:
(f<n>) → dest<n + 1>,
(f<7>) → C,
(C) → dest<0>
(STATUSS) → STATUS,
(BSRS) → BSR,
PCLATU, PCLATH are unchanged
Status Affected:
Encoding:
C, N, Z
Status Affected:
Encoding:
None
0011
01da
ffff
ffff
0000
0000
0001
001s
Description:
The contents of register ‘f’ are rotated
one bit to the left through the Carry flag.
If ‘d’ is ‘0’, the result is placed in W. If ‘d’
is ‘1’, the result is stored back in register
‘f’ (default).
Description:
Return from subroutine. The stack is
popped and the top of the stack (TOS)
is loaded into the program counter. If
‘s’= 1, the contents of the shadow
registers WS, STATUSS and BSRS are
loaded into their corresponding
registers W, STATUS and BSR. If
‘s’ = 0, no update of these registers
occurs (default).
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 26.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words:
Cycles:
1
2
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
No
operation
Process
Data
POP PC
register f
C
from stack
No
operation
No
operation
No
operation
No
operation
Words:
Cycles:
1
1
Q Cycle Activity:
Q1
Example:
RETURN
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write to
destination
After Instruction:
PC = TOS
Example:
RLCF
REG, 0, 0
Before Instruction
REG
C
=
=
1110 0110
0
After Instruction
REG
W
C
=
=
=
1110 0110
1100 1100
1
© 2008 Microchip Technology Inc.
DS39646C-page 353
PIC18F8722 FAMILY
RLNCF
Rotate Left f (no carry)
RRCF
Rotate Right f through Carry
Syntax:
RLNCF f {,d {,a}}
Syntax:
RRCF f {,d {,a}}
Operands:
0 ≤ f ≤ 255
d ∈ [0,1]
a ∈ [0,1]
Operands:
0 ≤ f ≤ 255
d ∈ [0,1]
a ∈ [0,1]
Operation:
(f<n>) → dest<n + 1>,
(f<7>) → dest<0>
Operation:
(f<n>) → dest<n – 1>,
(f<0>) → C,
(C) → dest<7>
Status Affected:
Encoding:
N, Z
Status Affected:
Encoding:
C, N, Z
0100
01da
ffff
ffff
0011
00da
ffff
ffff
Description:
The contents of register ‘f’ are rotated
one bit to the left. If ‘d’ is ‘0’, the result
is placed in W. If ‘d’ is ‘1’, the result is
stored back in register ‘f’ (default).
Description:
The contents of register ‘f’ are rotated
one bit to the right through the Carry
flag. If ‘d’ is ‘0’, the result is placed in W.
If ‘d’ is ‘1’, the result is placed back in
register ‘f’ (default).
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 26.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 26.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
register f
register f
C
Words:
Cycles:
1
1
Words:
Cycles:
1
1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Q Cycle Activity:
Q1
Decode
Read
register ‘f’
Process
Data
Write to
destination
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write to
destination
Example:
RLNCF
REG, 1, 0
Before Instruction
REG
After Instruction
Example:
RRCF
REG, 0, 0
=
1010 1011
0101 0111
Before Instruction
REG
=
REG
C
=
=
1110 0110
0
After Instruction
REG
W
C
=
=
=
1110 0110
0111 0011
0
DS39646C-page 354
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
RRNCF
Rotate Right f (no carry)
SETF
Set f
Syntax:
RRNCF f {,d {,a}}
Syntax:
SETF f {,a}
Operands:
0 ≤ f ≤ 255
d ∈ [0,1]
a ∈ [0,1]
Operands:
0 ≤ f ≤ 255
a ∈ [0,1]
Operation:
FFh → f
Operation:
(f<n>) → dest<n – 1>,
(f<0>) → dest<7>
Status Affected:
Encoding:
None
0110
100a
ffff
ffff
Status Affected:
Encoding:
N, Z
Description:
The contents of the specified register
are set to FFh.
0100
00da
ffff
ffff
Description:
The contents of register ‘f’ are rotated
one bit to the right. If ‘d’ is ‘0’, the result
is placed in W. If ‘d’ is ‘1’, the result is
placed back in register ‘f’ (default).
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 26.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
If ‘a’ is ‘0’, the Access Bank will be
selected, overriding the BSR value. If ‘a’
is ‘1’, then the bank will be selected as
per the BSR value (default).
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 26.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words:
Cycles:
1
1
Q Cycle Activity:
Q1
Q2
Q3
Q4
register f
Decode
Read
register ‘f’
Process
Data
Write
register ‘f’
Words:
Cycles:
1
1
Example:
SETF
REG,1
Q Cycle Activity:
Q1
Before Instruction
REG
After Instruction
REG
=
=
5Ah
FFh
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write to
destination
Example 1:
RRNCF
REG, 1, 0
Before Instruction
REG
After Instruction
REG
=
1101 0111
1110 1011
RRNCF REG, 0, 0
=
Example 2:
Before Instruction
W
REG
=
=
?
1101 0111
After Instruction
W
REG
=
=
1110 1011
1101 0111
© 2008 Microchip Technology Inc.
DS39646C-page 355
PIC18F8722 FAMILY
SLEEP
Enter Sleep Mode
SUBFWB
Subtract f from W with Borrow
Syntax:
SLEEP
None
Syntax:
SUBFWB f {,d {,a}}
Operands:
Operation:
Operands:
0 ≤ f ≤ 255
d ∈ [0,1]
a ∈ [0,1]
00h → WDT,
0 → WDT postscaler,
1 → TO,
Operation:
(W) – (f) – (C) → dest
0 → PD
Status Affected:
Encoding:
N, OV, C, DC, Z
Status Affected:
Encoding:
TO, PD
0101
01da
ffff
ffff
0000
0000
0000
0011
Description:
Subtract register ‘f’ and Carry flag
(borrow) from W (2’s complement
method). If ‘d’ is ‘0’, the result is stored in
W. If ‘d’ is ‘1’, the result is stored in
register ‘f’ (default).
Description:
The Power-Down status bit (PD) is
cleared. The Time-out status bit (TO)
is set. The Watchdog Timer and its
postscaler are cleared.
The processor is put into Sleep mode
with the oscillator stopped.
If ‘a’ is ‘0’, the Access Bank is selected. If
‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
Words:
Cycles:
1
1
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates in
Indexed Literal Offset Addressing mode
whenever f ≤ 95 (5Fh). See
Q Cycle Activity:
Q1
Q2
Q3
Q4
Section 26.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Decode
No
operation
Process
Data
Go to
Sleep
Words:
Cycles:
1
1
Example:
SLEEP
Before Instruction
TO
PD
=
=
?
?
Q Cycle Activity:
Q1
Q2
Q3
Q4
After Instruction
Decode
Read
register ‘f’
Process
Data
Write to
destination
TO
PD
=
=
1 †
0
Example 1:
SUBFWB
REG, 1, 0
†
If WDT causes wake-up, this bit is cleared.
Before Instruction
REG
W
C
=
=
=
3
2
1
After Instruction
REG
W
C
=
FF
2
=
=
=
=
0
Z
0
1
N
; result is negative
Example 2:
Before Instruction
SUBFWB
REG, 0, 0
REG
W
C
=
=
=
2
5
1
After Instruction
REG
W
C
=
2
3
1
0
=
=
=
=
Z
N
0
; result is positive
Example 3:
Before Instruction
SUBFWB
REG, 1, 0
REG
W
C
=
=
=
1
2
0
After Instruction
REG
W
C
=
0
2
1
1
0
=
=
=
=
Z
; result is zero
N
DS39646C-page 356
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
SUBLW
Subtract W from literal
SUBLW
SUBWF
Subtract W from f
Syntax:
k
Syntax:
SUBWF f {,d {,a}}
Operands:
Operation:
Status Affected:
Encoding:
Description:
0 ≤ k ≤ 255
Operands:
0 ≤ f ≤ 255
d ∈ [0,1]
a ∈ [0,1]
k – (W) → W
N, OV, C, DC, Z
Operation:
(f) – (W) → dest
0000
1000
kkkk
kkkk
Status Affected:
Encoding:
N, OV, C, DC, Z
W is subtracted from the eight-bit
literal ‘k’. The result is placed in W.
0101
11da
ffff
ffff
Description:
Subtract W from register ‘f’ (2’s
Words:
Cycles:
1
1
complement method). If ‘d’ is ‘0’, the
result is stored in W. If ‘d’ is ‘1’, the result
is stored back in register ‘f’ (default).
Q Cycle Activity:
Q1
Q2
Q3
Q4
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
Decode
Read
literal ‘k’
Process
Data
Write to
W
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 26.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Example 1:
SUBLW 02h
Before Instruction
W
C
=
=
01h
?
After Instruction
W
C
Z
=
01h
=
=
=
1
0
0
; result is positive
Words:
Cycles:
1
1
N
Example 2:
SUBLW 02h
Q Cycle Activity:
Q1
Before Instruction
Q2
Q3
Q4
W
C
=
=
02h
?
Decode
Read
register ‘f’
Process
Data
Write to
destination
After Instruction
W
C
Z
=
00h
Example 1:
SUBWF
REG, 1, 0
=
=
=
1
1
0
; result is zero
Before Instruction
N
REG
W
C
=
=
=
3
2
?
Example 3:
SUBLW 02h
Before Instruction
After Instruction
W
C
=
=
03h
?
REG
W
C
=
1
2
1
0
0
=
=
=
=
; result is positive
After Instruction
Z
W
C
Z
=
FFh ; (2’s complement)
N
=
=
=
0
0
1
; result is negative
Example 2:
Before Instruction
SUBWF
REG, 0, 0
N
REG
W
C
=
=
=
2
2
?
After Instruction
REG
W
C
=
2
0
1
1
0
=
=
=
=
; result is zero
Z
N
Example 3:
Before Instruction
SUBWF
REG, 1, 0
REG
W
C
=
=
=
1
2
?
After Instruction
REG
W
C
=
FFh ;(2’s complement)
2
0
0
1
=
=
=
=
; result is negative
Z
N
© 2008 Microchip Technology Inc.
DS39646C-page 357
PIC18F8722 FAMILY
SUBWFB
Subtract W from f with Borrow
SWAPF
Swap f
Syntax:
SUBWFB f {,d {,a}}
Syntax:
SWAPF f {,d {,a}}
Operands:
0 ≤ f ≤ 255
d ∈ [0,1]
a ∈ [0,1]
Operands:
0 ≤ f ≤ 255
d ∈ [0,1]
a ∈ [0,1]
Operation:
(f) – (W) – (C) → dest
Operation:
(f<3:0>) → dest<7:4>,
(f<7:4>) → dest<3:0>
Status Affected:
Encoding:
N, OV, C, DC, Z
0101
10da
ffff
ffff
Status Affected:
Encoding:
None
Description:
Subtract W and the Carry flag (borrow)
from register ‘f’ (2’s complement
method). If ‘d’ is ‘0’, the result is stored
in W. If ‘d’ is ‘1’, the result is stored back
in register ‘f’ (default).
0011
10da
ffff
ffff
Description:
The upper and lower nibbles of register
‘f’ are exchanged. If ‘d’ is ‘0’, the result
is placed in W. If ‘d’ is ‘1’, the result is
placed in register ‘f’ (default).
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 26.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 26.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words:
Cycles:
1
1
Words:
Cycles:
1
1
Q Cycle Activity:
Q1
Q Cycle Activity:
Q1
Q2
Read
register ‘f’
Q3
Process
Data
Q4
Decode
Write to
destination
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write to
destination
Example 1:
SUBWFB REG, 1, 0
Before Instruction
REG
W
C
=
=
=
19h
0Dh
1
(0001 1001)
(0000 1101)
Example:
SWAPF
REG, 1, 0
Before Instruction
REG
After Instruction
=
53h
35h
After Instruction
REG
W
C
=
0Ch
0Dh
1
(0000 1011)
(0000 1101)
=
=
=
=
REG
=
Z
0
N
0
; result is positive
Example 2:
Before Instruction
SUBWFB REG, 0, 0
REG
W
C
=
=
=
1Bh
1Ah
0
(0001 1011)
(0001 1010)
After Instruction
REG
W
C
=
1Bh
00h
1
(0001 1011)
=
=
=
=
Z
1
; result is zero
N
0
Example 3:
Before Instruction
SUBWFB REG, 1, 0
REG
W
C
=
=
=
03h
0Eh
1
(0000 0011)
(0000 1101)
After Instruction
REG
=
F5h
(1111 0100)
; [2’s comp]
W
C
Z
=
=
=
=
0Eh
0
0
1
(0000 1101)
N
; result is negative
DS39646C-page 358
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
TBLRD
Table Read
TBLRD
Table Read (Continued)
Syntax:
TBLRD ( *; *+; *-; +*)
None
Example 1:
TBLRD *+ ;
Operands:
Operation:
Before Instruction
TABLAT
TBLPTR
MEMORY(00A356h)
=
=
=
55h
00A356h
34h
if TBLRD *,
(Prog Mem (TBLPTR)) → TABLAT;
TBLPTR – No Change
if TBLRD *+,
(Prog Mem (TBLPTR)) → TABLAT;
(TBLPTR) + 1 → TBLPTR
if TBLRD *-,
(Prog Mem (TBLPTR)) → TABLAT;
(TBLPTR) – 1 → TBLPTR
if TBLRD +*,
(TBLPTR) + 1 → TBLPTR;
(Prog Mem (TBLPTR)) → TABLAT
After Instruction
TABLAT
TBLPTR
=
=
34h
00A357h
Example 2:
TBLRD +* ;
Before Instruction
TABLAT
TBLPTR
MEMORY(01A357h)
MEMORY(01A358h)
After Instruction
=
=
=
=
AAh
01A357h
12h
34h
TABLAT
TBLPTR
=
=
34h
01A358h
Status Affected: None
Encoding:
0000
0000
0000
10nn
nn=0 *
=1 *+
=2 *-
=3 +*
Description:
This instruction is used to read the contents
of Program Memory (P.M.). To address the
program memory, a pointer called Table
Pointer (TBLPTR) is used.
The TBLPTR (a 21-bit pointer) points to
each byte in the program memory. TBLPTR
has a 2-Mbyte address range.
TBLPTR<0> = 0:Least Significant Byte of
Program Memory Word
TBLPTR<0> = 1:Most Significant Byte of
Program Memory Word
The TBLRDinstruction can modify the value
of TBLPTR as follows:
•
•
•
•
no change
post-increment
post-decrement
pre-increment
Words:
Cycles:
1
2
Q Cycle Activity:
Q1
Q2
No
Q3
No
Q4
Decode
No
operation
operation
operation
No
No operation
No
No operation
(Write
TABLAT)
operation (Read Program operation
Memory)
© 2008 Microchip Technology Inc.
DS39646C-page 359
PIC18F8722 FAMILY
TBLWT
Table Write
TBLWT
Table Write (Continued)
Syntax:
TBLWT ( *; *+; *-; +*)
None
Example 1:
TBLWT *+;
Operands:
Operation:
Before Instruction
if TBLWT*,
TABLAT
TBLPTR
HOLDING REGISTER
(00A356h)
=
=
55h
00A356h
(TABLAT) → Holding Register;
TBLPTR – No Change
if TBLWT*+,
(TABLAT) → Holding Register;
(TBLPTR) + 1 → TBLPTR
if TBLWT*-,
(TABLAT) → Holding Register;
(TBLPTR) – 1 → TBLPTR
if TBLWT+*,
(TBLPTR) + 1 → TBLPTR;
(TABLAT) → Holding Register
=
FFh
After Instructions (table write completion)
TABLAT
TBLPTR
HOLDING REGISTER
(00A356h)
=
=
55h
00A357h
=
55h
Example 2:
TBLWT +*;
Before Instruction
TABLAT
TBLPTR
=
=
34h
01389Ah
HOLDING REGISTER
(01389Ah)
Status Affected: None
=
=
FFh
FFh
Encoding:
0000
0000
0000
11nn
nn=0 *
=1 *+
=2 *-
=3 +*
HOLDING REGISTER
(01389Bh)
After Instruction (table write completion)
TABLAT
TBLPTR
HOLDING REGISTER
(01389Ah)
HOLDING REGISTER
(01389Bh)
=
=
34h
01389Bh
Description:
This instruction uses the 3 LSBs of
TBLPTR to determine which of the
8 holding registers the TABLAT is written
to. The holding registers are used to
program the contents of Program Memory
(P.M.). (Refer to Section 5.0 “Memory
Organization” for additional details on
programming Flash memory.)
=
=
FFh
34h
The TBLPTR (a 21-bit pointer) points to
each byte in the program memory.
TBLPTR has a 2-Mbyte address range.
The LSb of the TBLPTR selects which
byte of the program memory location to
access.
TBLPTR<0> = 0:Least Significant Byte of
Program Memory Word
TBLPTR<0> = 1:Most Significant Byte of
Program Memory Word
The TBLWT instruction can modify the
value of TBLPTR as follows:
•
•
•
•
no change
post-increment
post-decrement
pre-increment
Words:
1
2
Cycles:
Q Cycle Activity:
Q1
Q2
No
Q3
No
Q4
No
Decode
operation operation operation
No
No No No
operation operation operation operation
(Read
TABLAT)
(Write to
Holding
Register)
DS39646C-page 360
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
TSTFSZ
Test f, Skip if 0
XORLW
Exclusive OR Literal with W
XORLW
Syntax:
TSTFSZ f {,a}
Syntax:
k
Operands:
0 ≤ f ≤ 255
a ∈ [0,1]
Operands:
Operation:
Status Affected:
Encoding:
Description:
0 ≤ k ≤ 255
(W) .XOR. k → W
N, Z
Operation:
skip if f = 0
Status Affected:
Encoding:
None
0000
1010
kkkk
kkkk
0110
011a
ffff
ffff
The contents of W are XORed with
the 8-bit literal ‘k’. The result is placed
in W.
Description:
If ‘f’ = 0, the next instruction fetched
during the current instruction execution
is discarded and a NOPis executed,
making this a two-cycle instruction.
Words:
Cycles:
1
1
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
literal ‘k’
Process
Data
Write to
W
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 26.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Example:
XORLW
0AFh
Before Instruction
W
=
B5h
1Ah
After Instruction
Words:
Cycles:
1
W
=
1(2)
Note: 3 cycles if skip and followed
by a 2-word instruction.
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
No
operation
If skip:
Q1
Q2
Q3
Q4
No
No
No
No
operation
operation
operation
operation
If skip and followed by 2-word instruction:
Q1
Q2
Q3
Q4
No
No
No
No
operation
operation
operation
operation
No
No
No
No
operation
operation
operation
operation
Example:
HERE
NZERO
ZERO
TSTFSZ CNT, 1
:
:
Before Instruction
PC
=
Address (HERE)
After Instruction
If CNT
PC
If CNT
PC
=
=
≠
=
00h,
Address (ZERO)
00h,
Address (NZERO)
© 2008 Microchip Technology Inc.
DS39646C-page 361
PIC18F8722 FAMILY
XORWF
Exclusive OR W with f
Syntax:
XORWF f {,d {,a}}
Operands:
0 ≤ f ≤ 255
d ∈ [0,1]
a ∈ [0,1]
Operation:
(W) .XOR. (f) → dest
Status Affected:
Encoding:
N, Z
0001
10da
ffff
ffff
Description:
Exclusive OR the contents of W with
register ‘f’. If ‘d’ is ‘0’, the result is stored
in W. If ‘d’ is ‘1’, the result is stored back
in the register ‘f’ (default).
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank (default).
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 26.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words:
Cycles:
1
1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write to
destination
Example:
XORWF
REG, 1, 0
Before Instruction
REG
W
=
=
AFh
B5h
After Instruction
REG
W
=
=
1Ah
B5h
DS39646C-page 362
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
A summary of the instructions in the extended instruc-
tion set is provided in Table 26-3. Detailed descriptions
are provided in Section 26.2.2 “Extended Instruction
Set”. The opcode field descriptions in Table 26-1
(page 322) apply to both the standard and extended
PIC18 instruction sets.
26.2 Extended Instruction Set
In addition to the standard 75 instructions of the PIC18
instruction set, the PIC18F8722 family of devices also
provide an optional extension to the core CPU function-
ality. The added features include eight additional
instructions that augment Indirect and Indexed
Addressing operations and the implementation of
Indexed Literal Offset Addressing for many of the
standard PIC18 instructions.
Note:
The instruction set extension and the
Indexed Literal Offset Addressing mode
were designed for optimizing applications
written in C; the user may likely never use
these instructions directly in assembler.
The syntax for these commands is
provided as a reference for users who may
be reviewing code that has been
generated by a compiler.
The additional features of the extended instruction set
are enabled by default. To enable them, users must set
the XINST Configuration bit.
The instructions in the extended set can all be
classified as literal operations, which either manipulate
the File Select Registers, or use them for Indexed
Addressing. Two of the instructions, ADDFSR and
SUBFSR, each have an additional special instantiation
for using FSR2. These versions (ADDULNK and
SUBULNK) allow for automatic return after execution.
26.2.1
EXTENDED INSTRUCTION SYNTAX
Most of the extended instructions use indexed argu-
ments, using one of the File Select Registers and some
offset to specify a source or destination register. When
an argument for an instruction serves as part of
Indexed Addressing, it is enclosed in square brackets
(“[ ]”). This is done to indicate that the argument is used
as an index or offset. The MPASM™ Assembler will
flag an error if it determines that an index or offset value
is not bracketed.
The extended instructions are specifically implemented
to optimize re-entrant program code (that is, code that
is recursive or that uses a software stack) written in
high-level languages, particularly C. Among other
things, they allow users working in high-level
languages to perform certain operations on data
structures more efficiently. These include:
When the extended instruction set is enabled, brackets
are also used to indicate index arguments in
byte-oriented and bit-oriented instructions. This is in
addition to other changes in their syntax. For more
details, see Section 26.2.3.1 “Extended Instruction
Syntax with Standard PIC18 Commands”.
• dynamic allocation and deallocation of software
stack space when entering and leaving
subroutines
• function pointer invocation
• software Stack Pointer manipulation
• manipulation of variables located in a software
stack
Note:
In the past, square brackets have been
used to denote optional arguments in the
PIC18 and earlier instruction sets. In this
text and going forward, optional
arguments are denoted by braces (“{ }”).
TABLE 26-3: EXTENSIONS TO THE PIC18 INSTRUCTION SET
16-Bit Instruction Word
MSb LSb
Mnemonic,
Operands
Status
Affected
Description
Cycles
ADDFSR
ADDULNK
CALLW
f, k
k
Add Literal to FSR
Add Literal to FSR2 and Return
Call Subroutine using WREG
1
2
2
2
1110 1000 ffkk kkkk
1110 1000 11kk kkkk
0000 0000 0001 0100
1110 1011 0zzz zzzz
1111 ffff ffff ffff
1110 1011 1zzz zzzz
1111 xxxx xzzz zzzz
1110 1010 kkkk kkkk
None
None
None
None
MOVSF
zs, fd Move zs (source) to 1st word
fd (destination) 2nd word
zs, zd Move zs (source) to 1st word
zd (destination) 2nd word
MOVSS
PUSHL
2
1
None
None
k
Store Literal at FSR2,
Decrement FSR2
SUBFSR
SUBULNK
f, k
k
Subtract Literal from FSR
Subtract Literal from FSR2 and
Return
1
2
1110 1001 ffkk kkkk
1110 1001 11kk kkkk
None
None
© 2008 Microchip Technology Inc.
DS39646C-page 363
PIC18F8722 FAMILY
26.2.2
EXTENDED INSTRUCTION SET
ADDFSR
Add Literal to FSR
ADDULNK
Add Literal to FSR2 and Return
Syntax:
ADDFSR f, k
Syntax:
ADDULNK k
Operands:
0 ≤ k ≤ 63
f ∈ [ 0, 1, 2 ]
Operands:
Operation:
0 ≤ k ≤ 63
FSR2 + k → FSR2,
(TOS) → PC
None
Operation:
FSR(f) + k → FSR(f)
Status Affected:
Encoding:
None
Status Affected:
Encoding:
1110
1000
ffkk
kkkk
1110
1000
11kk
kkkk
Description:
The 6-bit literal ‘k’ is added to the
contents of the FSR specified by ‘f’.
Description:
The 6-bit literal ‘k’ is added to the
contents of FSR2. A RETURNis then
executed by loading the PC with the
TOS.
Words:
1
1
Cycles:
Q Cycle Activity:
Q1
The instruction takes two cycles to
execute; a NOPis performed during
the second cycle.
Q2
Q3
Q4
Decode
Read
literal ‘k’
Process
Data
Write to
FSR
This may be thought of as a special
case of the ADDFSRinstruction,
where f = 3 (binary ‘11’); it operates
only on FSR2.
Example:
ADDFSR 2, 23h
Words:
1
2
Before Instruction
FSR2
After Instruction
FSR2
Cycles:
=
03FFh
0422h
Q Cycle Activity:
Q1
=
Q2
Q3
Q4
Decode
Read
literal ‘k’
Process
Data
Write to
FSR
No
No
No
No
Operation
Operation
Operation
Operation
Example:
ADDULNK 23h
Before Instruction
FSR2
PC
=
=
03FFh
0100h
After Instruction
FSR2
PC
=
=
0422h
(TOS)
Note:
All PIC18 instructions may take an optional label argument preceding the instruction mnemonic for use in
symbolic addressing. If a label is used, the instruction format then becomes: {label} instruction argument(s).
DS39646C-page 364
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
CALLW
Subroutine Call using WREG
MOVSF
Move Indexed to f
Syntax:
CALLW
None
Syntax:
MOVSF [z ], f
s
d
Operands:
Operation:
Operands:
0 ≤ z ≤ 127
s
0 ≤ f ≤ 4095
d
(PC + 2) → TOS,
(W) → PCL,
Operation:
((FSR2) + z ) → f
s
d
(PCLATH) → PCH,
(PCLATU) → PCU
Status Affected:
None
Encoding:
1st word (source)
2nd word (destin.)
Status Affected:
Encoding:
None
1110
1111
1011
ffff
0zzz
ffff
zzzzs
ffffd
0000
0000
0001
0100
Description
First, the return address (PC + 2) is
pushed onto the return stack. Next, the
contents of W are written to PCL; the
existing value is discarded. Then, the
contents of PCLATH and PCLATU are
latched into PCH and PCU,
respectively. The second cycle is
executed as a NOPinstruction while the
new next instruction is fetched.
Description:
The contents of the source register are
moved to destination register ‘f ’. The
d
actual address of the source register is
determined by adding the 7-bit literal
offset ‘z ’, in the first word, to the value
s
of FSR2. The address of the destination
register is specified by the 12-bit literal
‘f ’ in the second word. Both addresses
d
can be anywhere in the 4096-byte data
space (000h to FFFh).
Unlike CALL, there is no option to
update W, STATUS or BSR.
The MOVSFinstruction cannot use the
PCL, TOSU, TOSH or TOSL as the
destination register.
Words:
Cycles:
1
2
If the resultant source address points to
an indirect addressing register, the
value returned will be 00h.
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
WREG
Push PC to
stack
No
operation
Words:
Cycles:
2
2
No
No
No
No
Q Cycle Activity:
Q1
operation
operation
operation
operation
Q2
Q3
Q4
Decode
Determine
source addr source addr source reg
Determine
Read
Example:
HERE
CALLW
Before Instruction
Decode
No
operation
No
operation
Write
register ‘f’
(dest)
PC
=
address (HERE)
PCLATH =
PCLATU =
10h
00h
06h
No dummy
read
W
=
After Instruction
PC
=
001006h
TOS
=
address (HERE + 2)
Example:
MOVSF
[05h], REG2
PCLATH =
PCLATU =
W
10h
00h
06h
Before Instruction
=
FSR2
=
80h
33h
Contents
of 85h
REG2
=
=
11h
After Instruction
FSR2
=
80h
Contents
of 85h
REG2
=
=
33h
33h
© 2008 Microchip Technology Inc.
DS39646C-page 365
PIC18F8722 FAMILY
MOVSS
Move Indexed to Indexed
PUSHL
Store Literal at FSR2, Decrement FSR2
Syntax:
MOVSS [z ], [z ]
Syntax:
PUSHL k
s
d
Operands:
0 ≤ z ≤ 127
s
Operands:
Operation:
0 ≤ k ≤ 255
0 ≤ z ≤ 127
d
k → (FSR2),
FSR2 – 1→ FSR2
Operation:
((FSR2) + z ) → ((FSR2) + z )
s d
Status Affected:
None
Status Affected:
Encoding:
None
Encoding:
1st word (source)
2nd word (dest.)
1111
1010
kkkk
kkkk
1110
1111
1011
xxxx
1zzz
xzzz
zzzzs
zzzzd
Description:
The 8-bit literal ‘k’ is written to the data
memory address specified by FSR2.
FSR2 is decremented by 1 after the
operation.
Description
The contents of the source register are
moved to the destination register. The
addresses of the source and destination
registers are determined by adding the
This instruction allows users to push
values onto a software stack.
7-bit literal offsets ‘z ’ or ‘z ’,
s
d
respectively, to the value of FSR2. Both
registers can be located anywhere in
the 4096-byte data memory space
(000h to FFFh).
Words:
Cycles:
1
1
Q Cycle Activity:
Q1
The MOVSSinstruction cannot use the
PCL, TOSU, TOSH or TOSL as the
destination register.
Q2
Q3
Q4
Decode
Read ‘k’
Process
data
Write to
destination
If the resultant source address points to
an Indirect Addressing register, the
value returned will be 00h. If the
Example:
PUSHL 08h
resultant destination address points to
an Indirect Addressing register, the
instruction will execute as a NOP.
Before Instruction
FSR2H:FSR2L
Memory (01ECh)
=
=
01ECh
00h
Words:
2
2
After Instruction
Cycles:
FSR2H:FSR2L
Memory (01ECh)
=
=
01EBh
08h
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Determine
Determine
Read
source addr source addr source reg
Decode
Determine
dest addr
Determine
dest addr
Write
to dest reg
Example:
MOVSS [05h], [06h]
Before Instruction
FSR2
=
=
=
80h
33h
11h
Contents
of 85h
Contents
of 86h
After Instruction
FSR2
=
=
=
80h
33h
33h
Contents
of 85h
Contents
of 86h
DS39646C-page 366
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
SUBFSR
Subtract Literal from FSR
SUBULNK
Subtract Literal from FSR2 and Return
Syntax:
SUBFSR f, k
0 ≤ k ≤ 63
Syntax:
SUBULNK k
Operands:
Operands:
Operation:
0 ≤ k ≤ 63
f ∈ [ 0, 1, 2 ]
FSRf – k → FSRf
None
FSR2 – k → FSR2
(TOS) → PC
Operation:
Status Affected:
Encoding:
Status Affected: None
1110
1001
ffkk
kkkk
Encoding:
1110
1001
11kk
kkkk
Description:
The 6-bit literal ‘k’ is subtracted from
the contents of the FSR specified
by ‘f’.
Description:
The 6-bit literal ‘k’ is subtracted from the
contents of the FSR2. A RETURNis then
executed by loading the PC with the
TOS.
Words:
1
1
Cycles:
The instruction takes two cycles to
execute; a NOPis performed during the
second cycle.
Q Cycle Activity:
Q1
Q2
Q3
Q4
This may be thought of as a special case
of the SUBFSRinstruction, where f = 3
(binary ‘11’); it operates only on FSR2.
Decode
Read
register ‘f’
Process
Data
Write to
destination
Words:
1
2
Example:
SUBFSR 2, 23h
03FFh
Cycles:
Before Instruction
FSR2
After Instruction
FSR2
Q Cycle Activity:
Q1
=
Q2
Q3
Q4
Decode
Read
register ‘f’
Process
Data
Write to
destination
=
03DCh
No
No
No
No
Operation
Operation
Operation
Operation
Example:
SUBULNK 23h
Before Instruction
FSR2
PC
=
=
03FFh
0100h
After Instruction
FSR2
PC
=
=
03DCh
(TOS)
© 2008 Microchip Technology Inc.
DS39646C-page 367
PIC18F8722 FAMILY
26.2.3
BYTE-ORIENTED AND
BIT-ORIENTED INSTRUCTIONS IN
INDEXED LITERAL OFFSET MODE
26.2.3.1
Extended Instruction Syntax with
Standard PIC18 Commands
When the extended instruction set is enabled, the file
register argument ‘f’ in the standard byte-oriented and
bit-oriented commands is replaced with the literal offset
value ‘k’. As already noted, this occurs only when ‘f’ is
less than or equal to 5Fh. When an offset value is used,
it must be indicated by square brackets (“[ ]”). As with
the extended instructions, the use of brackets indicates
to the compiler that the value is to be interpreted as an
index or an offset. Omitting the brackets, or using a
value greater than 5Fh within the brackets, will
generate an error in the MPASM Assembler.
Note: Enabling the PIC18 instruction set exten-
sion may cause legacy applications to
behave erratically or fail entirely.
In addition to eight new commands in the extended set,
enabling the extended instruction set also enables
Indexed Literal Offset Addressing (Section 5.5.1
“Indexed Addressing with Literal Offset”). This has
a significant impact on the way that many commands of
the standard PIC18 instruction set are interpreted.
When the extended set is disabled, addresses embed-
ded in opcodes are treated as literal memory locations:
either as a location in the Access Bank (a = 0) or in a
GPR bank designated by the BSR (a = 1). When the
extended instruction set is enabled and a = 0, however,
a file register argument of 5Fh or less is interpreted as
an offset from the pointer value in FSR2 and not as a
literal address. For practical purposes, this means that
all instructions that use the Access RAM bit as an
argument – that is, all byte-oriented and bit-oriented
instructions, or almost half of the core PIC18 instruc-
tions – may behave differently when the extended
instruction set is enabled.
If the index argument is properly bracketed for Indexed
Literal Offset Addressing, the Access RAM argument is
never specified; it will automatically be assumed to be
‘0’. This is in contrast to standard operation (extended
instruction set disabled), when ‘a’ is set on the basis of
the target address. Declaring the Access RAM bit in
this mode will also generate an error in the MPASM
Assembler.
The destination argument ‘d’ functions as before.
In the latest versions of the MPASM Assembler,
language support for the extended instruction set must
be explicitly invoked. This is done with either the
command line option, /y, or the PE directive in the
source listing.
When the content of FSR2 is 00h, the boundaries of the
Access RAM are essentially remapped to their original
values. This may be useful in creating
backward-compatible code. If this technique is used, it
may be necessary to save the value of FSR2 and
restore it when moving back and forth between C and
assembly routines in order to preserve the Stack
Pointer. Users must also keep in mind the syntax
requirements of the extended instruction set (see
Section 26.2.3.1 “Extended Instruction Syntax with
Standard PIC18 Commands”).
26.2.4
CONSIDERATIONS WHEN
ENABLING THE EXTENDED
INSTRUCTION SET
It is important to note that the extensions to the instruc-
tion set may not be beneficial to all users. In particular,
users who are not writing code that uses a software
stack may not benefit from using the extensions to the
instruction set.
Although the Indexed Literal Offset Addressing mode
can be very useful for dynamic stack and pointer
manipulation, it can also be very annoying if a simple
arithmetic operation is carried out on the wrong
register. Users who are accustomed to the PIC18 pro-
gramming must keep in mind that, when the extended
instruction set is enabled, register addresses of 5Fh or
less are used for Indexed Literal Offset Addressing.
Additionally, the Indexed Literal Offset Addressing
mode may create issues with legacy applications
written to the PIC18 assembler. This is because
instructions in the legacy code may attempt to address
registers in the Access Bank below 5Fh. Since these
addresses are interpreted as literal offsets to FSR2
when the instruction set extension is enabled, the
application may read or write to the wrong data
addresses.
Representative examples of typical byte-oriented and
bit-oriented instructions in the Indexed Literal Offset
Addressing mode are provided on the following page to
show how execution is affected. The operand condi-
tions shown in the examples are applicable to all
instructions of these types.
When porting an application to the PIC18F8722 family,
it is very important to consider the type of code. A large,
re-entrant application that is written in C and would
benefit from efficient compilation will do well when
using the instruction set extensions. Legacy applica-
tions that heavily use the Access Bank will most likely
not benefit from using the extended instruction set.
DS39646C-page 368
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
ADD W to Indexed
(Indexed Literal Offset mode)
Bit Set Indexed
(Indexed Literal Offset mode)
ADDWF
BSF
Syntax:
ADDWF
[k] {,d}
Syntax:
BSF [k], b
Operands:
0 ≤ k ≤ 95
d ∈ [0,1]
Operands:
0 ≤ f ≤ 95
0 ≤ b ≤ 7
Operation:
(W) + ((FSR2) + k) → dest
Operation:
1 → ((FSR2) + k)<b>
Status Affected:
Encoding:
N, OV, C, DC, Z
Status Affected:
Encoding:
None
0010
01d0
kkkk
kkkk
1000
bbb0
kkkk
kkkk
Description:
The contents of W are added to the
contents of the register indicated by
FSR2, offset by the value ‘k’.
Description:
Bit ‘b’ of the register indicated by FSR2,
offset by the value ‘k’, is set.
Words:
Cycles:
1
1
If ‘d’ is ‘0’, the result is stored in W. If ‘d’
is ‘1’, the result is stored back in
register ‘f’ (default).
Q Cycle Activity:
Q1
Q2
Q3
Q4
Words:
Cycles:
1
1
Decode
Read
register ‘f’
Process
Data
Write to
destination
Q Cycle Activity:
Q1
Example:
BSF
[FLAG_OFST], 7
Q2
Q3
Q4
Decode
Read ‘k’
Process
Data
Write to
destination
Before Instruction
FLAG_OFST
FSR2
=
=
0Ah
0A00h
Contents
of 0A0Ah
After Instruction
Example:
ADDWF
[OFST],0
=
55h
D5h
Before Instruction
W
OFST
FSR2
=
=
=
17h
Contents
of 0A0Ah
2Ch
=
0A00h
Contents
of 0A2Ch
=
20h
After Instruction
Set Indexed
(Indexed Literal Offset mode)
SETF
W
=
=
37h
20h
Contents
of 0A2Ch
Syntax:
SETF [k]
Operands:
Operation:
Status Affected:
Encoding:
Description:
0 ≤ k ≤ 95
FFh → ((FSR2) + k)
None
0110
1000
kkkk
kkkk
The contents of the register indicated by
FSR2, offset by ‘k’, are set to FFh.
Words:
Cycles:
1
1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read ‘k’
Process
Data
Write
register
Example:
SETF
[OFST]
2Ch
Before Instruction
OFST
FSR2
=
=
0A00h
Contents
of 0A2Ch
=
00h
After Instruction
Contents
of 0A2Ch
=
FFh
© 2008 Microchip Technology Inc.
DS39646C-page 369
PIC18F8722 FAMILY
To develop software for the extended instruction set,
the user must enable support for the instructions and
the Indexed Addressing mode in their language tool(s).
Depending on the environment being used, this may be
done in several ways:
26.2.5
SPECIAL CONSIDERATIONS WITH
MICROCHIP MPLAB® IDE TOOLS
The latest versions of Microchip’s software tools have
been designed to fully support the extended instruction
set for the PIC18F8722 family. This includes the
MPLAB C18 C Compiler, MPASM assembly language
and MPLAB Integrated Development Environment
(IDE).
• A menu option or dialog box within the
environment that allows the user to configure the
language tool and its settings for the project
• A command line option
When selecting
a
target device for software
• A directive in the source code
development, MPLAB IDE will automatically set default
Configuration bits for that device. The default setting for
the XINST Configuration is ‘0’, disabling the extended
instruction set and Indexed Literal Offset Addressing
mode. For proper execution of applications developed
to take advantage of the extended instruction set,
XINST must be set during programming.
These options vary between different compilers,
assemblers and development environments. Users are
encouraged to review the documentation accompany-
ing their development systems for the appropriate
information.
DS39646C-page 370
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
27.1 MPLAB Integrated Development
Environment Software
27.0 DEVELOPMENT SUPPORT
The PIC® microcontrollers are supported with a full
range of hardware and software development tools:
The MPLAB IDE software brings an ease of software
development previously unseen in the 8/16-bit micro-
controller market. The MPLAB IDE is a Windows®
operating system-based application that contains:
• Integrated Development Environment
- MPLAB® IDE Software
• Assemblers/Compilers/Linkers
- MPASMTM Assembler
- MPLAB C18 and MPLAB C30 C Compilers
- MPLINKTM Object Linker/
MPLIBTM Object Librarian
• A single graphical interface to all debugging tools
- Simulator
- Programmer (sold separately)
- Emulator (sold separately)
- In-Circuit Debugger (sold separately)
• A full-featured editor with color-coded context
• A multiple project manager
• Customizable data windows with direct edit of
contents
• High-level source code debugging
• Visual device initializer for easy register
initialization
- MPLAB ASM30 Assembler/Linker/Library
• Simulators
- MPLAB SIM Software Simulator
• Emulators
- MPLAB ICE 2000 In-Circuit Emulator
- MPLAB REAL ICE™ In-Circuit Emulator
• In-Circuit Debugger
- MPLAB ICD 2
• Mouse over variable inspection
• Drag and drop variables from source to watch
windows
• Device Programmers
- PICSTART® Plus Development Programmer
- MPLAB PM3 Device Programmer
- PICkit™ 2 Development Programmer
• Low-Cost Demonstration and Development
Boards and Evaluation Kits
• Extensive on-line help
• Integration of select third party tools, such as
HI-TECH Software C Compilers and IAR
C Compilers
The MPLAB IDE allows you to:
• Edit your source files (either assembly or C)
• One touch assemble (or compile) and download
to PIC MCU emulator and simulator tools
(automatically updates all project information)
• Debug using:
- Source files (assembly or C)
- Mixed assembly and C
- Machine code
MPLAB IDE supports multiple debugging tools in a
single development paradigm, from the cost-effective
simulators, through low-cost in-circuit debuggers, to
full-featured emulators. This eliminates the learning
curve when upgrading to tools with increased flexibility
and power.
© 2008 Microchip Technology Inc.
DS39646C-page 371
PIC18F8722 FAMILY
27.2 MPASM Assembler
27.5 MPLAB ASM30 Assembler, Linker
and Librarian
The MPASM Assembler is a full-featured, universal
macro assembler for all PIC MCUs.
MPLAB ASM30 Assembler produces relocatable
machine code from symbolic assembly language for
dsPIC30F devices. MPLAB C30 C Compiler uses the
assembler to produce its object file. The assembler
generates relocatable object files that can then be
archived or linked with other relocatable object files and
archives to create an executable file. Notable features
of the assembler include:
The MPASM Assembler generates relocatable object
files for the MPLINK Object Linker, Intel® standard HEX
files, MAP files to detail memory usage and symbol
reference, absolute LST files that contain source lines
and generated machine code and COFF files for
debugging.
The MPASM Assembler features include:
• Support for the entire dsPIC30F instruction set
• Support for fixed-point and floating-point data
• Command line interface
• Rich directive set
• Flexible macro language
• Integration into MPLAB IDE projects
• User-defined macros to streamline
assembly code
• Conditional assembly for multi-purpose
source files
• MPLAB IDE compatibility
• Directives that allow complete control over the
assembly process
27.6 MPLAB SIM Software Simulator
27.3 MPLAB C18 and MPLAB C30
C Compilers
The MPLAB SIM Software Simulator allows code
development in a PC-hosted environment by simulat-
ing the PIC MCUs and dsPIC® DSCs on an instruction
level. On any given instruction, the data areas can be
examined or modified and stimuli can be applied from
a comprehensive stimulus controller. Registers can be
logged to files for further run-time analysis. The trace
buffer and logic analyzer display extend the power of
the simulator to record and track program execution,
actions on I/O, most peripherals and internal registers.
The MPLAB C18 and MPLAB C30 Code Development
Systems are complete ANSI
C
compilers for
Microchip’s PIC18 and PIC24 families of microcon-
trollers and the dsPIC30 and dsPIC33 family of digital
signal controllers. These compilers provide powerful
integration capabilities, superior code optimization and
ease of use not found with other compilers.
For easy source level debugging, the compilers provide
symbol information that is optimized to the MPLAB IDE
debugger.
The MPLAB SIM Software Simulator fully supports
symbolic debugging using the MPLAB C18 and
MPLAB C30 C Compilers, and the MPASM and
MPLAB ASM30 Assemblers. The software simulator
offers the flexibility to develop and debug code outside
of the hardware laboratory environment, making it an
excellent, economical software development tool.
27.4 MPLINK Object Linker/
MPLIB Object Librarian
The MPLINK Object Linker combines relocatable
objects created by the MPASM Assembler and the
MPLAB C18 C Compiler. It can link relocatable objects
from precompiled libraries, using directives from a
linker script.
The MPLIB Object Librarian manages the creation and
modification of library files of precompiled code. When
a routine from a library is called from a source file, only
the modules that contain that routine will be linked in
with the application. This allows large libraries to be
used efficiently in many different applications.
The object linker/library features include:
• Efficient linking of single libraries instead of many
smaller files
• Enhanced code maintainability by grouping
related modules together
• Flexible creation of libraries with easy module
listing, replacement, deletion and extraction
DS39646C-page 372
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
27.7 MPLAB ICE 2000
High-Performance
27.9 MPLAB ICD 2 In-Circuit Debugger
Microchip’s In-Circuit Debugger, MPLAB ICD 2, is a
powerful, low-cost, run-time development tool,
connecting to the host PC via an RS-232 or high-speed
USB interface. This tool is based on the Flash PIC
MCUs and can be used to develop for these and other
PIC MCUs and dsPIC DSCs. The MPLAB ICD 2 utilizes
the in-circuit debugging capability built into the Flash
devices. This feature, along with Microchip’s In-Circuit
Serial ProgrammingTM (ICSPTM) protocol, offers cost-
effective, in-circuit Flash debugging from the graphical
user interface of the MPLAB Integrated Development
Environment. This enables a designer to develop and
debug source code by setting breakpoints, single step-
ping and watching variables, and CPU status and
peripheral registers. Running at full speed enables
testing hardware and applications in real time. MPLAB
ICD 2 also serves as a development programmer for
selected PIC devices.
In-Circuit Emulator
The MPLAB ICE 2000 In-Circuit Emulator is intended
to provide the product development engineer with a
complete microcontroller design tool set for PIC
microcontrollers. Software control of the MPLAB ICE
2000 In-Circuit Emulator is advanced by the MPLAB
Integrated Development Environment, which allows
editing, building, downloading and source debugging
from a single environment.
The MPLAB ICE 2000 is a full-featured emulator
system with enhanced trace, trigger and data monitor-
ing features. Interchangeable processor modules allow
the system to be easily reconfigured for emulation of
different processors. The architecture of the MPLAB
ICE 2000 In-Circuit Emulator allows expansion to
support new PIC microcontrollers.
The MPLAB ICE 2000 In-Circuit Emulator system has
been designed as a real-time emulation system with
advanced features that are typically found on more
expensive development tools. The PC platform and
Microsoft® Windows® 32-bit operating system were
chosen to best make these features available in a
simple, unified application.
27.10 MPLAB PM3 Device Programmer
The MPLAB PM3 Device Programmer is a universal,
CE compliant device programmer with programmable
voltage verification at VDDMIN and VDDMAX for
maximum reliability. It features a large LCD display
(128 x 64) for menus and error messages and a modu-
lar, detachable socket assembly to support various
package types. The ICSP™ cable assembly is included
as a standard item. In Stand-Alone mode, the MPLAB
PM3 Device Programmer can read, verify and program
PIC devices without a PC connection. It can also set
code protection in this mode. The MPLAB PM3
connects to the host PC via an RS-232 or USB cable.
The MPLAB PM3 has high-speed communications and
optimized algorithms for quick programming of large
memory devices and incorporates an SD/MMC card for
file storage and secure data applications.
27.8 MPLAB REAL ICE In-Circuit
Emulator System
MPLAB REAL ICE In-Circuit Emulator System is
Microchip’s next generation high-speed emulator for
Microchip Flash DSC and MCU devices. It debugs and
programs PIC® Flash MCUs and dsPIC® Flash DSCs
with the easy-to-use, powerful graphical user interface of
the MPLAB Integrated Development Environment (IDE),
included with each kit.
The MPLAB REAL ICE probe is connected to the design
engineer’s PC using a high-speed USB 2.0 interface and
is connected to the target with either a connector
compatible with the popular MPLAB ICD 2 system
(RJ11) or with the new high-speed, noise tolerant, Low-
Voltage Differential Signal (LVDS) interconnection
(CAT5).
MPLAB REAL ICE is field upgradeable through future
firmware downloads in MPLAB IDE. In upcoming
releases of MPLAB IDE, new devices will be supported,
and new features will be added, such as software break-
points and assembly code trace. MPLAB REAL ICE
offers significant advantages over competitive emulators
including low-cost, full-speed emulation, real-time
variable watches, trace analysis, complex breakpoints, a
ruggedized probe interface and long (up to three meters)
interconnection cables.
© 2008 Microchip Technology Inc.
DS39646C-page 373
PIC18F8722 FAMILY
®
27.11 PICSTART Plus Development
27.13 Demonstration, Development and
Evaluation Boards
Programmer
The PICSTART® Plus Development Programmer is an
easy-to-use, low-cost, prototype programmer. It
connects to the PC via a COM (RS-232) port. MPLAB
Integrated Development Environment software makes
using the programmer simple and efficient. The
PICSTART Plus Development Programmer supports
most PIC devices in DIP packages up to 40 pins.
Larger pin count devices, such as the PIC16C92X and
PIC17C76X, may be supported with an adapter socket.
The PICSTART Plus Development Programmer is CE
compliant.
A wide variety of demonstration, development and
evaluation boards for various PIC MCUs and dsPIC
DSCs allows quick application development on fully func-
tional systems. Most boards include prototyping areas for
adding custom circuitry and provide application firmware
and source code for examination and modification.
The boards support a variety of features, including LEDs,
temperature sensors, switches, speakers, RS-232
interfaces, LCD displays, potentiometers and additional
EEPROM memory.
The demonstration and development boards can be
used in teaching environments, for prototyping custom
circuits and for learning about various microcontroller
applications.
27.12 PICkit™ 2 Development
Programmer
The PICkit™ 2 Development Programmer is a low-cost
programmer and selected Flash device debugger with
an easy-to-use interface for programming many of
Microchip’s baseline, mid-range and PIC18F families of
Flash memory microcontrollers. The PICkit 2 Starter Kit
includes a prototyping development board, twelve
sequential lessons, software and HI-TECH’s PICC™
Lite C compiler, and is designed to help get up to speed
quickly using PIC® microcontrollers. The kit provides
everything needed to program, evaluate and develop
applications using Microchip’s powerful, mid-range
Flash memory family of microcontrollers.
In addition to the PICDEM™ and dsPICDEM™ demon-
stration/development board series of circuits, Microchip
has a line of evaluation kits and demonstration software
®
for analog filter design, KEELOQ security ICs, CAN,
IrDA®, PowerSmart battery management, SEEVAL®
evaluation system, Sigma-Delta ADC, flow rate
sensing, plus many more.
Check the Microchip web page (www.microchip.com)
for the complete list of demonstration, development
and evaluation kits.
DS39646C-page 374
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
28.0 ELECTRICAL CHARACTERISTICS
(†)
Absolute Maximum Ratings
Ambient temperature under bias.............................................................................................................-40°C to +125°C
Storage temperature .............................................................................................................................. -65°C to +150°C
Voltage on any pin with respect to VSS (except VDD and MCLR) ................................................... -0.3V to (VDD + 0.3V)
Voltage on VDD with respect to VSS ......................................................................................................... -0.3V to +7.5V
Voltage on MCLR with respect to VSS (Note 2) ......................................................................................... 0V to +13.25V
Total power dissipation (Note 1) ...............................................................................................................................1.0W
Maximum current out of VSS pin ...........................................................................................................................300 mA
Maximum current into VDD pin ..............................................................................................................................250 mA
Input clamp current, IIK (VI < 0 or VI > VDD)...................................................................................................................... ±20 mA
Output clamp current, IOK (VO < 0 or VO > VDD) .............................................................................................................. ±20 mA
Maximum output current sunk by any I/O pin..........................................................................................................25 mA
Maximum output current sourced by any I/O pin ....................................................................................................25 mA
Maximum current sunk by all ports .......................................................................................................................200 mA
Maximum current sourced by all ports ..................................................................................................................200 mA
Note 1: Power dissipation is calculated as follows:
Pdis = VDD x {IDD – ∑ IOH} + ∑ {(VDD – VOH) x IOH} + ∑(VOL x IOL)
2: Voltage spikes below VSS at the RG5/MCLR/VPP pin, inducing currents greater than 80 mA, may cause
latch-up. Thus, a series resistor of 50-100Ω should be used when applying a “low” level to the RG5/MCLR/
VPP pin, rather than pulling this pin directly to VSS.
† NOTICE: Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to the
device. This is a stress rating only and functional operation of the device at those or any other conditions above those
indicated in the operation listings of this specification is not implied. Exposure to maximum rating conditions for
extended periods may affect device reliability.
© 2008 Microchip Technology Inc.
DS39646C-page 375
PIC18F8722 FAMILY
FIGURE 28-1:
PIC18F8722 DEVICE FAMILY VOLTAGE-FREQUENCY GRAPH (INDUSTRIAL)
6.0V
5.5V
PIC18F6627/6622/6627/6722
PIC18F8527/8622/8627/8722
5.0V
4.5V
4.0V
4.2V
3.5V
3.0V
2.5V
2.0V
FMAX
Frequency
FMAX = 20 MHz in 8-bit External Memory mode.
FMAX = 40 MHz in all other modes.
FIGURE 28-2:
PIC18F8722 DEVICE FAMILY VOLTAGE-FREQUENCY GRAPH (EXTENDED)
6.0V
5.5V
PIC18F6627/6622/6627/6722
PIC18F8527/8622/8627/8722
5.0V
4.5V
4.2V
4.0V
3.5V
3.0V
2.5V
2.0V
FMAX
Frequency
FMAX = 20 MHz in 8-bit External Memory mode.
FMAX = 25 MHz in all other modes.
DS39646C-page 376
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
FIGURE 28-3:
PIC18LF8722 DEVICE FAMILY VOLTAGE-FREQUENCY GRAPH (INDUSTRIAL)
6.0V
5.5V
PIC18LF6627/6622/6627/6722
PIC18LF8527/8622/8627/8722
5.0V
4.5V
4.0V
4.2V
3.5V
3.0V
2.5V
2.0V
FMAX
4 MHz
Frequency
In 8-bit External Memory mode:
FMAX = (9.55 MHz/V) (VDDAPPMIN – 2.0V) + 4 MHz, if VDDAPPMIN ≤ 4.2V;
FMAX = 25 MHz, if VDDAPPMIN > 4.2V.
In all other modes:
FMAX = (16.36 MHz/V) (VDDAPPMIN – 2.0V) + 4 MHz;
FMAX = 40 MHz, if VDDAPPMIN > 4.2V.
Note: VDDAPPMIN is the minimum voltage of the PIC® device in the application.
© 2008 Microchip Technology Inc.
DS39646C-page 377
PIC18F8722 FAMILY
28.1 DC Characteristics: Supply Voltage
PIC18F6X27/6X22/8X27/8X22 (Industrial, Extended)
PIC18LF6X27/6X22/8X27/8X22 (Industrial)
PIC18LF6X27/6X22/8X27/8X22
Standard Operating Conditions (unless otherwise stated)
(Industrial)
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
Standard Operating Conditions (unless otherwise stated)
PIC18F6X27/6X22/8X27/8X22
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
-40°C ≤ TA ≤ +125°C for extended
(Industrial, Extended)
Param
No.
Symbol
Characteristic
Supply Voltage
Min
Typ Max Units
Conditions
D001
VDD
PIC18LF6X27/6X22/8X27/8X22 2.0
PIC18F6X27/6X22/8X27/8X22 4.2
—
—
—
5.5
5.5
—
V
V
V
D002
D003
VDR
RAM Data Retention
1.5
(1)
Voltage
VPOR
VDD Start Voltage
to Ensure Internal
Power-on Reset Signal
—
—
—
0.7
—
V
See Section 4.3 “Power-on Reset (POR)” for
details
D004
D005
SVDD
VBOR
VDD Rise Rate
to Ensure Internal
Power-on Reset Signal
0.05
V/ms See Section 4.3 “Power-on Reset (POR)” for
details
Brown-out Reset Voltage
BORV<1:0> = 11
2.00 2.05 2.16
2.00 2.11 2.22
V
V
V
V
V
PIC18LF6627/6722/8627/8722
PIC18LF6527/6622/8527/8622
PIC18LF6X27/6X22/8X27/8X22
All devices
BORV<1:0> = 11
BORV<1:0> = 10
BORV<1:0> = 01(2)
2.65 2.79 2.93
4.11 4.33 4.55
4.36 4.59 4.82
BORV<1:0> = 00
All devices
Legend:
Shading of rows is to assist in readability of the table.
Note 1: This is the limit to which VDD can be lowered in Sleep mode, or during a device Reset, without losing RAM data.
2: With BOR enabled, full-speed operation (FOSC = 40 MHz) is supported until a BOR occurs. The VDD may be below the
minimum voltage for this frequency.
DS39646C-page 378
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
28.2 DC Characteristics: Power-Down and Supply Current
PIC18F6X27/6X22/8X27/8X22 (Industrial, Extended)
PIC18LF6X27/6X22/8X27/8X22 (Industrial)
PIC18LF6X27/6X22/8X27/8X22
Standard Operating Conditions (unless otherwise stated)
(Industrial)
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
Standard Operating Conditions (unless otherwise stated)
PIC18F6X27/6X22/8X27/8X22
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
-40°C ≤ TA ≤ +125°C for extended
(Industrial, Extended)
Param
Device
No.
Typ
Max Units
Conditions
(1)
Power-Down Current (IPD)
PIC18LF6X27/6X22/8X27/8X22 120
700
700
3.0
900
900
6
nA
nA
μA
nA
nA
μA
μA
μA
μA
μA
-40°C
+25°C
+85°C
-40°C
VDD = 2.0V
(Sleep mode)
120
0.24
PIC18LF6X27/6X22/8X27/8X22 120
VDD = 3.0V
(Sleep mode)
120
+25°C
+85°C
-40°C
0.36
All devices 0.12
0.12
2
2
+25°C
+85°C
+125°C
VDD = 5.0V
(Sleep mode)
0.48
9
Extended devices only
12
100
Legend:
Shading of rows is to assist in readability of the table.
Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with
the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta
current disabled (such as WDT, Timer1 Oscillator, BOR, etc.).
2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading
and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on
the current consumption.
The test conditions for all IDD measurements in active operation mode are:
OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD OR VSS;
MCLR = VDD; WDT enabled/disabled as specified.
3: When operation below -10°C is expected, use T1OSC High-Power mode, where LPT1OSC (CONFIG3H<2>) = 0. When
operation will always be above -10°C, then the low-power Timer1 oscillator may be selected.
4: BOR and HLVD enable internal band gap reference. With both modules enabled, current consumption will be less than
the sum of both specifications.
© 2008 Microchip Technology Inc.
DS39646C-page 379
PIC18F8722 FAMILY
28.2 DC Characteristics: Power-Down and Supply Current
PIC18F6X27/6X22/8X27/8X22 (Industrial, Extended)
PIC18LF6X27/6X22/8X27/8X22 (Industrial) (Continued)
PIC18LF6X27/6X22/8X27/8X22
Standard Operating Conditions (unless otherwise stated)
(Industrial)
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
Standard Operating Conditions (unless otherwise stated)
PIC18F6X27/6X22/8X27/8X22
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
-40°C ≤ TA ≤ +125°C for extended
(Industrial, Extended)
Param
Device
No.
Typ
Max Units
Conditions
(2)
Supply Current (IDD)
PIC18LF6X27/6X22/8X27/8X22
18
18
18
48
42
36
25
22
μA
μA
μA
μA
μA
μA
μA
μA
μA
μA
μA
μA
μA
μA
μA
μA
mA
mA
mA
mA
-40°C
+25°C
+85°C
-40°C
VDD = 2.0V
VDD = 3.0V
25
PIC18LF6X27/6X22/8X27/8X22
70
FOSC = 31 kHz
(RC_RUN mode,
50
+25°C
+85°C
-40°C
47
Internal oscillator source)
All devices 126
180
150
140
230
440
440
440
800
740
740
1.4
1.3
1.3
1.4
108
96
+25°C
+85°C
+125°C
-40°C
VDD = 5.0V
Extended devices only
96
PIC18LF6X27/6X22/8X27/8X22 380
380
+25°C
+85°C
-40°C
VDD = 2.0V
VDD = 3.0V
380
PIC18LF6X27/6X22/8X27/8X22 720
FOSC = 1 MHz
(RC_RUN mode,
700
+25°C
+85°C
-40°C
720
Internal oscillator source)
All devices 1.2
1.2
1.2
+25°C
+85°C
+125°C
VDD = 5.0V
Extended devices only 1.2
Legend:
Shading of rows is to assist in readability of the table.
Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with
the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta
current disabled (such as WDT, Timer1 Oscillator, BOR, etc.).
2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading
and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on
the current consumption.
The test conditions for all IDD measurements in active operation mode are:
OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD OR VSS;
MCLR = VDD; WDT enabled/disabled as specified.
3: When operation below -10°C is expected, use T1OSC High-Power mode, where LPT1OSC (CONFIG3H<2>) = 0. When
operation will always be above -10°C, then the low-power Timer1 oscillator may be selected.
4: BOR and HLVD enable internal band gap reference. With both modules enabled, current consumption will be less than
the sum of both specifications.
DS39646C-page 380
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
28.2 DC Characteristics: Power-Down and Supply Current
PIC18F6X27/6X22/8X27/8X22 (Industrial, Extended)
PIC18LF6X27/6X22/8X27/8X22 (Industrial) (Continued)
PIC18LF6X27/6X22/8X27/8X22
Standard Operating Conditions (unless otherwise stated)
(Industrial)
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
Standard Operating Conditions (unless otherwise stated)
PIC18F6X27/6X22/8X27/8X22
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
-40°C ≤ TA ≤ +125°C for extended
(Industrial, Extended)
Param
Device
No.
Typ
Max Units
Conditions
(2)
Supply Current (IDD)
PIC18LF6X27/6X22/8X27/8X22 1.0
1.3
1.3
1.3
1.9
1.9
1.9
3.5
3.4
3.4
3.4
5
mA
mA
mA
mA
mA
mA
mA
mA
mA
mA
μA
μA
μA
μA
μA
μA
μA
μA
μA
μA
-40°C
1.0
+25°C
+85°C
-40°C
+25°C
+85°C
-40°C
VDD = 2.0V
VDD = 3.0V
1.0
PIC18LF6X27/6X22/8X27/8X22 1.6
FOSC = 4 MHz
(RC_RUN mode,
1.6
1.6
Internal oscillator source)
All devices 3.0
3.0
+25°C
+85°C
+125°C
-40°C
VDD = 5.0V
3.0
Extended devices only 3.0
PIC18LF6X27/6X22/8X27/8X22 3.5
3.7
5
+25°C
+85°C
-40°C
VDD = 2.0V
VDD = 3.0V
4.3
9.5
7
PIC18LF6X27/6X22/8X27/8X22 5.4
FOSC = 31 kHz
(RC_IDLE mode,
5.7
7.0
8
+25°C
+85°C
-40°C
15
15
15
35
200
Internal oscillator source)
All devices
11
11.8
13.5
25
+25°C
+85°C
+125°C
VDD = 5.0V
Extended devices only
Legend:
Shading of rows is to assist in readability of the table.
Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with
the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta
current disabled (such as WDT, Timer1 Oscillator, BOR, etc.).
2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading
and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on
the current consumption.
The test conditions for all IDD measurements in active operation mode are:
OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD OR VSS;
MCLR = VDD; WDT enabled/disabled as specified.
3: When operation below -10°C is expected, use T1OSC High-Power mode, where LPT1OSC (CONFIG3H<2>) = 0. When
operation will always be above -10°C, then the low-power Timer1 oscillator may be selected.
4: BOR and HLVD enable internal band gap reference. With both modules enabled, current consumption will be less than
the sum of both specifications.
© 2008 Microchip Technology Inc.
DS39646C-page 381
PIC18F8722 FAMILY
28.2 DC Characteristics: Power-Down and Supply Current
PIC18F6X27/6X22/8X27/8X22 (Industrial, Extended)
PIC18LF6X27/6X22/8X27/8X22 (Industrial) (Continued)
PIC18LF6X27/6X22/8X27/8X22
Standard Operating Conditions (unless otherwise stated)
(Industrial)
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
Standard Operating Conditions (unless otherwise stated)
PIC18F6X27/6X22/8X27/8X22
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
-40°C ≤ TA ≤ +125°C for extended
(Industrial, Extended)
Param
Device
No.
Typ
Max Units
Conditions
(2)
Supply Current (IDD)
PIC18LF6X27/6X22/8X27/8X22 200
250
250
270
360
360
380
600
600
620
800
500
490
490
800
790
800
1.4
μA
μA
μA
μA
μA
μA
μA
μA
μA
μA
μA
μA
μA
μA
μA
μA
mA
mA
mA
mA
-40°C
210
+25°C
+85°C
-40°C
VDD = 2.0V
VDD = 3.0V
228
PIC18LF6X27/6X22/8X27/8X22 300
FOSC = 1 MHz
(RC_IDLE mode,
324
+25°C
+85°C
-40°C
350
Internal oscillator source)
All devices 500
520
+25°C
+85°C
+125°C
-40°C
VDD = 5.0V
550
Extended devices only 720
PIC18LF6X27/6X22/8X27/8X22 410
420
+25°C
+85°C
-40°C
VDD = 2.0V
VDD = 3.0V
430
PIC18LF6X27/6X22/8X27/8X22 630
FOSC = 4 MHz
(RC_IDLE mode,
650
+25°C
+85°C
-40°C
690
Internal oscillator source)
All devices 1.2
1.3
1.2
1.4
+25°C
+85°C
+125°C
VDD = 5.0V
1.4
Extended devices only 1.2
1.6
Legend:
Shading of rows is to assist in readability of the table.
Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with
the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta
current disabled (such as WDT, Timer1 Oscillator, BOR, etc.).
2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading
and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on
the current consumption.
The test conditions for all IDD measurements in active operation mode are:
OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD OR VSS;
MCLR = VDD; WDT enabled/disabled as specified.
3: When operation below -10°C is expected, use T1OSC High-Power mode, where LPT1OSC (CONFIG3H<2>) = 0. When
operation will always be above -10°C, then the low-power Timer1 oscillator may be selected.
4: BOR and HLVD enable internal band gap reference. With both modules enabled, current consumption will be less than
the sum of both specifications.
DS39646C-page 382
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
28.2 DC Characteristics: Power-Down and Supply Current
PIC18F6X27/6X22/8X27/8X22 (Industrial, Extended)
PIC18LF6X27/6X22/8X27/8X22 (Industrial) (Continued)
PIC18LF6X27/6X22/8X27/8X22
Standard Operating Conditions (unless otherwise stated)
(Industrial)
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
Standard Operating Conditions (unless otherwise stated)
PIC18F6X27/6X22/8X27/8X22
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
-40°C ≤ TA ≤ +125°C for extended
(Industrial, Extended)
Param
Device
No.
Typ
Max Units
Conditions
(2)
Supply Current (IDD)
PIC18LF6X27/6X22/8X27/8X22 300
350
350
350
800
700
670
1.75
1.4
1.3
1.4
1.2
1.2
1.2
1.9
1.8
1.8
3.6
3.5
3.5
3.5
μA
μA
-40°C
310
+25°C
+85°C
-40°C
+25°C
+85°C
-40°C
VDD = 2.0V
VDD = 3.0V
300
μA
PIC18LF6X27/6X22/8X27/8X22 660
μA
FOSC = 1 MHZ
(PRI_RUN mode,
EC oscillator)
580
μA
550
μA
All devices 1.2
mA
mA
mA
mA
mA
mA
mA
mA
mA
mA
mA
mA
mA
mA
1.1
+25°C
+85°C
+125°C
-40°C
VDD = 5.0V
1.0
Extended devices only 1.0
PIC18LF6X27/6X22/8X27/8X22 0.86
0.88
+25°C
+85°C
-40°C
+25°C
+85°C
-40°C
+25°C
+85°C
+125°C
VDD = 2.0V
VDD = 3.0V
0.88
PIC18LF6X27/6X22/8X27/8X22 1.6
FOSC = 4 MHz
(PRI_RUN mode,
EC oscillator)
1.6
1.6
All devices 3.2
3.1
3.0
VDD = 5.0V
Extended devices only 3.1
Legend:
Shading of rows is to assist in readability of the table.
Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with
the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta
current disabled (such as WDT, Timer1 Oscillator, BOR, etc.).
2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading
and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on
the current consumption.
The test conditions for all IDD measurements in active operation mode are:
OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD OR VSS;
MCLR = VDD; WDT enabled/disabled as specified.
3: When operation below -10°C is expected, use T1OSC High-Power mode, where LPT1OSC (CONFIG3H<2>) = 0. When
operation will always be above -10°C, then the low-power Timer1 oscillator may be selected.
4: BOR and HLVD enable internal band gap reference. With both modules enabled, current consumption will be less than
the sum of both specifications.
© 2008 Microchip Technology Inc.
DS39646C-page 383
PIC18F8722 FAMILY
28.2 DC Characteristics: Power-Down and Supply Current
PIC18F6X27/6X22/8X27/8X22 (Industrial, Extended)
PIC18LF6X27/6X22/8X27/8X22 (Industrial) (Continued)
PIC18LF6X27/6X22/8X27/8X22
Standard Operating Conditions (unless otherwise stated)
(Industrial)
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
Standard Operating Conditions (unless otherwise stated)
PIC18F6X27/6X22/8X27/8X22
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
-40°C ≤ TA ≤ +125°C for extended
(Industrial, Extended)
Param
Device
No.
Typ
Max Units
Conditions
(2)
Supply Current (IDD)
Extended devices only
10
13
15
18
mA
mA
+125°C
VDD = 4.2V
VDD = 5.0V
FOSC = 25 MHz
(PRI_RUN mode,
EC oscillator)
+125°C
All devices
All devices
18
19
19
25
25
25
23.5
23.5
23.5
29
mA
mA
mA
mA
mA
mA
-40°C
+25°C
+85°C
-40°C
+25°C
+85°C
VDD = 4.2V
VDD = 5.0V
FOSC = 40 MHZ
(PRI_RUN mode,
EC oscillator)
29
29
Legend:
Shading of rows is to assist in readability of the table.
Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with
the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta
current disabled (such as WDT, Timer1 Oscillator, BOR, etc.).
2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading
and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on
the current consumption.
The test conditions for all IDD measurements in active operation mode are:
OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD OR VSS;
MCLR = VDD; WDT enabled/disabled as specified.
3: When operation below -10°C is expected, use T1OSC High-Power mode, where LPT1OSC (CONFIG3H<2>) = 0. When
operation will always be above -10°C, then the low-power Timer1 oscillator may be selected.
4: BOR and HLVD enable internal band gap reference. With both modules enabled, current consumption will be less than
the sum of both specifications.
DS39646C-page 384
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
28.2 DC Characteristics: Power-Down and Supply Current
PIC18F6X27/6X22/8X27/8X22 (Industrial, Extended)
PIC18LF6X27/6X22/8X27/8X22 (Industrial) (Continued)
PIC18LF6X27/6X22/8X27/8X22
Standard Operating Conditions (unless otherwise stated)
(Industrial)
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
Standard Operating Conditions (unless otherwise stated)
PIC18F6X27/6X22/8X27/8X22
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
-40°C ≤ TA ≤ +125°C for extended
(Industrial, Extended)
Param
Device
No.
Typ
Max Units
Conditions
(2)
Supply Current (IDD)
All devices 9.0
13
13
mA
mA
mA
mA
mA
mA
mA
mA
mA
mA
mA
mA
mA
mA
-40°C
FOSC = 4 MHZ,
16 MHz internal
(PRI_RUN HS+PLL)
9.0
9.0
+25°C
VDD = 4.2V
+85°C
13
Extended devices only 9.6
15
+125°C
-40°C
All devices
12
12
12
12
18
19
19
25
25
25
15
FOSC = 4 MHZ,
16 MHz internal
(PRI_RUN HS+PLL)
15
+25°C
+85°C
+125°C
-40°C
VDD = 5.0V
15
Extended devices only
All devices
17
23.5
23.5
23.5
29
FOSC = 10 MHZ,
40 MHz internal
(PRI_RUN HS+PLL)
+25°C
+85°C
-40°C
VDD = 4.2V
VDD = 5.0V
All devices
FOSC = 10 MHZ,
40 MHz internal
(PRI_RUN HS+PLL)
29
+25°C
+85°C
29
Legend:
Shading of rows is to assist in readability of the table.
Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with
the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta
current disabled (such as WDT, Timer1 Oscillator, BOR, etc.).
2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading
and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on
the current consumption.
The test conditions for all IDD measurements in active operation mode are:
OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD OR VSS;
MCLR = VDD; WDT enabled/disabled as specified.
3: When operation below -10°C is expected, use T1OSC High-Power mode, where LPT1OSC (CONFIG3H<2>) = 0. When
operation will always be above -10°C, then the low-power Timer1 oscillator may be selected.
4: BOR and HLVD enable internal band gap reference. With both modules enabled, current consumption will be less than
the sum of both specifications.
© 2008 Microchip Technology Inc.
DS39646C-page 385
PIC18F8722 FAMILY
28.2 DC Characteristics: Power-Down and Supply Current
PIC18F6X27/6X22/8X27/8X22 (Industrial, Extended)
PIC18LF6X27/6X22/8X27/8X22 (Industrial) (Continued)
PIC18LF6X27/6X22/8X27/8X22
Standard Operating Conditions (unless otherwise stated)
(Industrial)
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
Standard Operating Conditions (unless otherwise stated)
PIC18F6X27/6X22/8X27/8X22
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
-40°C ≤ TA ≤ +125°C for extended
(Industrial, Extended)
Param
Device
No.
Typ
Max Units
Conditions
(2)
Supply Current (IDD)
PIC18LF6X27/6X22/8X27/8X22
78
78
84
100
100
110
150
150
160
280
290
300
500
375
385
380
660
670
680
1.2
μA
μA
μA
μA
μA
μA
μA
μA
μA
μA
μA
μA
μA
μA
μA
μA
mA
mA
mA
mA
-40°C
+25°C
+85°C
-40°C
VDD = 2.0V
VDD = 3.0V
PIC18LF6X27/6X22/8X27/8X22 130
FOSC = 1 MHz
(PRI_IDLE mode,
EC oscillator)
130
+25°C
+85°C
-40°C
140
All devices 230
235
+25°C
+85°C
+125°C
-40°C
VDD = 5.0V
240
Extended devices only 260
PIC18LF6X27/6X22/8X27/8X22 312
305
+25°C
+85°C
-40°C
VDD = 2.0V
VDD = 3.0V
324
PIC18LF6X27/6X22/8X27/8X22 500
FOSC = 4 MHz
(PRI_IDLE mode,
EC oscillator)
600
+25°C
+85°C
-40°C
600
All devices 1.1
1.1
1.1
1.2
+25°C
+85°C
+125°C
VDD = 5.0V
1.2
Extended devices only 1.2
1.3
Legend:
Shading of rows is to assist in readability of the table.
Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with
the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta
current disabled (such as WDT, Timer1 Oscillator, BOR, etc.).
2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading
and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on
the current consumption.
The test conditions for all IDD measurements in active operation mode are:
OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD OR VSS;
MCLR = VDD; WDT enabled/disabled as specified.
3: When operation below -10°C is expected, use T1OSC High-Power mode, where LPT1OSC (CONFIG3H<2>) = 0. When
operation will always be above -10°C, then the low-power Timer1 oscillator may be selected.
4: BOR and HLVD enable internal band gap reference. With both modules enabled, current consumption will be less than
the sum of both specifications.
DS39646C-page 386
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
28.2 DC Characteristics: Power-Down and Supply Current
PIC18F6X27/6X22/8X27/8X22 (Industrial, Extended)
PIC18LF6X27/6X22/8X27/8X22 (Industrial) (Continued)
PIC18LF6X27/6X22/8X27/8X22
Standard Operating Conditions (unless otherwise stated)
(Industrial)
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
Standard Operating Conditions (unless otherwise stated)
PIC18F6X27/6X22/8X27/8X22
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
-40°C ≤ TA ≤ +125°C for extended
(Industrial, Extended)
Param
Device
No.
Typ
Max Units
Conditions
(2)
Supply Current (IDD)
Extended devices only 3.4
5.2
5.8
7
mA
mA
+125°C
VDD = 4.2V
VDD = 5.0V
FOSC = 25 MHz
(PRI_IDLE mode,
EC oscillator)
+125°C
All devices 7.2
10
10
10
12
12
12
mA
mA
mA
mA
mA
mA
-40°C
+25°C
+85°C
-40°C
+25°C
+85°C
7.4
VDD = 4.2 V
VDD = 5.0V
FOSC = 40 MHz
(PRI_IDLE mode,
EC oscillator)
7.8
All devices 9.7
11
10
Legend:
Shading of rows is to assist in readability of the table.
Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with
the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta
current disabled (such as WDT, Timer1 Oscillator, BOR, etc.).
2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading
and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on
the current consumption.
The test conditions for all IDD measurements in active operation mode are:
OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD OR VSS;
MCLR = VDD; WDT enabled/disabled as specified.
3: When operation below -10°C is expected, use T1OSC High-Power mode, where LPT1OSC (CONFIG3H<2>) = 0. When
operation will always be above -10°C, then the low-power Timer1 oscillator may be selected.
4: BOR and HLVD enable internal band gap reference. With both modules enabled, current consumption will be less than
the sum of both specifications.
© 2008 Microchip Technology Inc.
DS39646C-page 387
PIC18F8722 FAMILY
28.2 DC Characteristics: Power-Down and Supply Current
PIC18F6X27/6X22/8X27/8X22 (Industrial, Extended)
PIC18LF6X27/6X22/8X27/8X22 (Industrial) (Continued)
PIC18LF6X27/6X22/8X27/8X22
Standard Operating Conditions (unless otherwise stated)
(Industrial)
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
Standard Operating Conditions (unless otherwise stated)
PIC18F6X27/6X22/8X27/8X22
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
-40°C ≤ TA ≤ +125°C for extended
(Industrial, Extended)
Param
Device
No.
Typ
Max Units
Conditions
(2)
Supply Current (IDD)
PIC18LF6X27/6X22/8X27/8X22
17
18
19
48
42
37
28
25
μA
μA
μA
μA
μA
μA
μA
μA
μA
μA
μA
μA
μA
μA
μA
μA
μA
μA
-40°C
+25°C
+70°C
-40°C
+25°C
+70°C
-40°C
+25°C
+70°C
-40°C
+25°C
+70°C
-40°C
+25°C
+70°C
-40°C
+25°C
+70°C
VDD = 2.0V
VDD = 3.0V
VDD = 5.0V
VDD = 2.0V
VDD = 3.0V
VDD = 5.0V
28
PIC18LF6X27/6X22/8X27/8X22
70
(3)
FOSC = 32 kHz
52
(SEC_RUN mode,
Timer1 as clock)
48
All devices 120
180
130
125
10
97
90
PIC18LF6X27/6X22/8X27/8X22 3.0
4.4
6.8
10
5.4
PIC18LF6X27/6X22/8X27/8X22 6.0
15
(3)
FOSC = 32 kHz
6.5
10
(SEC_IDLE mode,
Timer1 as clock)
7.6
All devices 10.0
10.5
15
25
15
11.0
25
Legend:
Shading of rows is to assist in readability of the table.
Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with
the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta
current disabled (such as WDT, Timer1 Oscillator, BOR, etc.).
2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading
and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on
the current consumption.
The test conditions for all IDD measurements in active operation mode are:
OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD OR VSS;
MCLR = VDD; WDT enabled/disabled as specified.
3: When operation below -10°C is expected, use T1OSC High-Power mode, where LPT1OSC (CONFIG3H<2>) = 0. When
operation will always be above -10°C, then the low-power Timer1 oscillator may be selected.
4: BOR and HLVD enable internal band gap reference. With both modules enabled, current consumption will be less than
the sum of both specifications.
DS39646C-page 388
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
28.2 DC Characteristics: Power-Down and Supply Current
PIC18F6X27/6X22/8X27/8X22 (Industrial, Extended)
PIC18LF6X27/6X22/8X27/8X22 (Industrial) (Continued)
PIC18LF6X27/6X22/8X27/8X22
Standard Operating Conditions (unless otherwise stated)
(Industrial)
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
Standard Operating Conditions (unless otherwise stated)
PIC18F6X27/6X22/8X27/8X22
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
-40°C ≤ TA ≤ +125°C for extended
(Industrial, Extended)
Param
Device
No.
Typ
Max Units
Conditions
Module Differential Currents (ΔIWDT, ΔIBOR, ΔILVD, ΔIOSCB, ΔIAD)
D022
(ΔIWDT)
Watchdog Timer 1.5
2.2
2.2
2.3
3.5
3.5
3.5
7.5
7.5
7.8
10
50
55
55
2.4
6.0
38
40
45
45
9
μA
μA
μA
μA
μA
μA
μA
μA
μA
μA
μA
μA
-40°C
+25°C
VDD = 2.0V
VDD = 3.0V
1.6
1.7
2.3
2.4
3.4
4.8
6.0
6.1
+85°C
-40°C
+25°C
+85°C
-40°C
+25°C
VDD = 5.0V
VDD = 3.0V
VDD = 5.0V
+85°C
8
+125°C
-40°C to +85°C
-40°C to +85°C
(4)
D022A
(ΔIBOR)
Brown-out Reset
4.2
48
66
0
μA -40°C to +125°C
μA -40°C to +85°C
μA -40°C to +125°C
Sleep mode,
BOREN<1:0> = 10
0
(4)
D022B
(ΔILVD)
High/Low-Voltage Detect
2.7
30
35
36
μA
μA
μA
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
VDD = 2.0V
VDD = 3.0V
VDD = 5.0V
μA -40°C to +125°C
(3)
D025
(ΔIOSCB)
Timer1 Oscillator 4.5
μA
μA
μA
μA
μA
μA
μA
μA
μA
μA
μA
μA
-40°C
-10°C
+25°C
+85°C
.9
.9
1.7
2.2
2.2
10
1.8
2.3
2.3
11
VDD = 2.0V
32 kHz on Timer1
32 kHz on Timer1
32 kHz on Timer1
.9
(3)
4.8
1
-40°C
-10°C
+25°C
+85°C
VDD = 3.0V
VDD = 5.0V
1
1
(3)
6
-40°C
-10°C
+25°C
+85°C
1.6
1.6
1.6
6
6
6
Legend:
Shading of rows is to assist in readability of the table.
Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with
the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta
current disabled (such as WDT, Timer1 Oscillator, BOR, etc.).
2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading
and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on
the current consumption.
The test conditions for all IDD measurements in active operation mode are:
OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD OR VSS;
MCLR = VDD; WDT enabled/disabled as specified.
3: When operation below -10°C is expected, use T1OSC High-Power mode, where LPT1OSC (CONFIG3H<2>) = 0. When
operation will always be above -10°C, then the low-power Timer1 oscillator may be selected.
4: BOR and HLVD enable internal band gap reference. With both modules enabled, current consumption will be less than
the sum of both specifications.
© 2008 Microchip Technology Inc.
DS39646C-page 389
PIC18F8722 FAMILY
28.2 DC Characteristics: Power-Down and Supply Current
PIC18F6X27/6X22/8X27/8X22 (Industrial, Extended)
PIC18LF6X27/6X22/8X27/8X22 (Industrial) (Continued)
PIC18LF6X27/6X22/8X27/8X22
Standard Operating Conditions (unless otherwise stated)
(Industrial)
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
Standard Operating Conditions (unless otherwise stated)
PIC18F6X27/6X22/8X27/8X22
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
-40°C ≤ TA ≤ +125°C for extended
(Industrial, Extended)
Param
Device
No.
Typ
Max Units
Conditions
0.2
0.2
0.2
0.5
1
1
1
4
μA
μA
μA
-40°C to +85°C
VDD = 2.0V
VDD = 3.0V
D026
(ΔIAD)
A/D Converter
-40°C to +85°C
-40°C to +85°C
A/D on, not converting,
Sleep mode
VDD = 5.0V
μA -40°C to +125°C
Legend:
Shading of rows is to assist in readability of the table.
Note 1: The power-down current in Sleep mode does not depend on the oscillator type. Power-down current is measured with
the part in Sleep mode, with all I/O pins in high-impedance state and tied to VDD or VSS and all features that add delta
current disabled (such as WDT, Timer1 Oscillator, BOR, etc.).
2: The supply current is mainly a function of operating voltage, frequency and mode. Other factors, such as I/O pin loading
and switching rate, oscillator type and circuit, internal code execution pattern and temperature, also have an impact on
the current consumption.
The test conditions for all IDD measurements in active operation mode are:
OSC1 = external square wave, from rail-to-rail; all I/O pins tri-stated, pulled to VDD OR VSS;
MCLR = VDD; WDT enabled/disabled as specified.
3: When operation below -10°C is expected, use T1OSC High-Power mode, where LPT1OSC (CONFIG3H<2>) = 0. When
operation will always be above -10°C, then the low-power Timer1 oscillator may be selected.
4: BOR and HLVD enable internal band gap reference. With both modules enabled, current consumption will be less than
the sum of both specifications.
DS39646C-page 390
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
28.3 DC Characteristics: PIC18F8722 (Industrial, Extended)
PIC18LF6X27/6X22/8X27/8X22 (Industrial)
Standard Operating Conditions (unless otherwise stated)
Operating temperature -40°C ≤ TA ≤ +85°C for industrial
DC CHARACTERISTICS
Param
Symbol
No.
Characteristic
Min
Max
Units
Conditions
VIL
Input Low Voltage
I/O Ports:
with TTL Buffer
D030
D030A
D031
D032
D033
VSS
—
0.15 VDD
0.8
V
V
V
V
V
VDD < 4.5V
4.5V ≤ VDD ≤ 5.5V
with Schmitt Trigger Buffer
MCLR
VSS
VSS
VSS
0.2 VDD
0.2 VDD
0.3 VDD
OSC1
HS, HSPLL modes
D033A
D033B
D034
OSC1
OSC1
T13CKI
VSS
VSS
VSS
0.2 VDD
0.3
0.3
V
V
V
RC, EC modes(1)
XT, LP modes
VIH
Input High Voltage
I/O Ports:
D040
D040A
D041
D042
D043
with TTL Buffer
0.25 VDD + 0.8V
2.0
VDD
VDD
VDD
VDD
VDD
V
V
V
V
V
VDD < 4.5V
4.5V ≤ VDD ≤ 5.5V
with Schmitt Trigger Buffer
0.8 VDD
0.8 VDD
0.7 VDD
MCLR
OSC1
HS, HSPLL modes
D043A
D043B
D043C
D044
OSC1
OSC1
OSC1
T13CKI
0.8 VDD
0.9 VDD
1.6
VDD
VDD
VDD
VDD
V
V
V
V
EC mode
RC mode(1)
XT, LP modes
1.6
IIL
Input Leakage Current(2,3)
D060
I/O Ports
—
—
±200
±50
nA VDD < 5.5V
VSS ≤ VPIN ≤ VDD,
Pin at high-impedance
nA VDD < 3V
VSS ≤ VPIN ≤ VDD,
Pin at high-impedance
D061
D063
MCLR
—
—
±1
±1
μA Vss ≤ VPIN ≤ VDD
μA Vss ≤ VPIN ≤ VDD
OSC1
IPU
Weak Pull-up Current
PORTB Weak Pull-up Current
D070
IPURB
50
400
μA VDD = 5V, VPIN = VSS
Note 1: In RC oscillator configuration, the OSC1/CLKI pin is a Schmitt Trigger input. It is not recommended that the
PIC® device be driven with an external clock while in RC mode.
2: The leakage current on the MCLR pin is strongly dependent on the applied voltage level. The specified
levels represent normal operating conditions. Higher leakage current may be measured at different input
voltages.
3: Negative current is defined as current sourced by the pin.
© 2008 Microchip Technology Inc.
DS39646C-page 391
PIC18F8722 FAMILY
28.3 DC Characteristics: PIC18F8722 (Industrial, Extended)
PIC18LF6X27/6X22/8X27/8X22 (Industrial) (Continued)
Standard Operating Conditions (unless otherwise stated)
Operating temperature -40°C ≤ TA ≤ +85°C for industrial
DC CHARACTERISTICS
Param
Symbol
No.
Characteristic
Min
Max
Units
Conditions
VOL
Output Low Voltage
I/O Ports
D080
D083
—
—
0.6
0.6
V
V
IOL = 8.5 mA, VDD = 4.5V,
-40°C to +85°C
OSC2/CLKO
IOL = 1.6 mA, VDD = 4.5V,
(RC, RCIO, EC, ECIO modes)
Output High Voltage(3)
-40°C to +85°C
VOH
D090
D092
I/O Ports
VDD – 0.7
VDD – 0.7
—
—
V
V
IOH = -3.0 mA, VDD = 4.5V,
-40°C to +85°C
OSC2/CLKO
IOH = -1.3 mA, VDD = 4.5V,
(RC, RCIO, EC, ECIO modes)
-40°C to +85°C
Capacitive Loading Specs
on Output Pins
D100
COSC2 OSC2 Pin
—
15
pF In XT, HS and LP modes
when external clock is
used to drive OSC1
D101
D102
CIO
CB
All I/O Pins and OSC2
(in RC mode)
—
—
50
pF To meet the AC Timing
Specifications
pF I2C™ Specification
SCLx, SDAx
400
Note 1: In RC oscillator configuration, the OSC1/CLKI pin is a Schmitt Trigger input. It is not recommended that the
PIC® device be driven with an external clock while in RC mode.
2: The leakage current on the MCLR pin is strongly dependent on the applied voltage level. The specified
levels represent normal operating conditions. Higher leakage current may be measured at different input
voltages.
3: Negative current is defined as current sourced by the pin.
DS39646C-page 392
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
TABLE 28-1: MEMORY PROGRAMMING REQUIREMENTS
Standard Operating Conditions (unless otherwise stated)
Operating temperature -40°C ≤ TA ≤ +85°C for industrial
DC CHARACTERISTICS
Param
Sym
No.
Characteristic
Min
Typ†
Max
Units
Conditions
Data EEPROM Memory
D120
ED
Byte Endurance
100K
VMIN
1M
—
—
E/W -40°C to +85°C
D121 VDRW VDD for Read/Write
5.5
V
Using EECON to read/write
VMIN = Minimum operating
voltage
D122 TDEW Erase/Write Cycle Time
D123 TRETD Characteristic Retention
—
4
—
—
ms
40
—
Year Provided no other
specifications are violated
D124
D125
TREF
IDDP
Number of Total Erase/Write
Cycles before Refresh(1)
1M
—
10M
10
—
—
E/W -40°C to +85°C
Supply Current during
Programming
mA
Program Flash Memory
Cell Endurance
D130
D131
EP
10K
100K
—
—
E/W -40°C to +85°C
VPR
VDD for Read
VMIN
5.5
V
VMIN = Minimum operating
voltage
D132B VPEW VDD for Self-Timed Write and
Row Erase
VMIN
—
5.5
V
VMIN = Minimum operating
voltage
D133A TIW
Self-Timed Write Cycle Time
—
2
—
—
ms
D134 TRETD Characteristic Retention
40
100
Year Provided no other
specifications are violated
D135
IDDP
Supply Current during
Programming
—
10
—
mA
†
Data in “Typ” column is at 5.0V, 25°C unless otherwise stated. These parameters are for design guidance
only and are not tested.
Note 1: Refer to Section 8.8 “Using the Data EEPROM” for a more detailed discussion on data EEPROM
endurance.
© 2008 Microchip Technology Inc.
DS39646C-page 393
PIC18F8722 FAMILY
TABLE 28-2: COMPARATOR SPECIFICATIONS
Operating Conditions: 3.0V < VDD < 5.5V, -40°C < TA < +85°C (unless otherwise stated)
Param
No.
Sym
Characteristics
Input Offset Voltage
Min
Typ
Max
Units
Comments
D300
VIOFF
—
0
±5.0
—
±10
VDD – 1.5
—
mV
V
D301
D302
300
VICM
Input Common Mode Voltage
Common Mode Rejection Ratio
Response Time(1)
CMRR
TRESP
55
—
—
—
dB
ns
ns
150
150
400
PIC18FXXXX
300A
600
PIC18LFXXXX,
VDD = 2.0V
301
TMC2OV Comparator Mode Change to
Output Valid
—
—
10
μs
Note 1: Response time measured with one comparator input at (VDD – 1.5)/2, while the other input transitions
from VSS to VDD.
TABLE 28-3: COMPARATOR VOLTAGE REFERENCE SPECIFICATIONS
Operating Conditions: 3.0V < VDD < 5.5V, -40°C < TA < +85°C (unless otherwise stated)
Param
No.
Sym
Characteristics
Resolution
Min
Typ
Max
Units
Comments
D310
VRES
VDD/24
—
—
—
2k
—
VDD/32
1/2
LSb
LSb
Ω
D311
D312
310
VRAA
VRUR
TSET
Absolute Accuracy
Unit Resistor Value (R)
Settling Time(1)
—
—
—
10
μs
Note 1: Settling time measured while CVRR = 1and CVR<3:0> transitions from ‘0000’ to ‘1111’.
DS39646C-page 394
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
FIGURE 28-4:
HIGH/LOW-VOLTAGE DETECT CHARACTERISTICS
For VDIRMAG = 1:
VDD
VHLVD
(HLVDIF set by hardware)
(HLVDIF can be
cleared in software)
VHLVD
VDD
For VDIRMAG = 0:
HLVDIF
TABLE 28-4: HIGH/LOW-VOLTAGE DETECT CHARACTERISTICS
Standard Operating Conditions (unless otherwise stated)
Operating temperature -40°C ≤ TA ≤ +85°C for industrial
Param
No.
Sym
Characteristic
Min
Typ
Max Units
Conditions
D420
HLVD Voltage on VDD HLVDL<3:0> = 0000 2.06
2.17
2.23
2.36
2.44
2.60
2.79
2.89
3.12
3.39
3.55
3.71
3.90
4.11
4.33
4.59
2.28
2.34
2.48
2.56
2.73
2.93
3.04
3.28
3.56
3.73
3.90
4.10
4.32
4.55
4.82
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
Transition High-to-Low
HLVDL<3:0> = 0001 2.12
HLVDL<3:0> = 0010 2.24
HLVDL<3:0> = 0011 2.32
HLVDL<3:0> = 0100 2.47
HLVDL<3:0> = 0101 2.65
HLVDL<3:0> = 0110 2.74
HLVDL<3:0> = 0111 2.96
HLVDL<3:0> = 1000 3.22
HLVDL<3:0> = 1001 3.37
HLVDL<3:0> = 1010 3.52
HLVDL<3:0> = 1011 3.70
HLVDL<3:0> = 1100 3.90
HLVDL<3:0> = 1101 4.11
HLVDL<3:0> = 1110 4.36
© 2008 Microchip Technology Inc.
DS39646C-page 395
PIC18F8722 FAMILY
28.4 AC (Timing) Characteristics
28.4.1
TIMING PARAMETER SYMBOLOGY
The timing parameter symbols have been created
following one of the following formats:
1. TppS2ppS
2. TppS
T
3. TCC:ST
4. Ts
(I2C™ specifications only)
(I2C specifications only)
F
Frequency
T
Time
Lowercase letters (pp) and their meanings:
pp
cc
ck
cs
di
CCP1
CLKO
CS
osc
rd
OSC1
RD
rw
sc
ss
t0
RD or WR
SCK
SDI
do
dt
SDO
SS
Data in
I/O port
MCLR
T0CKI
T13CKI
WR
io
t1
mc
wr
Uppercase letters and their meanings:
S
F
Fall
P
R
V
Z
Period
H
High
Rise
I
L
Invalid (High-Impedance)
Low
Valid
High-Impedance
I2C only
AA
output access
Bus free
High
Low
High
Low
BUF
TCC:ST (I2C specifications only)
CC
HD
Hold
SU
Setup
ST
DAT
STA
DATA input hold
Start condition
STO
Stop condition
DS39646C-page 396
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
28.4.2
TIMING CONDITIONS
Note:
Because of space limitations, the generic
terms “PIC18FXXXX” and “PIC18LFXXXX”
are used throughout this section to refer to
the PIC18F6X27/6X22/8X27/8X22 and
PIC18LF6X27/6X22/8X27/8X22 families of
devices specifically and only those devices.
The temperature and voltages specified in Table 28-5
apply to all timing specifications unless otherwise
noted. Figure 28-5 specifies the load conditions for the
timing specifications.
TABLE 28-5: TEMPERATURE AND VOLTAGE SPECIFICATIONS – AC
Standard Operating Conditions (unless otherwise stated)
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
-40°C ≤ TA ≤ +125°C for extended
AC CHARACTERISTICS
Operating voltage VDD range as described in the DC specifications in Section 28.1
and Section 28.3.
LF parts operate for industrial temperatures only.
FIGURE 28-5:
LOAD CONDITIONS FOR DEVICE TIMING SPECIFICATIONS
Load Condition 1 Load Condition 2
VDD/2
CL
RL
Pin
VSS
CL
Pin
RL = 464Ω
CL = 50 pF for all pins except OSC2/CLKO
and including D and E outputs as ports
VSS
© 2008 Microchip Technology Inc.
DS39646C-page 397
PIC18F8722 FAMILY
28.4.3
TIMING DIAGRAMS AND SPECIFICATIONS
FIGURE 28-6:
EXTERNAL CLOCK TIMING (ALL MODES EXCEPT PLL)
Q4
Q1
1
Q2
Q3
Q4
Q1
OSC1
CLKO
3
4
3
4
2
TABLE 28-6: EXTERNAL CLOCK TIMING REQUIREMENTS
Param.
Symbol
Characteristic
Min
Max
Units
Conditions
No.
1A
FOSC
External CLKI Frequency(1)
DC
DC
DC
DC
DC
0.1
4
1
25
31.25
40
4
MHz XT, RC Oscillator mode
MHz HS Oscillator mode
kHz LP Oscillator mode
MHz EC Oscillator mode
MHz RC Oscillator mode
MHz XT Oscillator mode
MHz HS Oscillator mode
MHz HS + PLL Oscillator mode
kHz LP Oscillator mode
Oscillator Frequency(1)
4
25
10
200
—
4
5
1
TOSC
External CLKI Period(1)
Oscillator Period(1)
1000
40
ns
ns
μs
ns
ns
μs
ns
ns
μs
ns
ns
ns
μs
ns
ns
ns
ns
XT, RC Oscillator mode
HS Oscillator mode
LP Oscillator mode
EC Oscillator mode
RC Oscillator mode
XT Oscillator mode
HS Oscillator mode
HS + PLL Oscillator mode
LP Oscillator mode
TCY = 4/FOSC, Industrial
TCY = 4/FOSC, Extended
XT Oscillator mode
LP Oscillator mode
HS Oscillator mode
XT Oscillator mode
LP Oscillator mode
HS Oscillator mode
—
32
—
25
—
250
250
40
—
1
250
250
200
—
100
5
2
3
TCY
Instruction Cycle Time(1)
100
160
30
—
TOSL,
TOSH
External Clock in (OSC1)
High or Low Time
—
2.5
10
—
—
4
TOSR,
TOSF
External Clock in (OSC1)
Rise or Fall Time
—
20
50
7.5
—
—
Note 1: Instruction cycle period (TCY) equals four times the input oscillator time base period for all configurations
except PLL. All specified values are based on characterization data for that particular oscillator type under
standard operating conditions with the device executing code. Exceeding these specified limits may result
in an unstable oscillator operation and/or higher than expected current consumption. All devices are tested
to operate at “min.” values with an external clock applied to the OSC1/CLKI pin. When an external clock
input is used, the “max.” cycle time limit is “DC” (no clock) for all devices.
DS39646C-page 398
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
TABLE 28-7: PLL CLOCK TIMING SPECIFICATIONS (VDD = 4.2V TO 5.5V)
Param
No.
Sym
Characteristic
Min
Typ†
Max
Units Conditions
F10
F11
F12
F13
FOSC Oscillator Frequency Range
4
—
—
—
—
10
40
2
MHz HS mode only
FSYS On-Chip VCO System Frequency
16
—
-2
MHz HS mode only
trc
PLL Start-up Time (Lock Time)
ms
%
ΔCLK CLKO Stability (Jitter)
+2
†
Data in “Typ” column is at 5V, 25°C, unless otherwise stated. These parameters are for design guidance
only and are not tested.
TABLE 28-8: AC CHARACTERISTICS:INTERNAL RC ACCURACY
PIC18F6X27/6X22/8X27/8X22 (INDUSTRIAL, EXTENDED)
PIC18LF6X27/6X22/8X27/8X22 (INDUSTRIAL)
PIC18LF6X27/6X22/8X27/8X22
Standard Operating Conditions (unless otherwise stated)
(Industrial)
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
Standard Operating Conditions (unless otherwise stated)
PIC18F6X27/6X22/8X27/8X22
Operating temperature
-40°C ≤ TA ≤ +85°C for industrial
-40°C ≤ TA ≤ +125°C for extended
(Industrial, Extended)
Param
Device
No.
Min
Typ
Max
Units
Conditions
(1)
INTOSC Accuracy @ Freq = 8 MHz, 4 MHz, 2 MHz, 1 MHz, 500 kHz, 250 kHz, 125 kHz
PIC18LF6X27/6X22/8X27/8X22
PIC18F6X27/6X22/8X27/8X22
INTRC Accuracy @ Freq = 31 kHz
-2
-5
-2
-5
+/-1
+/-1
+/-1
+/-1
2
5
2
5
%
%
%
%
+25°C
VDD = 2.7-3.3V
VDD = 2.7-3.3V
VDD = 4.5-5.5V
VDD = 4.5-5.5V
-40°C to +85°C
+25°C
-40°C to +85°C
PIC18LF6X27/6X22/8X27/8X22 26.562
PIC18F6X27/6X22/8X27/8X22 26.562
—
35.938
35.938
kHz
kHz
-40°C to +85°C
-40°C to +85°C
VDD = 2.7-3.3V
VDD = 4.5-5.5V
+/-8
Legend:
Shading of rows is to assist in readability of the table.
Note 1: Frequency calibrated at 25°C. OSCTUNE register can be used to compensate for temperature drift.
© 2008 Microchip Technology Inc.
DS39646C-page 399
PIC18F8722 FAMILY
FIGURE 28-7:
CLKO AND I/O TIMING
Q1
Q2
Q3
Q4
OSC1
11
10
CLKO
13
14
12
19
18
16
I/O pin
(Input)
15
17
I/O pin
(Output)
New Value
Old Value
20, 21
Note:
Refer to Figure 28-5 for load conditions.
TABLE 28-9: CLKO AND I/O TIMING REQUIREMENTS
Param
Symbol
Characteristic
Min
Typ
Max
Units Conditions
No.
10
TOSH2CKL OSC1 ↑ to CLKO ↓
TOSH2CKH OSC1 ↑ to CLKO ↑
—
75
75
35
35
—
—
—
50
—
—
200
200
100
100
ns
ns
ns
ns
(Note 1)
(Note 1)
(Note 1)
(Note 1)
(Note 1)
(Note 1)
(Note 1)
11
—
12
13
14
15
16
17
18
18A
TCKR
TCKF
CLKO Rise Time
CLKO Fall Time
—
—
TCKL2IOV CLKO ↓ to Port Out Valid
TIOV2CKH Port In Valid before CLKO ↑
TCKH2IOI Port In Hold after CLKO ↑
TOSH2IOV OSC1 ↑ (Q1 cycle) to Port Out Valid
—
0.5 TCY + 20 ns
0.25 TCY + 25
—
—
ns
ns
ns
ns
0
—
150
—
TOSH2IOI OSC1 ↑ (Q2 cycle) to
Port Input Invalid
PIC18FXXXX
100
200
PIC18LFXXXX
—
ns VDD = 2.0V
(I/O in hold time)
19
TIOV2OSH Port Input Valid to OSC1 ↑ (I/O in setup
0
—
—
ns
time)
20
TIOR
TIOF
Port Output Rise Time
Port Output Fall Time
PIC18FXXXX
PIC18LFXXXX
PIC18FXXXX
PIC18LFXXXX
—
—
10
—
10
—
—
—
25
60
25
60
—
—
ns
20A
21
ns VDD = 2.0V
—
ns
21A
22†
23†
—
ns VDD = 2.0V
TINP
INTx pin High or Low Time
TCY
TCY
ns
ns
TRBP
RB<7:4> Change INTx High or Low Time
†
These parameters are asynchronous events not related to any internal clock edges.
Note 1: Measurements are taken in RC mode, where CLKO output is 4 x TOSC.
DS39646C-page 400
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
FIGURE 28-8:
PROGRAM MEMORY READ TIMING DIAGRAM
Q1
Q2
Q3
Q4
Q1
Q2
OSC1
A<19:16>
BA0
Address
Address
Address
Data from External
Address
AD<15:0>
163
162
150
151
160
155
161
166
167
168
ALE
CE
164
169
171
171A
OE
165
Operating Conditions: 2.0V < VCC < 5.5V, -40°C < TA < +125°C unless otherwise stated.
TABLE 28-10: CLKO AND I/O TIMING REQUIREMENTS
Param.
Symbol
Characteristics
Min
Typ
Max
Units
No
150
TadV2alL Address Out Valid to ALE ↓ (address
0.25 TCY – 10
—
—
ns
setup time)
151
TalL2adl
ALE ↓ to Address Out Invalid (address
5
—
—
ns
hold time)
155
160
161
162
163
164
165
166
167
168
169
171
171A
TalL2oeL ALE ↓ to OE ↓
10
0.125 TCY
—
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
TadZ2oeL AD high-Z to OE ↓ (bus release to OE)
ToeH2adD OE ↑ to AD Driven
0
—
—
—
0.125 TCY – 5
—
TadV2oeH LS Data Valid before OE ↑ (data setup time)
ToeH2adl OE ↑ to Data In Invalid (data hold time)
20
—
—
0
—
—
—
TalH2alL
ALE Pulse Width
TCY
0.5 TCY
0.25 TCY
—
—
ToeL2oeH OE Pulse Width
0.5 TCY – 5
—
—
TalH2alH ALE ↑ to ALE ↑ (cycle time)
—
Tacc
Toe
Address Valid to Data Valid
0.75 TCY – 25
—
0.5 TCY – 25
0.625 TCY + 10
—
OE ↓ to Data Valid
—
TalL2oeH ALE ↓ to OE ↑
0.625 TCY – 10
0.25 TCY – 20
—
—
TalH2csL Chip Enable Active to ALE ↓
TubL2oeH AD Valid to Chip Enable Active
—
—
10
© 2008 Microchip Technology Inc.
DS39646C-page 401
PIC18F8722 FAMILY
FIGURE 28-9:
PROGRAM MEMORY WRITE TIMING DIAGRAM
Q1
Q2
Q3
Q4
Q1
Q2
OSC1
A<19:16>
BA0
Address
Address
166
Data
Address
Address
AD<15:0>
153
150
151
156
ALE
CE
171
171A
154
WRH or
WRL
157A
157
UB or
LB
Operating Conditions: 2.0V < VCC < 5.5V, -40°C < TA < +125°C unless otherwise stated.
TABLE 28-11: PROGRAM MEMORY WRITE TIMING REQUIREMENTS
Param.
Symbol
Characteristics
Min
Typ
Max
Units
No
150
TadV2alL Address Out Valid to ALE ↓ (address setup time)
TalL2adl ALE ↓ to Address Out Invalid (address hold time)
TwrH2adl WRn ↑ to Data Out Invalid (data hold time)
TwrL WRn Pulse Width
0.25 TCY – 10
5
—
—
—
—
—
—
—
—
ns
ns
ns
ns
ns
ns
151
153
154
156
157
5
—
0.5 TCY – 5
0.5 TCY – 10
0.25 TCY
0.5 TCY
—
TadV2wrH Data Valid before WRn ↑ (data setup time)
TbsV2wrL Byte Select Valid before WRn ↓ (byte select setup
—
time)
157A
166
TwrH2bsI WRn ↑ to Byte Select Invalid (byte select hold time)
TalH2alH ALE ↑ to ALE ↑ (cycle time)
0.125 TCY – 5
—
0.25 TCY
—
—
—
—
10
ns
ns
ns
ns
—
0.25 TCY – 20
—
171
TalH2csL Chip Enable Active to ALE ↓
171A
TubL2oeH AD Valid to Chip Enable Active
—
DS39646C-page 402
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
FIGURE 28-10:
RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER AND
POWER-UP TIMER TIMING
VDD
MCLR
30
Internal
POR
33
PWRT
Time-out
32
Oscillator
Time-out
Internal
Reset
Watchdog
Timer
Reset
31
34
34
I/O pins
Note:
Refer to Figure 28-5 for load conditions.
FIGURE 28-11:
BROWN-OUT RESET TIMING
BVDD
VDD
35
VBGAP = 1.2V
VIRVST
Enable Internal
Reference Voltage
Internal Reference
Voltage Stable
36
TABLE 28-12: RESET, WATCHDOG TIMER, OSCILLATOR START-UP TIMER, POWER-UP TIMER
AND BROWN-OUT RESET REQUIREMENTS
Param.
No.
Symbol
Characteristic
Min
Typ
Max
Units
Conditions
30
TmcL
TWDT
MCLR Pulse Width (low)
2
—
—
μs
31
Watchdog Timer Time-out Period
(no postscaler)
3.4
4.0
4.6
ms
32
33
34
TOST
Oscillation Start-up Timer Period
1024 TOSC
55.6
—
64
2
1024 TOSC
—
ms
μs
TOSC = OSC1 period
TPWRT Power-up Timer Period
75
—
TIOZ
I/O High-Impedance from MCLR
—
Low or Watchdog Timer Reset
35
36
TBOR
Brown-out Reset Pulse Width
200
—
—
—
μs VDD ≤ BVDD (see D005)
μs
TIRVST Time for Internal Reference
Voltage to become Stable
20
50
37
38
39
TLVD
TCSD
High/Low-Voltage Detect Pulse Width
CPU Start-up Time
200
—
—
10
1
—
—
—
μs
μs
μs
VDD ≤ VHLVD
TIOBST Time for INTOSC to Stabilize
—
© 2008 Microchip Technology Inc.
DS39646C-page 403
PIC18F8722 FAMILY
FIGURE 28-12:
TIMER0 AND TIMER1 EXTERNAL CLOCK TIMINGS
T0CKI
41
40
42
T1OSO/T13CKI
46
45
47
48
TMR0 or
TMR1
Note:
Refer to Figure 28-5 for load conditions.
TABLE 28-13: TIMER0 AND TIMER1 EXTERNAL CLOCK REQUIREMENTS
Param
Symbol
Characteristic
Min
Max Units
Conditions
No.
40
TT0H
T0CKI High Pulse Width
No prescaler
With prescaler
No prescaler
With prescaler
No prescaler
With prescaler
0.5 TCY + 20
10
—
—
—
—
—
—
ns
ns
ns
ns
ns
41
42
TT0L
TT0P
T0CKI Low Pulse Width
T0CKI Period
0.5 TCY + 20
10
TCY + 10
Greater of:
20 ns or
ns N = prescale
value
(TCY + 40)/N
(1, 2, 4,..., 256)
45
46
TT1H
TT1L
T13CKI
High Time
Synchronous, no prescaler
0.5 TCY + 20
—
—
—
—
—
—
—
—
—
—
—
ns
Synchronous,
with prescaler
PIC18FXXXX
10
ns
PIC18LFXXXX
25
ns VDD = 2.0V
Asynchronous PIC18FXXXX
PIC18LFXXXX
30
ns
50
ns VDD = 2.0V
T13CKI
Low Time
Synchronous, no prescaler
0.5 TCY + 5
ns
Synchronous,
with prescaler
PIC18FXXXX
10
25
30
50
ns
PIC18LFXXXX
ns VDD = 2.0V
ns
Asynchronous PIC18FXXXX
PIC18LFXXXX
ns VDD = 2.0V
47
48
TT1P
FT1
T13CKI
Input
Period
Synchronous
Greater of:
20 ns or
(TCY + 40)/N
ns N = prescale
value
(1, 2, 4, 8)
Asynchronous
60
DC
—
50
ns
kHz
—
T13CKI Oscillator Input Frequency Range
TCKE2TMRI Delay from External T13CKI Clock Edge to
Timer Increment
2 TOSC
7 TOSC
DS39646C-page 404
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
FIGURE 28-13:
CAPTURE/COMPARE/PWM TIMINGS (ALL ECCP/CCP MODULES)
CCPx
(Capture Mode)
50
51
52
54
CCPx
(Compare or PWM Mode)
53
Refer to Figure 28-5 for load conditions.
Note:
TABLE 28-14: CAPTURE/COMPARE/PWM REQUIREMENTS (ALL ECCP/CCP MODULES)
Param
Symbol
Characteristic
Min
Max
Units
Conditions
No.
50
TCCL
CCPx Input Low No prescaler
0.5 TCY + 20
—
—
—
—
—
—
—
ns
ns
ns
ns
ns
ns
ns
Time
With
PIC18FXXXX
10
prescaler
PIC18LFXXXX
20
VDD = 2.0V
VDD = 2.0V
51
TCCH
CCPx Input
High Time
No prescaler
0.5 TCY + 20
With
PIC18FXXXX
10
20
prescaler
PIC18LFXXXX
52
53
TCCP
TCCR
CCPx Input Period
3 TCY + 40
N
N = prescale
value (1, 4 or 16)
CCPx Output Fall Time
PIC18FXXXX
PIC18LFXXXX
PIC18FXXXX
PIC18LFXXXX
—
—
—
—
25
45
25
45
ns
ns
ns
ns
VDD = 2.0V
VDD = 2.0V
54
TCCF
CCPx Output Fall Time
© 2008 Microchip Technology Inc.
DS39646C-page 405
PIC18F8722 FAMILY
FIGURE 28-14:
PARALLEL SLAVE PORT TIMING (PIC18F8527/8622/8627/8722)
RE2/CS
RE0/RD
RE1/WR
65
RD7:RD0
62
64
63
Note:
Refer to Figure 28-5 for load conditions.
TABLE 28-15: PARALLEL SLAVE PORT REQUIREMENTS (PIC18F8527/8622/8627/8722)
Param.
Symbol
Characteristic
Min
Max Units
Conditions
No.
62
TdtV2wrH
TwrH2dtI
Data In Valid before WR ↑ or CS ↑ (setup time)
20
20
—
—
ns
ns
63
WR ↑ or CS ↑ to Data–In
PIC18FXXXX
Invalid (hold time)
PIC18LFXXXX 35
—
ns VDD = 2.0V
64
65
66
TrdL2dtV
TrdH2dtI
TibfINH
RD ↓ and CS ↓ to Data–Out Valid
RD ↑ or CS ↓ to Data–Out Invalid
—
10
—
80
ns
ns
30
Inhibit of the IBF Flag bit being Cleared from
3 TCY
WR ↑ or CS ↑
DS39646C-page 406
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
FIGURE 28-15:
EXAMPLE SPI MASTER MODE TIMING (CKE = 0)
SSx
70
SCKx
(CKP = 0)
71
72
78
79
79
SCKx
(CKP = 1)
78
80
MSb
bit 6 - - - - - - 1
LSb
SDOx
SDIx
75, 76
MSb In
74
bit 6 - - - - 1
LSb In
73
Note: Refer to Figure 28-5 for load conditions.
TABLE 28-16: EXAMPLE SPI MODE REQUIREMENTS (MASTER MODE, CKE = 0)
Param
No.
Symbol
Characteristic
Min
Max Units Conditions
70
TSSL2SCH, SSx ↓ to SCKx ↓ or SCKx ↑ Input
TCY
—
ns
TSSL2SCL
71
TSCH
SCKx Input High Time
(Slave mode)
Continuous
Single Byte
Continuous
Single Byte
1.25 TCY + 30
—
—
—
—
—
ns
71A
72
40
ns (Note 1)
TSCL
SCKx Input Low Time
(Slave mode)
1.25 TCY + 30
ns
72A
73
40
20
ns (Note 1)
TDIV2SCH, Setup Time of SDIx Data Input to SCKx Edge
TDIV2SCL
ns
73A
74
TB2B
Last Clock Edge of Byte 1 to the 1st Clock Edge 1.5 TCY + 40
of Byte 2
—
—
ns (Note 2)
TSCH2DIL, Hold Time of SDIx Data Input to SCKx Edge
TSCL2DIL
40
ns
75
TDOR
SDOx Data Output Rise Time PIC18FXXXX
PIC18LFXXXX
—
—
—
—
—
—
—
—
25
45
25
25
45
25
50
100
ns
ns VDD = 2.0V
76
78
TDOF
TSCR
SDOx Data Output Fall Time
ns
SCKx Output Rise Time
(Master mode)
PIC18FXXXX
PIC18LFXXXX
ns
ns VDD = 2.0V
79
80
TSCF
SCKx Output Fall Time (Master mode)
ns
TSCH2DOV, SDOx Data Output Valid after PIC18FXXXX
TSCL2DOV SCKx Edge
ns
PIC18LFXXXX
ns VDD = 2.0V
Note 1: Requires the use of Parameter #73A.
2: Only if Parameter #71A and #72A are used.
© 2008 Microchip Technology Inc.
DS39646C-page 407
PIC18F8722 FAMILY
FIGURE 28-16:
EXAMPLE SPI MASTER MODE TIMING (CKE = 1)
SSx
81
SCKx
(CKP = 0)
71
72
79
78
73
SCKx
(CKP = 1)
80
LSb
MSb
bit 6 - - - - - - 1
SDOx
SDIx
75, 76
MSb In
74
bit 6 - - - - 1
LSb In
Note: Refer to Figure 28-5 for load conditions.
TABLE 28-17: EXAMPLE SPI MODE REQUIREMENTS (MASTER MODE, CKE = 1)
Param.
No.
Symbol
TSCH
Characteristic
Min
Max Units Conditions
71
SCKx Input High Time
Continuous
Single Byte
Continuous
Single Byte
1.25 TCY + 30
—
—
—
—
—
ns
(Slave mode)
71A
72
40
ns (Note 1)
TSCL
SCKx Input Low Time
(Slave mode)
1.25 TCY + 30
ns
72A
73
40
20
ns (Note 1)
TDIV2SCH, Setup Time of SDIx Data Input to SCKx Edge
TDIV2SCL
ns
73A
74
TB2B
Last Clock Edge of Byte 1 to the 1st Clock Edge 1.5 TCY + 40
of Byte 2
—
—
ns (Note 2)
TSCH2DIL, Hold Time of SDIx Data Input to SCKx Edge
TSCL2DIL
40
ns
75
TDOR
SDOx Data Output Rise Time PIC18FXXXX
PIC18LFXXXX
—
—
25
45
25
25
45
25
50
100
—
ns
ns VDD = 2.0V
76
78
TDOF
TSCR
SDOx Data Output Fall Time
—
ns
SCKx Output Rise Time
(Master mode)
PIC18FXXXX
—
ns
PIC18LFXXXX
—
ns VDD = 2.0V
79
80
TSCF
SCKx Output Fall Time (Master mode)
—
ns
TSCH2DOV, SDOx Data Output Valid after PIC18FXXXX
TSCL2DOV SCKx Edge
—
ns
PIC18LFXXXX
—
ns VDD = 2.0V
ns
81
TDOV2SCH, SDOx Data Output Setup to SCKx Edge
TDOV2SCL
TCY
Note 1: Requires the use of Parameter #73A.
2: Only if Parameter #71A and #72A are used.
DS39646C-page 408
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
FIGURE 28-17:
EXAMPLE SPI SLAVE MODE TIMING (CKE = 0)
SSx
70
SCKx
(CKP = 0)
83
71
72
78
79
79
78
SCKx
(CKP = 1)
80
MSb
LSb
SDOx
SDIx
bit 6 - - - - - - 1
75, 76
77
MSb In
74
bit 6 - - - - 1
LSb In
73
Note:
Refer to Figure 28-5 for load conditions.
TABLE 28-18: EXAMPLE SPI MODE REQUIREMENTS (SLAVE MODE TIMING, CKE = 0)
Param
No.
Symbol
Characteristic
Min
Max Units Conditions
70
TSSL2SCH, SSx ↓ to SCKx ↓ or SCKx ↑ Input
3 TCY
—
ns
TSSL2SCL
71
TSCH
SCKx Input High Time
(Slave mode)
Continuous
Single Byte
Continuous
Single Byte
1.25 TCY + 30
—
—
—
—
—
ns
71A
72
40
ns (Note 1)
TSCL
SCKx Input Low Time
(Slave mode)
1.25 TCY + 30
ns
72A
73
40
20
ns (Note 1)
TDIV2SCH, Setup Time of SDIx Data Input to SCKx Edge
TDIV2SCL
ns
73A
74
TB2B
Last Clock Edge of Byte 1 to the First Clock Edge of Byte 2 1.5 TCY + 40
—
—
ns (Note 2)
TSCH2DIL, Hold Time of SDIx Data Input to SCKx Edge
TSCL2DIL
40
ns
75
TDOR
SDOx Data Output Rise Time
PIC18FXXXX
PIC18LFXXXX
—
25
45
25
50
25
45
25
50
100
—
ns
—
ns VDD = 2.0V
76
77
78
TDOF
SDOx Data Output Fall Time
—
ns
TSSH2DOZ SSx ↑ to SDOx Output High-Impedance
10
ns
TSCR
SCKx Output Rise Time (Master mode) PIC18FXXXX
PIC18LFXXXX
—
ns
—
ns VDD = 2.0V
79
80
TSCF
SCKx Output Fall Time (Master mode)
—
ns
TSCH2DOV, SDOx Data Output Valid after SCKx
TSCL2DOV Edge
PIC18FXXXX
—
—
ns
PIC18LFXXXX
ns VDD = 2.0V
ns
83
TSCH2SSH, SSx ↑ after SCKx Edge
1.5 TCY + 40
TSCL2SSH
Note 1: Requires the use of Parameter #73A.
2: Only if Parameter #71A and #72A are used.
© 2008 Microchip Technology Inc.
DS39646C-page 409
PIC18F8722 FAMILY
FIGURE 28-18:
EXAMPLE SPI SLAVE MODE TIMING (CKE = 1)
82
SSx
70
SCKx
83
(CKP = 0)
71
72
SCKx
(CKP = 1)
80
MSb
bit 6 - - - - - - 1
LSb
SDOx
SDIx
75, 76
77
MSb In
74
bit 6 - - - - 1
LSb In
Note: Refer to Figure 28-5 for load conditions.
TABLE 28-19: EXAMPLE SPI SLAVE MODE REQUIREMENTS (CKE = 1)
Param
No.
Symbol
Characteristic
Min
Max Units Conditions
70
TSSL2SCH, SSx ↓ to SCKx ↓ or SCKx ↑ Input
3 TCY
—
ns
TSSL2SCL
71
TSCH
TSCL
TB2B
SCKx Input High Time
(Slave mode)
Continuous
Single Byte
Continuous
Single Byte
1.25 TCY + 30
—
—
—
—
—
—
ns
71A
72
40
1.25 TCY + 30
40
ns (Note 1)
ns
SCKx Input Low Time
(Slave mode)
72A
73A
74
ns (Note 1)
ns (Note 2)
ns
Last Clock Edge of Byte 1 to the First Clock Edge of Byte 2 1.5 TCY + 40
TSCH2DIL, Hold Time of SDIx Data Input to SCKx Edge
TSCL2DIL
40
75
TDOR
SDOx Data Output Rise Time
PIC18FXXXX
—
25
45
25
50
25
45
25
50
100
50
100
—
ns
PIC18LFXXXX
—
ns VDD = 2.0V
76
77
78
TDOF
SDOx Data Output Fall Time
—
ns
TSSH2DOZ SSx ↑ to SDOx Output High-Impedance
10
ns
TSCR
SCKx Output Rise Time
(Master mode)
PIC18FXXXX
—
ns
PIC18LFXXXX
—
ns VDD = 2.0V
79
80
TSCF
SCKx Output Fall Time (Master mode)
—
ns
TSCH2DOV, SDOx Data Output Valid after SCKx PIC18FXXXX
TSCL2DOV Edge
—
ns
PIC18LFXXXX
—
ns VDD = 2.0V
82
83
TSSL2DOV SDOx Data Output Valid after SSx ↓
PIC18FXXXX
—
—
ns
Edge
PIC18LFXXXX
ns VDD = 2.0V
ns
TSCH2SSH, SSx ↑ after SCKx Edge
1.5 TCY + 40
TSCL2SSH
Note 1: Requires the use of Parameter #73A.
2: Only if Parameter #71A and #72A are used.
DS39646C-page 410
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
FIGURE 28-19:
SCLx
I2C™ BUS START/STOP BITS TIMING
91
93
90
92
SDAx
Stop
Condition
Start
Condition
Note: Refer to Figure 28-5 for load conditions.
TABLE 28-20: I2C™ BUS START/STOP BITS REQUIREMENTS (SLAVE MODE)
Param.
Symbol
Characteristic
Min
Max
Units
Conditions
No.
90
TSU:STA Start Condition
Setup Time
100 kHz mode
400 kHz mode
100 kHz mode
400 kHz mode
100 kHz mode
400 kHz mode
100 kHz mode
400 kHz mode
4700
600
—
—
—
—
—
—
—
—
ns
Only relevant for Repeated
Start condition
91
92
93
THD:STA Start Condition
Hold Time
4000
600
ns
ns
ns
After this period, the first
clock pulse is generated
TSU:STO Stop Condition
Setup Time
4700
600
THD:STO Stop Condition
Hold Time
4000
600
FIGURE 28-20:
I2C™ BUS DATA TIMING
103
102
100
101
SCLx
90
106
107
91
92
SDAx
In
110
109
109
SDAx
Out
Note: Refer to Figure 28-5 for load conditions.
© 2008 Microchip Technology Inc.
DS39646C-page 411
PIC18F8722 FAMILY
TABLE 28-21: I2C™ BUS DATA REQUIREMENTS (SLAVE MODE)
Param.
No.
Symbol
Characteristic
100 kHz mode
Min
Max
Units
Conditions
100
THIGH
Clock High Time
4.0
—
μs
PIC18FXXXX must operate at
a minimum of 1.5 MHz
400 kHz mode
0.6
—
μs
PIC18FXXXX must operate at
a minimum of 10 MHz
SSP Module
1.5 TCY
4.7
—
—
101
TLOW
Clock Low Time
100 kHz mode
μs
μs
PIC18FXXXX must operate at
a minimum of 1.5 MHz
400 kHz mode
1.3
—
PIC18FXXXX must operate at
a minimum of 10 MHz
SSP Module
1.5 TCY
—
—
102
103
TR
SDAx and SCLx Rise Time 100 kHz mode
400 kHz mode
1000
300
ns
ns
20 + 0.1 CB
CB is specified to be from
10 to 400 pF
TF
SDAx and SCLx Fall Time 100 kHz mode
400 kHz mode
—
300
300
ns
ns
20 + 0.1 CB
CB is specified to be from
10 to 400 pF
90
TSU:STA
Start Condition Setup Time 100 kHz mode
400 kHz mode
4.7
0.6
4.0
0.6
0
—
—
μs
μs
μs
μs
ns
μs
ns
ns
μs
μs
ns
ns
μs
μs
Only relevant for Repeated
Start condition
91
THD:STA Start Condition Hold Time 100 kHz mode
400 kHz mode
—
After this period, the first clock
pulse is generated
—
106
107
92
THD:DAT Data Input Hold Time
100 kHz mode
400 kHz mode
100 kHz mode
400 kHz mode
—
0
0.9
—
TSU:DAT Data Input Setup Time
250
100
4.7
0.6
—
(Note 2)
—
TSU:STO Stop Condition Setup Time 100 kHz mode
400 kHz mode
—
—
109
110
TAA
Output Valid from Clock
100 kHz mode
400 kHz mode
100 kHz mode
400 kHz mode
3500
—
(Note 1)
—
TBUF
Bus Free Time
4.7
1.3
—
Time the bus must be free
before a new transmission can
start
—
D102
CB
Bus Capacitive Loading
—
400
pF
Note 1: As a transmitter, the device must provide this internal minimum delay time to bridge the undefined region (min. 300 ns)
of the falling edge of SCLx to avoid unintended generation of Start or Stop conditions.
2
2
2: A Fast mode I C™ bus device can be used in a Standard mode I C bus system, but the requirement, TSU:DAT ≥ 250 ns,
must then be met. This will automatically be the case if the device does not stretch the LOW period of the SCLx signal.
If such a device does stretch the LOW period of the SCLx signal, it must output the next data bit to the SDAx line,
2
TR max. + TSU:DAT = 1000 + 250 = 1250 ns (according to the Standard mode I C bus specification), before the SCLx
line is released.
DS39646C-page 412
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
FIGURE 28-21:
SCLx
MASTER SSP I2C™ BUS START/STOP BITS TIMING WAVEFORMS
93
91
90
92
SDAx
Stop
Condition
Start
Condition
Note: Refer to Figure 28-5 for load conditions.
TABLE 28-22: MASTER SSP I2C™ BUS START/STOP BITS REQUIREMENTS
Param.
Symbol
Characteristic
Min
Max Units
Conditions
No.
90
TSU:STA Start Condition
Setup Time
100 kHz mode
400 kHz mode
1 MHz mode(1) 2(TOSC)(BRG + 1)
2(TOSC)(BRG + 1)
2(TOSC)(BRG + 1)
—
—
—
—
—
—
—
—
—
—
—
—
ns Only relevant for
Repeated Start
condition
91
92
93
THD:STA Start Condition
Hold Time
100 kHz mode
2(TOSC)(BRG + 1)
ns After this period, the
first clock pulse is
generated
400 kHz mode
1 MHz mode(1) 2(TOSC)(BRG + 1)
2(TOSC)(BRG + 1)
TSU:STO Stop Condition
Setup Time
100 kHz mode
2(TOSC)(BRG + 1)
ns
400 kHz mode
1 MHz mode(1) 2(TOSC)(BRG + 1)
2(TOSC)(BRG + 1)
THD:STO Stop Condition
Hold Time
100 kHz mode
2(TOSC)(BRG + 1)
ns
400 kHz mode
2(TOSC)(BRG + 1)
1 MHz mode(1) 2(TOSC)(BRG + 1)
Note 1: Maximum pin capacitance = 10 pF for all I2C™ pins.
FIGURE 28-22:
MASTER SSP I2C™ BUS DATA TIMING
103
102
100
101
SCLx
90
106
91
92
107
SDAx
In
110
109
109
SDAx
Out
Note: Refer to Figure 28-5 for load conditions.
© 2008 Microchip Technology Inc.
DS39646C-page 413
PIC18F8722 FAMILY
TABLE 28-23: MASTER SSP I2C™ BUS DATA REQUIREMENTS
Param.
Symbol
Characteristic
Min
Max Units
Conditions
No.
100
THIGH
Clock High Time 100 kHz mode
400 kHz mode
2(TOSC)(BRG + 1)
2(TOSC)(BRG + 1)
—
—
ms
ms
ms
ms
ms
ms
ns
1 MHz mode(1) 2(TOSC)(BRG + 1)
—
101
102
103
90
TLOW
TR
Clock Low Time 100 kHz mode
400 kHz mode
2(TOSC)(BRG + 1)
—
2(TOSC)(BRG + 1)
—
1 MHz mode(1) 2(TOSC)(BRG + 1)
—
SDAx and SCLx 100 kHz mode
—
1000
300
300
300
300
100
—
CB is specified to be from
10 to 400 pF
Rise Time
400 kHz mode
1 MHz mode(1)
20 + 0.1 CB
ns
—
—
ns
TF
SDAx and SCLx 100 kHz mode
ns
CB is specified to be from
10 to 400 pF
Fall Time
400 kHz mode
20 + 0.1 CB
—
ns
1 MHz mode(1)
ns
TSU:STA Start Condition 100 kHz mode
2(TOSC)(BRG + 1)
ms Only relevant for
Setup Time
Repeated Start
condition
ms
400 kHz mode
1 MHz mode(1) 2(TOSC)(BRG + 1)
2(TOSC)(BRG + 1)
—
ms
—
91
THD:STA Start Condition 100 kHz mode
2(TOSC)(BRG + 1)
—
ms After this period, the first
Hold Time
clock pulse is generated
400 kHz mode
2(TOSC)(BRG + 1)
—
ms
1 MHz mode(1) 2(TOSC)(BRG + 1)
—
ms
ns
106
107
92
THD:DAT Data Input
Hold Time
100 kHz mode
400 kHz mode
1 MHz mode(1)
100 kHz mode
400 kHz mode
1 MHz mode(1)
100 kHz mode
400 kHz mode
0
—
0
0.9
—
ms
ns
TBD
250
TSU:DAT Data Input
Setup Time
—
ns
ns
(Note 2)
100
—
TBD
—
ns
TSU:STO Stop Condition
Setup Time
2(TOSC)(BRG + 1)
—
ms
ms
ms
ns
2(TOSC)(BRG + 1)
—
1 MHz mode(1) 2(TOSC)(BRG + 1)
—
109
110
D102
TAA
TBUF
CB
Output Valid
from Clock
100 kHz mode
400 kHz mode
1 MHz mode(1)
100 kHz mode
400 kHz mode
1 MHz mode(1)
—
—
3500
1000
—
ns
—
ns
Bus Free Time
4.7
1.3
TBD
—
—
ms Time the bus must be free
before a new transmission
—
ms
can start
ms
—
Bus Capacitive Loading
400
pF
Legend: TBD = To Be Determined
Note 1: Maximum pin capacitance = 10 pF for all I2C™ pins.
2: A Fast mode I2C bus device can be used in a Standard mode I2C bus system, but parameter #107 ≥ 250 ns
must then be met. This will automatically be the case if the device does not stretch the LOW period of the
SCLx signal. If such a device does stretch the LOW period of the SCLx signal, it must output the next data
bit to the SDAx line, parameter #102 + parameter #107 = 1000 + 250 = 1250 ns (for 100 kHz mode,) before
the SCLx line is released.
DS39646C-page 414
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
FIGURE 28-23:
EUSART SYNCHRONOUS TRANSMISSION (MASTER/SLAVE) TIMING
CKx/TXx
pin
121
121
DTx/RXx
pin
122
120
Note: Refer to Figure 28-5 for load conditions.
TABLE 28-24: EUSART SYNCHRONOUS TRANSMISSION REQUIREMENTS
Param
Symbol
Characteristic
Min
Max
Units Conditions
No.
120
TCKH2DTV SYNC XMIT (MASTER and SLAVE)
Clock High to Data Out Valid
PIC18FXXXX
—
—
—
—
—
—
40
100
20
ns
PIC18LFXXXX
ns VDD = 2.0V
ns
121
122
TCKRF
TDTRF
Clock Out Rise Time and Fall Time PIC18FXXXX
(Master mode)
PIC18LFXXXX
PIC18FXXXX
PIC18LFXXXX
50
ns VDD = 2.0V
ns
Data Out Rise Time and Fall Time
20
50
ns VDD = 2.0V
FIGURE 28-24:
EUSART SYNCHRONOUS RECEIVE (MASTER/SLAVE) TIMING
CKx/TXx
pin
125
DTx/RXx
pin
126
Note: Refer to Figure 28-5 for load conditions.
TABLE 28-25: EUSART SYNCHRONOUS RECEIVE REQUIREMENTS
Param.
Symbol
Characteristic
Min
Max
Units
Conditions
No.
125
TDTV2CKL SYNC RCV (MASTER and SLAVE)
Data Hold before CKx ↓ (DTx hold time)
10
15
—
—
ns
ns
126
TCKL2DTL Data Hold after CKx ↓ (DTx hold time)
© 2008 Microchip Technology Inc.
DS39646C-page 415
PIC18F8722 FAMILY
TABLE 28-26: A/D CONVERTER CHARACTERISTICS: PIC18F6X27/6X22/8X27/8X22 (INDUSTRIAL)
PIC18LF6X27/6X22/8X27/8X22 (INDUSTRIAL)
Param
No.
Symbol
Characteristic
Min
Typ
Max
Units
Conditions
A01
NR
Resolution
—
—
—
—
—
—
10
bit ΔVREF ≥ 3.0V
A03
A04
A06
A07
A10
A20
EIL
Integral Linearity Error
Differential Linearity Error
Offset Error
—
<±1
<±1
<±2
<±1
LSb ΔVREF ≥ 3.0V
LSb ΔVREF ≥ 3.0V
LSb ΔVREF ≥ 3.0V
LSb ΔVREF ≥ 3.0V
EDL
EOFF
EGN
—
—
—
Gain Error
—
Monotonicity
Guaranteed(1)
—
VSS ≤ VAIN ≤ VREF
ΔVREF Reference Voltage Range
1.8
3
—
—
—
—
V
V
VDD < 3.0V
VDD ≥ 3.0V
(VREFH – VREFL)
A21
A22
A25
A30
VREFH Reference Voltage High
VSS
—
VREFH
VDD – 3.0V
VREFH
V
V
VREFL
VAIN
Reference Voltage Low
Analog Input Voltage
VSS – 0.3V
VREFL
—
—
—
—
V
ZAIN
Recommended Impedance of
Analog Voltage Source
2.5
kΩ
A40
A50
IAD
A/D Current
from VDD
PIC18FXXXX
PIC18LFXXXX
—
—
180
90
—
—
μA Average current during
conversion
μA
IREF
VREF Input Current(2)
—
—
—
—
5
150
μA During VAIN acquisition.
μA During A/D conversion
cycle.
Note 1: The A/D conversion result never decreases with an increase in the input voltage and has no missing codes.
2: VREFH current is from RA3/AN3/VREF+ pin or VDD, whichever is selected as the VREFH source.
VREFL current is from RA2/AN2/VREF- pin or VSS, whichever is selected as the VREFL source.
FIGURE 28-25:
A/D CONVERSION TIMING
BSF ADCON0, GO
(Note 1, 2)
131
130
Q4
132
A/D CLK
. . .
. . .
9
8
7
2
1
0
A/D DATA
ADRES
NEW_DATA
TCY
OLD_DATA
ADIF
GO
DONE
SAMPLING STOPPED
SAMPLE
Note 1: If the A/D clock source is selected as RC, a time of TCY is added before the A/D clock starts.
This allows the SLEEPinstruction to be executed.
2: This is a minimal RC delay (typically 100 ns), which also disconnects the holding capacitor from the analog input.
DS39646C-page 416
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
TABLE 28-27: A/D CONVERSION REQUIREMENTS
Param
Symbol
Characteristic
Min
Max
Units
Conditions
No.
130
TAD
A/D Clock Period
PIC18FXXXX
0.7
1.4
25.0(1)
25.0(1)
μs TOSC based, VREF ≥ 3.0V
PIC18LFXXXX
μs VDD = 2.0V;
TOSC based, VREF full range
PIC18FXXXX
—
—
11
1
3
μs A/D RC mode
μs VDD = 2.0V; A/D RC mode
TAD
PIC18LFXXXX
131
TCNV
Conversion Time
12
(not including acquisition time) (Note 2)
Acquisition Time (Note 3)
132
135
137
TACQ
TSWC
TDIS
1.4
—
—
(Note 4)
—
μs -40°C to +85°C
μs
Switching Time from Convert → Sample
Discharge Time
0.2
Legend: TBD = To Be Determined
Note 1: The time of the A/D clock period is dependent on the device frequency and the TAD clock divider.
2: ADRES register may be read on the following TCY cycle.
3: The time for the holding capacitor to acquire the “New” input voltage when the voltage changes full scale
after the conversion (VDD to VSS or VSS to VDD). The source impedance (RS) on the input channels is 50Ω.
4: On the following cycle of the device clock.
© 2008 Microchip Technology Inc.
DS39646C-page 417
PIC18F8722 FAMILY
NOTES:
DS39646C-page 418
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
29.0 PACKAGING INFORMATION
29.1 Package Marking Information
64-Lead TQFP
Example
XXXXXXXXXX
XXXXXXXXXX
XXXXXXXXXX
YYWWNNN
PIC18F6722
-I/PT
0810017
e
3
80-Lead TQFP
Example
XXXXXXXXXXXX
XXXXXXXXXXXX
YYWWNNN
PIC18F8722-E
/PT
0810017
e
3
Legend: XX...X Product-specific information
Y
YY
WW
NNN
Year code (last digit of calendar year)
Year code (last 2 digits of calendar year)
Week code (week of January 1 is week ‘01’)
Alphanumeric traceability code
e
3
Pb-free JEDEC designator for Matte Tin (Sn)
*
This package is Pb-free. The Pb-free JEDEC designator (
can be found on the outer packaging for this package.
)
e3
Note: In the event the full Microchip part number cannot be marked on one line, it will
be carried over to the next line, thus limiting the number of available
characters for customer-specific information.
© 2008 Microchip Technology Inc.
DS39646C-page 419
PIC18F8722 FAMILY
29.2 Package Details
The following sections give the technical details of the
packages.
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DS39646C-page 420
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
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© 2008 Microchip Technology Inc.
DS39646C-page 421
PIC18F8722 FAMILY
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DS39646C-page 422
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
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© 2008 Microchip Technology Inc.
DS39646C-page 423
PIC18F8722 FAMILY
NOTES:
DS39646C-page 424
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
Revision C (October 2008)
APPENDIX A: REVISION HISTORY
Revision A (September 2004)
Updated some specifications in Section 28.0 “Electrical
Characteristics”, package and land pattern illustrations
in Section 29.0 “Packaging Information” and the
format of all register tables.
Original data sheet for the PIC18F8722 family of
devices.
Revision B (December 2004)
APPENDIX B: DEVICE
DIFFERENCES
This revision includes updates to the Electrical Specifica-
tions in Section 28.0 “Electrical Characteristics”,
minor corrections to the data sheet text and information
to support the following devices has been added:
The differences between the devices listed in this data
sheet are shown in Table B-1.
• PIC18F6527
• PIC18F6622
• PIC18F8527
• PIC18F8622
• PIC18LF6527
• PIC18LF6622
• PIC18LF8527
• PIC18LF8622
TABLE B-1:
DEVICE DIFFERENCES (PIC18F6527/6622/6627/6722)
Features
PIC18F6527
PIC18F6622
PIC18F6627
PIC18F6722
Program Memory (Bytes)
Program Memory (Instructions)
Interrupt Sources
48K
24576
28
64K
32768
28
96K
49152
28
128K
65536
28
I/O Ports
Ports A, B, C, D, E, Ports A, B, C, D, E, Ports A, B, C, D, E, Ports A, B, C, D, E,
F, G
F, G
F, G
F, G
Capture/Compare/PWM Modules
2
2
2
2
Enhanced
3
3
3
3
Capture/Compare/PWM Modules
Parallel Communications (PSP)
External Memory Bus
10-bit Analog-to-Digital Module
Packages
Yes
No
Yes
No
Yes
No
Yes
No
12 input channels
64-pin TQFP
12 input channels
64-pin TQFP
12 input channels
64-pin TQFP
12 input channels
64-pin TQFP
TABLE B-2:
DEVICE DIFFERENCES (PIC18F8527/8622/8627/8722)
Features
PIC18F8527
PIC18F8622
PIC18F8627
PIC18F8722
Program Memory (Bytes)
Program Memory (Instructions)
Interrupt Sources
48K
24576
29
64K
32768
29
96K
49152
29
128K
65536
29
I/O Ports
Ports A, B, C, D, E, Ports A, B, C, D, E, Ports A, B, C, D, E, Ports A, B, C, D, E,
F, G, H, J
F, G, H, J
F, G, H, J
F, G, H, J
Capture/Compare/PWM Modules
2
3
2
3
2
3
2
3
Enhanced
Capture/Compare/PWM Modules
Parallel Communications (PSP)
External Memory Bus
10-bit Analog-to-Digital Module
Packages
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
16 input channels
80-pin TQFP
16 input channels
80-pin TQFP
16 input channels
80-pin TQFP
16 input channels
80-pin TQFP
© 2008 Microchip Technology Inc.
DS39646C-page 425
PIC18F8722 FAMILY
APPENDIX C: CONVERSION
CONSIDERATIONS
APPENDIX D: MIGRATION FROM
BASELINE TO
ENHANCED DEVICES
This appendix discusses the considerations for
converting from previous versions of a device to the
ones listed in this data sheet. Typically, these changes
are due to the differences in the process technology
used. An example of this type of conversion is from a
PIC16C74A to a PIC16C74B.
This section discusses how to migrate from a Baseline
device (i.e., PIC16C5X) to an Enhanced MCU device
(i.e., PIC18FXXX).
The following are the list of modifications over the
PIC16C5X microcontroller family:
Not Applicable
Not Currently Available
DS39646C-page 426
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
APPENDIX E: MIGRATION FROM
MID-RANGE TO
APPENDIX F: MIGRATION FROM
HIGH-END TO
ENHANCED DEVICES
ENHANCED DEVICES
A detailed discussion of the differences between the
mid-range MCU devices (i.e., PIC16CXXX) and the
enhanced devices (i.e., PIC18FXXX) is provided in
AN716, “Migrating Designs from PIC16C74A/74B to
PIC18C442”. The changes discussed, while device
specific, are generally applicable to all mid-range to
enhanced device migrations.
A detailed discussion of the migration pathway and
differences between the high-end MCU devices (i.e.,
PIC17CXXX) and the enhanced devices (i.e.,
PIC18FXXX) is provided in AN726, “PIC17CXXX to
PIC18CXXX Migration”.
This Application Note is available on our web site,
www.microchip.com, as Literature Number DS00726.
This Application Note is available on our web site,
www.microchip.com, as Literature Number DS00716.
© 2008 Microchip Technology Inc.
DS39646C-page 427
PIC18F8722 FAMILY
NOTES:
DS39646C-page 428
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
INDEX
Analog Input Model .................................................. 275
Baud Rate Generator .............................................. 232
Capture Mode Operation ......................................... 181
Comparator Analog Input Model .............................. 285
Comparator I/O Operating Modes ........................... 282
Comparator Output .................................................. 284
Comparator Voltage Reference ............................... 288
Comparator Voltage Reference Output
Buffer Example ................................................ 289
Compare Mode Operation ....................................... 182
Device Clock .............................................................. 37
Enhanced PWM ....................................................... 193
EUSART Receive .................................................... 260
EUSART Transmit ................................................... 258
External Power-on Reset Circuit
A
A/D ................................................................................... 271
A/D Converter Interrupt, Configuring ....................... 275
Acquisition Requirements ........................................ 276
ADCON0 Register .................................................... 271
ADCON1 Register .................................................... 271
ADCON2 Register .................................................... 271
ADRESH Register ............................................ 271, 274
ADRESL Register .................................................... 271
Analog Port Pins ...................................................... 158
Analog Port Pins, Configuring .................................. 278
Associated Registers ............................................... 280
Configuring the Module ............................................ 275
Conversion Clock (TAD) ........................................... 277
Conversion Status (GO/DONE Bit) .......................... 274
Conversions ............................................................. 279
Converter Characteristics ........................................ 416
Discharge ................................................................. 279
Operation in Power-Managed Modes ...................... 278
Selecting and Configuring Acquisition Time ............ 277
Special Event Trigger (ECCP) ................................. 192
Special Event Trigger (ECCP2) ............................... 280
Use of the ECCP2 Trigger ....................................... 280
Absolute Maximum Ratings ............................................. 375
AC (Timing) Characteristics ............................................. 396
Load Conditions for Device
(Slow VDD Power-up) ........................................ 51
Fail-Safe Clock Monitor (FSCM) .............................. 315
Generic I/O Port Operation ...................................... 135
High/Low-Voltage Detect with External Input .......... 292
HSPLL ....................................................................... 33
Interrupt Logic .......................................................... 120
INTOSC and PLL ....................................................... 34
2
MSSP (I C Master Mode) ........................................ 230
2
MSSP (I C Mode) .................................................... 215
MSSP (SPI Mode) ................................................... 205
On-Chip Reset Circuit ................................................ 49
PIC18F6527/6622/6627/6722 ................................... 11
PIC18F8527/8622/8627/8722 ................................... 12
PORTD and PORTE (Parallel Slave Port) ............... 158
PWM Operation (Simplified) .................................... 184
Reads from Flash Program Memory ......................... 91
Single Comparator ................................................... 283
Table Read Operation ............................................... 87
Table Write Operation ............................................... 88
Table Writes to Flash Program Memory .................... 93
Timer0 in 16-Bit Mode ............................................. 162
Timer0 in 8-Bit Mode ............................................... 162
Timer1 ..................................................................... 166
Timer1 (16-Bit Read/Write Mode) ............................ 166
Timer2 ..................................................................... 172
Timer3 ..................................................................... 174
Timer3 (16-Bit Read/Write Mode) ............................ 174
Timer4 ..................................................................... 178
Watchdog Timer ...................................................... 312
BN .................................................................................... 330
BNC ................................................................................. 331
BNN ................................................................................. 331
BNOV .............................................................................. 332
BNZ ................................................................................. 332
BOR. See Brown-out Reset.
BOV ................................................................................. 335
BRA ................................................................................. 333
Break Character (12-Bit) Transmit and Receive .............. 263
BRG. See Baud Rate Generator.
Brown-out Reset (BOR) ..................................................... 52
Detecting ................................................................... 52
Disabling in Sleep Mode ............................................ 52
Software Enabled ...................................................... 52
BSF .................................................................................. 333
BTFSC ............................................................................. 334
BTFSS ............................................................................. 334
BTG ................................................................................. 335
BZ .................................................................................... 336
Timing Specifications ....................................... 397
Parameter Symbology ............................................. 396
Temperature and Voltage Specifications ................. 397
Timing Conditions .................................................... 397
Access Bank
Mapping in Indexed Literal Offset Mode .................... 85
ACKSTAT ........................................................................ 236
ACKSTAT Status Flag ..................................................... 236
ADCON0 Register ............................................................ 271
GO/DONE Bit ........................................................... 274
ADCON1 Register ............................................................ 271
ADCON2 Register ............................................................ 271
ADDFSR .......................................................................... 364
ADDLW ............................................................................ 327
ADDULNK ........................................................................ 364
ADDWF ............................................................................ 327
ADDWFC ......................................................................... 328
ADRESH Register ............................................................ 271
ADRESL Register .................................................... 271, 274
Analog-to-Digital Converter. See A/D.
ANDLW ............................................................................ 328
ANDWF ............................................................................ 329
Assembler
MPASM Assembler .................................................. 372
Auto-Wake-up on Sync Break Character ......................... 262
B
Bank Select Register (BSR) ............................................... 72
Baud Rate Generator ....................................................... 232
BC .................................................................................... 329
BCF .................................................................................. 330
BF .................................................................................... 236
BF Status Flag ................................................................. 236
Block Diagrams
16-Bit Byte Select Mode .......................................... 103
16-Bit Byte Write Mode ............................................ 101
16-Bit Word Write Mode ........................................... 102
A/D ........................................................................... 274
© 2008 Microchip Technology Inc.
DS39646C-page 429
PIC18F8722 FAMILY
Operation ................................................................. 283
Operation During Sleep ........................................... 284
Outputs .................................................................... 283
Reference ................................................................ 283
External Signal ................................................ 283
C
C Compilers
MPLAB C18 .............................................................372
MPLAB C30 .............................................................372
CALL ................................................................................336
CALLW .............................................................................365
Capture (CCP Module) .....................................................181
Associated Registers ...............................................183
CCPRxH:CCPRxL Registers ...................................181
CCPx Pin Configuration ...........................................181
Prescaler ..................................................................181
Software Interrupt ....................................................181
Timer1/Timer3 Mode Selection ................................181
Capture (ECCP Module) ..................................................192
Capture/Compare/PWM (CCP) ........................................179
Capture Mode. See Capture.
Internal Signal .................................................. 283
Response Time ........................................................ 283
Comparator Specifications ............................................... 394
Comparator Voltage Reference ....................................... 287
Accuracy and Error .................................................. 288
Associated Registers ............................................... 289
Configuring .............................................................. 287
Connection Considerations ...................................... 288
Effects of a Reset .................................................... 288
Operation During Sleep ........................................... 288
Comparator Voltage Reference Specifications ................ 394
Compare (CCP Module) .................................................. 182
Associated Registers ............................................... 183
CCPRx Registers ..................................................... 182
Pin Configuration ..................................................... 182
Software Interrupt .................................................... 182
Special Event Trigger .............................................. 182
Timer1/Timer3 Mode Selection ................................ 182
Compare (CCP Modules)
CCP Mode and Timer Resources ............................180
CCPRxH Register ....................................................180
CCPRxL Register .....................................................180
Compare Mode. See Compare.
Interconnect Configurations .....................................180
Module Configuration ...............................................180
Clock Sources ....................................................................37
Selecting the 31 kHz Source ......................................38
Selection Using OSCCON Register ...........................38
CLRF ................................................................................337
CLRWDT ..........................................................................337
Code Examples
Special Event Trigger .............................................. 175
Compare (ECCP Module) ................................................ 192
Special Event Trigger .............................................. 192
Compare (ECCP2 Module)
Special Event Trigger .............................................. 280
Computed GOTO ............................................................... 68
Configuration Bits ............................................................ 297
Configuration Register Protection .................................... 320
Context Saving During Interrupts ..................................... 134
Conversion Considerations .............................................. 426
CPFSEQ .......................................................................... 338
CPFSGT .......................................................................... 339
CPFSLT ........................................................................... 339
Crystal Oscillator/Ceramic Resonator ................................ 31
Customer Change Notification Service ............................ 439
Customer Notification Service ......................................... 439
Customer Support ............................................................ 439
16 x 16 Signed Multiply Routine ..............................118
16 x 16 Unsigned Multiply Routine ..........................118
8 x 8 Signed Multiply Routine ..................................117
8 x 8 Unsigned Multiply Routine ..............................117
Changing Between Capture Prescalers ...................181
Computed GOTO Using an Offset Value ...................68
Data EEPROM Read ...............................................113
Data EEPROM Refresh Routine ..............................114
Data EEPROM Write ...............................................113
Erasing a Flash Program Memory Row .....................92
Fast Register Stack ....................................................68
How to Clear RAM (Bank 1) Using
Indirect Addressing ............................................81
Implementing a Real-Time Clock
D
Using a Timer1 Interrupt Service .....................169
Initializing PORTA ....................................................135
Initializing PORTB ....................................................137
Initializing PORTC ....................................................140
Initializing PORTD ....................................................143
Initializing PORTE ....................................................146
Initializing PORTF ....................................................149
Initializing PORTG ...................................................151
Initializing PORTH ....................................................154
Initializing PORTJ ....................................................156
Loading the SSP1BUF (SSP1SR) Register .............208
Reading a Flash Program Memory Word ..................91
Saving STATUS, WREG and BSR
Data Addressing Modes .................................................... 81
Comparing Addressing Modes with the
Extended Instruction Set Enabled ..................... 84
Direct ......................................................................... 81
Indexed Literal Offset ................................................ 83
Instructions Affected .......................................... 83
Indirect ....................................................................... 81
Inherent and Literal .................................................... 81
Data EEPROM
Code Protection ....................................................... 320
Data EEPROM Memory ................................................... 111
Associated Registers ............................................... 115
EEADR and EEADRH Registers ............................. 111
EECON1 and EECON2 Registers ........................... 111
Operation During Code-Protect ............................... 114
Protection Against Spurious Write ........................... 114
Reading ................................................................... 113
Using ....................................................................... 114
Write Verify .............................................................. 113
Writing ..................................................................... 113
Registers in RAM .............................................134
Writing to Flash Program Memory ....................... 94–95
Code Protection ...............................................................297
COMF ...............................................................................338
Comparator ......................................................................281
Analog Input Connection Considerations .................285
Associated Registers ...............................................285
Configuration ............................................................282
Effects of a Reset .....................................................284
Interrupts ..................................................................284
DS39646C-page 430
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
Data Memory ..................................................................... 72
Access Bank .............................................................. 74
and the Extended Instruction Set ............................... 83
Bank Select Register (BSR) ....................................... 72
General Purpose Registers ........................................ 74
Map for PIC18F8722 Family ...................................... 73
Special Function Registers ........................................ 75
DAW ................................................................................. 340
DC Characteristics ........................................................... 391
Power-Down and Supply Current ............................ 379
Supply Voltage ......................................................... 378
DCFSNZ .......................................................................... 341
DECF ............................................................................... 340
DECFSZ ........................................................................... 341
Development Support ...................................................... 371
Device Differences ........................................................... 425
Device Overview .................................................................. 7
Details on Individual Family Members ......................... 9
Features (table) ...................................................... 9, 10
New Core Features ...................................................... 7
Device Reset Timers .......................................................... 53
Oscillator Start-up Timer (OST) ................................. 53
PLL Lock Time-out ..................................................... 53
Power-up Timer (PWRT) ........................................... 53
Time-out Sequence .................................................... 53
Direct Addressing ............................................................... 82
Baud Rate Generator (BRG) ................................... 251
Associated Registers ....................................... 252
Auto-Baud Rate Detect .................................... 255
Baud Rate Error, Calculating ........................... 252
Baud Rates, Asynchronous Modes ................. 253
High Baud Rate Select (BRGH Bit) ................. 251
Sampling ......................................................... 251
Synchronous Master Mode ...................................... 264
Associated Registers, Receive ........................ 267
Associated Registers, Transmit ....................... 265
Reception ........................................................ 266
Transmission ................................................... 264
Synchronous Slave Mode ........................................ 268
Associated Registers, Receive ........................ 269
Associated Registers, Transmit ....................... 268
Reception ........................................................ 269
Transmission ................................................... 268
Extended Instruction Set
ADDFSR .................................................................. 364
ADDULNK ............................................................... 364
CALLW .................................................................... 365
MOVSF .................................................................... 365
MOVSS .................................................................... 366
PUSHL ..................................................................... 366
SUBFSR .................................................................. 367
SUBULNK ................................................................ 367
Extended Microcontroller Mode ....................................... 100
External Clock Input ........................................................... 32
External Memory Bus ........................................................ 97
16-Bit Byte Select Mode .......................................... 103
16-Bit Byte Write Mode ............................................ 101
16-Bit Data Width Modes ......................................... 100
16-Bit Mode Timing ................................................. 104
16-Bit Word Write Mode .......................................... 102
8-Bit Data Width Modes ........................................... 106
8-Bit Mode Timing ................................................... 107
I/O Port Functions ...................................................... 97
Operation in Power-Managed Modes ...................... 109
E
ECCP
Capture and Compare Modes .................................. 192
Standard PWM Mode ............................................... 192
Effect on Standard PIC MCU Instructions ........................ 368
Effects of Power-Managed Modes on Various
Clock Sources ............................................................ 40
Electrical Characteristics .................................................. 375
Enhanced Capture/Compare/PWM (ECCP) .................... 187
and Program Memory Modes .................................. 188
Capture Mode. See Capture (ECCP Module).
Outputs and Configuration ....................................... 188
Pin Configurations for ECCP1 ................................. 189
Pin Configurations for ECCP2 ................................. 190
Pin Configurations for ECCP3 ................................. 191
PWM Mode. See PWM (ECCP Module).
F
Fail-Safe Clock Monitor ........................................... 297, 315
Exiting Operation ..................................................... 315
Interrupts in Power-Managed Modes ...................... 316
POR or Wake from Sleep ........................................ 316
WDT During Oscillator Failure ................................. 315
Fast Register Stack ........................................................... 68
Firmware Instructions ...................................................... 321
Flash Program Memory ..................................................... 87
Associated Registers ................................................. 95
Control Registers ....................................................... 88
EECON1 and EECON2 ..................................... 88
TABLAT (Table Latch) Register ........................ 90
TBLPTR (Table Pointer) Register ...................... 90
Erase Sequence ........................................................ 92
Erasing ...................................................................... 92
Operation During Code-Protect ................................. 95
Reading ..................................................................... 91
Table Pointer
Boundaries Based on Operation ....................... 90
Table Pointer Boundaries .......................................... 90
Table Reads and Table Writes .................................. 87
Write Sequence ......................................................... 93
Writing To .................................................................. 93
Protection Against Spurious Writes ................... 95
Unexpected Termination ................................... 95
Write Verify ........................................................ 95
FSCM. See Fail-Safe Clock Monitor.
Timer Resources ...................................................... 192
Enhanced PWM Mode. See PWM (ECCP Module).
Enhanced Universal Synchronous Asynchronous
Receiver Transmitter (EUSART). See EUSART.
Equations
A/D Acquisition Time ................................................ 276
A/D Minimum Charging Time ................................... 276
A/D, Calculating the Minimum Required
Acquisition Time .............................................. 276
Errata ................................................................................... 5
EUSART
Asynchronous Mode ................................................ 257
12-Bit Break Transmit and Receive ................. 263
Associated Registers, Receive ........................ 261
Associated Registers, Transmit ....................... 259
Auto-Wake-up on Sync Break ......................... 262
Receiver ........................................................... 260
Setting up 9-Bit Mode with
Address Detect ........................................ 260
Transmitter ....................................................... 257
Baud Rate Generator
Operation in Power-Managed Modes .............. 251
© 2008 Microchip Technology Inc.
DS39646C-page 431
PIC18F8722 FAMILY
Indexed Literal Offset Addressing
G
and Standard PIC18 Instructions ............................. 368
Indexed Literal Offset Mode ............................................. 368
Indirect Addressing ............................................................ 82
INFSNZ ............................................................................ 343
Initialization Conditions for all Registers ...................... 57–61
Instruction Cycle ................................................................ 69
Clocking Scheme ....................................................... 69
Instruction Flow/Pipelining ................................................. 69
Instruction Set .................................................................. 321
ADDLW .................................................................... 327
ADDWF .................................................................... 327
ADDWF (Indexed Literal Offset Mode) .................... 369
ADDWFC ................................................................. 328
ANDLW .................................................................... 328
ANDWF .................................................................... 329
BC ............................................................................ 329
BCF ......................................................................... 330
BN ............................................................................ 330
BNC ......................................................................... 331
BNN ......................................................................... 331
BNOV ...................................................................... 332
BNZ ......................................................................... 332
BOV ......................................................................... 335
BRA ......................................................................... 333
BSF .......................................................................... 333
BSF (Indexed Literal Offset Mode) .......................... 369
BTFSC ..................................................................... 334
BTFSS ..................................................................... 334
BTG ......................................................................... 335
BZ ............................................................................ 336
CALL ........................................................................ 336
CLRF ....................................................................... 337
CLRWDT ................................................................. 337
COMF ...................................................................... 338
CPFSEQ .................................................................. 338
CPFSGT .................................................................. 339
CPFSLT ................................................................... 339
DAW ........................................................................ 340
DCFSNZ .................................................................. 341
DECF ....................................................................... 340
DECFSZ .................................................................. 341
Extended Instructions .............................................. 363
Considerations when Enabling ........................ 368
Syntax .............................................................. 363
Use with MPLAB IDE Tools ............................. 370
General Format ........................................................ 323
GOTO ...................................................................... 342
INCF ........................................................................ 342
INCFSZ .................................................................... 343
INFSNZ .................................................................... 343
IORLW ..................................................................... 344
IORWF ..................................................................... 344
LFSR ....................................................................... 345
MOVF ...................................................................... 345
MOVFF .................................................................... 346
MOVLB .................................................................... 346
MOVLW ................................................................... 347
MOVWF ................................................................... 347
MULLW .................................................................... 348
MULWF .................................................................... 348
NEGF ....................................................................... 349
NOP ......................................................................... 349
POP ......................................................................... 350
PUSH ....................................................................... 350
General Call Address Support .........................................229
GOTO ...............................................................................342
H
Hardware Multiplier ..........................................................117
Introduction ..............................................................117
Operation .................................................................117
Performance Comparison ........................................117
High/Low-Voltage Detect .................................................291
Applications ..............................................................294
Associated Registers ...............................................295
Characteristics .........................................................395
Current Consumption ...............................................293
Effects of a Reset .....................................................295
Operation .................................................................292
During Sleep ....................................................295
Setup ........................................................................293
Start-up Time ...........................................................293
Typical Application ...................................................294
HLVD. See High/Low-Voltage Detect. .............................291
I
I/O Ports ...........................................................................135
2
I C Mode (MSSP)
Acknowledge Sequence Timing ...............................239
Associated Registers ...............................................245
Baud Rate Generator ...............................................232
Bus Collision
During a Repeated Start Condition ..................243
During a Stop Condition ...................................244
Clock Arbitration .......................................................233
Clock Stretching .......................................................225
10-Bit Slave Receive Mode (SEN = 1) .............225
10-Bit Slave Transmit Mode .............................225
7-Bit Slave Receive Mode (SEN = 1) ...............225
7-Bit Slave Transmit Mode ...............................225
Clock Synchronization and the CKP bit ...................226
Effects of a Reset .....................................................240
General Call Address Support .................................229
2
I C Clock Rate w/BRG .............................................232
Master Mode ............................................................230
Operation .........................................................231
Reception .........................................................236
Repeated Start Condition Timing .....................235
Start Condition Timing .....................................234
Transmission ....................................................236
Multi-Master Communication, Bus Collision
and Arbitration ..................................................240
Multi-Master Mode ...................................................240
Operation .................................................................219
Read/Write Bit Information (R/W Bit) ............... 219, 220
Registers ..................................................................215
Serial Clock (RC3/SCKx/SCLx) ...............................220
Slave Mode ..............................................................219
Addressing .......................................................219
Reception .........................................................220
Transmission ....................................................220
Sleep Operation .......................................................240
Stop Condition Timing ..............................................239
ID Locations ............................................................. 297, 320
INCF .................................................................................342
INCFSZ ............................................................................343
In-Circuit Debugger ..........................................................320
In-Circuit Serial Programming (ICSP) ......................297, 320
DS39646C-page 432
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
RCALL ..................................................................... 351
RESET ..................................................................... 351
RETFIE .................................................................... 352
RETLW .................................................................... 352
RETURN .................................................................. 353
RLCF ........................................................................ 353
RLNCF ..................................................................... 354
RRCF ....................................................................... 354
RRNCF .................................................................... 355
SETF ........................................................................ 355
SETF (Indexed Literal Offset Mode) ........................ 369
SLEEP ..................................................................... 356
Standard Instructions ............................................... 321
SUBFWB .................................................................. 356
SUBLW .................................................................... 357
SUBWF .................................................................... 357
SUBWFB .................................................................. 358
SWAPF .................................................................... 358
TBLRD ..................................................................... 359
TBLWT ..................................................................... 360
TSTFSZ ................................................................... 361
XORLW .................................................................... 361
XORWF .................................................................... 362
L
LFSR ............................................................................... 345
Low-Voltage ICSP Programming. See Single-Supply
ICSP Programming
M
Master Clear (MCLR) ......................................................... 51
Master Synchronous Serial Port (MSSP). See MSSP.
Memory
Mode Memory Access ............................................... 64
Memory Maps for PIC18F8722 Family
Program Memory Modes ........................................... 65
Memory Organization ........................................................ 63
Data Memory ............................................................. 72
Program Memory ....................................................... 63
Modes ................................................................ 63
Memory Programming Requirements .............................. 393
Microchip Internet Web Site ............................................. 439
Microcontroller Mode ....................................................... 100
Microprocessor Mode ...................................................... 100
Microprocessor with Boot Block Mode ............................. 100
Migration from Baseline to Enhanced Devices ................ 426
Migration from High-End to Enhanced Devices ............... 427
Migration from Mid-Range to Enhanced Devices ............ 427
MOVF .............................................................................. 345
MOVFF ............................................................................ 346
MOVLB ............................................................................ 346
MOVLW ........................................................................... 347
MOVSF ............................................................................ 365
MOVSS ............................................................................ 366
MOVWF ........................................................................... 347
MPLAB ASM30 Assembler, Linker, Librarian .................. 372
MPLAB ICD 2 In-Circuit Debugger .................................. 373
MPLAB ICE 2000 High-Performance
INTCON Register
RBIF Bit .................................................................... 137
INTCON Registers ........................................................... 121
2
Inter-Integrated Circuit. See I C.
Internal Oscillator Block ..................................................... 34
Adjustment ................................................................. 34
INTIO Modes .............................................................. 34
INTOSC Frequency Drift ............................................ 35
INTOSC Output Frequency ........................................ 34
OSCTUNE Register ................................................... 34
PLL in INTOSC Modes .............................................. 35
Internal RC Oscillator
Use with WDT .......................................................... 312
Internet Address ............................................................... 439
Interrupt Sources ............................................................. 297
A/D Conversion Complete ....................................... 275
Capture Complete (CCP) ......................................... 181
Compare Complete (CCP) ....................................... 182
Interrupt-on-Change (RB7:RB4) .............................. 137
INTx Pin ................................................................... 134
PORTB, Interrupt-on-Change .................................. 134
TMR0 ....................................................................... 134
TMR0 Overflow ........................................................ 163
TMR1 Overflow ........................................................ 165
TMR2 to PR2 Match (PWM) ............................ 184, 192
TMR3 Overflow ................................................ 173, 175
TMR4 to PR4 Match ................................................ 178
TMR4 to PR4 Match (PWM) .................................... 177
Interrupts .......................................................................... 119
Interrupts, Flag Bits
Universal In-Circuit Emulator ................................... 373
MPLAB Integrated Development
Environment Software ............................................. 371
MPLAB PM3 Device Programmer ................................... 373
MPLAB REAL ICE In-Circuit Emulator System ............... 373
MPLINK Object Linker/MPLIB Object Librarian ............... 372
MSSP
ACK Pulse ....................................................... 219, 220
Control Registers (general) ..................................... 205
I C Mode. See I C Mode.
2
2
Module Overview ..................................................... 205
SPI Master/Slave Connection .................................. 209
TMR4 Output for Clock Shift .................................... 178
MULLW ............................................................................ 348
MULWF ............................................................................ 348
N
NEGF ............................................................................... 349
NOP ................................................................................. 349
Interrupt-on-Change (RB7:RB4) Flag
O
(RBIF Bit) ........................................................ 137
INTOSC, INTRC. See Internal Oscillator Block.
Opcode Field Descriptions ............................................... 322
Oscillator Configuration ..................................................... 31
EC .............................................................................. 31
ECIO .......................................................................... 31
HS .............................................................................. 31
HSPLL ....................................................................... 31
Internal Oscillator Block ............................................. 34
INTIO1 ....................................................................... 31
INTIO2 ....................................................................... 31
LP .............................................................................. 31
IORLW ............................................................................. 344
IORWF ............................................................................. 344
IPR Registers ................................................................... 130
K
Key Features
Easy Migration ............................................................. 8
Expanded Memory ....................................................... 7
External Memory Interface ........................................... 8
© 2008 Microchip Technology Inc.
DS39646C-page 433
PIC18F8722 FAMILY
RC ..............................................................................31
RCIO ..........................................................................31
XT ..............................................................................31
Oscillator Selection ..........................................................297
Oscillator Start-up Timer (OST) ................................... 40, 53
Oscillator Switching ............................................................37
Oscillator Transitions ..........................................................38
Oscillator, Timer1 ..................................................... 165, 175
Oscillator, Timer3 .............................................................173
RD7/AD7/PSP7/SS2 .................................................. 25
RD7/PSP7/SS2 ......................................................... 17
RE0/AD8/RD/P2D ...................................................... 26
RE0/RD/P2D .............................................................. 18
RE1/AD9/WR/P2C ..................................................... 26
RE1/WR/P2C ............................................................. 18
RE2/AD10/CS/P2B .................................................... 26
RE2/CS/P2D .............................................................. 18
RE3/AD11/P3C .......................................................... 26
RE3/P3C .................................................................... 18
RE4/AD12/P3B .......................................................... 26
RE4/P3B .................................................................... 18
RE5/AD13/P1C .......................................................... 26
RE5/P1C .................................................................... 18
RE6/AD14/P1B .......................................................... 26
RE6/P1B .................................................................... 18
RE7/AD15/ECCP2/P2A ............................................. 26
RE7/ECCP2/P2A ....................................................... 18
RF0/AN5 .............................................................. 19, 27
RF1/AN6/C2OUT ................................................. 19, 27
RF2/AN7/C1OUT ................................................. 19, 27
RF3/AN8 .............................................................. 19, 27
RF4/AN9 .............................................................. 19, 27
RF5/AN10/CVREF ................................................ 19, 27
RF6/AN11 ............................................................ 19, 27
RF7/SS1 .............................................................. 19, 27
RG0/ECCP3/P3A ................................................. 20, 28
RG1/TX2/CK2 ...................................................... 20, 28
RG2/RX2/DT2 ...................................................... 20, 28
RG3/CCP4/P3D ................................................... 20, 28
RG4/CCP5/P1D ................................................... 20, 28
RG5 ..................................................................... 20, 28
RG5/MCLR/VPP ................................................... 13, 21
RH0/A16 .................................................................... 29
RH1/A17 .................................................................... 29
RH2/A18 .................................................................... 29
RH3/A19 .................................................................... 29
RH4/AN12/P3C .......................................................... 29
RH5/AN13/P3B .......................................................... 29
RH6/AN14/P1C .......................................................... 29
RH7/AN15/P1B .......................................................... 29
RJ0/ALE .................................................................... 30
RJ1/OE ...................................................................... 30
RJ2/WRL ................................................................... 30
RJ3/WRH ................................................................... 30
RJ4/BA0 .................................................................... 30
RJ5/CE ...................................................................... 30
RJ6/LB ....................................................................... 30
RJ7/UB ...................................................................... 30
VDD ............................................................................ 20
VDD ............................................................................ 30
VSS ............................................................................ 20
VSS ............................................................................ 30
Pinout I/O Descriptions
P
Packaging ........................................................................419
Details ......................................................................420
Marking ....................................................................419
Parallel Slave Port (PSP) .................................................158
Associated Registers ...............................................160
RE0/RD Pin ..............................................................158
RE1/WR Pin .............................................................158
RE2/CS Pin ..............................................................158
Select (PSPMODE Bit) ............................................158
PICSTART Plus Development Programmer ....................374
PIE Registers ...................................................................127
Pin Functions
AVDD ..........................................................................20
AVDD ..........................................................................30
AVSS ..........................................................................20
AVSS ..........................................................................30
OSC1/CLKI/RA7 .................................................. 13, 21
OSC2/CLKO/RA6 ................................................ 13, 21
RA0/AN0 .............................................................. 14, 22
RA1/AN1 .............................................................. 14, 22
RA2/AN2/VREF- .................................................... 14, 22
RA3/AN3/VREF+ ................................................... 14, 22
RA4/T0CKI ........................................................... 14, 22
RA5/AN4/HLVDIN ................................................ 14, 22
RB0/INT0/FLT0 .................................................... 15, 23
RB1/INT1 ............................................................. 15, 23
RB2/INT2 ............................................................. 15, 23
RB3/INT3 ...................................................................15
RB3/INT3/ECCP2/P2A ..............................................23
RB4/KBI0 ............................................................. 15, 23
RB5/KBI1/PGM .................................................... 15, 23
RB6/KBI2/PGC .................................................... 15, 23
RB7/KBI3/PGD .................................................... 15, 23
RC0/T1OSO/T13CKI ...........................................16, 24
RC1/T1OSI/ECCP2/P2A ...................................... 16, 24
RC2/ECCP1/P1A ................................................. 16, 24
RC3/SCK1/SCL1 ................................................. 16, 24
RC4/SDI1/SDA1 .................................................. 16, 24
RC5/SDO1 ........................................................... 16, 24
RC6/TX1/CK1 ...................................................... 16, 24
RC7/RX1/DT1 ...................................................... 16, 24
RD0/AD0/PSP0 ..........................................................25
RD0/PSP0 ..................................................................17
RD1/AD1/PSP1 ..........................................................25
RD1/PSP1 ..................................................................17
RD2/AD2/PSP2 ..........................................................25
RD2/PSP2 ..................................................................17
RD3/AD3/PSP3 ..........................................................25
RD3/PSP3 ..................................................................17
RD4/AD4/PSP4/SDO2 ...............................................25
RD4/PSP4/SDO2 .......................................................17
RD5/AD5/PSP5/SDI2/SDA2 ......................................25
RD5/PSP5/SDI2/SDA2 ..............................................17
RD6/AD6/PSP6/SCK2/SCL2 .....................................25
RD6/PSP6/SCK2/SCL2 .............................................17
PIC18F6527/6622/6627/6722 ................................... 13
PIC18F8527/8622/8627/8722 ................................... 21
PIR Registers ................................................................... 124
PLL Frequency Multiplier ................................................... 33
HSPLL Oscillator Mode ............................................. 33
Use with INTOSC ...................................................... 33
POP ................................................................................. 350
POR. See Power-on Reset.
DS39646C-page 434
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
PORTA
Associated Registers ............................................... 136
Power-Managed Modes ..................................................... 41
and A/D Operation ................................................... 278
and EUSART Operation .......................................... 251
and Multiple Sleep Commands .................................. 42
and PWM Operation ................................................ 203
and SPI Operation ................................................... 213
Associated Registers ............................................... 109
Clock Transitions and Status Indicators .................... 42
Effects on Clock Sources .......................................... 40
Entering ..................................................................... 41
Exiting Idle and Sleep Modes .................................... 47
by Interrupt ........................................................ 47
by Reset ............................................................ 47
by WDT Time-out .............................................. 47
Without a Start-up Delay ................................... 48
Idle Modes ................................................................. 45
PRI_IDLE .......................................................... 46
RC_IDLE ........................................................... 47
SEC_IDLE ......................................................... 46
Run Modes ................................................................ 42
PRI_RUN ........................................................... 42
RC_RUN ............................................................ 43
SEC_RUN ......................................................... 42
Selecting .................................................................... 41
Sleep Mode ............................................................... 45
Summary (table) ........................................................ 41
Power-on Reset (POR) ...................................................... 51
Power-up Timer (PWRT) ........................................... 53
Time-out Sequence ................................................... 53
Power-up Delays ............................................................... 40
Power-up Timer (PWRT) ................................................... 40
Prescaler
Timer2 ..................................................................... 193
Prescaler, Timer0 ............................................................ 163
Prescaler, Timer2 ............................................................ 185
PRI_IDLE Mode ................................................................. 46
PRI_RUN Mode ................................................................. 42
Program Counter ............................................................... 66
PCL, PCH and PCU Registers .................................. 66
PCLATH and PCLATU Registers .............................. 66
Program Memory
and Extended Instruction Set .................................... 85
Code Protection ....................................................... 318
Extended Microcontroller Mode ................................. 63
Instructions ................................................................ 70
Two-Word .......................................................... 71
Interrupt Vector .......................................................... 63
Look-up Tables .......................................................... 68
Map and Stack (diagram) .......................................... 64
Microcontroller Mode ................................................. 63
Microprocessor Mode ................................................ 63
Microprocessor with Boot Block Mode ...................... 63
Reset Vector .............................................................. 63
Program Verification and Code Protection ...................... 317
Associated Registers ............................................... 318
Programming, Device Instructions ................................... 321
PSP.See Parallel Slave Port.
Functions ................................................................. 136
LATA Register .......................................................... 135
PORTA Register ...................................................... 135
TRISA Register ........................................................ 135
PORTB
Associated Registers ............................................... 139
Functions ................................................................. 138
LATB Register .......................................................... 137
PORTB Register ...................................................... 137
RB7:RB4 Interrupt-on-Change Flag
(RBIF Bit) ......................................................... 137
TRISB Register ........................................................ 137
PORTC
Associated Registers ............................................... 142
Functions ................................................................. 141
LATC Register ......................................................... 140
PORTC Register ...................................................... 140
RC3/SCKx/SCLx Pin ................................................ 220
TRISC Register ........................................................ 140
PORTD ............................................................................ 158
Associated Registers ............................................... 145
Functions ................................................................. 144
LATD Register ......................................................... 143
PORTD Register ...................................................... 143
TRISD Register ........................................................ 143
PORTE
Analog Port Pins ...................................................... 158
Associated Registers ............................................... 148
Functions ................................................................. 147
LATE Register .......................................................... 146
PORTE Register ...................................................... 146
PSP Mode Select (PSPMODE Bit) .......................... 158
RE0/RD Pin .............................................................. 158
RE1/WR Pin ............................................................. 158
RE2/CS Pin .............................................................. 158
TRISE Register ........................................................ 146
PORTF
Associated Registers ............................................... 150
Functions ................................................................. 150
LATF Register .......................................................... 149
PORTF Register ...................................................... 149
TRISF Register ........................................................ 149
PORTG
Associated Registers ............................................... 153
Functions ................................................................. 152
LATG Register ......................................................... 151
PORTG Register ...................................................... 151
TRISG Register ........................................................ 151
PORTH
Associated Registers ............................................... 155
Functions ................................................................. 155
LATH Register ......................................................... 154
PORTH Register ...................................................... 154
TRISH Register ........................................................ 154
PORTJ
Associated Registers ............................................... 157
Functions ................................................................. 157
LATJ Register .......................................................... 156
PORTJ Register ....................................................... 156
TRISJ Register ......................................................... 156
Pulse-Width Modulation. See PWM (CCP Module)
and PWM (ECCP Module).
PUSH ............................................................................... 350
PUSH and POP Instructions .............................................. 67
PUSHL ............................................................................. 366
© 2008 Microchip Technology Inc.
DS39646C-page 435
PIC18F8722 FAMILY
PWM (CCP Module)
DEVID2 (Device ID 2) .............................................. 311
ECCPxDEL (Enhanced PWM
Associated Registers ...............................................186
Duty Cycle ................................................................184
Example Frequencies/Resolutions ..........................185
Period .......................................................................184
Setup for PWM Operation ........................................185
TMR2 to PR2 Match ................................................184
TMR4 to PR4 Match ................................................177
PWM (ECCP Module) ......................................................192
Associated Registers ...............................................204
CCPR1H:CCPR1L Registers ...................................192
Direction Change in Full-Bridge Output Mode .........198
Duty Cycle ................................................................193
Effects of a Reset .....................................................203
Enhanced PWM Auto-Shutdown .............................200
Example Frequencies/Resolutions ..........................193
Full-Bridge Application Example ..............................198
Full-Bridge Mode ......................................................197
Half-Bridge Mode .....................................................196
Half-Bridge Output Mode
Dead-Band Delay) ........................................... 200
EECON1 (Data EEPROM Control 1) ....................... 112
EECON1 (EEPROM Control 1) ................................. 89
HLVDCON (High/Low-Voltage Detect Control) ....... 291
INTCON (Interrupt Control) ...................................... 121
INTCON2 (Interrupt Control 2) ................................. 122
INTCON3 (Interrupt Control 3) ................................. 123
IPR1 (Peripheral Interrupt Priority 1) ....................... 130
IPR2 (Peripheral Interrupt Priority 2) ....................... 131
MEMCON (External Memory Bus Control) ................ 98
OSCCON (Oscillator Control) .................................... 39
OSCTUNE (Oscillator Tuning) ................................... 35
PIR1 (Peripheral Interrupt Request (Flag) 1) ........... 124
PIR2 (Peripheral Interrupt Request (Flag) 2) ........... 125
PSPCON (Parallel Slave Port Control) .................... 159
RCON (Reset Control) ....................................... 50, 133
RCSTAx (Receive Status and Control) .................... 249
2
SSPxCON1 (MSSPx Control 1, I C Mode) .............. 217
Applications Example .......................................196
Operation in Power-Managed Modes ......................203
Operation with Fail-Safe Clock Monitor ...................203
Output Configurations ..............................................194
Output Relationships (Active-High) ..........................194
Output Relationships (Active-Low) ...........................195
Period .......................................................................192
Programmable Dead-Band Delay ............................200
Setup for PWM Operation ........................................203
Start-up Considerations ...........................................202
TMR2 to PR2 Match ................................................192
SSPxCON1 (MSSPx Control 1, SPI Mode) ............. 207
2
SSPxCON2 (MSSPx Control 2, I C Mode) .............. 219
2
SSPxSTAT (MSSPx Status, I C Mode) ................... 216
SSPxSTAT (MSSPx Status, SPI Mode) .................. 206
STATUS (Arithmetic Status) ...................................... 80
STKPTR (Stack Pointer) ............................................ 67
T0CON (Timer0 Control) ......................................... 161
T1CON (Timer1 Control) ......................................... 165
T2CON (Timer2 Control) ......................................... 171
T3CON (Timer3 Control) ......................................... 173
T4CON (Timer 4 Control) ........................................ 177
TXSTAx (Transmit Status and Control) ................... 248
WDTCON (Watchdog Timer Control) ...................... 313
RESET ............................................................................. 351
Reset State of Registers .................................................... 56
Resets ........................................................................ 49, 297
Brown-out Reset (BOR) ........................................... 297
Oscillator Start-up Timer (OST) ............................... 297
Power-on Reset (POR) ............................................ 297
Power-up Timer (PWRT) ......................................... 297
RETFIE ............................................................................ 352
RETLW ............................................................................ 352
RETURN .......................................................................... 353
Return Address Stack ........................................................ 66
Return Stack Pointer (STKPTR) ........................................ 67
Revision History ............................................................... 425
RLCF ............................................................................... 353
RLNCF ............................................................................. 354
RRCF ............................................................................... 354
RRNCF ............................................................................ 355
Q
Q Clock .................................................................... 185, 193
R
RAM. See Data Memory.
RC Oscillator ......................................................................33
RCIO Oscillator Mode ................................................33
RC_IDLE Mode ..................................................................47
RC_RUN Mode ..................................................................43
RCALL ..............................................................................351
RCON Register
Bit Status During Initialization ....................................56
Reader Response ............................................................440
Register File .......................................................................74
Registers
ADCON0 (A/D Control 0) .........................................271
ADCON1 (A/D Control 1) .........................................272
ADCON2 (A/D Control 2) .........................................273
BAUDCONx (Baud Rate Control) ............................250
CCPxCON (CCPx Control, CCP4 and CCP5) .........179
CMCON (Comparator Control) ................................281
CONFIG1H (Configuration 1 High) ..........................299
CONFIG2H (Configuration 2 High) ..........................301
CONFIG2L (Configuration 2 Low) ............................300
CONFIG3H (Configuration 3 High) ..........................303
CONFIG3L (Configuration 3 Low) ............................302
CONFIG4L (Configuration 4 Low) ............................304
CONFIG5H (Configuration 5 High) ..........................306
CONFIG5L (Configuration 5 Low) ............................305
CONFIG6H (Configuration 6 High) ..........................308
CONFIG6L (Configuration 6 Low) ............................307
CONFIG7H (Configuration 7 High) ..........................310
CONFIG7L (Configuration 7 Low) ............................309
DEVID1 (Device ID 1) ..............................................311
S
SCKx ................................................................................ 205
SDIx ................................................................................. 205
SDOx ............................................................................... 205
SEC_IDLE Mode ............................................................... 46
SEC_RUN Mode ................................................................ 42
Serial Clock, SCKx .......................................................... 205
Serial Data In (SDIx) ........................................................ 205
Serial Data Out (SDOx) ................................................... 205
Serial Peripheral Interface. See SPI Mode.
SETF ................................................................................ 355
Single-Supply ICSP Programming.
Slave Select (SSx) ........................................................... 205
Slave Select Synchronization .......................................... 211
SLEEP ............................................................................. 356
DS39646C-page 436
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
Sleep
OSC1 and OSC2 Pin States ...................................... 40
Sleep Mode ........................................................................ 45
Software Simulator (MPLAB SIM) .................................... 372
Special Event Trigger. See Compare (CCP Mode).
Timer1 ............................................................................. 165
16-Bit Read/Write Mode .......................................... 167
Associated Registers ............................................... 169
Interrupt ................................................................... 168
Operation ................................................................. 166
Oscillator .......................................................... 165, 167
Layout Considerations ..................................... 168
Overflow Interrupt .................................................... 165
Resetting, Using the CCP
Special Event Trigger. See Compare (ECCP Module).
Special Features of the CPU ........................................... 297
Special Function Registers ................................................ 75
Map ............................................................................ 75
SPI Mode (MSSP) ............................................................ 205
Associated Registers ............................................... 214
Bus Mode Compatibility ........................................... 213
Clock Speed, Interactions ........................................ 213
Effects of a Reset ..................................................... 213
Enabling SPI I/O ...................................................... 209
Master Mode ............................................................ 210
Master/Slave Connection ......................................... 209
Operation ................................................................. 208
Operation in Power-Managed Modes ...................... 213
Serial Clock .............................................................. 205
Serial Data In ........................................................... 205
Serial Data Out ........................................................ 205
Slave Mode .............................................................. 211
Slave Select ............................................................. 205
Slave Select Synchronization .................................. 211
SPI Clock ................................................................. 210
SSPxBUF Register .................................................. 210
SSPxSR Register ..................................................... 210
Typical Connection .................................................. 209
SSPOV ............................................................................. 236
SSPOV Status Flag ......................................................... 236
SSPxSTAT Register
Special Event Trigger ...................................... 168
Special Event Trigger (ECCP) ................................. 192
TMR1H Register ...................................................... 165
TMR1L Register ...................................................... 165
Use as a Real-Time Clock ....................................... 168
Timer2 ............................................................................. 171
Associated Registers ............................................... 172
Interrupt ................................................................... 172
Operation ................................................................. 171
Output ...................................................................... 172
PR2 Register ................................................... 184, 192
TMR2 to PR2 Match Interrupt .......................... 184, 192
Timer3 ............................................................................. 173
16-Bit Read/Write Mode .......................................... 175
Associated Registers ............................................... 175
Operation ................................................................. 174
Oscillator .......................................................... 173, 175
Overflow Interrupt ............................................ 173, 175
Special Event Trigger (CCP) ................................... 175
TMR3H Register ...................................................... 173
TMR3L Register ...................................................... 173
Timer4 ............................................................................. 177
Associated Registers ............................................... 178
MSSP Clock Shift .................................................... 178
Operation ................................................................. 177
Postscaler. See Postscaler, Timer4.
R/W Bit ............................................................. 219, 220
SSx .................................................................................. 205
Stack Full/Underflow Resets .............................................. 68
SUBFSR .......................................................................... 367
SUBFWB .......................................................................... 356
SUBLW ............................................................................ 357
SUBULNK ........................................................................ 367
SUBWF ............................................................................ 357
SUBWFB .......................................................................... 358
SWAPF ............................................................................ 358
PR4 Register ........................................................... 177
Prescaler. See Prescaler, Timer4.
TMR4 Register ........................................................ 177
TMR4 to PR4 Match Interrupt .......................... 177, 178
Timing Diagrams
A/D Conversion ....................................................... 416
Asynchronous Reception ......................................... 261
Asynchronous Transmission ................................... 258
Asynchronous Transmission (Back to Back) ........... 258
Automatic Baud Rate Calculation ............................ 256
Auto-Wake-up Bit (WUE) During
Normal Operation ............................................ 262
Auto-Wake-up Bit (WUE) During Sleep ................... 262
Baud Rate Generator with Clock Arbitration ............ 233
BRG Overflow Sequence ........................................ 256
BRG Reset Due to SDAx Arbitration
During Start Condition ..................................... 242
Brown-out Reset (BOR) ........................................... 403
Bus Collision During a Repeated Start
Condition (Case 1) ........................................... 243
Bus Collision During a Repeated Start
T
Table Pointer Operations (table) ........................................ 90
Table Reads/Table Writes ................................................. 69
TBLRD ............................................................................. 359
TBLWT ............................................................................. 360
Time-out in Various Situations (table) ................................ 53
Timer0 .............................................................................. 161
Associated Registers ............................................... 163
Operation ................................................................. 162
Overflow Interrupt .................................................... 163
Prescaler .................................................................. 163
Prescaler Assignment (PSA Bit) .............................. 163
Prescaler Select (T0PS2:T0PS0 Bits) ..................... 163
Prescaler. See Prescaler, Timer0.
Condition (Case 2) ........................................... 243
Bus Collision During a Start
Condition (SCLx = 0) ....................................... 242
Bus Collision During a Stop
Condition (Case 1) ........................................... 244
Bus Collision During a Stop
Reads and Writes in 16-Bit Mode ............................ 162
Source Edge Select (T0SE Bit) ................................ 162
Source Select (T0CS Bit) ......................................... 162
Switching Prescaler Assignment .............................. 163
Condition (Case 2) ........................................... 244
© 2008 Microchip Technology Inc.
DS39646C-page 437
PIC18F8722 FAMILY
Bus Collision During Start
Reset, Watchdog Timer (WDT), Oscillator Start-up
Timer (OST) and Power-up Timer (PWRT) ..... 403
Send Break Character Sequence ............................ 263
Slave Synchronization ............................................. 211
Slow Rise Time (MCLR Tied to VDD,
VDD Rise > TPWRT) ............................................ 55
SPI Mode (Master Mode) ......................................... 210
SPI Mode (Slave Mode, CKE = 0) ........................... 212
SPI Mode (Slave Mode, CKE = 1) ........................... 212
Synchronous Reception (Master Mode, SREN) ...... 266
Synchronous Transmission ..................................... 264
Synchronous Transmission (Through TXEN) .......... 265
Time-out Sequence on POR w/PLL Enabled
(MCLR Tied to VDD) .......................................... 55
Time-out Sequence on Power-up
Condition (SDAx Only) .....................................241
Bus Collision for Transmit and Acknowledge ...........240
Capture/Compare/PWM (All ECCP/CCP
Modules) ..........................................................405
CLKO and I/O ..........................................................400
Clock Synchronization .............................................226
Clock/Instruction Cycle ..............................................69
EUSART Synchronous Receive
(Master/Slave) ..................................................415
EUSART Synchronous Transmission
(Master/Slave) ..................................................415
Example SPI Master Mode (CKE = 0) .....................407
Example SPI Master Mode (CKE = 1) .....................408
Example SPI Slave Mode (CKE = 0) .......................409
Example SPI Slave Mode (CKE = 1) .......................410
External Clock (All Modes Except PLL) ...................398
External Memory Bus for Sleep
(Microprocessor Mode) ............................ 105, 108
External Memory Bus for TBLRD (Extended
Microcontroller Mode) .............................. 104, 107
External Memory Bus for TBLRD
(MCLR Not Tied to VDD, Case 1) ...................... 54
Time-out Sequence on Power-up
(MCLR Not Tied to VDD, Case 2) ...................... 54
Time-out Sequence on Power-up
(MCLR Tied to VDD, VDD Rise < TPWRT) ........... 54
Timer0 and Timer1 External Clock .......................... 404
Transition for Entry to Idle Mode ................................ 46
Transition for Entry to SEC_RUN Mode .................... 43
Transition for Entry to Sleep Mode ............................ 45
Transition for Two-Speed Start-up
(INTOSC to HSPLL) ........................................ 314
Transition for Wake from Idle to Run Mode ............... 46
Transition for Wake from Sleep (HSPLL) .................. 45
Transition from RC_RUN Mode to
(Microprocessor Mode) ....................................107
External Memory Bus for TBLRD with 1 TCY
Wait State (Microprocessor Mode) ..................104
Fail-Safe Clock Monitor (FSCM) ..............................316
First Start Bit Timing ................................................234
Full-Bridge PWM Output ..........................................197
Half-Bridge PWM Output .........................................196
High/Low-Voltage Detect Characteristics ................395
High-Voltage Detect Operation
PRI_RUN Mode ................................................. 44
Transition from SEC_RUN Mode to
(VDIRMAG = 1) ................................................294
I C Acknowledge Sequence ....................................239
I C Bus Data ............................................................411
I C Bus Start/Stop Bits .............................................411
I C Master Mode (7 or 10-Bit Transmission) ...........237
I C Master Mode (7-Bit Reception) ..........................238
I C Slave Mode (10-Bit Reception, SEN = 0) ..........223
I C Slave Mode (10-Bit Reception, SEN = 1) ..........228
I C Slave Mode (10-Bit Transmission) .....................224
I C Slave Mode (7-bit Reception, SEN = 0) .............221
I C Slave Mode (7-Bit Reception, SEN = 1) ............227
I C Slave Mode (7-Bit Transmission) .......................222
PRI_RUN Mode (HSPLL) .................................. 43
Transition to RC_RUN Mode ..................................... 44
Typical Opcode Fetch, 8-Bit Mode .......................... 108
Timing Diagrams and Specifications
2
2
2
2
A/D Conversion Requirements ................................ 417
AC Characteristics
Internal RC Accuracy ....................................... 399
Capture/Compare/PWM Requirements
(All ECCP/CCP Modules) ................................ 405
CLKO and I/O Requirements ........................... 400, 401
EUSART Synchronous Receive
Requirements .................................................. 415
EUSART Synchronous Transmission
2
2
2
2
2
2
2
2
I C Slave Mode General Call Address
Sequence (7 or 10-Bit Address Mode) .............229
I C Stop Condition Receive or Transmit Mode ........239
Requirements .................................................. 415
Example SPI Mode Requirements
2
Low-Voltage Detect Operation (VDIRMAG = 0) .......293
(Master Mode, CKE = 0) .................................. 407
Example SPI Mode Requirements
(Master Mode, CKE = 1) .................................. 408
Example SPI Mode Requirements
2
Master SSP I C Bus Data ........................................413
2
Master SSP I C Bus Start/Stop Bits ........................413
Parallel Slave Port
(PIC18F8527/8622/8627/8722) .......................406
Parallel Slave Port (PSP) Read ...............................160
Parallel Slave Port (PSP) Write ...............................160
Program Memory Read ............................................401
Program Memory Write ............................................402
PWM Auto-Shutdown (P1RSEN = 0,
(Slave Mode, CKE = 0) .................................... 409
Example SPI Slave Mode Requirements
(CKE = 1) ......................................................... 410
External Clock Requirements .................................. 398
2
I C Bus Data Requirements (Slave Mode) .............. 412
2
I C Bus Start/Stop Bits Requirements
Auto-Restart Disabled) .....................................202
PWM Auto-Shutdown (P1RSEN = 1,
Auto-Restart Enabled) .....................................202
PWM Direction Change ...........................................199
PWM Direction Change at Near
(Slave Mode) ................................................... 411
2
Master SSP I C Bus Data Requirements ................ 414
2
Master SSP I C Bus Start/Stop Bits
Requirements .................................................. 413
Parallel Slave Port Requirements
100% Duty Cycle .............................................199
PWM Output ............................................................184
Repeated Start Condition .........................................235
(PIC18F8527/8622/8627/8722) ....................... 406
PLL Clock ................................................................ 399
Program Memory Write Requirements .................... 402
DS39646C-page 438
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
Reset, Watchdog Timer, Oscillator Start-up
Timer, Power-up Timer and Brown-out
Reset Requirements ........................................ 403
Timer0 and Timer1 External Clock
W
Watchdog Timer (WDT) ........................................... 297, 312
Associated Registers ............................................... 313
Control Register ....................................................... 312
During Oscillator Failure .......................................... 315
Programming Considerations .................................. 312
WCOL ...................................................... 234, 235, 236, 239
WCOL Status Flag ................................... 234, 235, 236, 239
WWW Address ................................................................ 439
WWW, On-Line Support ...................................................... 5
Requirements ................................................. 404
Top-of-Stack Access .......................................................... 66
TRISE Register
PSPMODE Bit .......................................................... 158
TSTFSZ ........................................................................... 361
Two-Speed Start-up ................................................. 297, 314
IESO (CONFIG1H, Internal/External
Oscillator Switchover Bit .................................. 299
Two-Word Instructions
Example Cases .......................................................... 71
TXSTAx Register
X
XORLW ........................................................................... 361
XORWF ........................................................................... 362
BRGH Bit ................................................................. 251
© 2008 Microchip Technology Inc.
DS39646C-page 439
PIC18F8722 FAMILY
NOTES:
DS39646C-page 440
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
THE MICROCHIP WEB SITE
CUSTOMER SUPPORT
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To register, access the Microchip web site at
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© 2008 Microchip Technology Inc.
DS39646C-page 441
PIC18F8722 FAMILY
READER RESPONSE
It is our intention to provide you with the best documentation possible to ensure successful use of your Microchip prod-
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PIC18F8722 Family
DS39646C
Literature Number:
Device:
Questions:
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3. Do you find the organization of this document easy to follow? If not, why?
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DS39646C-page 442
© 2008 Microchip Technology Inc.
PIC18F8722 FAMILY
PIC18F8722 FAMILY PRODUCT IDENTIFICATION SYSTEM
To order or obtain information, e.g., on pricing or delivery, refer to the factory or the listed sales office.
PART NO.
Device
X
/XX
XXX
Examples:
Temperature
Range
Package
Pattern
a)
PIC18LF6622-I/PT 301 = Industrial temp.,
TQFP package, Extended VDD
limits, QTP pattern #301.
b)
PIC18LF6722-E/PT = Extended temp.,
TQFP package, standard VDD limits.
Device
PIC18F6527/6622/6627/6722(1), PIC18F8527/8622/8627/8722(1)
,
PIC18F6527/6622/6627/6722T(2), PIC18F8527/8622/8627/8722T(2)
VDD range 4.2V to 5.5V
;
PIC18LF6627/6722(1), PIC18LF8627/8722(1)
PIC18LF6627/6722T(2), PIC18LF8627/8722T(2)
VDD range 2.0V to 5.5V
,
;
Temperature
Range
I
E
=
=
-40°C to +85°C (Industrial)
-40°C to +125°C (Extended)
Package
Pattern
PT
=
TQFP (Thin Quad Flatpack)
Note 1:
2:
F
LF
T
=
=
=
Standard Voltage Range
Wide Voltage Range
in tape and reel TQFP
packages only.
QTP, SQTP, Code or Special Requirements
(blank otherwise)
© 2008 Microchip Technology Inc.
DS39646C-page 443
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Kokomo, IN
Tel: 765-864-8360
Fax: 765-864-8387
China - Shenyang
Tel: 86-24-2334-2829
Fax: 86-24-2334-2393
Singapore
Tel: 65-6334-8870
Fax: 65-6334-8850
China - Shenzhen
Tel: 86-755-8203-2660
Fax: 86-755-8203-1760
Taiwan - Hsin Chu
Tel: 886-3-572-9526
Fax: 886-3-572-6459
Los Angeles
Mission Viejo, CA
Tel: 949-462-9523
Fax: 949-462-9608
China - Wuhan
Tel: 86-27-5980-5300
Fax: 86-27-5980-5118
Taiwan - Kaohsiung
Tel: 886-7-536-4818
Fax: 886-7-536-4803
Santa Clara
Santa Clara, CA
Tel: 408-961-6444
Fax: 408-961-6445
China - Xiamen
Tel: 86-592-2388138
Fax: 86-592-2388130
Taiwan - Taipei
Tel: 886-2-2500-6610
Fax: 886-2-2508-0102
Toronto
Mississauga, Ontario,
Canada
Tel: 905-673-0699
Fax: 905-673-6509
China - Xian
Tel: 86-29-8833-7252
Fax: 86-29-8833-7256
Thailand - Bangkok
Tel: 66-2-694-1351
Fax: 66-2-694-1350
China - Zhuhai
Tel: 86-756-3210040
Fax: 86-756-3210049
01/02/08
DS39646C-page 444
© 2008 Microchip Technology Inc.
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