PIC18LF8490T-I/PT [MICROCHIP]

64/80-Pin Flash Microcontrollers with LCD Driver and nanoWatt Technology; 八十〇分之六十四引脚闪存微控制器与LCD驱动器和纳瓦技术
PIC18LF8490T-I/PT
型号: PIC18LF8490T-I/PT
厂家: MICROCHIP    MICROCHIP
描述:

64/80-Pin Flash Microcontrollers with LCD Driver and nanoWatt Technology
八十〇分之六十四引脚闪存微控制器与LCD驱动器和纳瓦技术

驱动器 闪存 微控制器 CD
文件: 总414页 (文件大小:6891K)
中文:  中文翻译
下载:  下载PDF数据表文档文件
PIC18F6390/6490/8390/8490  
Data Sheet  
64/80-Pin Flash Microcontrollers  
with LCD Driver and nanoWatt Technology  
© 2007 Microchip Technology Inc.  
DS39629C  
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and may be superseded by updates.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  
FITNESS FOR PURPOSE. Microchip disclaims all liability  
arising from this information and its use. Use of Microchip  
devices in life support and/or safety applications is entirely at  
the buyer’s risk, and the buyer agrees to defend, indemnify and  
hold harmless Microchip from any and all damages, claims,  
suits, or expenses resulting from such use. No licenses are  
conveyed, implicitly or otherwise, under any Microchip  
intellectual property rights.  
Trademarks  
The Microchip name and logo, the Microchip logo, Accuron,  
dsPIC, KEELOQ, KEELOQ logo, microID, MPLAB, PIC,  
PICmicro, PICSTART, PRO MATE, rfPIC and SmartShunt are  
registered trademarks of Microchip Technology Incorporated  
in the U.S.A. and other countries.  
AmpLab, FilterLab, Linear Active Thermistor, Migratable  
Memory, 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, FlexROM, fuzzyLAB,  
In-Circuit Serial Programming, ICSP, ICEPIC, Mindi, MiWi,  
MPASM, MPLAB Certified logo, MPLIB, MPLINK, PICkit,  
PICDEM, PICDEM.net, PICLAB, PICtail, PowerCal,  
PowerInfo, PowerMate, PowerTool, REAL ICE, rfLAB, Select  
Mode, Smart Serial, SmartTel, Total Endurance, UNI/O,  
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.  
© 2007, 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.  
DS39629C-page ii  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
64/80-Pin Flash Microcontrollers with LCD Driver  
and nanoWatt Technology  
LCD Driver Module Features:  
Peripheral Highlights:  
• High-Current Sink/Source 25 mA/25 mA  
• Four External Interrupts  
• Four Input Change Interrupts  
• Four 8-Bit/16-Bit Timer/Counter modules  
• Real-Time Clock (RTC) Software module:  
- Configurable 24-hour clock, calendar, automatic  
100-year or 12800-year, day-of-week calculator  
- Uses Timer1  
• Direct Driving of LCD Panel  
• Up to 48 Segments: Software Selectable  
• Programmable LCD Timing module:  
- Multiple LCD timing sources available  
- Up to 4 commons: Static, 1/2, 1/3 or 1/4 multiplex  
- Static, 1/2 or 1/3 bias configuration  
• Can drive LCD Panel while in Sleep mode  
• Up to 2 Capture/Compare/PWM (CCP) modules  
• Master Synchronous Serial Port (MSSP) module  
supporting 3-Wire SPI (all 4 modes) and I2C™  
Master and Slave modes  
Power-Managed Modes:  
• Run: CPU On, Peripherals On  
• Idle: CPU Off, Peripherals On  
• Sleep: CPU Off, Peripherals Off  
• Run mode Currents Down to 14.0 μA Typical  
• Idle mode Currents Down to 5.8 μA Typical  
• Sleep Current Down to 0.1 μA Typical  
• Timer1 Oscillator: 1.8 μA, 32 kHz, 2V  
• Watchdog Timer: 2.1 μA  
• Addressable USART module:  
- Supports RS-485 and RS-232  
• Enhanced Addressable USART module:  
- Supports RS-485, RS-232 and LIN 1.2  
- Auto-wake-up on Start bit  
- Auto-Baud Detect  
• 10-Bit, up to 12-Channel Analog-to-Digital (A/D)  
Converter module:  
• Two-Speed Oscillator Start-up  
- Auto-acquisition capability  
Flexible Oscillator Structure:  
- Conversion available during Sleep  
• Dual Analog Comparators with Input Multiplexing  
• Four Crystal modes:  
- LP: up to 200 kHz  
- XT: up to 4 MHz  
- HS: up to 40 MHz  
Special Microcontroller Features:  
• C Compiler Optimized Architecture:  
- Optional extended instruction set designed to  
optimize re-entrant code  
• 1000 Erase/Write Cycle Flash Program Memory Typical  
• Flash Retention: 100 Years Typical  
• Priority Levels for Interrupts  
- HSPLL: 4-10 MHz (16-40 MHz internal)  
• 4x Phase Lock Loop (available for crystal and  
internal oscillators)  
• Two External RC modes, up to 4 MHz  
• Two External Clock modes, up to 40 MHz  
• Internal Oscillator Block:  
- 8 user-selectable frequencies, from 31 kHz to 8 MHz  
- 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:  
• 8 x 8 Single-Cycle Hardware Multiplier  
• Extended Watchdog Timer (WDT):  
- Programmable period from 4 ms to 132s  
- 2% stability over VDD and temperature  
• In-Circuit Serial Programming™ (ICSP™) via Two Pins  
• In-Circuit Debug (ICD) via Two Pins  
• Wide Operating Voltage Range: 2.0V to 5.5V  
- Allows for safe shut down of device if primary  
or secondary clock fails  
Data  
Memory  
Program Memory  
MSSP  
LCD  
10-Bit  
CCP  
Timers  
8/16-Bit  
Device  
I/O  
Comparators  
(pixel) A/D (ch) (PWM)  
Flash # Single-Word SRAM  
(bytes) Instructions (bytes)  
Master  
SPI  
2
I C™  
PIC18F6390  
8K  
4096  
8192  
4096  
8192  
768  
768  
768  
768  
50  
50  
66  
66  
128  
128  
192  
192  
12  
12  
12  
12  
2
2
2
2
Y
Y
Y
Y
Y
Y
Y
Y
1/1  
1/1  
1/1  
1/1  
2
2
2
2
1/3  
1/3  
1/3  
1/3  
PIC18F6490 16K  
PIC18F8390 8K  
PIC18F8490 16K  
© 2007 Microchip Technology Inc.  
DS39629C-page 1  
PIC18F6390/6490/8390/8490  
Pin Diagrams  
64-Pin TQFP  
64  
63 62 61 60 59 58 57 56 55 54 53 52 51  
50 49  
RB0/INT0  
LCDBIAS2  
LCDBIAS1  
48  
47  
46  
45  
44  
43  
42  
41  
40  
39  
38  
37  
36  
35  
34  
33  
1
RB1/INT1/SEG8  
RB2/INT2/SEG9  
RB3/INT3/SEG10  
RB4/KBI0/SEG11  
RB5/KBI1  
2
RG0/SEG30  
3
RG1/TX2/CK2/SEG29  
RG2/RX2/DT2/SEG28  
RG3/SEG27  
4
5
6
RB6/KBI2/PGC  
VSS  
MCLR/VPP/RG5  
RG4/SEG26  
7
PIC18F6390  
PIC18F6490  
8
VSS  
OSC2/CLKO/RA6  
OSC1/CLKI/RA7  
VDD  
9
VDD  
10  
11  
12  
13  
14  
15  
16  
RF7/SS/SEG25  
RF6/AN11/SEG24  
RF5/AN10/CVREF/SEG23  
RF4/AN9/SEG22  
RF3/AN8/SEG21  
RF2/AN7/C1OUT/SEG20  
RB7/KBI3/PGD  
RC5/SDO/SEG12  
RC4/SDI/SDA  
RC3/SCK/SCL  
RC2/CCP1/SEG13  
17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32  
Note 1: RE7 is the alternate pin for CCP2 multiplexing.  
DS39629C-page 2  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
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/SEG45  
1
RJ2/SEG34  
RJ3/SEG35  
RB0/INT0  
60  
59  
58  
57  
56  
55  
54  
53  
52  
51  
50  
49  
48  
47  
46  
45  
44  
43  
42  
41  
RH3/SEG44  
2
LCDBIAS2  
3
RB1/INT1/SEG8  
LCDBIAS1  
4
RG0/SEG30  
5
RB2/INT2/SEG9  
RB3/INT3/SEG10  
RB4/KBI0/SEG11  
RB5/KBI1  
RG1/TX2/CK2/SEG29  
6
RG2/RX2/DT2/SEG28  
7
RG3/SEG27  
8
RB6/KBI2/PGC  
VSS  
MCLR/VPP/RG5  
9
PIC18F8390  
PIC18F8490  
RG4/SEG26  
10  
VSS  
VDD  
OSC2/CLKO/RA6  
OSC1/CLKI/RA7  
VDD  
11  
12  
13  
14  
15  
16  
17  
18  
19  
20  
RF7/SS/SEG25  
RB7/KBI3/PGD  
RC5/SDO/SEG12  
RC4/SDI/SDA  
RC3/SCK/SCL  
RC2/CCP1/SEG13  
RJ7/SEG36  
RF6/AN11/SEG24  
RF5/AN10/CVREF/SEG23  
RF4/AN9/SEG22  
RF3/AN8/SEG21  
RF2/AN7/C1OUT/SEG20  
RH7/SEG43  
RJ6/SEG37  
RH6/SEG42  
40  
21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39  
Note 1: RE7 is the alternate pin for CCP2 multiplexing.  
© 2007 Microchip Technology Inc.  
DS39629C-page 3  
PIC18F6390/6490/8390/8490  
Table of Contents  
1.0 Device Overview .......................................................................................................................................................................... 7  
2.0 Oscillator Configurations ............................................................................................................................................................ 31  
3.0 Power-Managed Modes ............................................................................................................................................................. 41  
4.0 Reset.......................................................................................................................................................................................... 51  
5.0 Memory Organization................................................................................................................................................................. 65  
6.0 Flash Program Memory.............................................................................................................................................................. 87  
7.0 8 x 8 Hardware Multiplier............................................................................................................................................................ 91  
8.0 Interrupts .................................................................................................................................................................................... 93  
9.0 I/O Ports ................................................................................................................................................................................... 109  
10.0 Timer0 Module ......................................................................................................................................................................... 131  
11.0 Timer1 Module ......................................................................................................................................................................... 135  
12.0 Timer2 Module ......................................................................................................................................................................... 141  
13.0 Timer3 Module ......................................................................................................................................................................... 143  
14.0 Capture/Compare/PWM (CCP) Modules ................................................................................................................................. 147  
15.0 Master Synchronous Serial Port (MSSP) Module .................................................................................................................... 157  
16.0 Enhanced Universal Synchronous Asynchronous Receiver Transmitter (EUSART)............................................................... 197  
17.0 Addressable Universal Synchronous Asynchronous Receiver Transmitter (AUSART) ........................................................... 217  
18.0 10-Bit Analog-to-Digital Converter (A/D) Module ..................................................................................................................... 231  
19.0 Comparator Module.................................................................................................................................................................. 241  
20.0 Comparator Voltage Reference Module................................................................................................................................... 247  
21.0 High/Low-Voltage Detect (HLVD)............................................................................................................................................. 251  
22.0 Liquid Crystal Display (LCD) Driver Module............................................................................................................................. 257  
23.0 Special Features of the CPU.................................................................................................................................................... 281  
24.0 Instruction Set Summary.......................................................................................................................................................... 295  
25.0 Development Support............................................................................................................................................................... 345  
26.0 Electrical Characteristics .......................................................................................................................................................... 349  
27.0 DC and AC Characteristics Graphs and Tables....................................................................................................................... 387  
28.0 Packaging Information.............................................................................................................................................................. 389  
Appendix A: Revision History............................................................................................................................................................. 395  
Appendix B: Device Differences......................................................................................................................................................... 395  
Appendix C: Conversion Considerations ........................................................................................................................................... 396  
Appendix D: Migration from Baseline to Enhanced Devices.............................................................................................................. 396  
Appendix E: migration from Mid-Range to Enhanced Devices .......................................................................................................... 397  
Appendix F: Migration from High-End to Enhanced Devices............................................................................................................. 397  
Index .................................................................................................................................................................................................. 399  
The Microchip Web Site..................................................................................................................................................................... 409  
Customer Change Notification Service .............................................................................................................................................. 409  
Customer Support.............................................................................................................................................................................. 409  
Reader Response .............................................................................................................................................................................. 410  
PIC18F6390/6490/8390/8490 Product Identification System ............................................................................................................ 411  
DS39629C-page 4  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
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  
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If you have any questions or comments regarding this publication, please contact the Marketing Communications Department via  
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We welcome your feedback.  
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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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© 2007 Microchip Technology Inc.  
DS39629C-page 5  
PIC18F6390/6490/8390/8490  
NOTES:  
DS39629C-page 6  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
1.1.2  
MULTIPLE OSCILLATOR OPTIONS  
AND FEATURES  
1.0  
DEVICE OVERVIEW  
This document contains device-specific information for  
the following devices:  
All of the devices in the PIC18F6390/6490/8390/8490  
family offer ten different oscillator options, allowing  
users a wide range of choices in developing application  
hardware. These include:  
• PIC18F6390  
• PIC18F6490  
• PIC18F8390  
• PIC18F8490  
• Four Crystal modes using crystals or ceramic  
resonators.  
This family offers the advantages of all PIC18  
microcontrollers namely, high computational  
• 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).  
performance at an economical price. In addition to  
these features, the PIC18F6390/6490/8390/8490  
family introduces design enhancements that make  
these microcontrollers a logical choice for many  
high-performance, power-sensitive applications.  
• 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 (±2% accuracy) and an INTRC  
source (approximately 31 kHz, stable over  
temperature and VDD), as well as a range of six  
user-selectable clock frequencies between  
125 kHz to 4 MHz for a total of eight clock  
frequencies. This option frees the two oscillator  
pins for use as additional general purpose I/O.  
1.1  
New Core Features  
1.1.1  
nanoWatt TECHNOLOGY  
All of the devices in the PIC18F6390/6490/8390/8490  
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 reduced by as much as 90%.  
• A Phase Lock Loop (PLL) frequency multiplier,  
available to both the High-Speed Crystal and  
Internal 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.  
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 – to as little as 4% of normal  
operation requirements.  
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:  
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.  
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.  
Lower Consumption in Key Modules: The  
power requirements for both Timer1 and the  
Watchdog Timer have been reduced by up to  
80%, with typical values of 1.1 μA and 2.1 μA,  
respectively.  
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.  
© 2007 Microchip Technology Inc.  
DS39629C-page 7  
PIC18F6390/6490/8390/8490  
1.2  
Other Special Features  
1.3  
Details on Individual Family  
Members  
Memory Endurance: The Flash cells for program  
memory are rated to last for approximately a  
thousand erase/write cycles. Data retention  
without refresh is conservatively estimated to be  
greater than 100 years.  
Devices in the PIC18F6390/6490/8390/8490 family are  
available in 64-pin (PIC18F6X90) and 80-pin  
(PIC18F8X90) packages. Block diagrams for the two  
groups are shown in Figure 1-1 and Figure 1-2,  
respectively.  
Extended Instruction Set: The  
PIC18F6390/6490/8390/8490 family introduces  
an optional extension to the PIC18 instruction set,  
which adds 8 new instructions 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.  
The devices are differentiated from each other in three  
ways:  
1. I/O Ports: 7 bidirectional ports on 64-pin  
devices; 9 bidirectional ports on 80-pin devices.  
2. LCD Pixels: 128 (32 SEGs x 4 COMs) pixels can  
be driven by 64-pin devices; 192 (48 SEGs x  
4 COMs) pixels can be driven by 80-pin devices.  
3. Flash Program Memory:  
8
Kbytes for  
Enhanced Addressable USART: This serial  
communication module is capable of standard  
RS-232 operation and provides support for the LIN  
bus protocol. Other enhancements include  
Automatic Baud Rate Detection and a 16-bit Baud  
Rate Generator for improved resolution. When the  
microcontroller is using the internal oscillator  
block, the EUSART provides stable operation for  
applications that talk to the outside world, without  
using an external crystal (or its accompanying  
power requirement).  
PIC18FX390 devices; 16 Kbytes for PIC18FX490.  
All other features for devices in this family are identical.  
These are summarized in Table 1-1.  
The pinouts for all devices are listed in Table 1-2 and  
Table 1-3.  
Like all Microchip PIC18 devices, members of the  
PIC18F6390/6490/8390/8490 family are available as  
both standard and low-voltage devices. Standard  
devices with Flash memory, designated with an “F” in  
the part number (such as PIC18F6390), accommodate  
an operating VDD range of 4.2V to 5.5V. Low-voltage  
parts, designated by “LF” (such as PIC18LF6490),  
function over an extended VDD range of 2.0V to 5.5V.  
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, reduces code overhead.  
Extended Watchdog Timer (WDT): This  
enhanced version incorporates a 16-bit prescaler,  
allowing a time-out range from 4 ms to over  
10 minutes that is stable across operating voltage  
and temperature.  
DS39629C-page 8  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
TABLE 1-1:  
DEVICE FEATURES  
Features  
PIC18F6390  
PIC18F6490  
PIC18F8390  
PIC18F8490  
Operating Frequency  
Program Memory (Bytes)  
Program Memory (Instructions)  
Data Memory (Bytes)  
Interrupt Sources  
DC – 40 MHz  
DC – 40 MHz  
DC – 40 MHz  
DC – 40 MHz  
8K  
4096  
768  
22  
16K  
8192  
768  
22  
8K  
4096  
768  
22  
16K  
8192  
768  
22  
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, H, J  
F, G, H, J  
Number of Pixels the LCD Driver  
can Drive  
128 (32 SEGs x  
4 COMs)  
128 (32 SEGs x  
4 COMs)  
192 (48 SEGs x  
4 COMs)  
192 (48 SEGs x  
4 COMs)  
Timers  
4
4
4
4
Capture/Compare/PWM Modules  
Serial Communications  
2
2
2
2
MSSP, AUSART  
MSSP, AUSART  
MSSP, AUSART  
MSSP, AUSART  
Enhanced USART Enhanced USART Enhanced USART Enhanced USART  
10-Bit Analog-to-Digital Module  
Resets (and Delays)  
12 Input Channels 12 Input Channels 12 Input Channels 12 Input Channels  
POR, BOR,  
POR, BOR,  
POR, BOR,  
POR, BOR,  
RESETInstruction, RESETInstruction, RESETInstruction, RESETInstruction,  
Stack Full,  
Stack Underflow  
(PWRT, OST),  
Stack Full,  
Stack Underflow  
(PWRT, OST),  
Stack Full,  
Stack Underflow  
(PWRT, OST),  
Stack Full,  
Stack Underflow  
(PWRT, OST),  
MCLR (optional), MCLR (optional), MCLR (optional), MCLR (optional),  
WDT  
WDT  
WDT  
WDT  
Programmable Low-Voltage Detect  
Programmable Brown-out Reset  
Instruction Set  
Yes  
Yes  
Yes  
Yes  
Yes  
Yes  
Yes  
Yes  
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  
80-Pin TQFP  
80-Pin TQFP  
© 2007 Microchip Technology Inc.  
DS39629C-page 9  
PIC18F6390/6490/8390/8490  
FIGURE 1-1:  
PIC18F6X90 (64-PIN) BLOCK DIAGRAM  
Data Bus<8>  
PORTA  
Table Pointer<21>  
RA0/AN0  
RA1/AN1  
Data Latch  
RA2/AN2/VREF-/SEG16  
RA3/AN3/VREF+/SEG17  
RA4/T0CKI/SEG14  
RA5/AN4/HLVDIN/SEG15  
OSC2/CLKO(3)/RA6  
OSC1/CLKI(3)/RA7  
8
8
inc/dec logic  
21  
Data Memory  
(3.9 Kbytes)  
PCLATH  
PCLATU  
Address Latch  
20  
PCU PCH PCL  
Program Counter  
12  
PORTB  
RB0/INT0  
Data Address<12>  
RB1/INT1/SEG8  
RB2/INT2/SEG9  
RB3/INT3/SEG10  
RB4/KBI0/SEG11  
RB5/KBI1  
31 Level Stack  
STKPTR  
4
BSR  
12  
FSR0  
FSR1  
FSR2  
4
Address Latch  
Access  
Bank  
Program Memory  
(48/64 Kbytes)  
RB6/KBI2/PGC  
RB7/KBI3/PGD  
12  
Data Latch  
inc/dec  
logic  
PORTC  
8
RC0/T1OSO/T13CKI  
RC1/T1OSI/CCP2(1)  
RC2/CCP1/SEG13  
RC3/SCK/SCL  
RC4/SDI/SDA  
RC5/SDO/SEG12  
RC6/TX1/CK1  
Table Latch  
Address  
Decode  
ROM Latch  
IR  
Instruction Bus <16>  
RC7/RX1/DT1  
8
PORTD  
PORTE  
State Machine  
Control Signals  
Instruction  
Decode and  
Control  
RD7/SEG7:RD0/SEG0  
PRODH PRODL  
8 x 8 Multiply  
3
8
LCDBIAS1  
LCDBIAS2  
LCDBIAS3  
BITOP  
8
W
8
8
COM0  
Internal  
Oscillator  
Block  
OSC1(3)  
OSC2(3)  
T1OSI  
Power-up  
Timer  
RE4/COM1  
RE5/COM2  
RE6/COM3  
RE7/CCP2(1)/SEG31  
8
8
Oscillator  
Start-up Timer  
ALU<8>  
8
INTRC  
Oscillator  
Power-on  
Reset  
PORTF  
8 MHz  
Oscillator  
RF0/AN5/SEG18  
RF1/AN6/C2OUT/SEG19  
RF2/AN7/C1OUT/SEG20  
RF3/AN8/SEG21  
RF4/AN9/SEG22  
RF5/AN10/CVREF/SEG23  
RF6/AN11/SEG24  
RF7/SS/SEG25  
Watchdog  
Timer  
T1OSO  
Precision  
Band Gap  
Reference  
Brown-out  
Reset  
Fail-Safe  
MCLR(2)  
VDD, VSS  
Single-Supply  
Programming  
In-Circuit  
Clock Monitor  
Debugger  
PORTG  
ADC  
10-Bit  
BOR  
RG0/SEG30  
RG1/TX2/CK2/SEG29  
Timer0  
Timer1  
Timer2  
Timer3  
HLVD  
RG2/RX2/DT2/SEG28  
RG3/SEG27  
RG4/SEG26  
MCLR/VPP/RG5(2)  
LCD  
Driver  
MSSP  
Comparators  
CCP1  
CCP2  
EUSART1  
AUSART2  
Note 1: CCP2 is multiplexed with RC1 when Configuration bit, CCP2MX, is set, or RE7 when CCP2MX is not set.  
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.  
DS39629C-page 10  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
FIGURE 1-2:  
PIC18F8X90 (80-PIN) BLOCK DIAGRAM  
PORTA  
Data Bus<8>  
RA0/AN0  
Table Pointer<21>  
RA1/AN1  
RA2/AN2/VREF-/SEG16  
RA3/AN3/VREF+/SEG17  
RA4/T0CKI/SEG14  
RA5/AN4/HLVDIN/SEG15  
OSC2/CLKO(3)/RA6  
OSC1/CLKI(3)/RA7  
Data Latch  
8
8
inc/dec logic  
21  
Data Memory  
(3.9 Kbytes)  
PCLATH  
PCLATU  
Address Latch  
20  
PCU PCH PCL  
Program Counter  
PORTB  
RB0/INT0  
12  
RB1/INT1/SEG8  
RB2/INT2/SEG9  
RB3/INT3/SEG10  
RB4/KBI0/SEG11  
RB5/KBI1  
Data Address<12>  
31 Level Stack  
STKPTR  
4
BSR  
12  
FSR0  
FSR1  
FSR2  
4
Address Latch  
Access  
Bank  
Program Memory  
(48/64 Kbytes)  
RB6/KBI2/PGC  
RB7/KBI3/PGD  
12  
Data Latch  
PORTC  
RC0/T1OSO/T13CKI  
RC1/T1OSI/CCP2(1)  
RC2/CCP1/SEG13  
RC3/SCK/SCL  
RC4/SDI/SDA  
inc/dec  
logic  
8
Table Latch  
Address  
Decode  
RC5/SDO/SEG12  
RC6/TX1/CK1  
RC7/RX1/DT1  
ROM Latch  
IR  
Instruction Bus <16>  
PORTD  
PORTE  
8
RD7/SEG7:RD0/SEG0  
State Machine  
Control Signals  
Instruction  
Decode and  
Control  
PRODH PRODL  
8 x 8 Multiply  
LCDBIAS1  
LCDBIAS2  
LCDBIAS3  
3
8
COM0  
RE4/COM1  
RE5/COM2  
RE6/COM3  
RE7/CCP2(1)/SEG31  
W
BITOP  
8
8
8
Internal  
Oscillator  
Block  
OSC1(3)  
OSC2(3)  
T1OSI  
Power-up  
Timer  
8
8
PORTF  
RF0/AN5/SEG18  
RF1/AN6/C2OUT/SEG19  
RF2/AN7/C1OUT/SEG20  
RF3/AN8/SEG21  
RF4/AN9/SEG22  
RF5/AN10/CVREF/SEG23  
RF6/AN11/SEG24  
RF7/SS/SEG25  
Oscillator  
Start-up Timer  
ALU<8>  
INTRC  
Oscillator  
Power-on  
Reset  
8
8 MHz  
Oscillator  
Watchdog  
Timer  
T1OSO  
Precision  
Band Gap  
Reference  
Brown-out  
Reset  
Fail-Safe  
MCLR(2)  
VDD, VSS  
Single-Supply  
Programming  
In-Circuit  
PORTG  
RG0/SEG30  
RG1/TX2/CK2/SEG29  
Clock Monitor  
Debugger  
RG2/RX2/DT2/SEG28  
RG3/SEG27  
RG4/SEG26  
MCLR/VPP/RG5(2)  
PORTH  
PORTJ  
ADC  
10-Bit  
BOR  
Timer0  
Timer1  
Timer2  
Timer3  
RH3/SEG47:RH0/SEG44  
RH7/SEG40:RH4/SEG43  
HLVD  
RJ3/SEG35:RJ0/SEG32  
RJ7/SEG36:RJ4/SEG39  
LCD  
Driver  
CCP2  
MSSP  
Comparators  
CCP1  
EUSART1  
AUSART2  
Note 1: CCP2 is multiplexed with RC1 when Configuration bit, CCP2MX, is set and RE7 when CCP2MX is not set.  
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.  
© 2007 Microchip Technology Inc.  
DS39629C-page 11  
PIC18F6390/6490/8390/8490  
TABLE 1-2:  
PIC18F6X90 PINOUT I/O DESCRIPTIONS  
Pin Number  
Pin Buffer  
Pin Name  
Description  
Type Type  
TQFP  
MCLR/VPP/RG5  
MCLR  
7
Master Clear (input) or programming voltage (input).  
Master Clear (Reset) input. This pin is an active-low  
Reset to the device.  
I
ST  
VPP  
RG5  
P
I
Programming voltage input.  
Digital input.  
ST  
ST  
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.  
I
I
CLKI  
CMOS  
TTL  
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  
ST = Schmitt Trigger input with CMOS levels  
CMOS = CMOS compatible input or output  
Analog = Analog input  
I
= Input  
O
= Output  
P
= Power  
OD  
= Open-Drain (no P diode to VDD)  
Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set.  
2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.  
DS39629C-page 12  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
TABLE 1-2:  
PIC18F6X90 PINOUT I/O DESCRIPTIONS (CONTINUED)  
Pin Number  
TQFP  
Pin Buffer  
Type Type  
Pin Name  
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-/SEG16  
RA2  
I/O  
TTL  
Digital I/O.  
AN2  
VREF-  
SEG16  
I
I
O
Analog  
Analog  
Analog  
Analog input 2.  
A/D reference voltage (Low) input.  
SEG16 output for LCD.  
RA3/AN3/VREF+/SEG17  
21  
RA3  
I/O  
TTL  
Digital I/O.  
AN3  
VREF+  
SEG17  
I
I
O
Analog  
Analog  
Analog  
Analog input 3.  
A/D reference voltage (High) input.  
SEG17 output for LCD.  
RA4/T0CKI/SEG14  
RA4  
28  
27  
I/O ST/OD  
Digital I/O. Open-drain when configured as output.  
Timer0 external clock input.  
SEG14 output for LCD.  
T0CKI  
SEG14  
I
ST  
O
Analog  
RA5/AN4/HLVDIN/SEG15  
RA5  
I/O  
TTL  
Digital I/O.  
AN4  
HLVDIN  
SEG15  
I
I
O
Analog  
Analog  
Analog  
Analog input 4.  
Low-Voltage Detect input.  
SEG15 output for LCD.  
RA6  
RA7  
See the OSC2/CLKO/RA6 pin.  
See the OSC1/CLKI/RA7 pin.  
Legend: TTL = TTL compatible input  
ST = Schmitt Trigger input with CMOS levels  
CMOS = CMOS compatible input or output  
Analog = Analog input  
I
= Input  
O
= Output  
P
= Power  
OD  
= Open-Drain (no P diode to VDD)  
Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set.  
2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.  
© 2007 Microchip Technology Inc.  
DS39629C-page 13  
PIC18F6390/6490/8390/8490  
TABLE 1-2:  
PIC18F6X90 PINOUT I/O DESCRIPTIONS (CONTINUED)  
Pin Number  
Pin Buffer  
Pin Name  
Description  
Type Type  
TQFP  
PORTB is a bidirectional I/O port. PORTB can be software  
programmed for internal weak pull-ups on all inputs.  
RB0/INT0  
RB0  
48  
47  
I/O  
I
TTL  
ST  
Digital I/O.  
External interrupt 0.  
INT0  
RB1/INT1/SEG8  
RB1  
I/O  
I
O
TTL  
ST  
Analog  
Digital I/O.  
External interrupt 1.  
SEG8 output for LCD.  
INT1  
SEG8  
RB2/INT2/SEG9  
RB2  
46  
45  
44  
I/O  
I
O
TTL  
ST  
Analog  
Digital I/O.  
External interrupt 2.  
SEG9 output for LCD.  
INT2  
SEG9  
RB3/INT3/SEG10  
RB3  
I/O  
I
O
TTL  
ST  
Analog  
Digital I/O.  
External interrupt 3.  
SEG10 output for LCD.  
INT3  
SEG10  
RB4/KBI0/SEG11  
RB4  
I/O  
I
O
TTL  
TTL  
Analog  
Digital I/O.  
Interrupt-on-change pin.  
SEG11 output for LCD.  
KBI0  
SEG11  
RB5/KBI1  
RB5  
43  
42  
I/O  
I
TTL  
TTL  
Digital I/O.  
Interrupt-on-change pin.  
KBI1  
RB6/KBI2/PGC  
RB6  
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  
37  
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  
ST = Schmitt Trigger input with CMOS levels  
CMOS = CMOS compatible input or output  
Analog = Analog input  
I
= Input  
O
= Output  
P
= Power  
OD  
= Open-Drain (no P diode to VDD)  
Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set.  
2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.  
DS39629C-page 14  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
TABLE 1-2:  
PIC18F6X90 PINOUT I/O DESCRIPTIONS (CONTINUED)  
Pin Number  
TQFP  
Pin Buffer  
Type Type  
Pin Name  
Description  
PORTC is a bidirectional I/O port.  
RC0/T1OSO/T13CKI  
RC0  
30  
29  
33  
34  
35  
36  
31  
32  
I/O  
O
I
ST  
ST  
Digital I/O.  
Timer1 oscillator output.  
Timer1/Timer3 external clock input.  
T1OSO  
T13CKI  
RC1/T1OSI/CCP2  
RC1  
I/O  
I
I/O  
ST  
CMOS  
ST  
Digital I/O.  
Timer1 oscillator input.  
Capture 2 input/Compare 2 output/PWM2 output.  
T1OSI  
CCP2(1)  
RC2/CCP1/SEG13  
RC2  
I/O  
I/O  
O
ST  
ST  
Analog  
Digital I/O.  
CCP1  
SEG13  
Capture 1 input/Compare 1 output/PWM1 output.  
SEG13 output for LCD.  
RC3/SCK/SCL  
RC3  
I/O  
I/O  
I/O  
ST  
ST  
ST  
Digital I/O.  
SCK  
SCL  
Synchronous serial clock input/output for SPI mode.  
Synchronous serial clock input/output for I2C™ mode.  
RC4/SDI/SDA  
RC4  
I/O  
I
I/O  
ST  
ST  
ST  
Digital I/O.  
SDI  
SDA  
SPI data in.  
I2C data I/O.  
RC5/SDO/SEG12  
RC5  
I/O  
O
O
ST  
Analog  
Digital I/O.  
SPI data out.  
SEG12 output for LCD.  
SDO  
SEG12  
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  
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  
ST = Schmitt Trigger input with CMOS levels  
CMOS = CMOS compatible input or output  
Analog = Analog input  
I
= Input  
O
= Output  
P
= Power  
OD  
= Open-Drain (no P diode to VDD)  
Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set.  
2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.  
© 2007 Microchip Technology Inc.  
DS39629C-page 15  
PIC18F6390/6490/8390/8490  
TABLE 1-2:  
PIC18F6X90 PINOUT I/O DESCRIPTIONS (CONTINUED)  
Pin Number  
Pin Buffer  
Pin Name  
Description  
Type Type  
TQFP  
PORTD is a bidirectional I/O port.  
RD0/SEG0  
RD0  
58  
I/O  
O
ST  
Analog  
Digital I/O.  
SEG0 output for LCD.  
SEG0  
RD1/SEG1  
RD1  
55  
54  
53  
52  
51  
50  
49  
I/O  
O
ST  
Analog  
Digital I/O.  
SEG1 output for LCD.  
SEG1  
RD2/SEG2  
RD2  
I/O  
O
ST  
Analog  
Digital I/O.  
SEG2 output for LCD.  
SEG2  
RD3/SEG3  
RD3  
I/O  
O
ST  
Analog  
Digital I/O.  
SEG3 output for LCD.  
SEG3  
RD4/SEG4  
RD4  
I/O  
O
ST  
Analog  
Digital I/O.  
SEG4 output for LCD.  
SEG4  
RD5/SEG5  
RD5  
I/O  
O
ST  
Analog  
Digital I/O.  
SEG5 output for LCD.  
SEG5  
RD6/SEG6  
RD6  
I/O  
O
ST  
Analog  
Digital I/O.  
SEG6 output for LCD.  
SEG6  
RD7/SEG7  
RD7  
I/O  
O
ST  
Analog  
Digital I/O.  
SEG7 output for LCD.  
SEG7  
Legend: TTL = TTL compatible input  
ST = Schmitt Trigger input with CMOS levels  
CMOS = CMOS compatible input or output  
Analog = Analog input  
I
= Input  
O
= Output  
P
= Power  
OD  
= Open-Drain (no P diode to VDD)  
Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set.  
2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.  
DS39629C-page 16  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
TABLE 1-2:  
PIC18F6X90 PINOUT I/O DESCRIPTIONS (CONTINUED)  
Pin Number  
TQFP  
Pin Buffer  
Type Type  
Pin Name  
Description  
PORTE is a bidirectional I/O port.  
LCDBIAS1  
LCDBIAS1  
2
I
I
Analog  
Analog  
Analog  
Analog  
BIAS1 input for LCD.  
BIAS2 input for LCD.  
BIAS3 input for LCD.  
COM0 output for LCD.  
LCDBIAS2  
LCDBIAS2  
1
LCDBIAS3  
LCDBIAS3  
64  
63  
62  
I
COM0  
COM0  
O
RE4/COM1  
RE4  
I/O  
O
ST  
Analog  
Digital I/O.  
COM1 output for LCD.  
COM1  
RE5/COM2  
RE5  
61  
60  
59  
I/O  
O
ST  
Analog  
Digital I/O.  
COM2 output for LCD.  
COM2  
RE6/COM3  
RE6  
I/O  
O
ST  
Analog  
Digital I/O.  
COM3 output for LCD.  
COM3  
RE7/CCP2/SEG31  
RE7  
I/O  
I/O  
O
ST  
ST  
Analog  
Digital I/O.  
CCP2(2)  
Capture 2 input/Compare 2 output/PWM2 output.  
SEG31 output for LCD.  
SEG31  
Legend: TTL = TTL compatible input  
ST = Schmitt Trigger input with CMOS levels  
CMOS = CMOS compatible input or output  
Analog = Analog input  
I
= Input  
O
= Output  
P
= Power  
OD  
= Open-Drain (no P diode to VDD)  
Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set.  
2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.  
© 2007 Microchip Technology Inc.  
DS39629C-page 17  
PIC18F6390/6490/8390/8490  
TABLE 1-2:  
PIC18F6X90 PINOUT I/O DESCRIPTIONS (CONTINUED)  
Pin Number  
Pin Buffer  
Pin Name  
Description  
Type Type  
TQFP  
PORTF is a bidirectional I/O port.  
RF0/AN5/SEG18  
RF0  
18  
I/O  
I
O
ST  
Analog  
Analog  
Digital I/O.  
Analog input 5.  
SEG18 output for LCD.  
AN5  
SEG18  
RF1/AN6/C2OUT/SEG19  
17  
16  
RF1  
AN6  
C2OUT  
SEG19  
I/O  
I
O
O
ST  
Analog  
Digital I/O.  
Analog input 6.  
Comparator 2 output.  
SEG19 output for LCD.  
Analog  
RF2/AN7/C1OUT/SEG20  
RF2  
AN7  
C1OUT  
SEG20  
I/O  
I
O
O
ST  
Analog  
Digital I/O.  
Analog input 7.  
Comparator 1 output.  
SEG20 output for LCD.  
Analog  
RF3/AN8/SEG21  
RF3  
15  
14  
13  
I/O  
I
O
ST  
Analog  
Analog  
Digital I/O.  
Analog input 8.  
SEG21 output for LCD.  
AN8  
SEG21  
RF4/AN9/SEG22  
RF4  
I/O  
I
O
ST  
Analog  
Analog  
Digital I/O.  
Analog input 9.  
SEG22 output for LCD.  
AN9  
SEG22  
RF5/AN10/CVREF/SEG23  
RF5  
I/O  
I
O
O
ST  
Digital I/O.  
Analog input 10.  
Comparator reference voltage output.  
SEG23 output for LCD.  
AN10  
CVREF  
SEG23  
Analog  
Analog  
Analog  
RF6/AN11/SEG24  
RF6  
12  
11  
I/O  
I
O
ST  
Analog  
Analog  
Digital I/O.  
Analog input 11.  
SEG24 output for LCD.  
AN11  
SEG24  
RF7/SS/SEG25  
RF7  
SS  
SEG25  
I/O  
I
O
ST  
TTL  
Analog  
Digital I/O.  
SPI slave select input.  
SEG25 output for LCD.  
Legend: TTL = TTL compatible input  
ST = Schmitt Trigger input with CMOS levels  
CMOS = CMOS compatible input or output  
Analog = Analog input  
I
= Input  
O
= Output  
P
= Power  
OD  
= Open-Drain (no P diode to VDD)  
Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set.  
2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.  
DS39629C-page 18  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
TABLE 1-2:  
PIC18F6X90 PINOUT I/O DESCRIPTIONS (CONTINUED)  
Pin Number  
TQFP  
Pin Buffer  
Type Type  
Pin Name  
Description  
PORTG is a bidirectional I/O port.  
RG0/SEG30  
RG0  
3
4
I/O  
O
ST  
Analog  
Digital I/O.  
SEG30 output for LCD.  
SEG30  
RG1/TX2/CK2/SEG29  
RG1  
TX2  
CK2  
I/O  
O
I/O  
O
ST  
ST  
Digital I/O.  
AUSART2 asynchronous transmit.  
AUSART2 synchronous clock (see related RX2/DT2).  
SEG29 output for LCD.  
SEG29  
Analog  
RG2/RX2/DT2/SEG28  
5
RG2  
RX2  
DT2  
SEG28  
I/O  
I
I/O  
O
ST  
ST  
ST  
Digital I/O.  
AUSART2 asynchronous receive.  
AUSART2 synchronous data (see related TX2/CK2).  
SEG28 output for LCD.  
Analog  
RG3/SEG27  
RG3  
6
8
I/O  
O
ST  
Analog  
Digital I/O.  
SEG27 output for LCD.  
SEG27  
RG4/SEG26  
RG4  
I/O  
O
ST  
Analog  
Digital I/O.  
SEG26 output for LCD.  
SEG26  
RG5  
VSS  
See MCLR/VPP/RG5 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.  
VDD  
10, 26, 38, 57  
AVSS  
AVDD  
20  
19  
Legend: TTL = TTL compatible input  
ST = Schmitt Trigger input with CMOS levels  
CMOS = CMOS compatible input or output  
Analog = Analog input  
I
= Input  
O
= Output  
P
= Power  
OD  
= Open-Drain (no P diode to VDD)  
Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set.  
2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.  
© 2007 Microchip Technology Inc.  
DS39629C-page 19  
PIC18F6390/6490/8390/8490  
TABLE 1-3:  
PIC18F8X90 PINOUT I/O DESCRIPTIONS  
Pin Number  
Pin Buffer  
Pin Name  
Description  
Type Type  
TQFP  
MCLR/VPP/RG5  
MCLR  
9
Master Clear (input) or programming voltage (input).  
Master Clear (Reset) input. This pin is an active-low  
Reset to the device.  
I
ST  
VPP  
RG5  
P
I
Programming voltage input.  
Digital input.  
ST  
ST  
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.  
I
I
CLKI  
CMOS  
TTL  
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  
ST = Schmitt Trigger input with CMOS levels  
CMOS = CMOS compatible input or output  
Analog = Analog input  
I
= Input  
O
= Output  
P
= Power  
OD  
= Open-Drain (no P diode to VDD)  
Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set.  
2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.  
DS39629C-page 20  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
TABLE 1-3:  
PIC18F8X90 PINOUT I/O DESCRIPTIONS (CONTINUED)  
Pin Number  
TQFP  
Pin Buffer  
Type Type  
Pin Name  
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-/SEG16  
RA2  
I/O  
TTL  
Digital I/O.  
AN2  
VREF-  
SEG16  
I
I
O
Analog  
Analog  
Analog  
Analog input 2.  
A/D reference voltage (Low) input.  
SEG16 output for LCD.  
RA3/AN3/VREF+/SEG17  
27  
RA3  
I/O  
TTL  
Digital I/O.  
AN3  
VREF+  
SEG17  
I
I
O
Analog  
Analog  
Analog  
Analog input 3.  
A/D reference voltage (High) input.  
SEG17 output for LCD.  
RA4/T0CKI/SEG14  
RA4  
34  
33  
I/O ST/OD  
Digital I/O. Open-drain when configured as output.  
Timer0 external clock input.  
SEG14 output for LCD.  
T0CKI  
SEG14  
I
ST  
O
Analog  
RA5/AN4/HLVDIN/SEG15  
RA5  
I/O  
TTL  
Digital I/O.  
AN4  
HLVDIN  
SEG15  
I
I
O
Analog  
Analog  
Analog  
Analog input 4.  
Low-Voltage Detect input.  
SEG15 output for LCD.  
RA6  
RA7  
See the OSC2/CLKO/RA6 pin.  
See the OSC1/CLKI/RA7 pin.  
Legend: TTL = TTL compatible input  
ST = Schmitt Trigger input with CMOS levels  
CMOS = CMOS compatible input or output  
Analog = Analog input  
I
= Input  
O
= Output  
P
= Power  
OD  
= Open-Drain (no P diode to VDD)  
Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set.  
2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.  
© 2007 Microchip Technology Inc.  
DS39629C-page 21  
PIC18F6390/6490/8390/8490  
TABLE 1-3:  
PIC18F8X90 PINOUT I/O DESCRIPTIONS (CONTINUED)  
Pin Number  
Pin Buffer  
Pin Name  
Description  
Type Type  
TQFP  
PORTB is a bidirectional I/O port. PORTB can be software  
programmed for internal weak pull-ups on all inputs.  
RB0/INT0  
RB0  
58  
57  
I/O  
I
TTL  
ST  
Digital I/O.  
External interrupt 0.  
INT0  
RB1/INT1/SEG8  
RB1  
I/O  
I
O
TTL  
ST  
Analog  
Digital I/O.  
External interrupt 1.  
SEG8 output for LCD.  
INT1  
SEG8  
RB2/INT2/SEG9  
RB2  
56  
55  
54  
I/O  
I
O
TTL  
ST  
Analog  
Digital I/O.  
External interrupt 2.  
SEG9 output for LCD.  
INT2  
SEG9  
RB3/INT3/SEG10  
RB3  
I/O  
I
O
TTL  
ST  
Analog  
Digital I/O.  
External interrupt 3.  
SEG10 output for LCD.  
INT3  
SEG10  
RB4/KBI0/SEG11  
RB4  
I/O  
I
O
TTL  
TTL  
Analog  
Digital I/O.  
Interrupt-on-change pin.  
SEG11 output for LCD.  
KBI0  
SEG11  
RB5/KBI1  
RB5  
53  
52  
I/O  
I
TTL  
TTL  
Digital I/O.  
Interrupt-on-change pin.  
KBI1  
RB6/KBI2/PGC  
RB6  
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  
47  
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  
ST = Schmitt Trigger input with CMOS levels  
CMOS = CMOS compatible input or output  
Analog = Analog input  
I
= Input  
O
= Output  
P
= Power  
OD  
= Open-Drain (no P diode to VDD)  
Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set.  
2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.  
DS39629C-page 22  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
TABLE 1-3:  
PIC18F8X90 PINOUT I/O DESCRIPTIONS (CONTINUED)  
Pin Number  
TQFP  
Pin Buffer  
Type Type  
Pin Name  
Description  
PORTC is a bidirectional I/O port.  
RC0/T1OSO/T13CKI  
RC0  
36  
35  
43  
44  
45  
46  
37  
38  
I/O  
O
I
ST  
ST  
Digital I/O.  
Timer1 oscillator output.  
Timer1/Timer3 external clock input.  
T1OSO  
T13CKI  
RC1/T1OSI/CCP2  
RC1  
I/O  
I
I/O  
ST  
CMOS  
ST  
Digital I/O.  
Timer1 oscillator input.  
Capture 2 input/Compare 2 output/PWM2 output.  
T1OSI  
CCP2(1)  
RC2/CCP1/SEG13  
RC2  
I/O  
I/O  
O
ST  
ST  
Analog  
Digital I/O.  
CCP1  
SEG13  
Capture 1 input/Compare 1 output/PWM1 output.  
SEG13 output for LCD.  
RC3/SCK/SCL  
RC3  
I/O  
I/O  
I/O  
ST  
ST  
ST  
Digital I/O.  
SCK  
SCL  
Synchronous serial clock input/output for SPI mode.  
Synchronous serial clock input/output for I2C™ mode.  
RC4/SDI/SDA  
RC4  
I/O  
I
I/O  
ST  
ST  
ST  
Digital I/O.  
SDI  
SDA  
SPI data in.  
I2C data I/O.  
RC5/SDO/SEG12  
RC5  
I/O  
O
O
ST  
Analog  
Digital I/O.  
SPI data out.  
SEG12 output for LCD.  
SDO  
SEG12  
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  
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  
ST = Schmitt Trigger input with CMOS levels  
CMOS = CMOS compatible input or output  
Analog = Analog input  
I
= Input  
O
= Output  
P
= Power  
OD  
= Open-Drain (no P diode to VDD)  
Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set.  
2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.  
© 2007 Microchip Technology Inc.  
DS39629C-page 23  
PIC18F6390/6490/8390/8490  
TABLE 1-3:  
PIC18F8X90 PINOUT I/O DESCRIPTIONS (CONTINUED)  
Pin Number  
Pin Buffer  
Pin Name  
Description  
Type Type  
TQFP  
PORTD is a bidirectional I/O port.  
RD0/SEG0  
RD0  
72  
I/O  
O
ST  
Analog  
Digital I/O.  
SEG0 output for LCD.  
SEG0  
RD1/SEG1  
RD1  
69  
68  
67  
66  
65  
64  
63  
I/O  
O
ST  
Analog  
Digital I/O.  
SEG1 output for LCD.  
SEG1  
RD2/SEG2  
RD2  
I/O  
O
ST  
Analog  
Digital I/O.  
SEG2 output for LCD.  
SEG2  
RD3/SEG3  
RD3  
I/O  
O
ST  
Analog  
Digital I/O.  
SEG3 output for LCD.  
SEG3  
RD4/SEG4  
RD4  
I/O  
O
ST  
Analog  
Digital I/O.  
SEG4 output for LCD.  
SEG4  
RD5/SEG5  
RD5  
I/O  
O
ST  
Analog  
Digital I/O.  
SEG5 output for LCD.  
SEG5  
RD6/SEG6  
RD6  
I/O  
O
ST  
Analog  
Digital I/O.  
SEG6 output for LCD.  
SEG6  
RD7/SEG7  
RD7  
I/O  
O
ST  
Analog  
Digital I/O.  
SEG7 output for LCD.  
SEG7  
Legend: TTL = TTL compatible input  
ST = Schmitt Trigger input with CMOS levels  
CMOS = CMOS compatible input or output  
Analog = Analog input  
I
= Input  
O
= Output  
P
= Power  
OD  
= Open-Drain (no P diode to VDD)  
Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set.  
2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.  
DS39629C-page 24  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
TABLE 1-3:  
PIC18F8X90 PINOUT I/O DESCRIPTIONS (CONTINUED)  
Pin Number  
TQFP  
Pin Buffer  
Type Type  
Pin Name  
Description  
PORTE is a bidirectional I/O port.  
LCDBIAS1  
LCDBIAS1  
4
I
I
Analog  
Analog  
Analog  
Analog  
BIAS1 input for LCD.  
BIAS2 input for LCD.  
BIAS3 input for LCD.  
COM0 output for LCD.  
LCDBIAS2  
LCDBIAS2  
3
LCDBIAS3  
LCDBIAS3  
78  
77  
76  
I
COM0  
COM0  
O
RE4/COM1  
RE4  
I/O  
O
ST  
Analog  
Digital I/O.  
COM1 output for LCD.  
COM1  
RE5/COM2  
RE5  
75  
74  
73  
I/O  
O
ST  
Analog  
Digital I/O.  
COM2 output for LCD.  
COM2  
RE6/COM3  
RE6  
I/O  
O
ST  
Analog  
Digital I/O.  
COM3 output for LCD.  
COM3  
RE7/CCP2/SEG31  
RE7  
I/O  
I/O  
O
ST  
ST  
Analog  
Digital I/O.  
CCP2(2)  
Capture 2 input/Compare 2 output/PWM2 output.  
SEG31 output for LCD.  
SEG31  
Legend: TTL = TTL compatible input  
ST = Schmitt Trigger input with CMOS levels  
CMOS = CMOS compatible input or output  
Analog = Analog input  
I
= Input  
O
= Output  
P
= Power  
OD  
= Open-Drain (no P diode to VDD)  
Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set.  
2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.  
© 2007 Microchip Technology Inc.  
DS39629C-page 25  
PIC18F6390/6490/8390/8490  
TABLE 1-3:  
PIC18F8X90 PINOUT I/O DESCRIPTIONS (CONTINUED)  
Pin Number  
Pin Buffer  
Pin Name  
Description  
Type Type  
TQFP  
PORTF is a bidirectional I/O port.  
RF0/AN5/SEG18  
RF0  
24  
I/O  
I
O
ST  
Analog  
Analog  
Digital I/O.  
Analog input 5.  
SEG18 output for LCD.  
AN5  
SEG18  
RF1/AN6/C2OUT/SEG19  
23  
18  
RF1  
AN6  
C2OUT  
SEG19  
I/O  
I
O
O
ST  
Analog  
Digital I/O.  
Analog input 6.  
Comparator 2 output.  
SEG19 output for LCD.  
Analog  
RF2/AN7/C1OUT/SEG20  
RF2  
AN7  
C1OUT  
SEG20  
I/O  
I
O
O
ST  
Analog  
Digital I/O.  
Analog input 7.  
Comparator 1 output.  
SEG20 output for LCD.  
Analog  
RF3/AN8/SEG21  
RF3  
17  
16  
15  
I/O  
I
O
ST  
Analog  
Analog  
Digital I/O.  
Analog input 8.  
SEG21 output for LCD.  
AN8  
SEG21  
RF4/AN9/SEG22  
RF4  
I/O  
I
O
ST  
Analog  
Analog  
Digital I/O.  
Analog input 9.  
SEG22 output for LCD.  
AN9  
SEG22  
RF5/AN10/CVREF/SEG23  
RF5  
I/O  
I
O
O
ST  
Digital I/O.  
Analog input 10.  
Comparator reference voltage output.  
SEG23 output for LCD.  
AN10  
CVREF  
SEG23  
Analog  
Analog  
Analog  
RF6/AN11/SEG24  
RF6  
14  
13  
I/O  
I
O
ST  
Analog  
Analog  
Digital I/O.  
Analog input 11.  
SEG24 output for LCD.  
AN11  
SEG24  
RF7/SS/SEG25  
RF7  
SS  
SEG25  
I/O  
I
O
ST  
TTL  
Analog  
Digital I/O.  
SPI slave select input.  
SEG25 output for LCD.  
Legend: TTL = TTL compatible input  
ST = Schmitt Trigger input with CMOS levels  
CMOS = CMOS compatible input or output  
Analog = Analog input  
I
= Input  
O
= Output  
P
= Power  
OD  
= Open-Drain (no P diode to VDD)  
Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set.  
2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.  
DS39629C-page 26  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
TABLE 1-3:  
PIC18F8X90 PINOUT I/O DESCRIPTIONS (CONTINUED)  
Pin Number  
TQFP  
Pin Buffer  
Type Type  
Pin Name  
Description  
PORTG is a bidirectional I/O port.  
RG0/SEG30  
RG0  
5
6
I/O  
O
ST  
Analog  
Digital I/O.  
SEG30 output for LCD.  
SEG30  
RG1/TX2/CK2/SEG29  
RG1  
TX2  
CK2  
I/O  
O
I/O  
O
ST  
ST  
Digital I/O.  
AUSART2 asynchronous transmit.  
AUSART2 synchronous clock (see related RX2/DT2).  
SEG29 output for LCD.  
SEG29  
Analog  
RG2/RX2/DT2/SEG28  
7
RG2  
RX2  
DT2  
SEG28  
I/O  
I
I/O  
O
ST  
ST  
ST  
Digital I/O.  
AUSART2 asynchronous receive.  
AUSART2 synchronous data (see related TX2/CK2).  
SEG28 output for LCD.  
Analog  
RG3/SEG27  
RG3  
8
I/O  
O
ST  
Analog  
Digital I/O.  
SEG27 output for LCD.  
SEG27  
RG4/SEG26  
RG4  
10  
I/O  
O
ST  
Analog  
Digital I/O.  
SEG26 output for LCD.  
SEG26  
RG5  
See MCLR/VPP/RG5 pin.  
Legend: TTL = TTL compatible input  
ST = Schmitt Trigger input with CMOS levels  
CMOS = CMOS compatible input or output  
Analog = Analog input  
I
= Input  
O
= Output  
P
= Power  
OD  
= Open-Drain (no P diode to VDD)  
Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set.  
2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.  
© 2007 Microchip Technology Inc.  
DS39629C-page 27  
PIC18F6390/6490/8390/8490  
TABLE 1-3:  
PIC18F8X90 PINOUT I/O DESCRIPTIONS (CONTINUED)  
Pin Number  
Pin Buffer  
Pin Name  
Description  
Type Type  
TQFP  
PORTH is a bidirectional I/O port.  
RH0/SEG47  
RH0  
79  
I/O  
O
ST  
Analog  
Digital I/O.  
SEG47 output for LCD.  
SEG47  
RH1/SEG46  
RH1  
80  
1
I/O  
O
ST  
Analog  
Digital I/O.  
SEG46 output for LCD.  
SEG46  
RH2/SEG45  
RH2  
I/O  
O
ST  
Analog  
Digital I/O.  
SEG45 output for LCD.  
SEG45  
RH3/SEG44  
RH3  
2
I/O  
O
ST  
Analog  
Digital I/O.  
SEG44 output for LCD.  
SEG44  
RH4/SEG40  
RH4  
22  
21  
20  
19  
I/O  
O
ST  
Analog  
Digital I/O.  
SEG40 output for LCD.  
SEG40  
RH5/SEG41  
RH5  
I/O  
O
ST  
Analog  
Digital I/O.  
SEG41 output for LCD.  
SEG41  
RH6/SEG42  
RH6  
I/O  
O
ST  
Analog  
Digital I/O.  
SEG42 output for LCD.  
SEG42  
RH7/SEG43  
RH7  
I/O  
O
ST  
Analog  
Digital I/O.  
SEG43 output for LCD.  
SEG43  
Legend: TTL = TTL compatible input  
ST = Schmitt Trigger input with CMOS levels  
CMOS = CMOS compatible input or output  
Analog = Analog input  
I
= Input  
O
= Output  
P
= Power  
OD  
= Open-Drain (no P diode to VDD)  
Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set.  
2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.  
DS39629C-page 28  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
TABLE 1-3:  
PIC18F8X90 PINOUT I/O DESCRIPTIONS (CONTINUED)  
Pin Number  
TQFP  
Pin Buffer  
Type Type  
Pin Name  
Description  
PORTJ is a bidirectional I/O port.  
RJ0/SEG32  
RJ0  
62  
61  
60  
59  
39  
40  
41  
42  
I/O  
O
ST  
Analog  
Digital I/O.  
SEG32 output for LCD.  
SEG32  
RJ1/SEG33  
RJ1  
I/O  
O
ST  
Analog  
Digital I/O.  
SEG33 output for LCD.  
SEG33  
RJ2/SEG34  
RJ2  
I/O  
O
ST  
Analog  
Digital I/O.  
SEG34 output for LCD.  
SEG34  
RJ3/SEG35  
RJ3  
I/O  
O
ST  
Analog  
Digital I/O.  
SEG35 output for LCD.  
SEG35  
RJ4/SEG39  
RJ4  
I/O  
O
ST  
Analog  
Digital I/O.  
SEG39 output for LCD.  
SEG39  
RJ5/SEG38  
RJ5  
I/O  
O
ST  
Analog  
Digital I/O  
SEG38 output for LCD.  
SEG38  
RJ6/SEG37  
RJ6  
I/O  
O
ST  
Analog  
Digital I/O.  
SEG37 output for LCD.  
SEG37  
RJ7/SEG36  
RJ7  
I/O  
O
ST  
Analog  
Digital I/O.  
SEG36 output for LCD.  
SEG36  
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.  
VDD  
12, 32, 48, 71  
AVSS  
AVDD  
26  
25  
Legend: TTL = TTL compatible input  
ST = Schmitt Trigger input with CMOS levels  
CMOS = CMOS compatible input or output  
Analog = Analog input  
I
= Input  
O
= Output  
P
= Power  
OD  
= Open-Drain (no P diode to VDD)  
Note 1: Default assignment for CCP2 when Configuration bit, CCP2MX, is set.  
2: Alternate assignment for CCP2 when Configuration bit, CCP2MX, is cleared.  
© 2007 Microchip Technology Inc.  
DS39629C-page 29  
PIC18F6390/6490/8390/8490  
NOTES:  
DS39629C-page 30  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
FIGURE 2-1:  
CRYSTAL/CERAMIC  
RESONATOROPERATION  
(XT, LP, HS OR HSPLL  
CONFIGURATION)  
2.0  
2.1  
OSCILLATOR  
CONFIGURATIONS  
Oscillator Types  
(1)  
PIC18F6390/6490/8390/8490 devices can be operated  
in ten different oscillator modes. The user can program  
the Configuration bits, FOSC3:FOSC0, in Configuration  
Register 1H to select one of these ten modes:  
C1  
OSC1  
To  
Internal  
Logic  
(3)  
RF  
XTAL  
1. LP  
2. XT  
3. HS  
Low-Power Crystal  
Sleep  
(2)  
Crystal/Resonator  
RS  
(1)  
PIC18FXXXX  
C2  
High-Speed Crystal/Resonator  
OSC2  
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  
455 kHz  
2.0 MHz  
4.0 MHz  
56 pF  
47 pF  
33 pF  
56 pF  
47 pF  
33 pF  
2.2  
Crystal Oscillator/Ceramic  
Resonators  
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.  
HS  
8.0 MHz  
16.0 MHz  
27 pF  
22 pF  
27 pF  
22 pF  
Capacitor values are for design guidance only.  
These capacitors were tested with the resonators  
listed below for basic start-up and operation. These  
values are not optimized.  
The oscillator design requires the use of a parallel cut  
crystal.  
Note:  
Use of a series cut crystal may give a fre-  
quency out of the crystal manufacturer’s  
specifications.  
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.  
See the notes following Table 2-2 for additional  
information.  
Resonators Used:  
455 kHz  
2.0 MHz  
4.0 MHz  
8.0 MHz  
16.0 MHz  
© 2007 Microchip Technology Inc.  
DS39629C-page 31  
PIC18F6390/6490/8390/8490  
An external clock source may also be connected to the  
OSC1 pin in the HS mode, as shown in Figure 2-2.  
TABLE 2-2:  
CAPACITOR SELECTION FOR  
CRYSTAL OSCILLATOR  
Typical Capacitor Values  
FIGURE 2-2:  
EXTERNAL CLOCK  
INPUT OPERATION  
(HS CONFIGURATION)  
Crystal  
Freq  
Tested:  
Osc Type  
C1  
C2  
LP  
XT  
HS  
32 kHz  
200 kHz  
1 MHz  
4 MHz  
4 MHz  
8 MHz  
20 MHz  
33 pF  
15 pF  
33 pF  
27 pF  
27 pF  
22 pF  
15 pF  
33 pF  
15 pF  
33 pF  
27 pF  
27 pF  
22 pF  
15 pF  
OSC1  
Clock from  
Ext. System  
PIC18FXXXX  
(HS Mode)  
OSC2  
Open  
2.3  
External Clock Input  
Capacitor values are for design guidance only.  
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.  
These capacitors were tested with the crystals listed  
below for basic start-up and operation. These values  
are not optimized.  
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.  
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.  
See the notes following this table for additional  
information.  
FIGURE 2-3:  
EXTERNAL CLOCK  
INPUT OPERATION  
(EC CONFIGURATION)  
Crystals Used:  
32 kHz  
200 kHz  
1 MHz  
4 MHz  
8 MHz  
20 MHz  
OSC1/CLKI  
Clock from  
Ext. System  
PIC18FXXXX  
OSC2/CLKO  
FOSC/4  
Note 1: Higher capacitance increases the stability  
of oscillator, but also increases the  
start-up time.  
The ECIO Oscillator mode functions like the EC mode,  
except that the OSC2 pin becomes an additional gen-  
eral 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.  
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  
OSC1/CLKI  
PIC18FXXXX  
I/O (OSC2)  
Clock from  
Ext. System  
crystals with low drive level specification.  
5: Always verify oscillator performance over  
the VDD and temperature range that is  
expected for the application.  
RA6  
DS39629C-page 32  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
2.4  
RC Oscillator  
2.5  
PLL Frequency Multiplier  
For timing insensitive applications, the “RC” and  
“RCIO” device options 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 want 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  
temperature 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.  
• Normal manufacturing variation  
The PLL is only available to the crystal oscillator when  
the FOSC3:FOSC0 Configuration bits are programmed  
for HSPLL mode (= 0110).  
• Difference in lead frame capacitance between  
package types (especially for low CEXT values)  
• Variations within the tolerance of limits of REXT  
and CEXT  
FIGURE 2-7:  
PLL BLOCK DIAGRAM  
(HS MODE)  
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.  
HS Oscillator Enable  
PLL Enable  
(from Configuration Register 1H)  
OSC2  
OSC1  
FIGURE 2-5:  
RC OSCILLATOR MODE  
Phase  
Comparator  
HS Mode  
Crystal  
FIN  
VDD  
FOUT  
Oscillator  
REXT  
Internal  
OSC1  
Loop  
Filter  
Clock  
CEXT  
VSS  
PIC18FXXXX  
÷4  
VCO  
OSC2/CLKO  
SYSCLK  
FOSC/4  
Recommended values: 3 kΩ ≤ REXT 100 kΩ  
CEXT > 20 pF  
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  
in selected oscillator modes. 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  
CEXT > 20 pF  
© 2007 Microchip Technology Inc.  
DS39629C-page 33  
PIC18F6390/6490/8390/8490  
When the OSCTUNE register is modified, the INTOSC  
and INTRC frequencies will begin shifting to the new  
frequency. The INTRC clock will reach the new  
2.6  
Internal Oscillator Block  
The PIC18F6390/6490/8390/8490 devices include an  
internal oscillator block, which generates two different  
clock signals; either can be used as the micro-  
controller’s clock source. This may eliminate the need  
for external oscillator circuits on the OSC1 and/or  
OSC2 pins.  
frequency within  
8 clock cycles (approximately  
8 * 32 μs = 256 μs). The INTOSC clock will stabilize  
within 1 ms. Code execution continues during this shift.  
There is no indication that the shift has occurred.  
The OSCTUNE register also implements the INTSRC  
and PLLEN 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”.  
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 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:  
The PLLEN bit controls the operation of the frequency  
multiplier, PLL, in internal oscillator modes.  
2.6.4  
PLL IN INTOSC MODES  
The 4x frequency multiplier can be used with the inter-  
nal oscillator block to produce faster device clock  
speeds than are normally possible with an internal  
oscillator. When enabled, the PLL produces a clock  
speed of up to 32 MHz.  
• Power-up Timer  
• Fail-Safe Clock Monitor  
• Watchdog Timer  
• Two-Speed Start-up  
Unlike HSPLL mode, the PLL is controlled through  
software. The control bit, PLLEN (OSCTUNE<6>), is  
used to enable or disable its operation.  
• LCD with INTRC as its clock source  
These features are discussed in greater detail in  
Section 23.0 “Special Features of the CPU”.  
The PLL is available when the device is configured to use  
the internal oscillator block as its primary clock source  
(FOSC3:FOSC0 = 1001or 1000). Additionally, the PLL  
will only function when the selected output frequency is  
either 4 MHz or 8 MHz (OSCCON<6:4> = 111or 110). If  
both of these conditions are not met, the PLL is disabled.  
The clock source frequency (INTOSC direct, INTRC  
direct or INTOSC postscaler) is selected by configuring  
the IRCF bits of the OSCCON register (Register 2-2).  
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:  
The PLLEN control bit is only functional in those inter-  
nal oscillator modes where the PLL is available. In all  
other modes, it is forced to ‘0’ and is effectively  
unavailable.  
• In INTIO1 mode, the OSC2 pin outputs FOSC/4,  
while OSC1 functions as RA7 for digital input and  
output.  
2.6.5  
INTOSC FREQUENCY DRIFT  
The factory calibrates the internal oscillator block  
output (INTOSC) for 8 MHz. However, this frequency  
may drift as VDD or temperature changes, which can  
affect the controller operation in a variety of ways. It is  
possible to adjust the INTOSC frequency by modifying  
the value in the OSTUNE register. This has no effect on  
the INTRC clock source frequency.  
• In INTIO2 mode, OSC1 functions as RA7 and  
OSC2 functions as RA6, both for digital input and  
output.  
2.6.2  
INTOSC OUTPUT FREQUENCY  
The internal oscillator block is calibrated at the factory  
to produce an INTOSC output frequency of 8.0 MHz.  
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 AUSART”, Section 2.6.5.2 “Compensating with  
the Timers” and Section 2.6.5.3 “Compensating  
with the Timers”, but other techniques may be used.  
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 and vice versa.  
2.6.3  
OSCTUNE REGISTER  
The internal oscillator’s output has been calibrated at  
the factory, but can be adjusted in the user’s applica-  
tion. This is done by writing to the OSCTUNE register  
(Register 2-1). The tuning sensitivity is constant  
throughout the tuning range.  
DS39629C-page 34  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
is greater than expected, then the internal oscillator  
block is running too fast. To adjust for this, decrement  
the OSCTUNE register.  
2.6.5.1  
Compensating with the AUSART  
An adjustment may be required when the AUSART  
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 OSTUNE to  
reduce the clock frequency. On the other hand, errors  
in data may suggest that the clock speed is too low. To  
compensate, increment OSTUNE to increase the clock  
frequency.  
2.6.5.3  
Compensating with the Timers  
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. 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, then the internal oscillator block is  
running too fast. To compensate, decrement the  
OSTUNE register. If the measured time is much less  
than the calculated time, then the internal oscillator  
block is running too slow. To compensate, increment  
the OSTUNE 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  
REGISTER 2-1:  
OSCTUNE: OSCILLATOR TUNING REGISTER  
R/W-0  
R/W-0(1)  
PLLEN(1)  
U-0  
R/W-0  
TUN4  
R/W-0  
TUN3  
R/W-0  
TUN2  
R/W-0  
TUN1  
R/W-0  
TUN0  
INTSRC  
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  
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’  
TUN4:TUN0: 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 read as ‘0’. See  
Section 2.6.4 “PLL in INTOSC Modes” for details.  
© 2007 Microchip Technology Inc.  
DS39629C-page 35  
PIC18F6390/6490/8390/8490  
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  
Like  
previous  
PIC18  
devices,  
the  
PIC18F6390/6490/8390/8490 family includes a feature  
that allows the device clock source to be switched from  
the main oscillator to an alternate low-frequency clock  
source. PIC18F6390/6490/8390/8490 devices offer  
two alternate clock sources. When an alternate clock  
source is enabled, the various power-managed  
operating modes are available.  
PIC18F6390/6490/8390/8490 devices offer 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 Oscillator mode circuit, loading  
capacitors are also connected from each pin to ground.  
Essentially, there are three clock sources for these  
devices:  
The Timer1 oscillator is discussed in greater detail in  
Section 11.3 “Timer1 Oscillator”.  
• Primary oscillators  
• Secondary oscillators  
• Internal oscillator block  
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 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 FOSC3:FOSC0  
Configuration bits. The details of these modes are  
covered earlier in this chapter.  
The clock sources for the PIC18F6390/6490/8390/8490  
devices are shown in Figure 2-8. See Section 23.0  
“Special Features of the CPU” for Configuration  
register details.  
FIGURE 2-8:  
PIC18F6390/6490/8390/8490 CLOCK DIAGRAM  
PIC18F6X90/8X90  
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  
FOSC3:FOSC0  
OSCCON<1:0>  
Clock Source Option  
for Other Modules  
1
0
31 kHz (INTRC)  
OSCTUNE<7>  
WDT, PWRT, FSCM  
and Two-Speed Start-up  
DS39629C-page 36  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
The IDLEN bit determines if the device goes into Sleep  
mode or one of the Idle modes when the SLEEP  
instruction is executed.  
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 use of the flag and control bits in the OSCCON  
register is discussed in more detail in Section 3.0  
“Power-Managed Modes”.  
The System Clock Select bits, SCS1:SCS0, select the  
clock source. The available clock sources are the pri-  
mary clock (defined by the FOSC:FOSC0 Configuration  
bits), the secondary clock (Timer1 oscillator) and the  
internal oscillator block. The clock source changes  
immediately after one or more of the bits is written to,  
following a brief clock transition interval. The SCS bits  
are cleared on all forms of Reset.  
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 when executing a  
SLEEPinstruction will be ignored.  
The Internal Oscillator Frequency Select bits,  
IRCF2:IRCF0, select the frequency output of the  
internal oscillator block to drive the device clock. The  
choices are the INTRC source, 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  
immediate change on the internal oscillator’s output.  
2: It is recommended that the Timer1  
oscillator be operating and stable before  
executing the SLEEPinstruction, or a very  
long delay may occur while the Timer1  
oscillator starts.  
2.7.2  
OSCILLATOR TRANSITIONS  
When an output frequency of 31 kHz is selected  
(IRCF2:IRCF0 = 000), users may choose which inter-  
nal 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 by enabling the divide-by-256 output of the  
INTOSC postscaler. Clearing INTSRC selects INTRC  
(nominally 31 kHz) as the clock source.  
PIC18F6390/6490/8390/8490 devices contain circuitry  
to prevent clock “glitches” when switching between  
clock sources. A short pause in the device clock occurs  
during 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.  
Clock transitions are discussed in greater detail in  
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. 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.  
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  
has timed out and 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.  
© 2007 Microchip Technology Inc.  
DS39629C-page 37  
PIC18F6390/6490/8390/8490  
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 Idle mode on SLEEPinstruction  
0= Device enters Sleep mode on SLEEPinstruction  
bit 6-4  
IRCF2:IRCF0: Internal Oscillator Frequency Select bits  
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 Timer Time-out Status bit(1)  
1= Oscillator Start-up Timer time-out has expired; primary oscillator is running  
0= Oscillator Start-up Timer 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  
SCS1:SCS0: System Clock Select bits  
1x= Internal oscillator block  
01= Timer1 oscillator  
00= Primary oscillator  
Note 1: Depends on state of the IESO Configuration bit.  
2: Source selected by the INTSRC bit (OSCTUNE<7>), see Section 2.6.3 “OSCTUNE Register”.  
3: Default output frequency of INTOSC on Reset.  
DS39629C-page 38  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
2.8  
Effects of Power-Managed Modes  
on the Various Clock Sources  
2.9  
Power-up Delays  
Power-up delays are controlled by two 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 circum-  
stances and the primary clock is operating and stable.  
For additional information on power-up delays, see  
Section 4.5 “Device Reset Timers”.  
When PRI_IDLE mode is selected, the designated pri-  
mary 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, if used by the oscillator) 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 26-10). It is enabled by clearing (= 0) the  
PWRTEN Configuration bit.  
The second timer is the Oscillator Start-up Timer  
(OST), intended to keep the chip in Reset 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.  
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 var-  
ious special features, regardless of the power-managed  
mode (see Section 23.2 “Watchdog Timer (WDT)”  
through Section 23.4 “Fail-Safe Clock Monitor” for  
more information on WDT, Fail-Safe Clock Monitor and  
Two-Speed Start-up). 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.  
When the HSPLL Oscillator mode is selected, the  
device is kept in Reset for an additional 2 ms, following  
the HS mode OST delay, so the PLL can lock to the  
incoming clock frequency.  
There is a delay of interval TCSD (parameter 38,  
Table 26-10) following POR while 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., MSSP slave,  
INTx pins and others). Peripherals that may add signif-  
icant current consumption are listed in Section 26.2  
“DC Characteristics: Power-Down and Supply  
Current”.  
TABLE 2-3:  
OSC1 AND OSC2 PIN STATES IN SLEEP MODE  
OSC1 Pin  
Oscillator Mode  
OSC2 Pin  
RC, INTIO1  
RCIO, INTIO2  
ECIO  
Floating, external resistor should pull high At logic low (clock/4 output)  
Floating, external resistor should pull high Configured as PORTA, bit 6  
Floating, pulled by external clock  
Floating, pulled by external clock  
Configured as PORTA, bit 6  
At logic low (clock/4 output)  
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.  
© 2007 Microchip Technology Inc.  
DS39629C-page 39  
PIC18F6390/6490/8390/8490  
NOTES:  
DS39629C-page 40  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
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:  
PIC18F6390/6490/8390/8490 devices offer a total of  
seven operating modes for more efficient power  
management. 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  
FOSC3:FOSC0 Configuration bits  
• the secondary clock (the Timer1 oscillator)  
• the internal oscillator block (for RC modes)  
There are three categories of power-managed modes:  
3.1.2  
ENTERING POWER-MANAGED  
MODES  
• Sleep mode  
• Idle modes  
• Run modes  
Entering power-managed Run mode, or switching from  
one power-managed mode to another, begins by  
loading the OSCCON register. The SCS1:SCS0 bits  
select the clock source and determine which Run or  
Idle mode is being 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 INTOSC multiplexer);  
the Sleep mode does not use a clock source.  
The power-managed modes include several  
power-saving features. One of these is the clock  
switching feature, offered in other PIC18 devices,  
allowing the controller to use the Timer1 oscillator 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 transi-  
tions 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 deciding if  
the CPU is to be clocked or not and selecting a clock  
source. The IDLEN bit controls CPU clocking, while the  
SCS1:SCS0 bits select a clock source. The individual  
modes, bit settings, clock sources and affected  
modules are summarized in Table 3-1.  
TABLE 3-1:  
Mode  
POWER-MANAGED MODES  
OSCCON<7,1:0>  
Module Clocking  
Available Clock and Oscillator Source  
IDLEN(1) SCS1:SCS0  
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, INTRC(2)  
This is the normal, full-power execution mode.  
:
SEC_RUN  
RC_RUN  
PRI_IDLE  
SEC_IDLE  
RC_IDLE  
N/A  
N/A  
1
01  
1x  
00  
01  
1x  
Clocked  
Clocked  
Off  
Clocked Secondary – Timer1 Oscillator  
Clocked Internal Oscillator Block(2)  
Clocked Primary – LP, XT, HS, HSPLL, RC, EC  
Clocked Secondary – Timer1 Oscillator  
Clocked 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.  
© 2007 Microchip Technology Inc.  
DS39629C-page 41  
PIC18F6390/6490/8390/8490  
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 23.3 “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 provides  
a stable, 8 MHz clock source to a divider that actually  
drives the device clock. When the T1RUN bit is set, the  
Timer1 oscillator provides the clock. If none of these  
bits are set, then either the INTRC clock source clocks  
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  
primary clock source by the FOSC3:FOSC0  
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  
power-managed RC mode at the same frequency  
would clear the OSTS bit.  
SEC_RUN mode is entered by setting the SCS1:SCS0  
bits to ‘01’. The device clock source is switched to the  
Timer1 oscillator (see Figure 3-1), the primary  
oscillator 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  
SCS1:SCS0 bits are set to ‘01’, entry to  
SEC_RUN 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.  
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  
provides 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.  
DS39629C-page 42  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
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  
OSC1  
Clock Transition  
CPU  
Clock  
Peripheral  
Clock  
Program  
Counter  
PC  
PC + 2  
PC + 4  
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)  
(1)  
TOST  
TPLL  
PLL Clock  
Output  
1
2
n-1  
Clock  
Transition  
n
CPU Clock  
Peripheral  
Clock  
Program  
Counter  
PC + 2  
PC + 4  
PC  
SCS1:SCS0 bits Changed  
Note 1: TOST = 1024 TOSC; TPLL = 2 ms (approx). These intervals are not shown to scale.  
OSTS bit Set  
© 2007 Microchip Technology Inc.  
DS39629C-page 43  
PIC18F6390/6490/8390/8490  
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 provides the device  
clocks.  
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 and 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.  
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.  
If the primary clock source is the internal oscillator block  
(either INTRC or INTOSC), there are no distinguishable  
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.  
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.  
On transitions from RC_RUN mode to PRI_RUN, 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 provides 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.  
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  
compatibility 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.  
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.  
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  
CPU  
Clock  
Peripheral  
Clock  
Program  
Counter  
PC  
PC + 2  
PC + 4  
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  
CPU Clock  
Peripheral  
Clock  
Program  
Counter  
PC + 2  
PC + 4  
PC  
SCS1:SCS0 bits Changed  
Note 1: TOST = 1024 TOSC; TPLL = 2 ms (approx). These intervals are not shown to scale.  
OSTS bit Set  
DS39629C-page 44  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
3.3  
Sleep Mode  
3.4  
Idle Modes  
The  
power-managed  
Sleep  
mode  
in  
the  
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.  
PIC18F6390/6490/8390/8490 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 SLEEPinstruction.  
This shuts down the selected oscillator (see  
Figure 3-5). All clock source status bits are cleared.  
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 SCS1:SCS0 bits;  
however, the CPU will not be clocked. The clock source  
status bits are not affected. Setting IDLEN and execut-  
ing SLEEPprovides 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 primary clock source becomes ready (see  
Figure 3-6), or it will be clocked from the internal oscil-  
lator block if either the Two-Speed Start-up or the  
Fail-Safe Clock Monitor are enabled (see Section 23.0  
“Special Features of the CPU”). In either case, the  
OSTS bit is set when the primary clock provides 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 26-10) 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 SCS1:SCS0 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  
Note 1: TOST = 1024 TOSC; TPLL = 2 ms (approx). These intervals are not shown to scale.  
OSTS bit Set  
© 2007 Microchip Technology Inc.  
DS39629C-page 45  
PIC18F6390/6490/8390/8490  
When a wake event occurs, the CPU is clocked from the  
primary clock source. A delay of interval TCSD 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).  
3.4.1  
PRI_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.  
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 FOSC3:FOSC0 Configuration bits. The OSTS  
bit remains set (see Figure 3-7).  
FIGURE 3-7:  
TRANSITION TIMING FOR ENTRY TO PRI_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  
DS39629C-page 46  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
3.4.2  
SEC_IDLE MODE  
3.4.3  
RC_IDLE MODE  
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 IDLEN first, then  
set SCS1:SCS0 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.  
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.  
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.  
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  
executing 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).  
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 26-10). 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 SLEEP instruction was  
executed 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.  
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.  
When a wake event occurs, the peripherals continue to  
be clocked from the INTOSC multiplexer. After a delay  
of TCSD following the wake event, the CPU begins  
executing code being clocked by the INTOSC multi-  
plexer. 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.  
© 2007 Microchip Technology Inc.  
DS39629C-page 47  
PIC18F6390/6490/8390/8490  
3.5.3  
EXIT BY RESET  
3.5  
Exiting Idle and Sleep Modes  
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.  
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” through  
Section 3.4 “Idle Modes”).  
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.  
3.5.1  
EXIT BY INTERRUPT  
Any of the available interrupt sources can cause the  
device to exit from an Idle or 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.  
Code execution can begin before the primary clock  
becomes ready. If either the Two-Speed Start-up (see  
Section 23.3 “Two-Speed Start-up”) or Fail-Safe  
Clock Monitor (see Section 23.4 “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  
internal 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.  
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  
execution continues or resumes without branching  
(see Section 8.0 “Interrupts”).  
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.  
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:  
3.5.2  
EXIT BY WDT TIME-OUT  
• PRI_IDLE mode, where the primary clock source  
is not stopped; and  
A WDT time-out will cause different actions depending  
on which power-managed mode the device is in when  
the time-out occurs.  
• the primary clock source is not any of the LP, XT,  
HS or HSPLL modes.  
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 23.2 “Watchdog  
Timer (WDT)”).  
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.  
The WDT timer and postscaler are cleared by execut-  
ing a SLEEPor CLRWDTinstruction, losing 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.  
DS39629C-page 48  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
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  
EC, RC, INTRC(1)  
INTOSC(3)  
OSTS  
Primary Device Clock  
(PRI_IDLE mode)  
(2)  
TCSD  
IOFS  
(4)  
LP, XT, HS  
TOST  
OSTS  
(4)  
HSPLL  
TOST + trc  
T1OSC or INTRC(1)  
(2)  
EC, RC, INTRC(1)  
INTOSC(3)  
TCSD  
(5)  
TIOBST  
IOFS  
(5)  
LP, XT, HS  
TOST  
OSTS  
(4)  
HSPLL  
TOST + trc  
INTOSC(3)  
EC, RC, INTRC(1)  
INTOSC(3)  
TCSD  
(2)  
None  
IOFS  
(4)  
LP, XT, HS  
TOST  
OSTS  
(4)  
HSPLL  
TOST + trc  
None  
(Sleep mode)  
EC, RC, INTRC(1)  
INTOSC(3)  
TCSD  
(2)  
(5)  
TIOBST  
IOFS  
Note 1: In this instance, refers specifically to the 31 kHz INTRC clock source.  
2: TCSD (parameter 38) 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”).  
3: Includes both the INTOSC 8 MHz source and postscaler derived frequencies.  
4: TOST is the Oscillator Start-up Timer (parameter 32). trc is the PLL Lock-out Timer (parameter F12); it is  
also designated as TPLL.  
5: Execution continues during TIOBST (parameter 39), the INTOSC stabilization period.  
© 2007 Microchip Technology Inc.  
DS39629C-page 49  
PIC18F6390/6490/8390/8490  
NOTES:  
DS39629C-page 50  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
4.1  
RCON Register  
4.0  
RESET  
Device Reset events are tracked through the RCON  
register (Register 4-1). The lower five bits of the  
register indicate that a specific Reset event has  
occurred. In most cases, these bits can only be set by  
the event and must be cleared 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”.  
The PIC18F6390/6490/8390/8490 devices differentiate  
between various kinds of Reset:  
a) Power-on Reset (POR)  
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  
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 8.0 “Interrupts”. BOR is covered in  
Section 4.4 “Brown-out Reset (BOR)”.  
g) Stack Full Reset  
h) Stack Underflow Reset  
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 5.1.2.4 “Stack Full and Underflow Resets”.  
WDT Resets are covered in Section 23.2 “Watchdog  
Timer (WDT)”.  
A simplified block diagram of the on-chip Reset circuit  
is shown in Figure 4-1.  
FIGURE 4-1:  
SIMPLIFIED BLOCK DIAGRAM OF ON-CHIP RESET CIRCUIT  
RESET  
Instruction  
Stack  
Pointer  
Stack Full/Underflow Reset  
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  
Q
R
OSC1  
32 μs  
65.5 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.  
© 2007 Microchip Technology Inc.  
DS39629C-page 51  
PIC18F6390/6490/8390/8490  
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  
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 BOREN1:BOREN0 = 01:  
1= BOR is enabled  
0= BOR is disabled  
If BOREN1:BOREN0 = 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  
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’.  
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 a Power-on Reset).  
DS39629C-page 52  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
FIGURE 4-2:  
EXTERNAL POWER-ON  
RESET CIRCUIT (FOR  
SLOW VDD POWER-UP)  
4.2  
Master Clear (MCLR)  
The MCLR pin provides a method for triggering a hard  
external Reset of the device. A Reset is generated by  
holding the pin low. PIC18 Extended MCU devices  
have a noise filter in the MCLR Reset path which  
detects and ignores small pulses.  
VDD  
VDD  
D
The MCLR pin is not driven low by any internal Resets,  
including the WDT.  
R
R1  
MCLR  
In PIC18F6390/6490/8390/8490 devices, the MCLR  
input can be disabled with the MCLRE Configuration  
bit. When MCLR is disabled, the pin becomes a digital  
input. See Section 9.7 “PORTG, TRISG and LATG  
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). For a slow rise  
time, see Figure 4-2.  
When the device starts normal operation (i.e., exits the  
Reset condition), device operating parameters  
(voltage, 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 Power-on  
Reset 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 Power-on Reset.  
© 2007 Microchip Technology Inc.  
DS39629C-page 53  
PIC18F6390/6490/8390/8490  
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  
consumes. While the BOR current is typically very  
small, it may have some impact in low-power  
applications.  
4.4  
Brown-out Reset (BOR)  
PIC18F6390/6490/8390/8490 devices implement  
BOR circuit that provides the user with a number of  
configuration and power-saving options. The BOR is  
a
controlled  
by  
the  
BORV1:BORV0  
and  
BOREN1:BOREN0 Configuration bits. There are a total  
of four BOR configurations, which are summarized in  
Table 4-1.  
The BOR threshold is set by the BORV1:BORV0 bits. If  
BOR is enabled (any values of BOREN1:BOREN0  
except ‘00’), any drop of VDD below VBOR (parameter  
D005) for greater than TBOR (parameter 35) 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 BORV1:BORV0 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). 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.  
BOR and the Power-up Timer (PWRT) are  
independently configured. Enabling the BOR Reset  
does not automatically enable the PWRT.  
4.4.3  
DISABLING BOR IN SLEEP MODE  
When BOREN1:BOREN0 = 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 BOREN1:BOREN0 = 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:  
BOR CONFIGURATIONS  
BOR Configuration  
Status of  
SBOREN  
(RCON<6>)  
BOR Operation  
BOREN1  
BOREN0  
0
0
Unavailable BOR is disabled; must be enabled by reprogramming the Configuration  
bits.  
0
1
1
0
Available  
BOR is enabled in software; operation controlled by SBOREN.  
Unavailable BOR is enabled in hardware and active during the Run and Idle modes,  
disabled during Sleep mode.  
1
1
Unavailable BOR is enabled in hardware; must be disabled by reprogramming the  
Configuration bits.  
DS39629C-page 54  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
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  
different 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.  
PIC18F6390/6490/8390/8490 devices incorporate  
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  
The  
POWER-UP TIMER (PWRT)  
Power-up Timer (PWRT)  
1. After the POR pulse has cleared, PWRT  
time-out is invoked (if enabled).  
of  
PIC18F6390/6490/8390/8490 devices is an 11-bit  
counter which uses the INTRC source as the clock  
input. This yields an approximate time interval of  
2048 x 32 μs = 65.6 ms. 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  
configuration 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 for details.  
The PWRT is enabled by clearing the PWRTEN  
Configuration bit.  
Since the time-outs occur from the POR pulse, if MCLR  
is kept low long enough, all time-outs will expire.  
Bringing MCLR high will begin execution immediately  
(Figure 4-5). This is useful for testing purposes, or to  
synchronize more than one PIC18FXXXX device  
operating in parallel.  
4.5.2  
OSCILLATOR START-UP  
TIMER (OST)  
The Oscillator Start-up Timer (OST) provides a  
1024 oscillator cycle (from OSC1 input) delay after the  
PWRT delay is over (parameter 33). This ensures that  
the crystal oscillator or resonator has started and is  
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  
HSPLL  
66 ms(1) + 1024 TOSC + 2 ms(2)  
66 ms(1) + 1024 TOSC  
66 ms(1)  
1024 TOSC + 2 ms(2)  
1024 TOSC + 2 ms(2)  
HS, XT, LP  
EC, ECIO  
1024 TOSC  
1024 TOSC  
RC, RCIO  
66 ms(1)  
66 ms(1)  
INTIO1, INTIO2  
Note 1: 66 ms (65.5 ms) is the nominal Power-up Timer (PWRT) delay.  
2: 2 ms is the nominal time required for the PLL to lock.  
© 2007 Microchip Technology Inc.  
DS39629C-page 55  
PIC18F6390/6490/8390/8490  
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  
DS39629C-page 56  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
FIGURE 4-6:  
SLOW RISE TIME (MCLR TIED TO VDD, VDD RISE > TPWRT)  
5V  
1V  
0V  
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 max. First three stages of the PWRT timer.  
© 2007 Microchip Technology Inc.  
DS39629C-page 57  
PIC18F6390/6490/8390/8490  
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. The 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  
operation. 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 Reset during  
power-managed Run modes  
MCLR Reset during  
power-managed Idle modes and  
Sleep  
0000h  
u(2)  
u
1
0
u
u
u
u
WDT time-out during full power  
or power-managed Run modes  
0000h  
0000h  
u(2)  
u(2)  
u
u
0
u
u
u
u
u
u
u
u
u
u
u
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(1)  
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  
(BOREN1:BOREN0 Configuration bits = 01and SBOREN = 1); otherwise, the Reset state is ‘0’.  
DS39629C-page 58  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
TABLE 4-4:  
Register  
INITIALIZATION CONDITIONS FOR ALL REGISTERS  
MCLR Resets  
WDT Reset  
Applicable  
Devices  
Power-on Reset,  
Brown-out Reset  
Wake-up via WDT  
or Interrupt  
RESETInstruction  
Stack Resets  
TOSU  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
---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  
00-0 0000  
---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)  
uuuu uuuu(3)  
uuuu uuuu(3)  
uu-u uuuu(3)  
---u uuuu  
uuuu uuuu  
PC + 2(2)  
--uu uuuu  
uuuu uuuu  
uuuu uuuu  
uuuu uuuu  
uuuu uuuu  
uuuu uuuu  
uuuu uuuu(1)  
uuuu uuuu(1)  
uuuu uuuu(1)  
N/A  
TOSH  
TOSL  
STKPTR  
PCLATU  
PCLATH  
PCL  
TBLPTRU  
TBLPTRH  
TBLPTRL  
TABLAT  
PRODH  
PRODL  
INTCON  
INTCON2  
INTCON3  
INDF0  
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  
N/A  
---- xxxx  
xxxx xxxx  
xxxx xxxx  
N/A  
---- uuuu  
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’.  
6: These registers are cleared on POR and unchanged on BOR.  
© 2007 Microchip Technology Inc.  
DS39629C-page 59  
PIC18F6390/6490/8390/8490  
TABLE 4-4:  
INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED)  
MCLR Resets  
Applicable  
Devices  
Power-on Reset,  
Brown-out Reset  
WDT Reset  
RESETInstruction  
Stack Resets  
Wake-up via WDT  
or Interrupt  
Register  
FSR1H  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
---- xxxx  
xxxx xxxx  
---- 0000  
N/A  
---- uuuu  
uuuu uuuu  
---- 0000  
N/A  
---- uuuu  
uuuu uuuu  
---- uuuu  
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  
---- xxxx  
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  
---- uuuu  
uuuu uuuu  
---u uuuu  
0000 0000  
uuuu uuuu  
1111 1111  
0100 00q0  
0-00 0101  
---- ---0  
0q-q qquu  
uuuu uuuu  
uuuu uuuu  
u0uu uuuu  
0000 0000  
1111 1111  
-000 0000  
uuuu uuuu  
0000 0000  
0000 0000  
0000 0000  
0000 0000  
---- 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  
1111 1111  
-uuu uuuu  
uuuu uuuu  
uuuu uuuu  
uuuu uuuu  
uuuu uuuu  
uuuu uuuu  
FSR2L  
STATUS  
TMR0H  
TMR0L  
T0CON  
OSCCON  
HLVDCON  
WDTCON  
RCON(4)  
TMR1H  
TMR1L  
T1CON  
TMR2  
PR2  
T2CON  
SSPBUF  
SSPADD  
SSPSTAT  
SSPCON1  
SSPCON2  
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’.  
6: These registers are cleared on POR and unchanged on BOR.  
DS39629C-page 60  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
TABLE 4-4:  
Register  
INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED)  
MCLR Resets  
WDT Reset  
Applicable  
Devices  
Power-on Reset,  
Brown-out Reset  
Wake-up via WDT  
or Interrupt  
RESETInstruction  
Stack Resets  
ADRESH  
ADRESL  
ADCON0  
ADCON1  
ADCON2  
CCPR1H  
CCPR1L  
CCP1CON  
CCPR2H  
CCPR2L  
CCP2CON  
CVRCON  
CMCON  
TMR3H  
TMR3L  
T3CON  
SPBRG1  
RCREG1  
TXREG1  
TXSTA1  
RCSTA1  
IPR3  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
xxxx xxxx  
xxxx xxxx  
--00 0000  
--00 0000  
0-00 0000  
xxxx xxxx  
xxxx xxxx  
--00 0000  
xxxx xxxx  
xxxx xxxx  
--00 0000  
000- 0000  
0000 0111  
xxxx xxxx  
xxxx xxxx  
0000 0000  
0000 0000  
0000 0000  
0000 0000  
0000 0010  
0000 000x  
-111 ----  
-000 ----  
-000 ----  
11-- 1111  
00-- 0000  
00-- 0000  
-111 1111  
-000 0000  
-000 0000  
00-0 0000  
uuuu uuuu  
uuuu uuuu  
--00 0000  
--00 0000  
0-00 0000  
uuuu uuuu  
uuuu uuuu  
--00 0000  
uuuu uuuu  
uuuu uuuu  
--00 0000  
000- 0000  
0000 0111  
uuuu uuuu  
uuuu uuuu  
uuuu uuuu  
0000 0000  
0000 0000  
0000 0000  
0000 0010  
0000 000x  
-111 ----  
-000 ----  
-000 ----  
11-- 1111  
00-- 0000  
00-- 0000  
-111 1111  
-000 0000  
-000 0000  
00-0 0000  
uuuu uuuu  
uuuu uuuu  
--uu uuuu  
--uu uuuu  
u-uu uuuu  
uuuu uuuu  
uuuu uuuu  
--uu uuuu  
uuuu uuuu  
uuuu uuuu  
--uu uuuu  
uuu- uuuu  
uuuu uuuu  
uuuu uuuu  
uuuu uuuu  
uuuu uuuu  
uuuu uuuu  
uuuu uuuu  
uuuu uuuu  
uuuu uuuu  
uuuu uuuu  
-uuu ----  
-uuu ----(1)  
-uuu ----  
uu-- uuuu  
uu-- uuuu(1)  
uu-- uuuu  
-uuu uuuu  
-uuu uuuu(1)  
-uuu uuuu  
uu-u uuuu  
PIR3  
PIE3  
IPR2  
PIR2  
PIE2  
IPR1  
PIR1  
PIE1  
OSCTUNE  
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’.  
6: These registers are cleared on POR and unchanged on BOR.  
© 2007 Microchip Technology Inc.  
DS39629C-page 61  
PIC18F6390/6490/8390/8490  
TABLE 4-4:  
INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED)  
MCLR Resets  
Applicable  
Devices  
Power-on Reset,  
Brown-out Reset  
WDT Reset  
RESETInstruction  
Stack Resets  
Wake-up via WDT  
or Interrupt  
Register  
TRISJ  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
1111 1111  
1111 1111  
---1 1111  
1111 1111  
1111 ----  
1111 1111  
1111 1111  
1111 1111  
1111 1111(5)  
xxxx xxxx  
xxxx xxxx  
---x xxxx  
xxxx xxxx  
xxxx ----  
xxxx xxxx  
xxxx xxxx  
xxxx xxxx  
xxxx xxxx(5)  
xxxx xxxx  
xxxx xxxx  
--xx xxxx  
xxxx xxxx  
xxxx ----  
xxxx xxxx  
xxxx xxxx  
xxxx xxxx  
xx0x 0000(5)  
0000 0000  
01-0 0-00  
1111 1111  
1111 1111  
---1 1111  
1111 1111  
1111 ----  
1111 1111  
1111 1111  
1111 1111  
1111 1111(5)  
uuuu uuuu  
uuuu uuuu  
---u uuuu  
uuuu uuuu  
uuuu ----  
uuuu uuuu  
uuuu uuuu  
uuuu uuuu  
uuuu uuuu(5)  
uuuu uuuu  
uuuu uuuu  
--uu uuuu  
uuuu uuuu  
uuuu ----  
uuuu uuuu  
uuuu uuuu  
uuuu uuuu  
uu0u 0000(5)  
0000 0000  
01-0 0-00  
uuuu uuuu  
uuuu uuuu  
---u uuuu  
uuuu uuuu  
uuuu ----  
uuuu uuuu  
uuuu uuuu  
uuuu uuuu  
uuuu uuuu(5)  
uuuu uuuu  
uuuu uuuu  
---u uuuu  
uuuu uuuu  
uuuu ----  
uuuu uuuu  
uuuu uuuu  
uuuu uuuu  
uuuu uuuu(5)  
uuuu uuuu  
uuuu uuuu  
--uu uuuu  
uuuu uuuu  
uuuu ----  
uuuu uuuu  
uuuu uuuu  
uuuu uuuu  
uuuu uuuu(5)  
uuuu uuuu  
uu-u u-uu  
TRISH  
TRISG  
TRISF  
TRISE  
TRISD  
TRISC  
TRISB  
TRISA(5)  
LATJ  
LATH  
LATG  
LATF  
LATE  
LATD  
LATC  
LATB  
LATA(5)  
PORTJ  
PORTH  
PORTG  
PORTF  
PORTE  
PORTD  
PORTC  
PORTB  
PORTA(5)  
SPBRGH1  
BAUDCON1  
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’.  
6: These registers are cleared on POR and unchanged on BOR.  
DS39629C-page 62  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
TABLE 4-4:  
Register  
INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED)  
MCLR Resets  
WDT Reset  
Applicable  
Devices  
Power-on Reset,  
Brown-out Reset  
Wake-up via WDT  
or Interrupt  
RESETInstruction  
Stack Resets  
LCDDATA23  
LCDDATA22  
LCDDATA21  
LCDDATA20  
LCDDATA19  
LCDDATA18  
LCDDATA17  
LCDDATA16  
LCDDATA15  
LCDDATA14  
LCDDATA13  
LCDDATA12  
LCDDATA11  
SPBRG2  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
xxxx xxxx  
xxxx xxxx  
xxxx xxxx  
xxxx xxxx  
xxxx xxxx  
xxxx xxxx  
xxxx xxxx  
xxxx xxxx  
xxxx xxxx  
xxxx xxxx  
xxxx xxxx  
xxxx xxxx  
xxxx xxxx  
0000 0000  
0000 0000  
0000 0000  
0000 -010  
0000 000x  
xxxx xxxx  
xxxx xxxx  
xxxx xxxx  
xxxx xxxx  
xxxx xxxx  
xxxx xxxx  
xxxx xxxx  
xxxx xxxx  
xxxx xxxx  
xxxx xxxx  
xxxx xxxx  
0000 0000  
0000 0000  
0000 0000  
0000 0000  
0000 0000  
0000 0000  
0000 0000  
0000 0000  
0000 0000  
0000 0000  
0000 0000  
0000 0000  
0000 0000  
0000 0000  
0000 0000  
0000 0000  
0000 -010  
0000 000x  
0000 0000  
0000 0000  
0000 0000  
0000 0000  
0000 0000  
0000 0000  
0000 0000  
0000 0000  
0000 0000  
0000 0000  
0000 0000  
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 -uuu  
uuuu uuuu  
uuuu uuuu  
uuuu uuuu  
uuuu uuuu  
uuuu uuuu  
uuuu uuuu  
uuuu uuuu  
uuuu uuuu  
uuuu uuuu  
uuuu uuuu  
uuuu uuuu  
uuuu uuuu  
RCREG2  
TXREG2  
TXSTA2  
RCSTA2  
LCDDATA10  
LCDDATA9  
LCDDATA8  
LCDDATA7  
LCDDATA6  
LCDDATA5  
LCDDATA4  
LCDDATA3  
LCDDATA2  
LCDDATA1  
LCDDATA0  
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’.  
6: These registers are cleared on POR and unchanged on BOR.  
© 2007 Microchip Technology Inc.  
DS39629C-page 63  
PIC18F6390/6490/8390/8490  
TABLE 4-4:  
INITIALIZATION CONDITIONS FOR ALL REGISTERS (CONTINUED)  
MCLR Resets  
Applicable  
Devices  
Power-on Reset,  
Brown-out Reset  
WDT Reset  
RESETInstruction  
Stack Resets  
Wake-up via WDT  
or Interrupt  
Register  
LCDSE5  
LCDSE4  
LCDSE3  
LCDSE2  
LCDSE1  
LCDSE0  
LCDCON  
LCDPS  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
6X90 8X90  
0000 0000  
0000 0000  
0000 0000  
0000 0000  
0000 0000  
0000 0000  
000- 0000  
0000 0000  
0000 0000(6)  
0000 0000(6)  
0000 0000(6)  
0000 0000(6)  
0000 0000(6)  
0000 0000(6)  
000- 0000  
uuuu uuuu  
uuuu uuuu  
uuuu uuuu  
uuuu uuuu  
uuuu uuuu  
uuuu uuuu  
uuu- uuuu  
uuuu uuuu  
0000 0000  
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’.  
6: These registers are cleared on POR and unchanged on BOR.  
DS39629C-page 64  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
5.1  
Program Memory Organization  
5.0  
MEMORY ORGANIZATION  
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).  
There are two types of memory in PIC18 Flash  
microcontroller devices:  
• Program Memory  
• Data RAM  
As Harvard architecture devices, the data and program  
memories use separate busses; this allows for  
concurrent access of the two memory spaces.  
The PIC18FX390 have 8 Kbytes of Flash memory and  
can store up to 4,096 single-word instructions and the  
PIC18FX490 have 16 Kbytes of Flash memory and can  
store up to 8,192 single-word instructions.  
Additional detailed information on the operation of the  
Flash program memory is provided in Section 6.0  
“Flash Program Memory”.  
PIC18 devices have two interrupt vectors. The Reset  
vector address is at 0000h and the interrupt vector  
addresses are at 0008h and 0018h.  
The  
program  
memory  
maps  
for  
PIC18F6390/6490/8390/8490 devices are shown in  
Figure 5-1.  
FIGURE 5-1:  
PROGRAM MEMORY MAP AND STACK FOR PIC18F6390/6490/8390/8490 DEVICES  
PIC18F6390/8390  
PIC18F6490/8490  
PC<20:0>  
PC<20:0>  
21  
21  
CALL,RCALL,RETURN  
RETFIE,RETLW  
CALL,RCALL,RETURN  
RETFIE,RETLW  
Stack Level 1  
Stack Level 1  
Stack Level 31  
Reset Vector  
Stack Level 31  
Reset Vector  
0000h  
0000h  
High-Priority Interrupt Vector  
Low-Priority Interrupt Vector  
High-Priority Interrupt Vector  
Low-Priority Interrupt Vector  
0008h  
0018h  
0008h  
0018h  
On-Chip  
Program Memory  
On-Chip  
Program Memory  
1FFFh  
2000h  
3FFFh  
4000h  
Read ‘0’  
Read ‘0’  
1FFFFFh  
1FFFFFh  
© 2007 Microchip Technology Inc.  
DS39629C-page 65  
PIC18F6390/6490/8390/8490  
The stack operates as a 31-word by 21-bit RAM and a  
5-bit Stack Pointer. 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  
Function Registers. Data can also be pushed to, or  
popped from the stack using these registers.  
5.1.1  
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 register 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 5.1.4.1 “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, 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.  
5.1.2.1  
Only the top of the return address stack (TOS) is read-  
able and writable. set of three registers,  
Top-of-Stack Access  
A
TOSU:TOSH:TOSL, hold the contents of the stack  
location pointed to by the lower five bits of the STKPTR  
register (Figure 5-2). 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.  
5.1.2  
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 5-2:  
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  
DS39629C-page 66  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
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 sets 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.  
5.1.2.2  
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.  
5.1.2.3  
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 execu-  
tion, 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 23.1 “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 push and the Stack Pointer will increment to 31.  
Any additional pushes will not overwrite the 31st push  
and STKPTR will remain at 31.  
The POP instruction discards the current TOS by  
decrementing 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)  
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 7  
bit 0  
Legend:  
C = Clearable only bit  
W = Writable bit  
‘1’ = Bit is set  
R = Readable bit  
-n = Value at POR  
U = Unimplemented bit, read as ‘0’  
‘0’ = Bit is cleared x = Bit is unknown  
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  
SP4:SP0: Stack Pointer Location bits  
Note 1: Bit 7 and bit 6 are cleared by user software or by a POR.  
© 2007 Microchip Technology Inc.  
DS39629C-page 67  
PIC18F6390/6490/8390/8490  
5.1.2.4  
Stack Full and Underflow Resets  
5.1.4  
LOOK-UP TABLES IN PROGRAM  
MEMORY  
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.  
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  
5.1.4.1  
Computed GOTO  
5.1.3  
FAST REGISTER STACK  
A computed GOTOis accomplished by adding an offset  
to the program counter. An example is shown in  
Example 5-2.  
A Fast Register Stack is provided for the STATUS,  
WREG and BSR registers, to provide a “fast return”  
option for interrupts. This stack is only one level deep  
and is neither readable nor writable. It is loaded with the  
current value of the corresponding register when the  
processor vectors for an interrupt. All interrupt sources  
will push values into the stack registers. The values in  
the registers are then loaded back into the working  
registers if the RETFIE, FAST instruction is used to  
return from the interrupt.  
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  
executing a call to that table. The first instruction of the  
called routine is the ADDWF PCLinstruction. The next  
instruction executed will be one of the RETLW nn  
instructions that returns the value ‘nn’ to the calling  
function.  
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  
register 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.  
The offset value (in WREG) specifies the number of  
bytes that the program counter should advance and  
should be multiples of 2 (LSb = 0).  
In this method, only one data byte may be stored in  
each instruction location and room on the return  
address stack is required.  
If interrupt priority is not used, all interrupts may use the  
Fast Register Stack for returns from interrupt. If no  
interrupts 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 CALL label, FAST  
instruction must be executed to save the STATUS,  
WREG and BSR registers to the Fast Register Stack. A  
RETURN, FASTinstruction is then executed to restore  
these registers from the Fast Register Stack.  
EXAMPLE 5-2:  
COMPUTED GOTOUSING  
AN OFFSET VALUE  
OFFSET, W  
TABLE  
MOVF  
CALL  
ORG  
TABLE  
nn00h  
ADDWF  
RETLW  
RETLW  
RETLW  
.
PCL  
nnh  
nnh  
nnh  
.
Example 5-1 shows a source code example that uses  
the Fast Register Stack during a subroutine call and  
return.  
.
5.1.4.2  
Table Reads  
A better method of storing data in program memory  
allows two bytes of data to be stored in each instruction  
location.  
EXAMPLE 5-1:  
FAST REGISTER STACK  
CODE EXAMPLE  
;STATUS, WREG, BSR  
;SAVED IN FAST REGISTER  
;STACK  
CALL SUB1, FAST  
Look-up table data may be stored two bytes per  
program word while programming. The Table Pointer  
register (TBLPTR) specifies the byte address and the  
Table Latch register (TABLAT) contains the data that is  
read from the program memory. Data is transferred  
from program memory one byte at a time.  
SUB1  
RETURN FAST  
;RESTORE VALUES SAVED  
;IN FAST REGISTER STACK  
Table read operation is discussed further in  
Section 6.1 “Table Reads”.  
DS39629C-page 68  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
5.2.2  
INSTRUCTION FLOW/PIPELINING  
5.2  
PIC18 Instruction Cycle  
An “Instruction Cycle” consists of four Q cycles, Q1  
through Q4. The instruction fetch and execute are pipe-  
lined in such a manner that a fetch takes one instruction  
cycle, while the decode and execute take another  
instruction cycle. However, due to the pipelining, 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).  
5.2.1  
CLOCKING SCHEME  
The microcontroller clock input, whether from an  
internal or external source, is internally divided by four  
to generate 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 memory and latched into the Instruc-  
tion Register (IR) during Q4. The instruction is decoded  
and executed during the following Q1 through Q4. The  
clocks and instruction execution flow are shown in  
Figure 5-3.  
A fetch cycle begins with the Program Counter (PC)  
incrementing in Q1.  
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).  
FIGURE 5-3:  
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.  
© 2007 Microchip Technology Inc.  
DS39629C-page 69  
PIC18F6390/6490/8390/8490  
number of single-word instructions that the PC will be  
offset by. Section 24.0 “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 5.1.1  
“Program Counter”).  
5.2.4  
TWO-WORD INSTRUCTIONS  
The standard PIC18 instruction set has four two-word  
instructions: CALL, MOVFF, GOTO and LSFR. 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.  
The use of ‘1111’ in the 4 MSbs of an instruction  
specifies 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 the instruction sequence. If the first word  
is skipped for some reason and the second word is  
executed by itself, a NOP is executed instead. This is  
necessary for cases when the two-word instruction is  
preceded by a conditional instruction that changes the  
PC. Example 5-4 shows how this works.  
Figure 5-4 shows an example of how instruction words  
are stored in the program memory.  
The CALLand GOTOinstructions have the absolute pro-  
gram memory address embedded into the instruction.  
Since instructions are always stored on word bound-  
aries, 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 5-4 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  
Note:  
See Section 5.5 “Program Memory and  
the Extended Instruction Set” for  
information on two-word instructions in the  
extended instruction set.  
FIGURE 5-4:  
INSTRUCTIONS IN PROGRAM MEMORY  
Word Address  
LSB = 1  
Program Memory  
Byte Locations →  
LSB = 0  
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  
EXAMPLE 5-4:  
CASE 1:  
TWO-WORD INSTRUCTIONS  
Object Code  
Source Code  
0110 0110 0000 0000  
1100 0001 0010 0011  
1111 0100 0101 0110  
0010 0100 0000 0000  
CASE 2:  
TSTFSZ  
MOVFF  
REG1  
; is RAM location 0?  
REG1, REG2 ; No, skip this word  
; Execute this word as a NOP  
; continue code  
ADDWF  
REG3  
REG1  
Object Code  
Source Code  
TSTFSZ  
0110 0110 0000 0000  
1100 0001 0010 0011  
1111 0100 0101 0110  
0010 0100 0000 0000  
; is RAM location 0?  
MOVFF  
REG1, REG2 ; Yes, execute this word  
; 2nd word of instruction  
ADDWF  
REG3  
; continue code  
DS39629C-page 70  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
5.3.1  
BANK SELECT REGISTER  
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 5.6 “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;  
PIC18F6390/6490/8390/8490 devices implement  
only 4 banks. Figure 5-5 shows the data memory  
organization for the PIC18F6390/6490/8390/8490  
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 (BSR3:BSR0). 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 5-6.  
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  
section.  
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 5-5 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.  
© 2007 Microchip Technology Inc.  
DS39629C-page 71  
PIC18F6390/6490/8390/8490  
FIGURE 5-5:  
DATA MEMORY MAP FOR PIC18F6390/6490/8390/8490 DEVICES  
When a = 0:  
The BSR is ignored and the  
BSR<3:0>  
Data Memory Map  
00h  
Access Bank is used.  
000h  
05Fh  
060h  
0FFh  
100h  
Access RAM  
GPR  
= 0000  
= 0001  
= 0010  
The first 128 bytes are  
general purpose RAM  
(from Bank 0).  
Bank 0  
FFh  
00h  
The second 128 bytes are  
Special Function Registers  
(from Bank 15).  
GPR  
GPR  
Bank 1  
Bank 2  
1FFh  
200h  
FFh  
00h  
When a = 1:  
FFh  
The BSR specifies the bank  
used by the instruction.  
2FFh  
300h  
= 0011  
Bank 3  
Access Bank  
00h  
Access RAM Low  
5Fh  
60h  
Access RAM High  
(SFRs)  
FFh  
Unused  
to  
Read as 00h  
= 1110  
Bank 14  
EFFh  
F00h  
F58h  
F60h  
FFFh  
00h  
FFh  
Unimplemented  
SFR  
= 1111  
Banked SFRs  
Bank 15  
DS39629C-page 72  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
FIGURE 5-6:  
USE OF THE BANK SELECT REGISTER (DIRECT ADDRESSING)  
Data Memory  
Bank 0  
(2)  
(1)  
From Opcode  
BSR  
000h  
100h  
7
0
7
0
00h  
0
0
0
0
0
0
1
0
1
1
1
1
1
1
1
1
FFh  
00h  
Bank 1  
(2)  
Bank Select  
FFh  
00h  
200h  
300h  
Bank 2  
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 MOVFF instruction embeds the entire 12-bit address in the instruction.  
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 80h 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.  
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.  
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 5.6.3 “Mapping the Access Bank in  
Indexed Literal Offset Mode”.  
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 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 5-5).  
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’,  
however, the instruction is forced to use the Access  
Bank address map; the current value of the BSR is  
ignored entirely.  
© 2007 Microchip Technology Inc.  
DS39629C-page 73  
PIC18F6390/6490/8390/8490  
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  
section. Registers related to the operation of the  
peripheral features 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  
three-quarters of Bank 15 (from F40h to FFFh). A list of  
these registers is given in Table 5-1 and Table 5-2.  
The SFRs are typically distributed among the  
peripherals whose functions they control. Unused SFR  
locations are unimplemented and read as ‘0’s.  
TABLE 5-1:  
SPECIAL FUNCTION REGISTER MAP FOR PIC18F6390/6490/8390/8490 DEVICES  
Address  
Name  
Address  
FDFh  
FDEh POSTINC2  
Name  
Address  
FBFh  
Name  
Address  
F9Fh  
Name  
(1)  
FFFh  
FFEh  
FFDh  
FFCh  
FFBh  
FFAh  
FF9h  
FF8h  
FF7h  
FF6h  
FF5h  
FF4h  
FF3h  
FF2h  
FF1h  
FF0h  
FEFh  
TOSU  
TOSH  
INDF2  
CCPR1H  
CCPR1L  
IPR1  
PIR1  
PIE1  
(1)  
(1)  
FBEh  
FBDh  
FBCh  
FBBh  
FBAh  
FB9h  
FB8h  
FB7h  
FB6h  
FB5h  
FB4h  
FB3h  
FB2h  
FB1h  
FB0h  
FAFh  
FAEh  
FADh  
FACh  
FABh  
FAAh  
FA9h  
FA8h  
FA7h  
FA6h  
FA5h  
FA4h  
FA3h  
FA2h  
FA1h  
FA0h  
F9Eh  
F9Dh  
TOSL  
FDDh POSTDEC2  
CCP1CON  
CCPR2H  
CCPR2L  
(1)  
(3)  
STKPTR  
PCLATU  
PCLATH  
PCL  
FDCh PREINC2  
F9Ch MEMCON  
(1)  
FDBh  
FDAh  
FD9h  
FD8h  
FD7h  
FD6h  
FD5h  
FD4h  
FD3h  
FD2h  
FD1h  
FD0h  
FCFh  
FCEh  
FCDh  
FCCh  
FCBh  
FCAh  
FC9h  
FC8h  
FC7h  
FC6h  
FC5h  
FC4h  
FC3h  
FC2h  
FC1h  
FC0h  
PLUSW2  
F9Bh  
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  
OSCTUNE  
(3)  
(3)  
FSR2H  
FSR2L  
CCP2CON  
TRISJ  
(2)  
TRISH  
TRISG  
TRISF  
TRISE  
TRISD  
TRISC  
TRISB  
TRISA  
(2)  
TBLPTRU  
TBLPTRH  
TBLPTRL  
TABLAT  
PRODH  
PRODL  
INTCON  
INTCON2  
INTCON3  
STATUS  
TMR0H  
TMR0L  
T0CON  
(2)  
(2)  
CVRCON  
CMCON  
TMR3H  
TMR3L  
(2)  
OSCCON  
HLVDCON  
WDTCON  
RCON  
(3)  
T3CON  
LATJ  
(2)  
(3)  
LATH  
(1)  
INDF0  
TMR1H  
SPBRG1  
RCREG1  
TXREG1  
TXSTA1  
RCSTA1  
LATG  
LATF  
LATE  
LATD  
LATC  
LATB  
LATA  
(1)  
FEEh POSTINC0  
FEDh POSTDEC0  
TMR1L  
(1)  
T1CON  
(1)  
FECh PREINC0  
TMR2  
(1)  
FEBh  
FEAh  
FE9h  
FE8h  
FE7h  
PLUSW0  
PR2  
(2)  
FSR0H  
FSR0L  
WREG  
T2CON  
(2)  
SSPBUF  
SSPADD  
SSPSTAT  
SSPCON1  
SSPCON2  
ADRESH  
ADRESL  
ADCON0  
ADCON1  
ADCON2  
(2)  
(3)  
PORTJ  
PORTH  
(1)  
(2)  
(3)  
INDF1  
(1)  
(1)  
(2)  
FE6h POSTINC1  
PORTG  
PORTF  
PORTE  
PORTD  
PORTC  
PORTB  
PORTA  
FE5h POSTDEC1  
IPR3  
PIR3  
PIE3  
IPR2  
PIR2  
PIE2  
(1)  
FE4h PREINC1  
(1)  
FE3h  
FE2h  
FE1h  
FE0h  
PLUSW1  
FSR1H  
FSR1L  
BSR  
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.  
4: This register is implemented but unused on 64-pin devices.  
DS39629C-page 74  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
TABLE 5-1:  
SPECIAL FUNCTION REGISTER MAP FOR PIC18F6390/6490/8390/8490 DEVICES  
(CONTINUED)  
Address  
Name  
Address  
F6Fh  
Name  
Address  
F5Fh  
Name  
Address  
F4Fh  
Name  
(3)  
(3)  
(2)  
F7Fh  
SPBRGH1  
SPBRG2  
RCREG2  
TXREG2  
TXSTA2  
RCSTA2  
LCDSE5  
LCDSE4  
(2)  
F7Eh BAUDCON1  
F6Eh  
F6Dh  
F6Ch  
F6Bh  
F5Eh  
F5Dh  
F5Ch  
F5Bh  
F5Ah  
F59h  
F58h  
F57h  
F56h  
F55h  
F54h  
F53h  
F52h  
F51h  
F50h  
F4Eh  
F4Dh  
F4Ch  
F4Bh  
F4Ah  
F49h  
F48h  
F47h  
F46h  
F45h  
F44h  
F43h  
F42h  
F41h  
F40h  
(2)  
(2)  
F7Dh  
LCDSE3  
LCDSE2  
LCDSE1  
LCDSE0  
LCDCON  
LCDPS  
(4)  
(4)  
(2)  
F7Ch LCDDATA23  
F7Bh LCDDATA22  
(2)  
(4)  
(2)  
F7Ah LCDDATA21  
F79h LCDDATA20  
F78h LCDDATA19  
F77h LCDDATA18  
F6Ah LCDDATA10  
(2)  
F69h  
F68h  
F67h  
F66h  
LCDDATA9  
(2)  
LCDDATA8  
LCDDATA7  
LCDDATA6  
(2)  
(2)  
(4)  
(2)  
(2)  
F76h LCDDATA17  
F75h LCDDATA16  
(4)  
(4)  
(2)  
(2)  
F65h LCDDATA5  
F64h LCDDATA4  
(4)  
(2)  
(2)  
F74h LCDDATA15  
F73h LCDDATA14  
F72h LCDDATA13  
F71h LCDDATA12  
(2)  
(2)  
F63h  
F62h  
F61h  
F60h  
LCDDATA3  
(2)  
(2)  
LCDDATA2  
LCDDATA1  
LCDDATA0  
(2)  
(2)  
(4)  
(2)  
(2)  
F70h LCDDATA11  
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.  
4: This register is implemented but unused on 64-pin devices.  
© 2007 Microchip Technology Inc.  
DS39629C-page 75  
PIC18F6390/6490/8390/8490  
TABLE 5-2:  
PIC18F6390/6490/8390/8490 REGISTER FILE SUMMARY  
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  
TOSU  
Top-of-Stack Upper Byte (TOS<20:16>)  
---0 0000 59, 66  
0000 0000 59, 66  
0000 0000 59, 66  
00-0 0000 59, 67  
---0 0000 59, 66  
0000 0000 59, 66  
0000 0000 59, 66  
--00 0000 59, 88  
0000 0000 59, 88  
0000 0000 59, 88  
0000 0000 59, 88  
xxxx xxxx 59, 91  
xxxx xxxx 59, 91  
0000 000x 59, 95  
1111 1111 59, 96  
1100 0000 59, 97  
TOSH  
Top-of-Stack High Byte (TOS<15:8>)  
Top-of-Stack Low Byte (TOS<7:0>)  
TOSL  
STKPTR  
PCLATU  
PCLATH  
PCL  
STKFUL  
STKUNF  
Return Stack Pointer  
Holding Register for PC<20:16>  
Holding Register for PC<15:8>  
PC Low Byte (PC<7:0>)  
TBLPTRU  
TBLPTRH  
TBLPTRL  
TABLAT  
PRODH  
PRODL  
bit 21  
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  
INTCON  
INTCON2  
INTCON3  
INDF0  
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)  
Uses contents of FSR0 to address data memory – value of FSR0 post-decremented (not a physical register)  
Uses contents of FSR0 to address data memory – value of FSR0 pre-incremented (not a physical register)  
N/A  
N/A  
N/A  
N/A  
N/A  
59, 82  
59, 83  
59, 83  
59, 83  
59, 83  
POSTINC0  
POSTDEC0  
PREINC0  
PLUSW0  
Uses contents of FSR0 to address data memory – value of FSR0 pre-incremented (not a physical register),  
value of FSR0 offset by W  
FSR0H  
Indirect Data Memory Address Pointer 0 High Byte  
---- xxxx 59, 82  
xxxx xxxx 59, 82  
FSR0L  
Indirect Data Memory Address Pointer 0 Low Byte  
Working Register  
WREG  
xxxx xxxx  
N/A  
59  
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)  
Uses contents of FSR1 to address data memory – value of FSR1 post-decremented (not a physical register)  
Uses contents of FSR1 to address data memory – value of FSR1 pre-incremented (not a physical register)  
59, 82  
59, 83  
59, 83  
59, 83  
59, 83  
POSTINC1  
POSTDEC1  
PREINC1  
PLUSW1  
N/A  
N/A  
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  
Indirect Data Memory Address Pointer 1 High Byte  
---- xxxx 60, 82  
xxxx xxxx 60, 82  
---- 0000 60, 71  
FSR1L  
Indirect Data Memory Address Pointer 1 Low Byte  
BSR  
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)  
Uses contents of FSR2 to address data memory – value of FSR2 post-decremented (not a physical register)  
Uses contents of FSR2 to address data memory – value of FSR2 pre-incremented (not a physical register)  
N/A  
N/A  
N/A  
N/A  
N/A  
60, 82  
60, 83  
60, 83  
60, 83  
60, 83  
POSTINC2  
POSTDEC2  
PREINC2  
PLUSW2  
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  
STATUS  
Indirect Data Memory Address Pointer 2 High Byte  
---- xxxx 60, 82  
xxxx xxxx 60, 82  
---x xxxx 60, 80  
Indirect Data Memory Address Pointer 2 Low Byte  
N
OV  
Z
DC  
C
Legend:  
x= unknown, u= unchanged, – = unimplemented, q= value depends on condition  
Note 1:  
The SBOREN bit is only available when the BOREN1:BOREN0 Configuration bits = 01; otherwise it is disabled and reads as ‘0’. See  
Section 4.4 “Brown-out Reset (BOR)”.  
2:  
3:  
These registers and/or bits are not implemented on 64-pin devices; read as ‘0’.  
The PLLEN bit is only available in specific oscillator configurations; otherwise, it is disabled and reads as ‘0’. See Section 2.6.4 “PLL in  
INTOSC Modes”.  
4:  
5:  
6:  
The RG5 bit is only available when Master Clear is disabled (MCLRE Configuration bit = 0); otherwise, RG5 reads as ‘0’. This bit is  
read-only.  
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’.  
These registers are implemented but unused in 64-pin devices and may be used as general-purpose data RAM if required.  
DS39629C-page 76  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
TABLE 5-2:  
PIC18F6390/6490/8390/8490 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  
TMR0H  
Timer0 Register High Byte  
Timer0 Register Low Byte  
0000 0000 60, 132  
xxxx xxxx 60, 132  
1111 1111 60, 131  
0100 q000 38, 60  
0-00 0101 60, 251  
--- ---0 60, 288  
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 52, 60,  
107  
TMR1H  
TMR1L  
T1CON  
TMR2  
Timer1 Register High Byte  
Timer1 Register Low Byte  
xxxx xxxx 60, 137  
xxxx xxxx 60, 137  
RD16  
T1RUN  
T1CKPS1  
T1CKPS0  
T1OSCEN  
T1SYNC  
TMR1CS  
T2CKPS1  
TMR1ON 0000 0000 60, 135  
0000 0000 60, 141  
Timer2 Register  
PR2  
Timer2 Period Register  
T2OUTPS3 T2OUTPS2 T2OUTPS1 T2OUTPS0 TMR2ON  
MSSP Receive Buffer/Transmit Register  
1111 1111 60, 141  
T2CON  
SSPBUF  
T2CKPS0 -000 0000 60, 141  
xxxx xxxx 60, 158,  
166  
SSPADD  
SSPSTAT  
MSSP Address Register in I2C™ Slave Mode. MSSP Baud Rate Reload Register in I2C Master Mode.  
0000 0000 60, 166  
SMP  
WCOL  
GCEN  
CKE  
D/A  
P
S
R/W  
SSPM2  
PEN  
UA  
BF  
0000 0000 60, 158,  
167  
SSPCON1  
SSPOV  
SSPEN  
ACKDT  
CKP  
SSPM3  
RCEN  
SSPM1  
RSEN  
SSPM0  
SEN  
0000 0000 60, 159,  
168  
SSPCON2  
ADRESH  
ADRESL  
ADCON0  
ADCON1  
ADCON2  
CCPR1H  
ACKSTAT  
ACKEN  
0000 0000 60, 169  
xxxx xxxx 61, 240  
xxxx xxxx 61, 240  
--00 0000 61, 231  
--00 0000 61, 232  
0-00 0000 61, 233  
A/D Result Register High Byte  
A/D Result Register Low Byte  
CHS3  
VCFG1  
ACQT2  
CHS2  
VCFG0  
ACQT1  
CHS1  
PCFG3  
ACQT0  
CHS0  
PCFG2  
ADCS2  
GO/DONE  
PCFG1  
ADON  
PCFG0  
ADCS0  
ADFM  
ADCS1  
Capture/Compare/PWM Register 1 High Byte  
xxxx xxxx 61, 152,  
155  
CCPR1L  
Capture/Compare/PWM Register 1 Low Byte  
xxxx xxxx 61, 152,  
155  
CCP1CON  
CCPR2H  
DC1B1  
DC1B0  
CCP1M3  
CCP1M2  
CCP1M1  
CCP1M0 --00 0000 61, 147  
Capture/Compare/PWM Register 2 High Byte  
xxxx xxxx 61, 152,  
155  
CCPR2L  
Capture/Compare/PWM Register 2 Low Byte  
xxxx xxxx 61, 152,  
155  
CCP2CON  
CVRCON  
CMCON  
TMR3H  
DC2B1  
CVRR  
C2INV  
DC2B0  
CVRSS  
C1INV  
CCP2M3  
CVR3  
CIS  
CCP2M2  
CVR2  
CCP2M1  
CVR1  
CCP2M0 --00 0000 61, 147  
CVREN  
C2OUT  
CVROE  
C1OUT  
CVR0  
CM0  
0000 0000 61, 247  
0000 0111 61, 241  
xxxx xxxx 61, 145  
xxxx xxxx 61, 145  
CM2  
CM1  
Timer3 Register High Byte  
Timer3 Register Low Byte  
TMR3L  
T3CON  
RD16  
T3CCP2  
T3CKPS1  
T3CKPS0  
T3CCP1  
T3SYNC  
TMR3CS  
TMR3ON 0000 0000 61, 143  
Legend:  
x= unknown, u= unchanged, – = unimplemented, q= value depends on condition  
Note 1:  
The SBOREN bit is only available when the BOREN1:BOREN0 Configuration bits = 01; otherwise it is disabled and reads as ‘0’. See  
Section 4.4 “Brown-out Reset (BOR)”.  
2:  
3:  
These registers and/or bits are not implemented on 64-pin devices; read as ‘0’.  
The PLLEN bit is only available in specific oscillator configurations; otherwise, it is disabled and reads as ‘0’. See Section 2.6.4 “PLL in  
INTOSC Modes”.  
4:  
5:  
6:  
The RG5 bit is only available when Master Clear is disabled (MCLRE Configuration bit = 0); otherwise, RG5 reads as ‘0’. This bit is  
read-only.  
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’.  
These registers are implemented but unused in 64-pin devices and may be used as general-purpose data RAM if required.  
© 2007 Microchip Technology Inc.  
DS39629C-page 77  
PIC18F6390/6490/8390/8490  
TABLE 5-2:  
PIC18F6390/6490/8390/8490 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  
SPBRG1  
RCREG1  
TXREG1  
TXSTA1  
RCSTA1  
IPR3  
EUSART1 Baud Rate Generator Register Low Byte  
EUSART1 Receive Register  
0000 0000 61, 201  
0000 0000 61, 208  
0000 0000 61, 206  
0000 0010 61, 198  
0000 000x 61, 199  
-111 ---- 61, 106  
-000 ---- 61, 100  
-000 ---- 61, 103  
11-- 1111 61, 105  
00-- 0000 61, 99  
00-- 0000 61, 102  
-111 1111 61, 104  
-000 0000 61, 98  
-000 0000 61, 101  
00-0 0000 35, 61  
1111 1111 62, 130  
1111 1111 62, 128  
---1 1111 62, 126  
1111 1111 62, 124  
1111 ---- 62, 121  
1111 1111 62, 119  
1111 1111 62, 117  
1111 1111 62, 114  
1111 1111 62, 111  
xxxx xxxx 62, 130  
xxxx xxxx 62, 128  
---x xxxx 62, 126  
xxxx xxxx 62, 124  
xxxx ---- 62, 121  
xxxx xxxx 62, 119  
xxxx xxxx 62, 117  
xxxx xxxx 62, 114  
xxxx xxxx 62, 111  
xxxx xxxx 62, 130  
xxxx xxxx 62, 128  
--xx xxxx 62, 126  
xxxx xxxx 62, 124  
xxxx ---- 62, 121  
xxxx xxxx 62, 119  
xxxx xxxx 62, 117  
xxxx xxxx 62, 114  
xx0x 0000 62, 111  
EUSART1 Transmit Register  
CSRC  
SPEN  
TX9  
RX9  
TXEN  
SREN  
RC2IP  
RC2IF  
RC2IE  
SYNC  
CREN  
TX2IP  
TX2IF  
TX2IE  
SENDB  
ADDEN  
BRGH  
FERR  
TRMT  
OERR  
TX9D  
RX9D  
LCDIP  
LCDIF  
LCDIE  
CMIP  
CMIF  
CMIE  
ADIP  
PIR3  
PIE3  
IPR2  
OSCFIP  
OSCFIF  
OSCFIE  
BCLIP  
BCLIF  
BCLIE  
SSPIP  
SSPIF  
SSPIE  
TUN3  
HLVDIP  
HLVDIF  
HLVDIE  
CCP1IP  
CCP1IF  
CCP1IE  
TUN2  
TMR3IP  
TMR3IF  
TMR3IE  
TMR2IP  
TMR2IF  
TMR2IE  
TUN1  
CCP2IP  
CCP2IF  
CCP2IE  
TMR1IP  
TMR1IF  
TMR1IE  
TUN0  
PIR2  
PIE2  
IPR1  
RC1IP  
RC1IF  
RC1IE  
TX1IP  
TX1IF  
TX1IE  
TUN4  
PIR1  
ADIF  
PIE1  
ADIE  
PLLEN(3)  
OSCTUNE  
TRISJ(2)  
TRISH(2)  
TRISG  
TRISF  
TRISE  
TRISD  
TRISC  
TRISB  
TRISA  
LATJ(2)  
LATH(2)  
LATG  
INTSRC  
PORTJ Data Direction Register  
PORTH Data Direction Register  
PORTG Data Direction Register  
PORTF Data Direction Register  
PORTE Data Direction Register  
PORTD Data Direction Register  
PORTC Data Direction Register  
PORTB Data Direction Register  
TRISA7(5)  
TRISA6(5) PORTA Data Direction Register  
LATJ Data Output Register  
LATH Data Output Register  
LATG Data Output Register  
LATF  
LATF Data Output Register  
LATE Data Output Register  
LATD Data Output Register  
LATC Data Output Register  
LATB Data Output Register  
LATE  
LATD  
LATC  
LATB  
LATA  
LATA7(5)  
LATA6(5) LATA Data Output Register  
PORTJ(2)  
PORTH(2)  
PORTG  
PORTF  
PORTE  
PORTD  
PORTC  
PORTB  
PORTA  
Read PORTJ pins, Write PORTJ Data Latch  
Read PORTH pins, Write PORTH Data Latch  
RG5(4)  
Read PORTG pins <4:0>, Write PORTG Data Latch <4:0>  
Read PORTF pins, Write PORTF Data Latch  
Read PORTE pins, Write PORTE Data Latch  
Read PORTD pins, Write PORTD Data Latch  
Read PORTC pins, Write PORTC Data Latch  
Read PORTB pins, Write PORTB Data Latch  
RA7(5)  
RA6(5)  
Read PORTA pins, Write PORTA Data Latch  
Legend:  
x= unknown, u= unchanged, – = unimplemented, q= value depends on condition  
Note 1:  
The SBOREN bit is only available when the BOREN1:BOREN0 Configuration bits = 01; otherwise it is disabled and reads as ‘0’. See  
Section 4.4 “Brown-out Reset (BOR)”.  
2:  
3:  
These registers and/or bits are not implemented on 64-pin devices; read as ‘0’.  
The PLLEN bit is only available in specific oscillator configurations; otherwise, it is disabled and reads as ‘0’. See Section 2.6.4 “PLL in  
INTOSC Modes”.  
4:  
5:  
6:  
The RG5 bit is only available when Master Clear is disabled (MCLRE Configuration bit = 0); otherwise, RG5 reads as ‘0’. This bit is  
read-only.  
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’.  
These registers are implemented but unused in 64-pin devices and may be used as general-purpose data RAM if required.  
DS39629C-page 78  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
TABLE 5-2:  
PIC18F6390/6490/8390/8490 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  
SPBRGH1  
BAUDCON1  
LCDDATA23(6)  
LCDDATA22(6)  
LCDDATA21  
LCDDATA20  
LCDDATA19  
LCDDATA18  
LCDDATA17(6)  
LCDDATA16(6)  
LCDDATA15  
LCDDATA14  
LCDDATA13  
LCDDATA12  
LCDDATA11(6)  
SPBRG2  
EUSART1 Baud Rate Generator Register High Byte  
0000 0000 62, 201  
01-0 0-00 62, 200  
xxxx xxxx 63, 261  
xxxx xxxx 63, 261  
xxxx xxxx 63, 261  
xxxx xxxx 63, 261  
xxxx xxxx 63, 261  
xxxx xxxx 63, 261  
xxxx xxxx 63, 261  
xxxx xxxx 63, 261  
xxxx xxxx 63, 261  
xxxx xxxx 63, 261  
xxxx xxxx 63, 261  
xxxx xxxx 63, 261  
xxxx xxxx 63, 261  
0000 0000 63, 220  
0000 0000 63, 224  
0000 0000 63, 222  
0000 -010 63, 218  
0000 000x 63, 219  
xxxx xxxx 63, 261  
xxxx xxxx 63, 261  
xxxx xxxx 63, 261  
xxxx xxxx 63, 261  
xxxx xxxx 63, 261  
xxxx xxxx 63, 261  
xxxx xxxx 63, 261  
xxxx xxxx 63, 261  
xxxx xxxx 63, 261  
xxxx xxxx 63, 261  
xxxx xxxx 63, 261  
0000 0000 64, 261  
0000 0000 64, 260  
0000 0000 64, 260  
0000 0000 64, 260  
0000 0000 64, 260  
0000 0000 64, 260  
000- 0000 64, 258  
0000 0000 64, 259  
ABDOVF  
S47C3  
S39C3  
S31C3  
S23C3  
S15C3  
S07C3  
S47C2  
S39C2  
S31C2  
S23C2  
S15C2  
S07C2  
S47C1  
RCIDL  
S46C3  
S38C3  
S30C3  
S22C3  
S14C3  
S06C3  
S46C2  
S38C2  
S30C2  
S22C2  
S14C2  
S06C2  
S46C1  
SCKP  
S44C3  
S36C3  
S28C3  
S20C3  
S12C3  
S04C3  
S44C2  
S36C2  
S28C2  
S20C2  
S12C2  
S04C2  
S44C1  
BRG16  
S43C3  
S35C3  
S27C3  
S19C3  
S11C3  
S03C3  
S43C2  
S35C2  
S27C2  
S19C2  
S11C2  
S03C2  
S43C1  
WUE  
ABDEN  
S40C3  
S32C3  
S24C3  
S16C3  
S08C3  
S00C3  
S40C2  
S32C2  
S24C2  
S16C2  
S08C2  
S00C2  
S40C1  
S45C3  
S37C3  
S29C3  
S21C3  
S13C3  
S05C3  
S45C2  
S37C2  
S29C2  
S21C2  
S13C2  
S05C2  
S45C1  
S42C3  
S34C3  
S26C3  
S18C3  
S10C3  
S02C3  
S42C2  
S34C2  
S26C2  
S18C2  
S10C2  
S02C2  
S42C1  
S41C3  
S33C3  
S25C3  
S17C3  
S09C3  
S01C3  
S41C2  
S33C2  
S25C2  
S17C2  
S09C2  
S01C2  
S41C1  
AUSART2 Baud Rate Generator Register  
AUSART2 Receive Register  
RCREG2  
TXREG2  
AUSART2 Transmit Register  
TXSTA2  
CSRC  
SPEN  
S39C1  
S31C1  
S23C1  
S15C1  
S07C1  
S47C0  
S39C0  
S31C0  
S23C0  
S15C0  
S07C0  
SE47  
TX9  
RX9  
TXEN  
SREN  
S37C1  
S29C1  
S21C1  
S13C1  
S05C1  
S45C0  
S37C0  
S29C0  
S21C0  
S13C0  
S05C0  
SE45  
SYNC  
CREN  
S36C1  
S28C1  
S20C1  
S12C1  
S04C1  
S44C0  
S36C0  
S28C0  
S20C0  
S12C0  
S04C0  
SE44  
SE36  
SE28  
SE20  
SE12  
SE4  
BRGH  
FERR  
S34C1  
S26C1  
S18C1  
S10C1  
S02C1  
S42C0  
S34C0  
S26C0  
S18C0  
S10C0  
S02C0  
SE42  
TRMT  
OERR  
S33C1  
S25C1  
S17C1  
S09C1  
S01C1  
S41C0  
S33C0  
S25C0  
S17C0  
S09C0  
S01C0  
SE41  
TX9D  
RX9D  
S32C1  
S24C1  
S16C1  
S08C1  
S00C1  
S40C0  
S32C0  
S24C0  
S16C0  
S08C0  
S00C0  
SE40  
RCSTA2  
ADDEN  
S35C1  
S27C1  
S19C1  
S11C1  
S03C1  
S43C0  
S35C0  
S27C0  
S19C0  
S11C0  
S03C0  
SE43  
LCDDATA10(6)  
LCDDATA9  
LCDDATA8  
LCDDATA7  
LCDDATA6  
LCDDATA5(6)  
LCDDATA4(6)  
LCDDATA3  
LCDDATA2  
LCDDATA1  
LCDDATA0  
LCDSE5(2)  
LCDSE4(2)  
LCDSE3  
S38C1  
S30C1  
S22C1  
S14C1  
S06C1  
S46C0  
S38C0  
S30C0  
S22C0  
S14C0  
S06C0  
SE46  
SE39  
SE38  
SE37  
SE35  
SE34  
SE33  
SE32  
SE31  
SE30  
SE29  
SE27  
SE26  
SE25  
SE24  
LCDSE2  
SE23  
SE22  
SE21  
SE19  
SE18  
SE17  
SE16  
LCDSE1  
SE15  
SE14  
SE13  
SE11  
SE10  
SE9  
SE8  
LCDSE0  
SE7  
SE6  
SE5  
SE3  
SE2  
SE1  
SE0  
LCDCON  
LCDEN  
WFT  
SLPEN  
BIASMD  
WERR  
LCDA  
CS1  
CS0  
LMUX1  
LP1  
LMUX0  
LP0  
LCDPS  
WA  
LP3  
LP2  
Legend:  
x= unknown, u= unchanged, – = unimplemented, q= value depends on condition  
Note 1:  
The SBOREN bit is only available when the BOREN1:BOREN0 Configuration bits = 01; otherwise it is disabled and reads as ‘0’. See  
Section 4.4 “Brown-out Reset (BOR)”.  
2:  
3:  
These registers and/or bits are not implemented on 64-pin devices; read as ‘0’.  
The PLLEN bit is only available in specific oscillator configurations; otherwise, it is disabled and reads as ‘0’. See Section 2.6.4 “PLL in  
INTOSC Modes”.  
4:  
5:  
6:  
The RG5 bit is only available when Master Clear is disabled (MCLRE Configuration bit = 0); otherwise, RG5 reads as ‘0’. This bit is  
read-only.  
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’.  
These registers are implemented but unused in 64-pin devices and may be used as general-purpose data RAM if required.  
© 2007 Microchip Technology Inc.  
DS39629C-page 79  
PIC18F6390/6490/8390/8490  
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 24-2 and  
Table 24-3.  
If the STATUS register is the destination for an instruc-  
tion that affects the Z, DC, C, OV or N bits, the results of  
the instruction are not written; instead, the status 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 a borrow and  
digit borrow bit respectively, in subtraction.  
REGISTER 5-2:  
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) 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.  
DS39629C-page 80  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
Purpose Register File”), or a location in the Access  
Bank (Section 5.3.2 “Access Bank”) as the data  
source for the instruction.  
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 5.6 “Data Memory  
and the Extended Instruction Set” for  
more information.  
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”) 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.  
While the program memory can be addressed in only  
one way – through the program counter – information  
in 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.  
A few instructions, such as MOVFF, include the entire  
12-bit address (either source or destination) in their  
op codes. In those cases, the BSR is ignored entirely.  
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 5.6.1 “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 Function Registers, they can also be directly  
manipulated 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  
argument 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, RESET  
and 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. It also enables users to perform  
Indexed Addressing and other Stack Pointer  
operations for program memory in data memory.  
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 ADDLW and 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  
5.4.2  
DIRECT ADDRESSING  
INDIRECT ADDRESSING  
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.  
LFSR  
CLRF  
FSR0, 100h  
;
NEXT  
POSTINC0  
; Clear INDF  
; register then  
; inc pointer  
; All done with  
; Bank1?  
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  
BTFSS  
BRA  
FSR0H, 1  
NEXT  
; NO, clear next  
; YES, continue  
CONTINUE  
© 2007 Microchip Technology Inc.  
DS39629C-page 81  
PIC18F6390/6490/8390/8490  
mapped in the SFR space but are not physically  
implemented. 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.  
5.4.3.1  
FSR Registers and the  
INDF Operand  
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.  
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.  
Indirect Addressing is accomplished with a set of  
Indirect File Operands, INDF0 through INDF2. These  
can be thought of as “virtual” registers: they are  
FIGURE 5-7:  
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 1  
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  
FCCh. This means the contents of  
location FCCh will be added to that  
of the W register and stored back in  
FCCh.  
Bank 14  
Bank 15  
F00h  
FFFh  
Data Memory  
DS39629C-page 82  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
5.4.3.2  
FSR Registers and POSTINC,  
5.4.3.3  
Operations by FSRs on FSRs  
POSTDEC, PREINC and PLUSW  
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.  
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  
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.  
• 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.  
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.  
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.  
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.  
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.).  
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.  
© 2007 Microchip Technology Inc.  
DS39629C-page 83  
PIC18F6390/6490/8390/8490  
When using the extended instruction set, this  
addressing mode requires the following:  
5.5  
Program Memory and the  
Extended Instruction Set  
• The use of the Access Bank is forced (‘a’ = 0);  
and  
The operation of program memory is unaffected by the  
use of the extended instruction set.  
• The file address argument is less than or equal to  
5Fh.  
Enabling the extended instruction set adds five addi-  
tional two-word commands to the existing PIC18  
instruction set: ADDFSR, CALLW, MOVSF, MOVSS and  
SUBFSR. These instructions are executed as described  
in Section 5.2.4 “Two-Word Instructions”.  
Under these conditions, the file address of the  
instruction 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.  
5.6  
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.  
Specifically, 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. This mode also alters the behavior of  
Indirect Addressing using FSR2 and its associated  
operands.  
5.6.2  
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. Instruc-  
tions that only use Inherent or Literal Addressing  
modes are unaffected.  
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 remains unchanged.  
Additionally, byte-oriented and bit-oriented instructions  
are not affected if they 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 different  
possible addressing modes when the extended  
instruction set is enabled is shown in Figure 5-8.  
5.6.1  
INDEXED ADDRESSING WITH  
LITERAL OFFSET  
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 24.2.1  
“Extended Instruction Syntax”.  
Enabling the PIC18 extended instruction set changes  
the behavior of Indirect Addressing using the FSR2  
register pair and its associated file operands. 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  
addressing mode is known as Indexed Addressing with  
Literal Offset, or Indexed Literal Offset mode.  
DS39629C-page 84  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
FIGURE 5-8:  
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 = 0and f 60h:  
The instruction executes in  
Direct Forced mode. ‘f’ is  
interpreted as a location in the  
Access RAM between 060h  
and FFFh. This is the same as  
locations F60h to FFFh  
(Bank 15) of data memory.  
060h  
100h  
Bank 0  
00h  
60h  
Bank 1  
through  
Bank 14  
Valid range  
for ‘f’  
Locations below 060h are not  
available in this addressing  
mode.  
FFh  
F00h  
Access RAM  
Bank 15  
SFRs  
F40h  
FFFh  
Data Memory  
When a = 0and f 5Fh:  
000h  
060h  
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  
F40h  
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  
060h  
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  
interpreted 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  
F40h  
Bank 15  
SFRs  
FFFh  
Data Memory  
© 2007 Microchip Technology Inc.  
DS39629C-page 85  
PIC18F6390/6490/8390/8490  
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. Any indirect or  
indexed operation that explicitly uses any of the indirect  
file operands (including FSR2) will continue to operate  
as standard Indirect Addressing. Any instruction that  
uses the Access Bank, but includes a register address  
of greater than 05Fh, will use Direct Addressing and  
the normal Access Bank map.  
5.6.3  
MAPPING THE ACCESS BANK IN  
INDEXED LITERAL OFFSET MODE  
The use of Indexed Literal Offset Addressing mode  
effectively changes how the lower part of Access RAM  
(00h to 5Fh) is mapped. Rather than containing just the  
contents of the bottom part 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 bound-  
ary 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 5-9.  
5.6.4  
BSR IN INDEXED LITERAL  
OFFSET MODE  
Although the Access Bank is remapped when the  
extended instruction set is enabled, the operation of the  
BSR remains unchanged. Direct Addressing, using the  
BSR to select the data memory bank, operates in the  
same manner as previously described.  
FIGURE 5-9:  
REMAPPING THE ACCESS BANK WITH INDEXED LITERAL  
OFFSET ADDRESSING  
Example Situation:  
000h  
ADDWF f, d, a  
FSR2H:FSR2L = 120h  
Not Accessible  
05Fh  
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  
Window  
Bank 1  
00h  
Bank 1 “Window”  
200h  
5Fh  
60h  
Special File Registers at  
F60h through FFFh are  
mapped to 60h through  
FFh, as usual.  
Bank 2  
through  
Bank 14  
SFRs  
Bank 0 addresses below  
5Fh are not available in  
this mode. They can still  
be addressed by using the  
BSR.  
FFh  
Access Bank  
F00h  
Bank 15  
SFRs  
F60h  
FFFh  
Data Memory  
DS39629C-page 86  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
Table reads work with byte entities. A table block  
6.0  
FLASH PROGRAM MEMORY  
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.  
In PIC18F6390/6490/8390/8490 devices, the program  
memory is implemented as read-only Flash memory. It  
is readable over the entire VDD range during normal  
operation. A read from program memory is executed on  
one byte at a time.  
Because the program memory cannot be written to or  
erased under normal operation, the TBLWToperation is  
not discussed here.  
Note 1: Although it cannot be used in  
PIC18F6390/6490/8390/8490 devices in  
normal operation, the TBLWT instruction  
is still implemented in the instruction set.  
Executing the instruction takes two  
instruction cycles, but effectively results  
in a NOP.  
6.1  
Table Reads  
For PIC18 devices, there are two operations that allow  
the processor to move bytes between the program  
memory space and the data RAM: table read (TBLRD)  
and table write (TBLWT).  
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.  
2: The TBLWTinstruction is available only in  
programming modes and is used during  
In-Circuit Serial Programming™ (ICSP™).  
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.  
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.  
© 2007 Microchip Technology Inc.  
DS39629C-page 87  
PIC18F6390/6490/8390/8490  
TABLE 6-1:  
TABLE POINTER  
6.2  
Control Registers  
OPERATIONS WITH TBLRD  
INSTRUCTIONS  
Two control registers are used in conjunction with the  
TBLRD instruction: the TABLAT register and the  
TBLPTR register set.  
Example  
Operation on Table Pointer  
TBLRD*  
TBLPTR is not modified  
6.2.1  
TABLE LATCH REGISTER (TABLAT)  
TBLRD*+  
TBLRD*-  
TBLRD+*  
TBLPTR is incremented after the read  
TBLPTR is decremented after the read  
TBLPTR is incremented before the read  
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.  
6.3  
Reading the Flash Program  
Memory  
6.2.2  
TABLE POINTER REGISTER  
(TBLPTR)  
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 Table Pointer register (TBLPTR) addresses a byte  
within the program memory. It is comprised of three  
SFR registers: Table Pointer Upper Byte, Table Pointer  
High Byte and Table Pointer Low Byte  
(TBLPTRU:TBLPTRH:TBLPTRL). Only the lower six  
bits of TBLPTRU are used with TBLPTRH and  
TBLPTRL to form a 22-bit wide pointer.  
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.  
The contents of TBLPTR indicates a location in  
program memory space. The low-order 21 bits allow  
the device to address the full 2 Mbytes of program  
memory space. The 22nd bit allows access to the  
configuration space, including the device ID, user ID  
locations and the Configuration bits.  
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 6-2  
shows the interface between the internal program  
memory and the TABLAT.  
The TBLPTR register set is updated when executing a  
TBLRDin one of four ways, based on the instruction’s  
arguments. These are detailed in Table 6-1. These  
operations on the TBLPTR only affect the low-order  
21 bits.  
A typical method for reading data from program memory  
is shown in Example 6-1.  
When a TBLRDis executed, all 22 bits of the TBLPTR  
determine which byte is read from program memory  
into TABLAT.  
FIGURE 6-2:  
READS FROM FLASH PROGRAM MEMORY  
Program Memory  
(Even Byte Address)  
(Odd Byte Address)  
TBLPTR = xxxxx1  
TBLPTR = xxxxx0  
TABLAT  
Instruction Register  
FETCH  
TBLRD  
(IR)  
Read Register  
DS39629C-page 88  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
EXAMPLE 6-1:  
READING A FLASH PROGRAM MEMORY WORD  
MOVLW  
CODE_ADDR_UPPER  
TBLPTRU  
CODE_ADDR_HIGH  
TBLPTRH  
CODE_ADDR_LOW  
TBLPTRL  
; Load TBLPTR with the base  
; address of the word  
MOVWF  
MOVLW  
MOVWF  
MOVLW  
MOVWF  
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  
MOVWF  
TABLE 6-2:  
Name  
REGISTERS ASSOCIATED WITH READING 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  
Program Memory Table Pointer Upper Byte  
(TBLPTR<20:16>)  
59  
TBLPTRH  
TBLPTRL  
TABLAT  
Program Memory Table Pointer High Byte (TBLPTR<15:8>)  
Program Memory Table Pointer Low Byte (TBLPTR<7:0>)  
Program Memory Table Latch  
59  
59  
59  
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used during Flash access.  
© 2007 Microchip Technology Inc.  
DS39629C-page 89  
PIC18F6390/6490/8390/8490  
NOTES:  
DS39629C-page 90  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
EXAMPLE 7-1:  
8 x 8 UNSIGNED  
MULTIPLY ROUTINE  
7.0  
7.1  
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 7-2:  
8 x 8 SIGNED MULTIPLY  
ROUTINE  
MOVF  
MULWF  
ARG1, W  
ARG2  
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  
applications 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 7-1.  
; 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  
7.2  
Operation  
Example 7-1 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 7-2 shows the sequence to do an 8 x 8 signed  
multiplication. To account for the signed bits of the  
arguments, each argument’s Most Significant bit (MSb)  
is tested and the appropriate subtractions are done.  
TABLE 7-1:  
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  
© 2007 Microchip Technology Inc.  
DS39629C-page 91  
PIC18F6390/6490/8390/8490  
Example 7-3 shows the sequence to do a 16 x 16  
unsigned multiplication. Equation 7-1 shows the  
algorithm that is used. The 32-bit result is stored in four  
registers (RES3:RES0).  
EQUATION 7-2:  
16 x 16 SIGNED  
MULTIPLICATION  
ALGORITHM  
RES3:RES0= ARG1H:ARG1L ARG2H:ARG2L  
= (ARG1H ARG2H 216) +  
EQUATION 7-1:  
16 x 16 UNSIGNED  
MULTIPLICATION  
ALGORITHM  
(ARG1H ARG2L 28) +  
(ARG1L ARG2H 28) +  
(ARG1L ARG2L) +  
(-1 ARG2H<7> ARG1H:ARG1L 216) +  
(-1 ARG1H<7> ARG2H:ARG2L 216)  
RES3:RES0  
=
=
ARG1H:ARG1L ARG2H:ARG2L  
(ARG1H ARG2H 216) +  
(ARG1H ARG2L 28) +  
(ARG1L ARG2H 28) +  
(ARG1L ARG2L)  
EXAMPLE 7-4:  
16 x 16 SIGNED  
MULTIPLY ROUTINE  
MOVF  
MULWF  
ARG1L, W  
ARG2L  
; ARG1L * ARG2L ->  
; PRODH:PRODL  
;
;
EXAMPLE 7-3:  
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  
; ARG1H * ARG2H ->  
; PRODH:PRODL  
;
;
MOVFF  
MOVFF  
PRODH, RES1  
PRODL, RES0  
MOVFF  
MOVFF  
PRODH, RES3  
PRODL, RES2  
;
;
MOVF  
MULWF  
ARG1H, W  
ARG2H  
; ARG1H * ARG2H->  
; PRODH:PRODL  
;
;
MOVF  
MULWF  
ARG1L, W  
ARG2H  
; ARG1L * ARG2H ->  
; PRODH:PRODL  
;
; Add cross  
; products  
MOVFF  
MOVFF  
PRODH, RES3  
PRODL, RES2  
MOVF  
ADDWF  
MOVF  
PRODL, W  
RES1, F  
PRODH, W  
MOVF  
MULWF  
ARG1L, W  
ARG2H  
; ARG1L * ARG2H->  
ADDWFC RES2, F  
CLRF WREG  
ADDWFC RES3, F  
;
;
;
; PRODH:PRODL  
;
; Add cross  
; products  
MOVF  
ADDWF  
MOVF  
PRODL, W  
RES1, F  
PRODH, W  
;
MOVF  
MULWF  
ARG1H, W  
ARG2L  
;
ADDWFC RES2, F  
CLRF WREG  
ADDWFC RES3, F  
;
;
;
; ARG1H * ARG2L ->  
; PRODH:PRODL  
MOVF  
ADDWF  
MOVF  
PRODL, W  
RES1, F  
PRODH, W  
;
;
; Add cross  
; products  
MOVF  
MULWF  
ARG1H,  
ARG2L  
W
;
; ARG1H * ARG2L->  
ADDWFC RES2, F  
CLRF WREG  
ADDWFC RES3, F  
;
;
;
; PRODH:PRODL  
;
; Add cross  
; products  
;
;
;
MOVF  
ADDWF  
MOVF  
ADDWFC RES2, F  
CLRF WREG  
ADDWFC RES3, F  
PRODL, W  
RES1, F  
PRODH, W  
;
;
BTFSS  
BRA  
MOVF  
SUBWF  
MOVF  
ARG2H, 7  
SIGN_ARG1  
ARG1L, W  
RES2  
; ARG2H:ARG2L neg?  
; no, check ARG1  
;
;
;
ARG1H, W  
Example 7-4 shows the sequence to do a 16 x 16  
signed multiply. Equation 7-2 shows the algorithm  
used. The 32-bit result is stored in four registers  
(RES3:RES0). To account for the signed bits of the  
arguments, the MSb for each argument pair is tested  
and the appropriate subtractions are done.  
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  
:
DS39629C-page 92  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
When the IPEN bit is cleared (default state), the  
interrupt priority feature is disabled and interrupts are  
8.0  
INTERRUPTS  
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.  
The PIC18F6390/6490/8390/8490 devices have  
multiple interrupt sources and an interrupt priority fea-  
ture 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 thirteen 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  
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.  
Priority bit to select high priority or low priority  
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.  
© 2007 Microchip Technology Inc.  
DS39629C-page 93  
PIC18F6390/6490/8390/8490  
FIGURE 8-1:  
PIC18F6X90/8X90 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<6:0>  
PIE1<6:0>  
IPR1<6:0>  
GIE/GIEH  
PIR2<7:6, 3:0>  
PIE2<7:6, 3:0>  
IPR2<7:6, 3:0>  
IPEN  
PIR3<6:4>  
PIE3<6:4>  
IPR3<6:4>  
IPEN  
PEIE/GIEL  
IPEN  
High-Priority Interrupt Generation  
Low-Priority Interrupt Generation  
PIR1<6:0>  
PIE1<6:0>  
IPR1<6:0>  
PIR2<7:6, 3:0>  
PIE2<7:6, 3:0>  
IPR2<7:6, 3:0>  
Interrupt to CPU  
Vector to Location  
0018h  
TMR0IF  
TMR0IE  
TMR0IP  
IPEN  
PIR3<6:4>  
PIE3<6:4>  
IPR3<6:4>  
RBIF  
RBIE  
RBIP  
GIEH/GIE  
GIEL/PEIE  
INT1IF  
INT1IE  
INT1IP  
INT2IF  
INT2IE  
INT2IP  
INT3IF  
INT3IE  
INT3IP  
DS39629C-page 94  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
8.1  
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 8-1:  
INTCON: INTERRUPT CONTROL REGISTER  
R/W-0  
R/W-0  
PEIE/GIEL  
R/W-0  
R/W-0  
R/W-0  
RBIE  
R/W-0  
R/W-0  
INT0IF  
R/W-x  
RBIF(1)  
GIE/GIEH  
bit 7  
TMR0IE  
INT0IE  
TMR0IF  
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  
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.  
© 2007 Microchip Technology Inc.  
DS39629C-page 95  
PIC18F6390/6490/8390/8490  
REGISTER 8-2:  
INTCON2: INTERRUPT CONTROL REGISTER 2  
R/W-1  
R/W-1  
INTEDG0  
R/W-1  
R/W-1  
R/W-1  
R/W-1  
R/W-1  
R/W-1  
RBIP  
RBPU  
bit 7  
INTEDG1  
INTEDG2  
INTEDG3  
TMR0IP  
INT3IP  
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.  
DS39629C-page 96  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
REGISTER 8-3:  
INTCON3: INTERRUPT CONTROL REGISTER 3  
R/W-1  
INT2IP  
bit 7  
R/W-1  
R/W-0  
R/W-0  
R/W-0  
R/W-0  
INT3IF  
R/W-0  
INT2IF  
R/W-0  
INT1IF  
INT1IP  
INT3IE  
INT2IE  
INT1IE  
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  
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.  
© 2007 Microchip Technology Inc.  
DS39629C-page 97  
PIC18F6390/6490/8390/8490  
8.2  
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 8-4:  
PIR1: PERIPHERAL INTERRUPT REQUEST (FLAG) REGISTER 1  
U-0  
R/W-0  
ADIF  
R-0  
R-0  
R/W-0  
SSPIF  
R/W-0  
R/W-0  
R/W-0  
RC1IF  
TX1IF  
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  
Unimplemented: Read as ‘0’  
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  
bit 5  
bit 4  
bit 3  
bit 2  
RC1IF: EUSART Receive Interrupt Flag bit  
1= The EUSART receive buffer, RCREG1, is full (cleared when RCREG1 is read)  
0= The EUSART receive buffer is empty  
TX1IF: EUSART Transmit Interrupt Flag bit  
1= The EUSART transmit buffer, TXREG1, is empty (cleared when TXREG1 is written)  
0= The EUSART transmit buffer is full  
SSPIF: Master Synchronous Serial Port Interrupt Flag bit  
1= The transmission/reception is complete (must be cleared in software)  
0= Waiting to transmit/receive  
CCP1IF: CCP1 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  
DS39629C-page 98  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
REGISTER 8-5:  
PIR2: PERIPHERAL INTERRUPT REQUEST (FLAG) REGISTER 2  
R/W-0  
OSCFIF  
bit 7  
R/W-0  
CMIF  
U-0  
U-0  
R/W-0  
BCLIF  
R/W-0  
R/W-0  
R/W-0  
HLVDIF  
TMR3IF  
CCP2IF  
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 5-4  
bit 3  
Unimplemented: Read as ‘0’  
BCLIF: Bus Collision Interrupt Flag bit  
1= A bus collision occurred (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: CCP2 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.  
© 2007 Microchip Technology Inc.  
DS39629C-page 99  
PIC18F6390/6490/8390/8490  
REGISTER 8-6:  
PIR3: PERIPHERAL INTERRUPT REQUEST (FLAG) REGISTER 3  
U-0  
R/W-0  
LCDIF  
R-0  
R/W-0  
TX2IF  
U-0  
U-0  
U-0  
U-0  
RC2IF  
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’  
LCDIF: LCD Interrupt Flag bit (valid when Type-B waveform with Non-Static mode is selected)  
1= LCD data of all COMs is output (must be cleared in software)  
0= LCD data of all COMs is not yet output  
bit 5  
RC2IF: AUSART Receive Interrupt Flag bit  
1= The AUSART receive buffer, RCREG2, is full (cleared when RCREG2 is read)  
0= The AUSART receive buffer is empty  
bit 4  
TX2IF: AUSART Transmit Interrupt Flag bit  
1= The AUSART transmit buffer, TXREG2, is empty (cleared when TXREG2 is written)  
0= The AUSART transmit buffer is full  
bit 3-0  
Unimplemented: Read as ‘0’  
DS39629C-page 100  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
8.3  
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 8-7:  
PIE1: PERIPHERAL INTERRUPT ENABLE REGISTER 1  
U-0  
R/W-0  
ADIE  
R/W-0  
RC1IE  
R/W-0  
TX1IE  
R/W-0  
SSPIE  
R/W-0  
R/W-0  
R/W-0  
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  
Unimplemented: Read as ‘0’  
ADIE: A/D Converter Interrupt Enable bit  
1= Enables the A/D interrupt  
0= Disables the A/D interrupt  
bit 5  
bit 4  
bit 3  
bit 2  
bit 1  
bit 0  
RC1IE: EUSART Receive Interrupt Enable bit  
1= Enables the EUSART receive interrupt  
0= Disables the EUSART receive interrupt  
TX1IE: EUSART Transmit Interrupt Enable bit  
1= Enables the EUSART transmit interrupt  
0= Disables the EUSART transmit interrupt  
SSPIE: Master Synchronous Serial Port Interrupt Enable bit  
1= Enables the MSSP interrupt  
0= Disables the MSSP interrupt  
CCP1IE: CCP1 Interrupt Enable bit  
1= Enables the CCP1 interrupt  
0= Disables the CCP1 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  
© 2007 Microchip Technology Inc.  
DS39629C-page 101  
PIC18F6390/6490/8390/8490  
REGISTER 8-8:  
PIE2: PERIPHERAL INTERRUPT ENABLE REGISTER 2  
R/W-0  
OSCFIE  
bit 7  
R/W-0  
CMIE  
U-0  
U-0  
R/W-0  
BCLIE  
R/W-0  
R/W-0  
R/W-0  
HLVDIE  
TMR3IE  
CCP2IE  
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 5-4  
bit 3  
Unimplemented: Read as ‘0’  
BCL1IE: Bus Collision Interrupt Enable bit  
1= Enabled  
0= Disabled  
bit 2  
bit 1  
bit 0  
HLVDIE: High/Low-Voltage Detect Interrupt Enable bit  
1= Enabled  
0= Disabled  
TMR3IE: TMR3 Overflow Interrupt Enable bit  
1= Enabled  
0= Disabled  
CCP2IE: CCP2 Interrupt Enable bit  
1= Enabled  
0= Disabled  
DS39629C-page 102  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
REGISTER 8-9:  
PIE3: PERIPHERAL INTERRUPT ENABLE REGISTER 3  
U-0  
R/W-0  
LCDIE  
R-0  
R-0  
U-0  
U-0  
U-0  
U-0  
RC2IE  
TX2IE  
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’  
LCDIE: LCD Interrupt Enable bit (valid when Type-B waveform with Non-Static mode is selected)  
1= Enabled  
0= Disabled  
bit 5  
RC2IE: AUSART Receive Interrupt Enable bit  
1= Enabled  
0= Disabled  
bit 4  
TX2IE: AUSART Transmit Interrupt Enable bit  
1= Enabled  
0= Disabled  
bit 3-0  
Unimplemented: Read as ‘0’  
© 2007 Microchip Technology Inc.  
DS39629C-page 103  
PIC18F6390/6490/8390/8490  
8.4  
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 8-10: IPR1: PERIPHERAL INTERRUPT PRIORITY REGISTER 1  
U-0  
R/W-1  
ADIP  
R/W-1  
RC1IP  
R/W-1  
TX1IP  
R/W-1  
SSPIP  
R/W-1  
R/W-1  
R/W-1  
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  
Unimplemented: Read as ‘0’  
ADIP: A/D Converter Interrupt Priority bit  
1= High priority  
0= Low priority  
bit 5  
bit 4  
RC1IP: EUSART Receive Interrupt Priority bit  
1= High priority  
0= Low priority  
TX1IP: EUSART Transmit Interrupt Priority bit  
1= High priority  
0= Low priority  
bit 3  
bit 2  
bit 1  
bit 0  
SSPIP: Master Synchronous Serial Port Interrupt Priority bit  
1= High priority  
0= Low priority  
CCP1IP: CCP1 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  
DS39629C-page 104  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
REGISTER 8-11: IPR2: PERIPHERAL INTERRUPT PRIORITY REGISTER 2  
R/W-1  
R/W-1  
CMIP  
U-0  
U-0  
R/W-1  
BCLIP  
R/W-1  
R/W-1  
R/W-1  
OSCFIP  
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 5-4  
bit 3  
Unimplemented: Read as ‘0’  
BCLIP: Bus Collision Interrupt Priority bit  
1= High priority  
0= Low priority  
bit 2  
bit 1  
bit 0  
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: CCP2 Interrupt Priority bit  
1= High priority  
0= Low priority  
© 2007 Microchip Technology Inc.  
DS39629C-page 105  
PIC18F6390/6490/8390/8490  
REGISTER 8-12: IPR3: PERIPHERAL INTERRUPT PRIORITY REGISTER 3  
U-0  
R/W-1  
LCDIP  
R/W-1  
RC2IP  
R/W-1  
TX2IP  
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  
bit 6  
Unimplemented: Read as ‘0’  
LCDIP: LCD Interrupt Priority bit (valid when Type-B waveform with Non-Static mode is selected)  
1= High priority  
0= Low priority  
bit 5  
RC2IP: AUSART Receive Interrupt Priority bit  
1= High priority  
0= Low priority  
bit 4  
TX2IP: AUSART Transmit Interrupt Priority bit  
1= High priority  
0= Low priority  
bit 3-0  
Unimplemented: Read as ‘0’  
DS39629C-page 106  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
8.5  
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 8-13: 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.  
© 2007 Microchip Technology Inc.  
DS39629C-page 107  
PIC18F6390/6490/8390/8490  
8.6  
INTx Pin Interrupts  
8.7  
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. The  
interrupt flag bit 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 regis-  
ter 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 10.0  
“Timer0 Module” for further details on the Timer0  
module.  
8.8  
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 the  
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.  
8.9  
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 8-1 saves and restores the WREG,  
STATUS and BSR registers during an Interrupt Service  
Routine.  
EXAMPLE 8-1:  
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  
DS39629C-page 108  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
9.1  
PORTA, TRISA and  
LATA Registers  
9.0  
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 and the LCD segment drive to become the  
RA4/T0CKI/SEG14 pin. Pins RA6 and RA7 are  
multiplexed with the main oscillator pins; they are  
enabled as oscillator or I/O pins by the selection of the  
main oscillator in the Configuration register (see  
Section 23.1 “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 9-1.  
FIGURE 9-1:  
GENERIC I/O PORT  
OPERATION  
The other PORTA pins are multiplexed with analog  
inputs and the analog VREF+ and VREF- inputs. The  
operation of pins RA3:RA0 and RA5 as A/D converter  
inputs is selected by clearing or setting the control bits  
in the ADCON1 register (A/D Control Register 1).  
RD LAT  
Data  
Bus  
D
Q
WR LAT  
or PORT  
I/O pin(1)  
CK  
Data Latch  
The RA4/T0CKI/SEG14 pin is a Schmitt Trigger input  
and an open-drain output. All other PORTA pins have  
TTL input levels and full CMOS output drivers.  
D
Q
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.  
WR TRIS  
RD TRIS  
CK  
TRIS Latch  
Input  
Buffer  
RA5:RA2 are also multiplexed with LCD segment  
drives controlled by bits in the LCDSE1 and  
LCDSE2 registers. I/O port functions are only  
available when the segments are disabled.  
Q
D
EN  
EXAMPLE 9-1:  
INITIALIZING PORTA  
CLRF  
PORTA  
LATA  
07h  
; Initialize PORTA by  
; clearing output  
; data latches  
; Alternate method  
; to clear output  
; data latches  
RD PORT  
Note 1: I/O pins have diode protection to VDD and VSS.  
CLRF  
MOVLW  
MOVWF  
MOVWF  
MOVWF  
MOVLW  
; Configure A/D  
ADCON1 ; for digital inputs  
07h  
CMCON  
0CFh  
; Configure comparators  
; for digital input  
; Value used to  
; initialize data  
; direction  
MOVWF  
TRISA  
; Set RA<3:0> as inputs  
; RA<5:4> as outputs  
© 2007 Microchip Technology Inc.  
DS39629C-page 109  
PIC18F6390/6490/8390/8490  
TABLE 9-1:  
Pin Name  
PORTA FUNCTIONS  
TRIS  
Function  
I/O  
Buffer  
Description  
Setting  
RA0/AN0  
RA0  
0
1
1
0
1
1
0
O
I
DIG LATA<0> data output. Not affected by analog pin setting.  
TTL PORTA<0> data input. Reads ‘0’ on POR.  
AN0  
RA1  
I
ANA A/D input channel 0. Default configuration on POR.  
DIG LATA<1> data output. Not affected by analog pin setting.  
TTL PORTA<1> data input. Reads ‘0’ on POR.  
RA1/AN1  
O
I
AN1  
RA2  
I
ANA A/D input channel 1. Default configuration on POR.  
RA2/AN2/VREF-/  
SEG16  
O
DIG LATA<2> data output. Not affected by analog pin setting; disabled  
when LCD segment enabled.  
1
1
1
x
0
I
I
TTL PORTA<2> data input. Reads ‘0’ on POR.  
ANA A/D input channel 2. Default configuration on POR.  
ANA A/D low reference voltage input.  
AN2  
VREF-  
SEG16  
RA3  
I
O
O
ANA Segment 16 analog output for LCD.  
RA3/AN3/VREF+/  
SEG17  
DIG LATA<3> data output. Output is unaffected by analog pin setting;  
disabled when LCD segment enabled.  
1
1
1
x
0
1
I
I
TTL PORTA<3> data input. Reads ‘0’ on POR.  
AN3  
VREF+  
SEG17  
RA4  
ANA A/D input channel 3. Default configuration on POR.  
ANA A/D high reference voltage input.  
I
O
O
I
ANA Segment 17 analog output for LCD. Disables all other digital outputs.  
DIG LATA<4> data output; disabled when LCD segment enabled.  
RA4/T0CKI/  
SEG14  
ST  
ST  
PORTA<4> data input.  
Timer0 clock input.  
T0CKI  
SEG14  
RA5  
I
x
0
O
O
ANA Segment 14 analog output for LCD.  
RA5/AN4/  
HLVDIN/SEG15  
DIG LATA<5> data output. Not affected by analog pin setting; disabled  
when LCD segment enabled.  
1
1
1
x
x
x
I
I
TTL PORTA<5> data input. Reads ‘0’ on POR.  
AN4  
HLVDIN  
SEG15  
OSC2  
ANA A/D input channel 5. Default configuration on POR.  
ANA High/Low-Voltage Detect external trip point input.  
ANA Segment 15 analog output for LCD.  
I
O
O
O
ANA Main oscillator feedback output connection (XT, HS and LP modes).  
OSC2/CLKO/RA6  
OSC1/CLKI/RA7  
CLKO  
DIG System cycle clock output (FOSC/4) in all oscillator modes except  
RCIO, INTIO2 and ECIO.  
RA6  
0
1
x
x
0
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, all modes except INTIO.  
ANA Main clock input connection, all modes except INTIO.  
OSC1  
CLKI  
RA7  
I
I
O
DIG LATA<7> data output. Available only in INTIO modes; otherwise reads  
as ‘0’.  
1
I
TTL PORTA<7> data input. Available only in INTIO modes; otherwise reads  
as ‘0’.  
Legend:  
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).  
DS39629C-page 110  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
TABLE 9-2:  
Name  
SUMMARY OF REGISTERS ASSOCIATED WITH PORTA  
Reset  
Values  
on Page  
Bit 7  
Bit 6  
Bit 5  
Bit 4  
Bit 3  
Bit 2  
Bit 1  
Bit 0  
PORTA  
LATA  
RA7(1)  
RA6(1)  
RA5  
RA4  
RA3  
RA2  
RA1  
RA0  
62  
62  
62  
61  
64  
64  
LATA7(1) LATA6(1) LATA Data Output Register  
TRISA7(1) TRISA6(1) PORTA Data Direction Register  
TRISA  
ADCON1  
LCDSE1  
LCDSE2  
VCFG1  
SE13  
VCFG0  
SE12  
PCFG3  
SE11  
PCFG2  
SE10  
PCFG1  
SE9  
PCFG0  
SE8  
SE15  
SE23  
SE14  
SE22  
SE21  
SE20  
SE19  
SE18  
SE17  
SE16  
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by PORTA.  
Note 1: RA7:RA6 and their associated latch and data direction bits are enabled as I/O pins based on oscillator  
configuration; otherwise, they are read as ‘0’.  
© 2007 Microchip Technology Inc.  
DS39629C-page 111  
PIC18F6390/6490/8390/8490  
Four of the PORTB pins (RB7:RB4) 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>).  
9.2  
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  
MOVFF (ANY), PORTB instruction). This will  
end the mismatch condition.  
EXAMPLE 9-2:  
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  
RB4:RB1 are also multiplexed with LCD segment  
drives controlled by bits in the LCDSE1 register. I/O  
port functions are only available when the segments  
are disabled.  
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.  
DS39629C-page 112  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
TABLE 9-3:  
Pin Name  
PORTB FUNCTIONS  
TRIS  
Function  
I/O  
Buffer  
Description  
Setting  
RB0/INT0  
RB0  
0
1
1
0
1
1
x
0
1
1
x
0
1
1
x
0
1
1
x
0
1
1
0
1
1
x
0
1
1
x
x
O
I
DIG  
TTL  
ST  
LATB<0> data output.  
PORTB<0> data input; programmable weak pull-up.  
External interrupt 0 input.  
INT0  
RB1  
I
RB1/INT1/SEG8  
RB2/INT2/SEG9  
O
I
DIG  
TTL  
ST  
LATB<1> data output; disabled when LCD segment enabled.  
PORTB<1> data input; weak pull-up when RBPU bit is cleared.  
External interrupt 1 input.  
INT1  
SEG8  
RB2  
I
O
O
I
ANA  
DIG  
TTL  
ST  
Segment 8 analog output for LCD. Disables digital output.  
LATB<2> data output; disabled when LCD segment enabled.  
PORTB<2> data input; weak pull-up when RBPU bit is cleared.  
External interrupt 2 input.  
INT2  
SEG9  
RB3  
I
O
O
I
ANA  
DIG  
TTL  
ST  
Segment 9 analog output for LCD  
RB3/INT3/  
SEG10  
LATB<3> data output; disabled when LCD segment enabled.  
PORTB<3> data input; weak pull-up when RBPU bit is cleared.  
External interrupt 3 input.  
INT3  
SEG10  
RB4  
I
O
O
I
ANA  
DIG  
TTL  
TTL  
ANA  
DIG  
TTL  
TTL  
DIG  
TTL  
TTL  
ST  
Segment 10 analog output for LCD.  
RB4/KBI0/  
SEG11  
LATB<4> data output; disabled when LCD segment enabled.  
PORTB<4> data input; weak pull-up when RBPU bit is cleared.  
Interrupt-on-pin change.  
KBI0  
SEG11  
RB5  
I
O
O
I
Segment 11 analog output for LCD.  
RB5/KBI1  
LATB<5> data output; disabled when LCD segment enabled.  
PORTB<5> data input; weak pull-up when RBPU bit is cleared.  
Interrupt-on-pin change.  
KBI1  
RB6  
I
RB6/KBI2/PGC  
O
I
LATB<6> data output; unavailable when ICD or ICSP™ enabled.  
PORTB<6> data input; unavailable when ICD or ICSP enabled.  
Interrupt-on-pin change; unavailable when ICD or ICSP enabled.  
KBI2  
PGC  
RB7  
I
(1)  
I
Serial execution (ICSP) clock input for ICSP and ICD operation.  
LATB<7> data output; unavailable when ICD or ICSP enabled.  
PORTB<7> data input; unavailable when ICD or ICSP enabled.  
Interrupt-on-pin change; unavailable when ICD or ICSP enabled.  
RB7/KBI3/PGD  
O
I
DIG  
TTL  
TTL  
DIG  
ST  
KBI3  
PGD  
I
(1)  
O
I
Serial execution data output for ICSP and ICD operation.  
(1)  
Serial execution data input for ICSP and ICD operation.  
Legend:  
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: All other pin functions are disabled when ICSP or ICD are enabled.  
© 2007 Microchip Technology Inc.  
DS39629C-page 113  
PIC18F6390/6490/8390/8490  
TABLE 9-4:  
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  
LATB  
RB7  
RB6  
RB5  
RB4  
RB3  
RB2  
RB1  
RB0  
62  
62  
62  
59  
59  
59  
64  
LATB Data Output Register  
TRISB  
PORTB Data Direction Register  
GIE/GIEH PEIE/GIEL TMR0IE  
INTCON  
INTCON2  
INTCON3  
LCDSE1  
INT0IE  
RBIE  
TMR0IF  
INT0IF  
INT3IP  
INT2IF  
SE9  
RBIF  
RBIP  
INT1IF  
SE8  
RBPU  
INT2IP  
SE15  
INTEDG0 INTEDG1 INTEDG2 INTEDG3 TMR0IP  
INT1IP  
SE14  
INT3IE  
SE13  
INT2IE  
SE12  
INT1IE  
SE11  
INT3IF  
SE10  
Legend: Shaded cells are not used by PORTB.  
DS39629C-page 114  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
9.3  
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.  
RC2 and RC5 are also multiplexed with LCD segment  
drives controlled by bits in the LCDSE1 register. I/O  
port functions are only available when the segments  
are disabled.  
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.  
EXAMPLE 9-3:  
INITIALIZING PORTC  
CLRF  
PORTC  
; Initialize PORTC by  
; clearing output  
; data latches  
PORTC is multiplexed with several peripheral functions  
(Table 9-5). The pins have Schmitt Trigger input  
buffers. RC1 is normally configured by Configuration  
bit, CCP2MX, as the default peripheral pin of the CCP2  
module (default/erased state, CCP2MX = 1).  
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  
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.  
TRISC  
© 2007 Microchip Technology Inc.  
DS39629C-page 115  
PIC18F6390/6490/8390/8490  
TABLE 9-5:  
PORTC FUNCTIONS  
TRIS  
Setting  
Pin Name  
Function  
I/O  
Buffer  
Description  
RC0/T1OSO/  
T13CKI/  
RC0  
0
1
x
x
0
1
x
0
1
0
1
0
1
x
0
1
0
1
0
1
0
1
1
1
1
0
1
0
x
0
1
1
O
I
DIG LATC<0> data output; disabled when Timer1 oscillator is used.  
ST PORTC<0> data input; disabled when Timer1 oscillator is used.  
ANA Timer1 oscillator output.  
ST Timer1/Timer3 clock input.  
DIG LATC<1> data output; disabled when Timer1 oscillator is used.  
ST PORTC<1> data input; disabled when Timer1 oscillator is used.  
T1OSO  
T13CKI  
RC1  
O
I
RC1/T1OSI/  
CCP2  
O
I
T1OSI  
I
ANA Timer1 oscillator input.  
(1)  
CCP2  
O
I
DIG CCP2 compare output or PWM output; takes priority over digital I/O data.  
ST  
DIG LATC<2> data output; disabled when LCD segment enabled.  
ST PORTC<2> data input.  
DIG CCP1 compare output or PWM output; takes priority over digital I/O data.  
ST CCP1 capture input.  
CCP2 capture input.  
RC2/CCP1/  
SEG13  
RC2  
O
I
CCP1  
O
I
SEG13  
RC3  
O
O
I
ANA Segment 13 analog output for LCD.  
DIG LATC<3> data output.  
RC3/SCK/SCL  
ST  
PORTC<3> data input.  
SCK  
SCL  
RC4  
O
I
DIG SPI clock output (MSSP module); takes priority over port data.  
ST  
SPI clock input (MSSP module).  
2
O
I
DIG I C™ clock output (MSSP module); takes priority over port data.  
2
ST  
I C clock input (MSSP module); input type depends on module setting.  
RC4/SDI/SDA  
O
I
DIG LATC<4> data output.  
ST  
ST  
PORTC<4> data input.  
SDI  
I
SPI data input (MSSP module).  
2
SDA  
O
I
DIG I C data output (MSSP module); takes priority over port data.  
2
ST  
I C data input (MSSP module); input type depends on module setting.  
RC5/SDO/  
SEG12  
RC5  
O
I
DIG LATC<5> data output; disabled when LCD segment enabled.  
ST PORTC<5> data input.  
SDO  
SEG12  
RC6  
O
O
O
I
DIG SPI data output (MSSP module); takes priority over port data.  
ANA Segment 12 analog output for LCD.  
DIG LATC<6> data output.  
RC6/TX1/CK1  
ST  
PORTC<6> data input.  
TX1  
CK1  
O
DIG Synchronous serial data output (EUSART module); takes priority over  
port data.  
1
O
DIG Synchronous serial data input (EUSART module). User must configure  
as an input.  
1
0
1
1
1
I
O
I
ST  
Synchronous serial clock input (EUSART module).  
RC7/RX1/DT1  
RC7  
DIG LATC<7> data output.  
ST  
ST  
PORTC<7> data input.  
RX1  
DT1  
I
Asynchronous serial receive data input (EUSART module).  
O
DIG Synchronous serial data output (EUSART module); takes priority over  
port data.  
1
I
ST  
Synchronous serial data input (EUSART module). User must configure  
as an input.  
Legend:  
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: Default assignment for CCP2 (CCP2MX Configuration bit = 1).  
DS39629C-page 116  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
TABLE 9-6:  
Name  
SUMMARY OF REGISTERS ASSOCIATED WITH PORTC  
Reset  
Values  
on Page  
Bit 7  
Bit 6  
Bit 5  
Bit 4  
Bit 3  
Bit 2  
Bit 1  
Bit 0  
PORTC  
LATC  
RC7  
RC6  
RC5  
RC4  
RC3  
RC2  
RC1  
RC0  
62  
62  
62  
64  
LATC Data Output Register  
TRISC  
LCDSE1  
PORTC Data Direction Register  
SE15  
SE14  
SE13  
SE12  
SE11  
SE10  
SE9  
SE8  
Legend: Shaded cells are not used by PORTC.  
© 2007 Microchip Technology Inc.  
DS39629C-page 117  
PIC18F6390/6490/8390/8490  
PORTD is also multiplexed with LCD segment drives  
controlled by the LCDSE0 register. I/O port functions  
are only available when the segments are disabled.  
9.4  
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 9-4:  
INITIALIZING PORTD  
CLRF  
PORTD  
; Initialize PORTD by  
; clearing output  
; data latches  
; Alternate method  
; to clear output  
; data latches  
; Value used to  
; initialize data  
; direction  
CLRF  
LATD  
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.  
MOVLW  
MOVWF  
0CFh  
TRISD  
; Set RD<3:0> as inputs  
; RD<5:4> as outputs  
; RD<7:6> as inputs  
All pins on PORTD 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.  
TABLE 9-7:  
Pin Name  
PORTD FUNCTIONS  
TRIS  
Function  
I/O  
Buffer  
Description  
Setting  
RD0/SEG0  
RD0  
0
1
x
0
1
x
0
1
x
0
1
x
0
1
x
0
1
x
0
1
x
0
1
x
O
I
DIG  
ST  
LATD<0> data output; disabled when LCD segment enabled.  
PORTD<0> data input.  
SEG0  
RD1  
O
O
I
ANA Segment 0 analog output for LCD.  
RD1/SEG1  
RD2/SEG2  
RD3/SEG3  
RD4/SEG4  
RD5/SEG5  
RD6/SEG6  
RD7/SEG7  
DIG  
ST  
LATD<1> data output; disabled when LCD segment enabled.  
PORTD<1> data input.  
SEG1  
RD2  
O
O
I
ANA Segment 1 analog output for LCD.  
DIG  
ST  
LATD<2> data output; disabled when LCD segment enabled.  
PORTD<2> data input.  
SEG2  
RD3  
O
O
I
ANA Segment 2 analog output for LCD.  
DIG  
ST  
LATD<3> data output; disabled when LCD segment enabled.  
PORTD<3> data input.  
SEG3  
RD4  
O
O
I
ANA Segment 3 analog output for LCD.  
DIG  
ST  
LATD<4> data output; disabled when LCD segment enabled.  
PORTD<4> data input.  
SEG4  
RD5  
O
O
I
ANA Segment 4 analog output for LCD module.  
DIG  
ST  
LATD<5> data output; disabled when LCD segment enabled.  
PORTD<5> data input.  
SEG5  
RD6  
O
O
I
ANA Segment 5 analog output for LCD.  
DIG  
ST  
LATD<6> data output; disabled when LCD segment enabled.  
PORTD<6> data input.  
SEG6  
RD7  
O
O
I
ANA Segment 6 analog output for LCD.  
DIG  
ST  
LATD<7> data output; disabled when LCD segment enabled.  
PORTD<7> data input.  
SEG7  
O
ANA Segment 7 analog output for LCD.  
Legend:  
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).  
DS39629C-page 118  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
TABLE 9-8:  
Name  
SUMMARY OF REGISTERS ASSOCIATED WITH PORTD  
Reset  
Values  
on Page  
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  
62  
62  
62  
64  
LATD Data Output Register  
TRISD  
LCDSE0  
PORTD Data Direction Register  
SE7  
SE6  
SE5  
SE4  
SE3  
SE2  
SE1  
SE0  
© 2007 Microchip Technology Inc.  
DS39629C-page 119  
PIC18F6390/6490/8390/8490  
RE7 also can be configured as the alternate peripheral  
pin for the CCP2 module. This is done by clearing the  
CCP2MX Configuration bit.  
9.5  
PORTE, TRISE and  
LATE Registers  
PORTE is a 4-bit wide, bidirectional port. The corre-  
sponding 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).  
TABLE 9-9:  
PORTE PINS AVAILABLE IN  
DIFFERENT LCD DRIVE  
CONFIGURATIONS  
LCDCON  
<1:0>  
Active LCD  
Commons  
PORTE Available  
for I/O  
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.  
00  
01  
10  
COM0  
RE6, RE5, RE4  
RE6, RE5  
RE6  
COM0, COM1  
COM0, COM1  
and COM2  
All pins on PORTE are implemented with Schmitt  
Trigger input buffers. Each pin is individually  
configurable as an input or output.  
11  
All (COM0  
through COM3)  
None  
Note: On a Power-on Reset, these pins are  
EXAMPLE 9-5:  
INITIALIZING PORTE  
configured as digital inputs.  
CLRF  
PORTE  
LATE  
30h  
; Initialize PORTE by  
; clearing output  
; data latches  
; Alternate method  
; to clear output  
; data latches  
; Value used to  
; initialize data  
; direction  
Pins RE6:RE4 are multiplexed with three of the LCD  
common drives. I/O port functions are only available on  
those PORTE pins, depending on which commons are  
active. The configuration is determined by the  
LMUX1:LMUX0 control bits (LCDCON<1:0>). The  
availability is summarized in Table 9-9.  
CLRF  
MOVLW  
MOVWF  
RE7 is also multiplexed with LCD segment drive  
(SEG31) controlled by the LCDSE3<7> bit. I/O port  
function is only available when the segment is disabled.  
TRISE  
; Set RE<5:4> as inputs  
; RE<7:6> as outputs  
Note: The pins corresponding to RE2:RE0 of  
other PIC18F parts have the function of  
LCDBIAS3:LCDBIAS1 and the pin  
corresponding to RE3 of other PIC18F  
parts has the function of COM0. These four  
pins cannot be used as digital I/O.  
DS39629C-page 120  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
TABLE 9-10:  
PORTE FUNCTIONS  
TRIS  
Setting  
Pad Name Function  
I/O  
Buffer  
Description  
RE4/COM1  
RE5/COM2  
RE6/COM3  
RE4  
0
1
x
0
1
x
0
1
x
0
1
0
1
x
O
I
DIG LATE<4> data output; disabled when LCD common enabled.  
ST  
PORTE<4> data input.  
COM1  
RE5  
O
O
I
ANA Common 1 analog output for LCD.  
DIG LATE<5> data output; disabled when LCD common enabled.  
ST  
PORTE<5> data input.  
COM2  
RE6  
O
O
I
ANA Common 2 analog output for LCD.  
DIG LATE<6> data output; disabled when LCD segment enabled.  
ST  
PORTE<6> data input.  
COM3  
RE7  
O
O
I
ANA Common 3 analog output for LCD.  
RE7/CCP2/  
SEG31  
DIG LATE<7> data output; disabled when LCD segment enabled.  
ST  
DIG CCP2 compare output and CCP2 PWM output; takes priority over port data.  
ST CCP2 capture input.  
ANA Segment 31 analog output for LCD.  
PORTE<7> data input.  
(1)  
CCP2  
O
I
SEG31  
O
Legend:  
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 CCP2 when the CCP2MX Configuration bit = 0.  
TABLE 9-11: SUMMARY OF REGISTERS ASSOCIATED WITH PORTE  
Reset  
Values  
on Page  
Name  
Bit 7  
Bit 6  
Bit 5  
Bit 4  
Bit 3  
Bit 2  
Bit 1  
Bit 0  
PORTE  
LATE  
RE7  
RE6  
RE5  
RE4  
62  
62  
62  
64  
64  
LATE Data Output Register  
TRISE  
PORTE Data Direction Register  
LCDCON  
LCDSE3  
LCDEN  
SE31  
SLPEN  
SE30  
WERR  
SE29  
CS1  
SE27  
CS0  
SE26  
LMUX1  
SE25  
LMUX0  
SE24  
SE28  
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by PORTE.  
© 2007 Microchip Technology Inc.  
DS39629C-page 121  
PIC18F6390/6490/8390/8490  
EXAMPLE 9-6:  
INITIALIZING PORTF  
9.6  
PORTF, LATF and TRISF Registers  
CLRF  
PORTF  
; Initialize PORTF by  
; clearing output  
; data latches  
; Alternate method  
; to clear output  
; data latches  
;
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).  
CLRF  
LATF  
MOVLW  
MOVWF  
MOVLW  
MOVWF  
MOVLW  
0x07  
CMCON  
0x0F  
; Turn off comparators  
;
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.  
ADCON1 ; Set PORTF as digital I/O  
0xCF  
; Value used to  
; initialize data  
; direction  
MOVWF  
TRISF  
; Set RF3:RF0 as inputs  
; RF5:RF4 as outputs  
; RF7:RF6 as inputs  
All pins on PORTF are implemented with Schmitt  
Trigger input buffers. Each pin is individually  
configurable as an input or output.  
PORTF is multiplexed with several analog peripheral  
functions, including the A/D converter inputs and  
comparator inputs, outputs and voltage reference.  
Note 1: On a Power-on Reset, the RF6:RF0 pins  
are configured as inputs and read as ‘0’.  
2: To configure PORTF as digital I/O, turn off  
comparators and set ADCON1 value.  
PORTF is also multiplexed with LCD segment drives  
controlled by bits in the LCDSE2 and LCDSE3  
registers. I/O port functions are only available when the  
segments are disabled.  
DS39629C-page 122  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
TABLE 9-12: PORTF FUNCTIONS  
TRIS  
Setting  
Pin Name  
Function  
I/O  
Buffer  
Description  
RF0/AN5/  
SEG18  
RF0  
0
O
DIG  
LATF<0> data output. Output is unaffected by analog input; disabled  
when LCD segment is enabled.  
1
1
x
0
I
ST  
PORTF<0> data input. Reads ‘0’ on POR.  
A/D input channel 5. Default configuration on POR.  
Segment 18 analog output for LCD.  
AN5  
SEG18  
RF1  
I
ANA  
ANA  
DIG  
O
O
RF1/AN6/  
C2OUT/SEG19  
LATF<1> data output. Output is unaffected by analog input; disabled  
when LCD segment is enabled.  
1
1
0
x
0
I
ST  
PORTF<1> data input. Reads ‘0’ on POR.  
A/D input channel 6. Default configuration on POR.  
Comparator 2 output; takes priority over port data.  
Segment 19 analog output for LCD.  
AN6  
C2OUT  
SEG19  
RF2  
I
ANA  
DIG  
ANA  
DIG  
O
O
O
RF2/AN7/  
C1OUT/SEG20  
LATF<2> data output. Output is unaffected by analog input; disabled  
when LCD segment is enabled.  
1
1
0
x
0
I
ST  
PORTF<2> data input. Reads ‘0’ on POR.  
A/D input channel 7. Default configuration on POR.  
Comparator 1 output; takes priority over port data.  
Segment 20 analog output for LCD.  
AN7  
C1OUT  
SEG20  
RF3  
I
ANA  
TTL  
ANA  
DIG  
O
O
O
RF3/AN8/  
SEG21  
LATF<3> data output. Output is unaffected by analog input; disabled  
when LCD segment is enabled.  
1
1
I
I
ST  
PORTF<3> data input. Reads ‘0’ on POR.  
AN8  
ANA  
A/D input channel 8 and Comparator C2+ input. Default input  
configuration on POR; not affected by analog output.  
SEG21  
RF4  
x
0
O
O
ANA  
DIG  
Segment 21 analog output for LCD.  
RF4/AN9/  
SEG22  
LATF<4> data output. Output is unaffected by analog input; disabled  
when LCD segment is enabled.  
1
1
I
I
ST  
PORTF<4> data input. Reads ‘0’ on POR.  
AN9  
ANA  
A/D input channel 9 and Comparator C2- input. Default input  
configuration on POR; does not affect digital output.  
SEG22  
RF5  
x
0
O
O
ANA  
DIG  
Segment 22 analog output for LCD.  
RF5/AN10/  
CVREF/SEG23  
LATF<5> data output. Output unaffected by analog input; disabled  
when either LCD segment or CVREF is enabled.  
1
1
I
I
ST  
PORTF<5> data input. Reads ‘0’ on POR.  
AN10  
ANA  
A/D input channel 10 and Comparator C1+ input. Default input  
configuration on POR.  
CVREF  
0
O
ANA  
Comparator voltage reference output. Enabling this feature disables  
digital I/O.  
SEG23  
RF6  
x
0
O
O
ANA  
DIG  
Segment 23 analog output for LCD.  
RF6/AN11/  
SEG24  
LATF<6> data output. Output is unaffected by analog input; disabled  
when LCD segment is enabled.  
1
1
I
I
ST  
PORTF<6> data input. Reads ‘0’ on POR.  
AN11  
ANA  
A/D input channel 11 and Comparator C1- input. Default input  
configuration on POR; does not affect digital output.  
SEG24  
RF7  
x
0
1
1
x
O
O
I
ANA  
DIG  
ST  
Segment 24 analog output for LCD.  
LATF<7> data output; disabled when LCD segment is enabled.  
PORTF<7> data input.  
RF7/SS/SEG25  
SS  
I
TTL  
ANA  
Slave select input for MSSP module.  
Segment 25 analog output for LCD.  
SEG25  
O
Legend:  
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).  
© 2007 Microchip Technology Inc.  
DS39629C-page 123  
PIC18F6390/6490/8390/8490  
TABLE 9-13: 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  
PORTF Data Direction Register  
62  
62  
62  
61  
61  
61  
64  
64  
PORTF  
LATF  
Read PORTF Data Latch/Write PORTF Data Latch  
LATF Data Output Register  
ADCON1  
CMCON  
CVRCON  
LCDSE2  
LCDSE3  
VCFG1 VCFG0 PCFG3 PCFG2 PCFG1 PCFG0  
C2OUT  
CVREN  
SE23  
C1OUT  
CVROE  
SE22  
C2INV  
CVRR  
SE21  
SE29  
C1INV  
CVRSS  
SE20  
CIS  
CM2  
CVR2  
SE18  
SE26  
CM1  
CVR1  
SE17  
SE25  
CM0  
CVR0  
SE16  
SE24  
CVR3  
SE19  
SE27  
SE31  
SE30  
SE28  
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by PORTF.  
DS39629C-page 124  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
PORTG<4:0> are also multiplexed with LCD segment  
drives controlled by bits in the LCDSE3 register. I/O  
port functions are only available when the segments  
9.7  
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).  
are disabled.  
The sixth pin of PORTG (MCLR/VPP/RG5) 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.  
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.  
Note:  
On a Power-on Reset, RG5 is enabled as  
digital input only if Master Clear  
a
PORTG is multiplexed with both USART and LCD  
functions (Table 9-14). PORTG pins have Schmitt  
Trigger input buffers.  
functionality is disabled. All other 5 pins  
are configured as digital inputs.  
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.  
EXAMPLE 9-7:  
INITIALIZING PORTG  
CLRF  
PORTG  
; Initialize PORTG by  
; clearing output  
; data latches  
; Alternate method  
; to clear output  
; data latches  
; Value used to  
; initialize data  
; direction  
CLRF  
LATG  
MOVLW  
MOVWF  
0x04  
TRISG  
; Set RG1:RG0 as outputs  
; RG2 as input  
; RG4:RG3 as inputs  
© 2007 Microchip Technology Inc.  
DS39629C-page 125  
PIC18F6390/6490/8390/8490  
TABLE 9-14: PORTG FUNCTIONS  
TRIS  
Setting  
Pin Name  
Function  
I/O  
Buffer  
Description  
RG0/SEG30  
RG0  
0
1
x
0
1
1
O
I
DIG LATG<0> data output; disabled when LCD segment enabled.  
ST PORTG<0> data input.  
SEG30  
RG1  
O
O
I
ANA Segment 30 analog output for LCD.  
RG1/TX2/CK2/  
SEG29  
DIG LATG<1> data output; disabled when LCD segment enabled.  
ST  
PORTG<1> data input.  
TX2  
CK2  
O
DIG Synchronous serial data output (AUSART module); takes priority over  
port data.  
1
O
DIG Synchronous serial data input (AUSART module). User must configure  
as an input.  
1
x
0
1
1
1
I
O
O
I
ST  
Synchronous serial clock input (AUSART module).  
SEG29  
RG2  
ANA Segment 29 analog output for LCD.  
RG2/RX2/DT2/  
SEG28  
DIG LATG<2> data output; disabled when LCD segment enabled.  
ST  
ST  
PORTG<2> data input.  
RX2  
DT2  
I
Asynchronous serial receive data input (AUSART module).  
O
DIG Synchronous serial data output (AUSART module); takes priority over  
port data.  
1
I
ST  
Synchronous serial data input (AUSART module). User must configure  
as an input.  
SEG28  
RG3  
x
0
1
0
0
1
x
O
O
I
ANA Segment 28 analog output for LCD.  
RG3/SEG27  
RG4/SEG26  
MCLR/VPP/RG5  
DIG LATG<3> data output; disabled when LCD segment enabled.  
ST  
PORTG<3> data input.  
SEG27  
RG4  
O
O
I
ANA Segment 27 analog output for LCD.  
DIG LATG<4> data output; disabled when LCD segment enabled.  
ST  
ANA Segment 26 analog output for LCD.  
ST External Master Clear input; enabled when MCLRE Configuration bit is set.  
PORTG<4> data input.  
SEG26  
MCLR  
VPP  
O
I
(1)  
(1)  
I
ANA High-voltage detection; used for ICSP™ mode entry detection. Always  
available, regardless of pin mode.  
(1)  
RG5  
I
ST  
PORTG<5> data input; enabled when MCLRE Configuration bit is clear.  
Legend:  
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.  
TABLE 9-15: 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) Read PORTG pin/Write PORTG Data Latch  
62  
62  
62  
64  
LATG Data Output Register  
TRISG  
LCDSE3  
PORTG Data Direction Register  
SE31  
SE30  
SE29  
SE28  
SE27  
SE26  
SE25  
SE24  
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by PORTG.  
Note 1: RG5 is available as an input only when MCLR is disabled.  
DS39629C-page 126  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
EXAMPLE 9-8:  
INITIALIZING PORTH  
9.8  
PORTH, LATH and  
TRISH Registers  
CLRF  
PORTH  
; Initialize PORTH by  
; clearing output  
; data latches  
Note: PORTH is available only on 80-pin  
devices.  
CLRF  
LATH  
; Alternate method  
; to clear output  
; data latches  
; Value used to  
; initialize data  
; direction  
; Set RH3:RH0 as inputs  
; RH5:RH4 as outputs  
; RH7:RH6 as inputs  
PORTH is an 8-bit wide, bidirectional I/O port. The cor-  
responding Data Direction register is TRISH. Setting 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).  
MOVLW  
MOVWF  
0CFh  
TRISH  
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.  
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.  
PORTH is also multiplexed with LCD segment drives  
controlled by the LCDSE5 register. I/O port functions  
are only available when the segments are disabled.  
© 2007 Microchip Technology Inc.  
DS39629C-page 127  
PIC18F6390/6490/8390/8490  
TABLE 9-16: PORTH FUNCTIONS  
TRIS  
Setting  
Pin Name  
Function  
I/O  
Buffer  
Description  
RH0/SEG47  
RH0  
0
1
x
0
1
x
0
1
x
0
1
x
0
1
x
0
1
x
0
1
x
0
1
x
O
I
DIG-4 LATH<0> data output; disabled when LCD segment enabled.  
ST PORTH<0> data input.  
ANA Segment 47 analog output for LCD.  
SEG47  
RH1  
O
O
I
RH1/SEG46  
RH2/SEG45  
RH3/SEG44  
RH4/SEG40  
RH5/SEG41  
RH6/SEG42  
RH7/SEG43  
DIG  
ST  
LATH<1> data output; disabled when LCD segment enabled.  
PORTH<1> data input.  
SEG46  
RH2  
O
O
I
ANA Segment 46 analog output for LCD.  
DIG  
ST  
LATH<2> data output; disabled when LCD segment enabled.  
PORTH<2> data input.  
SEG45  
RH3  
O
O
I
ANA Segment 45 analog output for LCD.  
DIG  
ST  
LATH<3> data output; disabled when LCD segment enabled.  
PORTH<3> data input.  
SEG44  
RH4  
O
O
I
ANA Segment 44 analog output for LCD.  
DIG  
ST  
LATH<4> data output; disabled when LCD segment enabled.  
PORTH<4> data input.  
SEG40  
RH5  
O
O
I
ANA Segment 40 analog output for LCD  
DIG  
ST  
LATH<5> data output; disabled when LCD segment enabled.  
PORTH<5> data input.  
SEG41  
RH6  
O
O
I
ANA Segment 41 analog output for LCD.  
DIG  
ST  
LATH<6> data output; disabled when LCD segment enabled.  
PORTH<6> data input.  
SEG42  
RH7  
O
O
I
ANA Segment 42 analog output for LCD.  
DIG  
ST  
LATH<7> data output; disabled when LCD segment enabled.  
PORTH<7> data input.  
SEG43  
O
ANA Segment 43 analog output for LCD.  
Legend:  
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 9-17: 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  
PORTH Data Direction Register  
62  
62  
62  
64  
PORTH  
LATH  
Read PORTH pin/Write PORTH Data Latch  
LATH Data Output Register  
LCDSE5  
SE47  
SE46  
SE45  
SE44  
SE43  
SE42  
SE41  
SE40  
DS39629C-page 128  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
EXAMPLE 9-9:  
INITIALIZING PORTJ  
9.9  
PORTJ, TRISJ and  
LATJ Registers  
CLRF  
PORTJ  
; Initialize PORTG by  
; clearing output  
; data latches  
; Alternate method  
; to clear output  
; data latches  
; Value used to  
; initialize data  
; direction  
Note: PORTJ is available only on 80-pin devices.  
CLRF  
LATJ  
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).  
MOVLW 0xCF  
MOVWF TRISJ  
; 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.  
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.  
PORTJ is also multiplexed with LCD segment drives  
controlled by the LCDSE4 register. I/O port functions  
are only available when the segments are disabled.  
© 2007 Microchip Technology Inc.  
DS39629C-page 129  
PIC18F6390/6490/8390/8490  
TABLE 9-18: PORTJ FUNCTIONS  
TRIS  
Setting  
Pin Name  
Function  
I/O  
Buffer  
Description  
RJ0/SEG32  
RJ0  
0
1
x
0
1
x
0
1
x
0
1
x
0
1
x
0
1
x
0
1
x
0
1
x
O
I
DIG  
ST  
LATJ<0> data output; disabled when LCD segment enabled.  
PORTJ<0> data input.  
SEG32  
RJ1  
O
O
I
ANA Segment 32 analog output for LCD.  
RJ1/SEG33  
RJ2/SEG34  
RJ3/SEG35  
RJ4/SEG39  
RJ5/SEG38  
RJ6/SEG37  
RJ7/SEG36  
DIG  
ST  
LATJ<1> data output; disabled when LCD segment enabled.  
PORTJ<1> data input.  
SEG33  
RJ2  
O
O
I
ANA Segment 33 analog output for LCD.  
DIG  
ST  
LATJ<2> data output; disabled when LCD segment enabled.  
PORTJ<2> data input.  
SEG34  
RJ3  
O
O
I
ANA Segment 34 analog output for LCD.  
DIG  
ST  
LATJ<3> data output; disabled when LCD segment enabled.  
PORTJ<3> data input.  
SEG35  
RJ4  
O
O
I
ANA Segment 35 analog output for LCD.  
DIG  
ST  
LATJ<4> data output; disabled when LCD segment enabled.  
PORTJ<4> data input.  
SEG39  
RJ5  
O
O
I
ANA Segment 39 analog output for LCD.  
DIG  
ST  
LATJ<5> data output; disabled when LCD segment enabled.  
PORTJ<5> data input.  
SEG38  
RJ6  
O
O
I
ANA Segment 38 analog output for LCD.  
DIG  
ST  
LATJ<6> data output; disabled when LCD segment enabled.  
PORTJ<6> data input.  
SEG37  
RJ7  
O
O
I
ANA Segment 37 analog output for LCD.  
DIG  
ST  
LATJ<7> data output; disabled when LCD segment enabled.  
PORTJ<7> data input.  
SEG36  
O
ANA Segment 36 analog output for LCD.  
Legend:  
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 9-19: 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  
Read PORTJ pin/Write PORTJ Data Latch  
LATJ Data Output Register  
62  
62  
62  
64  
LATJ  
TRISJ  
LCDSE4  
PORTJ Data Direction Register  
SE39  
SE38  
SE37  
SE36  
SE35  
SE34  
SE33  
SE32  
DS39629C-page 130  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
The T0CON register (Register 10-1) controls all  
aspects of the module’s operation, including the  
prescale selection. It is both readable and writable.  
10.0 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  
A simplified block diagram of the Timer0 module in  
8-bit mode is shown in Figure 10-1. Figure 10-2  
shows a simplified block diagram of the Timer0  
module in 16-bit mode.  
• Readable and writable registers  
• Dedicated 8-bit software programmable prescaler  
• Selectable clock source (internal or external)  
• Edge select for external clock  
• Interrupt-on-overflow  
REGISTER 10-1: 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  
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 2-0  
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.  
T0PS2:T0PS0: 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  
© 2007 Microchip Technology Inc.  
DS39629C-page 131  
PIC18F6390/6490/8390/8490  
internal phase clock (TOSC). There is a delay between  
synchronization and the onset of incrementing the  
timer/counter.  
10.1 Timer0 Operation  
Timer0 can operate as either a timer or a counter; the  
mode is selected by clearing 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 10.3 “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.  
10.2 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  
writable (refer to Figure 10-2). 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 Counter mode, Timer0 increments either on  
every rising or falling edge of pin RA4/T0CKI. The  
incrementing 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 10-1:  
TIMER0 BLOCK DIAGRAM (8-BIT MODE)  
FOSC/4  
0
1
1
0
Set  
TMR0IF  
on Overflow  
Sync with  
Internal  
Clocks  
TMR0L  
Programmable  
Prescaler  
T0CKI pin  
(2 TCY Delay)  
T0SE  
8
3
T0CS  
8
T0PS2:T0PS0  
PSA  
Internal Data Bus  
Note: Upon Reset, Timer0 is enabled in 8-bit mode with clock input from T0CKI maximum prescale.  
FIGURE 10-2:  
TIMER0 BLOCK DIAGRAM (16-BIT MODE)  
FOSC/4  
0
1
Sync with  
Set  
TMR0IF  
on Overflow  
TMR0  
High Byte  
1
TMR0L  
Internal  
Programmable  
Clocks  
T0CKI pin  
0
8
Prescaler  
(2 TCY Delay)  
T0SE  
T0CS  
3
Read TMR0L  
Write TMR0L  
T0PS2:T0PS0  
PSA  
8
8
TMR0H  
8
8
Internal Data Bus  
Note: Upon Reset, Timer0 is enabled in 8-bit mode with clock input from T0CKI maximum prescale.  
DS39629C-page 132  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
10.3.1  
SWITCHING PRESCALER  
ASSIGNMENT  
10.3 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 T0PS2:T0PS0 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.  
10.4 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 10-1: 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  
60  
60  
59  
60  
62  
TMR0H  
INTCON  
T0CON  
TRISA  
GIE/GIEH PEIE/GIEL TMR0IE  
TMR0ON T08BIT T0CS  
PORTA Data Direction Register  
INT0IE  
T0SE  
RBIE  
PSA  
TMR0IF  
T0PS2  
INT0IF  
T0PS1  
RBIF  
T0PS0  
Legend: Shaded cells are not used by Timer0.  
© 2007 Microchip Technology Inc.  
DS39629C-page 133  
PIC18F6390/6490/8390/8490  
NOTES:  
DS39629C-page 134  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
A simplified block diagram of the Timer1 module is  
shown in Figure 11-1. A block diagram of the module’s  
operation in Read/Write mode is shown in Figure 11-2.  
11.0 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)  
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.  
• Selectable clock source (internal or external) with  
device clock or Timer1 oscillator internal options  
• Interrupt-on-overflow  
Timer1 is controlled through the T1CON Control  
register (Register 11-1). It also contains the Timer1  
Oscillator Enable bit (T1OSCEN). Timer1 can be  
enabled or disabled by setting or clearing control bit,  
TMR1ON (T1CON<0>).  
• Reset on CCP Special Event Trigger  
• Device clock status flag (T1RUN)  
REGISTER 11-1: T1CON: TIMER1 CONTROL REGISTER  
R/W-0  
RD16  
R-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  
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  
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  
T1CKPS1:T1CKPS0: 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  
© 2007 Microchip Technology Inc.  
DS39629C-page 135  
PIC18F6390/6490/8390/8490  
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.  
11.1 Timer1 Operation  
Timer1 can operate in one of these modes:  
• Timer  
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’.  
• Synchronous Counter  
• Asynchronous Counter  
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 11-1:  
TIMER1 BLOCK DIAGRAM  
Timer1 Oscillator  
On/Off  
1
T1OSO/T13CKI  
T1OSI  
1
Synchronize  
Prescaler  
0
FOSC/4  
Internal  
Clock  
Detect  
1, 2, 4, 8  
0
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  
Note 1: When T1OSCEN is cleared, the inverter and feedback resistor are turned off to eliminate power drain.  
FIGURE 11-2:  
TIMER1 BLOCK DIAGRAM (16-BIT READ/WRITE MODE)  
Timer1 Oscillator  
1
0
T1OSO/T13CKI  
T1OSI  
1
Synchronize  
Prescaler  
FOSC/4  
Internal  
Clock  
Detect  
1, 2, 4, 8  
0
2
Sleep Input  
T1OSCEN(1)  
T1CKPS1:T1CKPS0  
T1SYNC  
Timer1  
On/Off  
TMR1CS  
TMR1ON  
Set  
TMR1IF  
on Overflow  
TMR1  
High Byte  
Clear TMR1  
(CCP Special Event Trigger)  
TMR1L  
8
Read TMR1L  
Write TMR1L  
8
8
TMR1H  
8
8
Internal Data Bus  
Note 1: When T1OSCEN is cleared, the inverter and feedback resistor are turned off to eliminate power drain.  
DS39629C-page 136  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
TABLE 11-1: CAPACITOR SELECTION FOR  
THE TIMER1 OSCILLATOR(2,3,4)  
11.2 Timer1 16-Bit Read/Write Mode  
Timer1 can be configured for 16-bit reads and writes  
(see Figure 11-2). 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 register. 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.  
3: Since each resonator/crystal has its own  
characteristics, the user should consult  
the resonator/crystal manufacturer for  
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.  
appropriate  
values  
of  
external  
components.  
4: Capacitor values are for design guidance  
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.  
only.  
11.3.1  
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, SCS1:SCS0 (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”.  
11.3 Timer1 Oscillator  
An on-chip crystal oscillator circuit is incorporated  
between pins T1OSI (input) and T1OSO (amplifier  
output). 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 11-3.  
Table 11-1 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 11-3:  
EXTERNAL  
COMPONENTS FOR THE  
TIMER1 LP OSCILLATOR  
11.3.2  
LOW-POWER TIMER1 OPTION  
C1  
33 pF  
PIC18FXXXX  
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  
relatively constant, regardless of the device’s operating  
mode. The default Timer1 configuration is the higher  
power mode.  
T1OSI  
XTAL  
32.768 kHz  
T1OSO  
C2  
33 pF  
Note:  
See the Notes with Table 11-1 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.  
© 2007 Microchip Technology Inc.  
DS39629C-page 137  
PIC18F6390/6490/8390/8490  
11.3.3  
TIMER1 OSCILLATOR LAYOUT  
CONSIDERATIONS  
11.5 Resetting Timer1 Using the CCP  
Special Event Trigger  
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.  
If either of the CCP modules is configured in Compare  
mode to generate  
a
Special Event Trigger  
(CCP1M3:CCP1M0 or CCP2M3:CCP2M0 = 1011),  
this signal will reset Timer1. The trigger from CCP2 will  
also start an A/D conversion if the A/D module is  
enabled (see Section 14.3.4 “Special Event Trigger”  
for more information.).  
The oscillator circuit, shown in Figure 11-3, 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.  
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.  
If a high-speed circuit must be located near the  
oscillator (such as the CCP1 pin in Output Compare or  
PWM mode, or the primary oscillator using the OSC2  
pin), a grounded guard ring around the oscillator circuit,  
as shown in Figure 11-4, may be helpful when used on  
a single sided PCB or in addition to a ground plane.  
If Timer1 is running in Asynchronous Counter mode,  
this Reset operation may not work.  
In the event that a write to Timer1 coincides with a  
Special Event Trigger, the write operation will take  
precedence.  
FIGURE 11-4:  
OSCILLATOR CIRCUIT  
WITH GROUNDED  
GUARD RING  
Note:  
The Special Event Triggers from the CCP2  
module will not set the TMR1IF interrupt  
flag bit (PIR1<0>).  
VDD  
VSS  
11.6 Using Timer1 as a  
Real-Time Clock  
OSC1  
OSC2  
Adding an external LP oscillator to Timer1 (such as the  
one described in Section 11.3 “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.  
RC0  
RC1  
RC2  
Note: Not drawn to scale.  
The application code routine, RTCisr, shown in  
Example 11-1, 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 overflows.  
11.4 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>).  
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  
preload it. The simplest method is to set the Most Sig-  
nificant bit of TMR1H with a BSFinstruction. Note that  
the TMR1L register is never preloaded or altered; doing  
so may introduce cumulative error over many cycles.  
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.  
DS39629C-page 138  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
EXAMPLE 11-1:  
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’  
T1OSC  
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  
CPFSGT  
RETURN  
CLRF  
TMR1H, 7  
PIR1, TMR1IF  
secs, F  
.59  
; Preload for 1 sec overflow  
; Clear interrupt flag  
; Increment seconds  
; 60 seconds elapsed?  
secs  
; No, done  
secs  
mins, F  
.59  
; Clear seconds  
; Increment minutes  
; 60 minutes elapsed?  
INCF  
MOVLW  
CPFSGT  
RETURN  
CLRF  
mins  
; No, done  
mins  
hours, F  
.23  
; clear minutes  
; Increment hours  
; 24 hours elapsed?  
INCF  
MOVLW  
CPFSGT  
RETURN  
MOVLW  
MOVWF  
RETURN  
hours  
; No, done  
; Reset hours to 1  
.01  
hours  
; Done  
TABLE 11-2: 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  
SSPIF  
SSPIE  
SSPIP  
TMR0IF  
CCP1IF  
CCP1IE  
CCP1IP  
INT0IF  
TMR2IF  
TMR2IE  
TMR2IP  
RBIF  
59  
61  
61  
61  
60  
60  
60  
ADIF  
ADIE  
ADIP  
RC1IF  
RC1IE  
RC1IP  
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: — = unimplemented, read as ‘0’. Shaded cells are not used by the Timer1 module.  
© 2007 Microchip Technology Inc.  
DS39629C-page 139  
PIC18F6390/6490/8390/8490  
NOTES:  
DS39629C-page 140  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
12.1 Timer2 Operation  
12.0 TIMER2 MODULE  
In normal operation, TMR2 is incremented from 00h on  
each clock (FOSC/4). A 2-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, T2CKPS1:T2CKPS0  
(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 comparator 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 12.2  
“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 MSSP  
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 12-1), 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  
A simplified block diagram of the module is shown in  
Figure 12-1.  
• any device Reset (Power-on Reset, MCLR Reset,  
Watchdog Timer Reset, or Brown-out Reset)  
TMR2 is not cleared when T2CON is written.  
REGISTER 12-1: 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  
T2OUTPS3:T2OUTPS0: 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  
T2CKPS1:T2CKPS0: Timer2 Clock Prescale Select bits  
00= Prescaler is 1  
01= Prescaler is 4  
1x= Prescaler is 16  
© 2007 Microchip Technology Inc.  
DS39629C-page 141  
PIC18F6390/6490/8390/8490  
12.2 Timer2 Interrupt  
12.3 TMR2 Output  
Timer2 also can generate an optional device interrupt.  
The Timer2 output signal (TMR2 to PR2 match)  
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.  
provides  
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>).  
Timer2 can be optionally used as the shift clock source  
for the MSSP module operating in SPI mode.  
Additional information is provided in Section 15.0  
“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, T2OUTPS3:T2OUTPS0 (T2CON<6:3>).  
FIGURE 12-1:  
TIMER2 BLOCK DIAGRAM  
4
1:1 to 1:16  
Set TMR2IF  
Postscaler  
T2OUTPS3:T2OUTPS0  
2
TMR2 Output  
T2CKPS1:T2CKPS0  
(to PWM or MSSP)  
TMR2/PR2  
Match  
Reset  
TMR2  
1:1, 1:4, 1:16  
Prescaler  
PR2  
FOSC/4  
Comparator  
8
8
8
Internal Data Bus  
TABLE 12-1: 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  
SSPIF  
SSPIE  
SSPIP  
TMR0IF  
CCP1IF  
CCP1IE  
CCP1IP  
INT0IF  
TMR2IF  
TMR2IE  
TMR2IP  
RBIF  
59  
61  
61  
61  
60  
60  
60  
PIR1  
ADIF  
ADIE  
ADIP  
RC1IF  
RC1IE  
RC1IP  
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.  
DS39629C-page 142  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
A simplified block diagram of the Timer3 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 TIMER3 MODULE  
The Timer3 timer/counter module incorporates these  
features:  
The Timer3 module is controlled through the T3CON  
register (Register 13-1). It also selects the clock source  
options for the CCP modules (see Section 14.1.1  
“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 13-1: 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  
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  
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  
T3CCP2:T3CCP1: Timer3 and Timer1 to CCPx Enable bits  
1x= Timer3 is the capture/compare clock source for the CCPx modules  
01= Timer3 is the capture/compare clock source for the CCP2 module;  
Timer1 is the capture/compare clock source for the CCP1 module  
00= Timer1 is the capture/compare clock source for the CCPx modules  
bit 5-4  
bit 2  
T3CKPS1:T3CKPS0: 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  
© 2007 Microchip Technology Inc.  
DS39629C-page 143  
PIC18F6390/6490/8390/8490  
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.  
13.1 Timer3 Operation  
Timer3 can operate in one of three modes:  
• Timer  
As  
with  
Timer1,  
the  
RC1/T1OSI  
and  
• Synchronous counter  
• Asynchronous counter  
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’.  
The operating mode is determined by the clock select  
bit, TMR3CS (T3CON<1>). When TMR3CS is cleared  
(= 0), Timer3 increments on every internal instruction  
FIGURE 13-1:  
TIMER3 BLOCK DIAGRAM  
Timer1 Oscillator  
1
T1OSO/T13CKI  
T1OSI  
1
0
Synchronize  
Prescaler  
FOSC/4  
Internal  
Clock  
0
Detect  
1, 2, 4, 8  
2
Sleep Input  
T1OSCEN(1)  
TMR3CS  
Timer3  
On/Off  
T3CKPS1:T3CKPS0  
T3SYNC  
TMR3ON  
CCP Special Event Trigger  
T3CCPx  
Clear TMR3  
Set  
TMR3  
High Byte  
TMR3L  
TMR3IF  
on Overflow  
Note 1: When T1OSCEN is cleared, the inverter and feedback resistor are turned off to eliminate power drain.  
FIGURE 13-2:  
TIMER3 BLOCK DIAGRAM (16-BIT READ/WRITE MODE)  
Timer1 Oscillator  
Timer1 Clock Input  
1
T1OSO/T13CKI  
T1OSI  
1
0
Synchronize  
Detect  
Prescaler  
1, 2, 4, 8  
FOSC/4  
Internal  
Clock  
0
2
Sleep Input  
T1OSCEN(1)  
T3CKPS1:T3CKPS0  
T3SYNC  
Timer3  
On/Off  
TMR3CS  
TMR3ON  
CCP Special Event Trigger  
T3CCPx  
Clear TMR3  
Set  
TMR3  
High Byte  
TMR3L  
TMR3IF  
on Overflow  
8
Read TMR3L  
Write TMR3L  
8
8
TMR3H  
8
8
Internal Data Bus  
Note 1: When T1OSCEN is cleared, the inverter and feedback resistor are turned off to eliminate power drain.  
DS39629C-page 144  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
13.2 Timer3 16-Bit Read/Write Mode  
13.4 Timer3 Interrupt  
Timer3 can be configured for 16-bit reads and writes  
(see Figure 13-2). 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 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.  
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>).  
13.5 Resetting Timer3 Using the CCP  
Special Event Trigger  
If either of the CCP modules is configured in Compare  
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.  
mode to generate  
a
Special Event Trigger  
(CCP1M3:CCP1M0 or CCP2M3:CCP2M0 = 1011),  
this signal will reset Timer1. The trigger from CCP2 will  
also start an A/D conversion if the A/D module is  
enabled (see Section 14.3.4 “Special Event Trigger”  
for more information.).  
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 CCPR2H:CCPR2L 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.  
13.3 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 CCP2  
module will not set the TMR3IF interrupt  
flag bit (PIR2<1>).  
The Timer1 oscillator is described in Section 11.0  
“Timer1 Module”.  
TABLE 13-1: 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  
RBIE  
BCLIF  
BCLIE  
BCLIP  
TMR0IF  
HLVDIF  
HLVDIE  
HLVDIP  
INT0IF  
TMR3IF  
TMR3IE  
TMR3IP  
RBIF  
59  
61  
61  
61  
61  
61  
60  
61  
OSCFIF  
OSCFIE  
OSCFIP  
CMIF  
CMIE  
CMIP  
CCP2IF  
CCP2IE  
CCP2IP  
PIE2  
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.  
© 2007 Microchip Technology Inc.  
DS39629C-page 145  
PIC18F6390/6490/8390/8490  
NOTES:  
DS39629C-page 146  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
Each CCP module contains a 16-bit register which can  
14.0 CAPTURE/COMPARE/PWM  
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 operation in the  
following sections is described with respect to CCP2,  
but is equally applicable to CCP1.  
(CCP) MODULES  
PIC18F6390/6490/8390/8490 devices have two CCP  
(Capture/Compare/PWM) modules, designated CCP1  
and CCP2. Both modules implement standard capture,  
compare and Pulse-Width Modulation (PWM) modes.  
REGISTER 14-1: CCPxCON: CCPx CONTROL REGISTER  
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’  
DCxB1:DCxB0: PWM Duty Cycle bit 1 and bit 0 for CCPx Module  
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 (DCxB9:DCxB2) of the duty cycle are found in CCPRxL.  
bit 3-0  
CCPxM3:CCPxM0: CCPx Module 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, reset timer, start A/D conversion on CCPx match (CCPxIF  
bit is set)(1)  
11xx= PWM mode  
Note 1: CCPxM3:CCPxM0 = 1011 will only reset the timer and not start the A/D conversion on the CCPx match.  
© 2007 Microchip Technology Inc.  
DS39629C-page 147  
PIC18F6390/6490/8390/8490  
The assignment of a particular timer to a module is  
14.1 CCP Module Configuration  
determined by the Timer to CCP enable bits in the  
T3CON register (Register 13-1). Both modules may be  
active at any given time and may share the same timer  
resource if they are configured to operate in the same  
mode (capture/compare or PWM) at the same time.  
The interactions between the two modules are  
summarized in Table 14-2.  
Each Capture/Compare/PWM module is associated  
with a control register (generically, CCPxCON) and a  
data register (CCPRx). The data register in turn is com-  
prised of two 8-bit registers: CCPRxL (low byte) and  
CCPRxH (high byte). All registers are both readable  
and writable.  
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 14-1.  
14.1.1  
CCP MODULES AND TIMER  
RESOURCES  
The CCP modules utilize Timers 1, 2 or 3, depending  
on the mode selected. Timer1 and Timer3 are available  
to modules in Capture or Compare modes, while  
Timer2 is available for modules in PWM mode.  
14.1.2  
CCP2 PIN ASSIGNMENT  
The pin assignment for CCP2 (capture input, compare  
and PWM output) can change based on device config-  
uration. The CCP2MX Configuration bit determines  
which pin CCP2 is multiplexed to. By default, it is  
assigned to RC1 (CCP2MX = 1). If the Configuration bit  
is cleared, CCP2 is multiplexed with RE7.  
TABLE 14-1: CCP MODE – TIMER  
RESOURCE  
CCP Mode  
Timer Resource  
Capture  
Compare  
PWM  
Timer1 or Timer3  
Timer1 or Timer3  
Timer2  
Changing the pin assignment of CCP2 does not  
automatically change any requirements for configuring  
the port pin. Users must always verify that the appropri-  
ate TRIS register is configured correctly for CCP2  
operation, regardless of where it is located.  
FIGURE 14-1:  
CCP AND TIMER INTERCONNECT CONFIGURATIONS  
T3CCP<2:1> = 00  
T3CCP<2:1> = 01  
T3CCP<2:1> = 1x  
TMR1  
TMR3  
TMR1  
TMR3  
TMR1  
TMR3  
CCP1  
CCP2  
CCP1  
CCP1  
CCP2  
CCP2  
TMR2  
TMR2  
TMR2  
Timer1 is used for all capture  
and compare operations for  
all CCP modules. Timer2 is  
used for PWM operations for  
all CCP modules. Modules  
may share either timer  
resource as a common time  
base.  
Timer1 is used for capture  
and compare operations for  
CCP1 and Timer 3 is used for  
CCP2.  
Timer3 is used for all capture  
and compare operations for  
all CCP modules. Timer2 is  
used for PWM operations for  
all CCP modules. Modules  
may share either timer  
resource as a common time  
base.  
Both the modules use Timer2  
as a common time base if they  
are in PWM modes.  
DS39629C-page 148  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
TABLE 14-2: INTERACTIONS BETWEEN CCP1 AND CCP2 FOR TIMER RESOURCES  
CCP1 Mode CCP2 Mode  
Interaction  
Capture  
Capture  
Each module can use TMR1 or TMR3 as the time base. The time base can be different  
for each CCP.  
Capture  
Compare CCP2 can be configured for the Special Event Trigger to reset TMR1 or TMR3  
(depending upon which time base is used). Automatic A/D conversions on trigger event  
can also be done. Operation of CCP1 could be affected if it is using the same timer as a  
time base.  
Compare  
Compare  
Capture  
CCP1 can be configured for the Special Event Trigger to reset TMR1 or TMR3  
(depending upon which time base is used). Operation of CCP2 could be affected if it is  
using the same timer as a time base.  
Compare Either module can be configured for the Special Event Trigger to reset the time base.  
Automatic A/D conversions on CCP2 trigger event can be done. Conflicts may occur if  
both modules are using the same time base.  
Capture  
Compare  
PWM*  
PWM*  
PWM*  
*
PWM*  
PWM*  
None  
None  
None  
Capture  
Compare None  
PWM  
Both PWMs will have the same frequency and update rate (TMR2 interrupt).  
Includes standard and Enhanced PWM operation.  
© 2007 Microchip Technology Inc.  
DS39629C-page 149  
PIC18F6390/6490/8390/8490  
14.2.3  
SOFTWARE INTERRUPT  
14.2 Capture Mode  
When the Capture mode is changed, a false capture  
interrupt may be generated. The user should keep bit  
CCP2IE (PIE2<0>) clear to avoid false interrupts and  
should clear the flag bit, CCP2IF, following any such  
change in operating mode.  
In Capture mode, the CCPR2H:CCPR2L register pair  
captures the 16-bit value of the TMR1 or TMR3  
registers when an event occurs on the CCP2 pin (RC1  
or RE7, depending on device configuration). An event  
is defined as one of the following:  
• every falling edge  
• every rising edge  
14.2.4  
CCP PRESCALER  
There are four prescaler settings in Capture mode; they  
are specified as part of the operating mode selected by  
the mode select bits (CCP2M3:CCP2M0). Whenever  
the CCP module is turned off, or the CCP module is not  
in Capture mode, the prescaler counter is cleared. This  
means that any Reset will clear the prescaler counter.  
• every 4th rising edge  
• every 16th rising edge  
The event is selected by the mode select bits,  
CCP2M3:CCP2M0 (CCP2CON<3:0>). When  
a
capture is made, the interrupt request flag bit, CCP2IF  
(PIR2<0>), is set; it must be cleared in software. If  
another capture occurs before the value in register  
CCPR2 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  
a
non-zero prescaler. Example 14-1 shows the  
recommended method for switching between capture  
prescalers. This example also clears the prescaler  
counter and will not generate the “false” interrupt.  
14.2.1  
CCP PIN CONFIGURATION  
In Capture mode, the appropriate CCPx pin should be  
configured as an input by setting the corresponding  
TRIS direction bit.  
EXAMPLE 14-1:  
CHANGING BETWEEN  
CAPTURE PRESCALERS  
Note:  
If RC1/CCP2 or RE7/CCP2 is configured  
as an output, a write to the port can cause  
a capture condition.  
CLRF  
CCP2CON  
; Turn CCP module off  
MOVLW NEW_CAPT_PS ; Load WREG with the  
; new prescaler mode  
; value and CCP ON  
; Load CCP2CON with  
; this value  
14.2.2  
TIMER1/TIMER3 MODE SELECTION  
MOVWF CCP2CON  
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 may not work. The timer to  
be used with each CCP module is selected in the T3CON  
register (see Section 14.1.1 “CCP Modules and Timer  
Resources”).  
FIGURE 14-2:  
CAPTURE MODE OPERATION BLOCK DIAGRAM  
TMR3H  
TMR3L  
Set CCP1IF  
T3CCP2  
TMR3  
Enable  
CCP1 pin  
Prescaler  
÷ 1, 4, 16  
and  
Edge Detect  
CCPR1H  
CCPR1L  
TMR1  
Enable  
T3CCP2  
TMR1H  
TMR3H  
TMR1L  
TMR3L  
4
4
CCP1CON<3:0>  
Q1:Q4  
Set CCP2IF  
4
CCP2CON<3:0>  
T3CCP1  
T3CCP2  
TMR3  
Enable  
CCP2 pin  
Prescaler  
÷ 1, 4, 16  
and  
Edge Detect  
CCPR2H  
CCPR2L  
TMR1L  
TMR1  
Enable  
T3CCP2  
T3CCP1  
TMR1H  
DS39629C-page 150  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
14.3.3  
SOFTWARE INTERRUPT MODE  
14.3 Compare Mode  
When the Generate Software Interrupt mode is chosen  
(CCP2M3:CCP2M0 = 1010), the CCP2 pin is not  
affected. Only a CCP interrupt is generated if enabled  
and the CCP2IE bit is set.  
In Compare mode, the 16-bit CCPR2 register value is  
constantly compared against either the TMR1 or TMR3  
register pair value. When a match occurs, the CCP2  
pin can be:  
• driven high  
14.3.4  
SPECIAL EVENT TRIGGER  
• driven low  
Both 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  
(CCP2M3:CCP2M0 = 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 (CCP2M3:CCP2M0). At the same time, the  
interrupt flag bit, CCP2IF, is set.  
For either CCP module, 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.  
14.3.1  
CCP PIN CONFIGURATION  
The user must configure the CCPx pin as an output by  
clearing the appropriate TRIS bit.  
The Special Event Trigger for CCP2 can also start an  
A/D conversion. In order to do this, the A/D converter  
must already be enabled.  
Note:  
Clearing the CCP2CON register will force  
the RC1 or RE7 compare output latch  
(depending on device configuration) to the  
default low level. This is not the PORTC or  
PORTE I/O data latch.  
Note:  
The Special Event Trigger of CCP1 only  
resets Timer1/Timer3 and cannot start an  
A/D conversion even when the A/D  
converter is enabled.  
14.3.2  
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 14-3:  
COMPARE MODE OPERATION BLOCK DIAGRAM  
Special Event Trigger  
(Timer1 Reset)  
Set CCP1IF  
CCPR1H  
CCPR1L  
CCP1 pin  
S
R
Q
Output  
Logic  
Compare  
Match  
Comparator  
TRIS  
Output Enable  
4
CCP1CON<3:0>  
TMR1H  
TMR3H  
TMR1L  
TMR3L  
0
0
1
1
Special Event Trigger  
(Timer1/Timer3 Reset, A/D Trigger)  
T3CCP1  
T3CCP2  
Set CCP2IF  
CCP2 pin  
S
R
Q
Compare  
Match  
Output  
Logic  
Comparator  
TRIS  
Output Enable  
4
CCPR2H  
CCPR2L  
CCP2CON<3:0>  
© 2007 Microchip Technology Inc.  
DS39629C-page 151  
PIC18F6390/6490/8390/8490  
TABLE 14-3: 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  
TO  
TMR0IF  
PD  
INT0IF  
POR  
RBIF  
BOR  
59  
60  
61  
61  
61  
61  
61  
61  
62  
62  
60  
60  
60  
61  
61  
61  
61  
61  
61  
61  
61  
61  
IPEN  
SBOREN  
ADIF  
RC1IF  
RC1IE  
RC1IP  
PIR1  
TX1IF  
TX1IE  
TX1IP  
SSPIF  
SSPIE  
SSPIP  
BCLIF  
BCLIE  
BCLIP  
CCP1IF  
TMR2IF TMR1IF  
PIE1  
ADIE  
CCP1IE TMR2IE TMR1IE  
CCP1IP TMR2IP TMR1IP  
IPR1  
ADIP  
PIR2  
OSCFIF  
OSCFIE  
OSCFIP  
CMIF  
CMIE  
CMIP  
HLVDIF  
TMR3IF  
CCP2IF  
PIE2  
HLVDIE TMR3IE CCP2IE  
HLVDIP TMR3IP CCP2IP  
IPR2  
TRISC  
TRISE  
PORTC Data Direction Register  
PORTE Data Direction Register  
Timer1 Register Low Byte  
TMR1L  
TMR1H  
T1CON  
TMR3H  
TMR3L  
T3CON  
CCPR1L  
CCPR1H  
CCP1CON  
CCPR2L  
CCPR2H  
CCP2CON  
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  
Capture/Compare/PWM Register 1 Low Byte  
Capture/Compare/PWM Register 1 High Byte  
DC1B1  
DC1B0 CCP1M3 CCP1M2 CCP1M1 CCP1M0  
Capture/Compare/PWM Register 2 Low Byte  
Capture/Compare/PWM Register 2 High Byte  
DC2B1  
DC2B0 CCP2M3 CCP2M2 CCP2M1 CCP2M0  
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by capture/compare, Timer1 or Timer3.  
DS39629C-page 152  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
A PWM output (Figure 14-5) 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).  
14.4 PWM Mode  
In Pulse-Width Modulation (PWM) mode, the CCP2 pin  
produces up to a 10-bit resolution PWM output. Since  
the CCP2 pin is multiplexed with a PORTC or PORTE  
data latch, the appropriate TRIS bit must be cleared to  
make the CCP2 pin an output.  
FIGURE 14-5:  
PWM OUTPUT  
Period  
Note:  
Clearing the CCP2CON register will force  
the RC1 or RE7 output latch (depending  
on device configuration) to the default low  
level. This is not the PORTC or PORTE  
I/O data latch.  
Duty Cycle  
TMR2 = PR2  
Figure 14-4 shows a simplified block diagram of the  
CCP2 module in PWM mode.  
TMR2 = Duty Cycle  
TMR2 = PR2  
For a step-by-step procedure on how to set up the CCP  
module for PWM operation, see Section 14.4.3  
“Setup for PWM Operation”.  
14.4.1  
PWM PERIOD  
The PWM period is specified by writing to the PR2  
register. The PWM period can be calculated using the  
following formula:  
FIGURE 14-4:  
SIMPLIFIED PWM BLOCK  
DIAGRAM  
CCP2CON<5:4>  
Duty Cycle Registers  
EQUATION 14-1:  
CCPR2L  
PWM Period = (PR2) + 1] • 4 • TOSC •  
(TMR2 Prescale Value)  
PWM frequency is defined as 1/[PWM period].  
CCPR2H (Slave)  
Comparator  
When TMR2 is equal to PR2, the following three events  
occur on the next increment cycle:  
Q
R
CCP2  
• TMR2 is cleared  
(Note 1)  
TMR2  
• The CCP2 pin is set (exception: if PWM duty  
cycle = 0%, the CCP2 pin will not be set)  
S
• The PWM duty cycle is latched from CCPR2L into  
CCPR2H  
TRISC<2>  
Comparator  
PR2  
Clear Timer,  
CCP2 pin and  
latch D.C.  
Note:  
The Timer2 postscalers (see Section 12.0  
“Timer2 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.  
Note 1: The 8-bit TMR2 value is concatenated with the 2-bit  
internal Q clock, or 2 bits of the prescaler, to create the  
10-bit time base.  
© 2007 Microchip Technology Inc.  
DS39629C-page 153  
PIC18F6390/6490/8390/8490  
The CCPR2H 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.  
14.4.2  
PWM DUTY CYCLE  
The PWM duty cycle is specified by writing to the  
CCPR2L register and to the CCP2CON<5:4> bits. Up  
to 10-bit resolution is available. The CCPR2L contains  
the eight MSbs and the CCP2CON<5:4> bits contain  
the two LSbs. This 10-bit value is represented by  
CCPR2L:CCP2CON<5:4>. The following equation is  
used to calculate the PWM duty cycle in time:  
When the CCPR2H and 2-bit latch match TMR2,  
concatenated with an internal 2-bit Q clock or 2 bits of  
the TMR2 prescaler, the CCP2 pin is cleared.  
The maximum PWM resolution (bits) for a given PWM  
frequency is given by the equation:  
EQUATION 14-2:  
PWM Duty Cycle = (CCPR2L:CCP2CON<5:4>) •  
TOSC • (TMR2 Prescale Value)  
EQUATION 14-3:  
FOSC  
log ---------------  
FPWM  
PWM Resolution (max)  
= ----------------------------- b i t s  
CCPR2L and CCP2CON<5:4> can be written to at any  
time, but the duty cycle value is not latched into  
CCPR2H until after a match between PR2 and TMR2  
occurs (i.e., the period is complete). In PWM mode,  
CCPR2H is a read-only register.  
log(2)  
Note:  
If the PWM duty cycle value is longer than  
the PWM period, the CCP2 pin will not be  
cleared.  
TABLE 14-4: 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  
14  
4
1
1
3Fh  
8
1
1Fh  
7
1
FFh  
12  
FFh  
10  
17h  
6.58  
Maximum Resolution (bits)  
DS39629C-page 154  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
3. Make the CCP2 pin an output by clearing the  
appropriate TRIS bit.  
14.4.3  
SETUP FOR PWM OPERATION  
The following steps should be taken when configuring  
the CCP2 module for PWM operation:  
4. Set the TMR2 prescale value, then enable  
Timer2 by writing to T2CON.  
1. Set the PWM period by writing to the PR2  
register.  
5. Configure the CCP2 module for PWM operation.  
2. Set the PWM duty cycle by writing to the  
CCPR2L register and CCP2CON<5:4> bits.  
TABLE 14-5: REGISTERS ASSOCIATED WITH PWM AND TIMER2  
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  
59  
60  
61  
61  
61  
62  
62  
60  
60  
60  
61  
61  
61  
61  
61  
61  
IPEN  
SBOREN  
ADIF  
RC1IF  
RC1IE  
RC1IP  
TX1IF  
TX1IE  
TX1IP  
SSPIF  
SSPIE  
SSPIP  
CCP1IF TMR2IF TMR1IF  
CCP1IE TMR2IE TMR1IE  
CCP1IP TMR2IP TMR1IP  
PIE1  
ADIE  
IPR1  
ADIP  
TRISC  
TRISE  
TMR2  
PR2  
PORTC Data Direction Register  
PORTE Data Direction Register  
Timer2 Register  
Timer2 Period Register  
T2CON  
T2OUTPS3 T2OUTPS2 T2OUTPS1 T2OUTPS0 TMR2ON T2CKPS1 T2CKPS0  
CCPR1L Capture/Compare/PWM Register 1 Low Byte  
CCPR1H Capture/Compare/PWM Register 1 High Byte  
CCP1CON  
DC1B1  
DC1B0  
CCP1M3 CCP1M2 CCP1M1 CCP1M0  
CCPR2L Capture/Compare/PWM Register 2 Low Byte  
CCPR2H Capture/Compare/PWM Register 2 High Byte  
CCP2CON  
DC2B1  
DC2B0  
CCP2M3 CCP2M2 CCP2M1 CCP2M0  
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by PWM or Timer2.  
© 2007 Microchip Technology Inc.  
DS39629C-page 155  
PIC18F6390/6490/8390/8490  
NOTES:  
DS39629C-page 156  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
15.3 SPI Mode  
15.0 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:  
15.1 Master SSP (MSSP) Module  
Overview  
• Serial Data Out (SDO) – RC5/SDO/SEG12  
• Serial Data In (SDI) – RC4/SDI/SDA  
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 Clock (SCK) – RC3/SCK/SCL  
Additionally, a fourth pin may be used when in a Slave  
mode of operation:  
• Slave Select (SS) – RF7/SS/SEG25  
Figure 15-1 shows the block diagram of the MSSP  
module when operating in SPI mode.  
• Serial Peripheral Interface (SPI)  
• Inter-Integrated Circuit (I2C)  
- Full Master mode  
FIGURE 15-1:  
MSSP BLOCK DIAGRAM  
(SPI MODE)  
- Slave mode (with general address call)  
The I2C interface supports the following modes in  
hardware:  
Internal  
Data Bus  
Read  
Write  
• Master mode  
• Multi-Master mode  
• Slave mode  
SSPBUF reg  
SSPSR reg  
15.2 Control Registers  
RC4/SDI/SDA  
The MSSP module has three associated registers.  
These include a status register (SSPSTAT) and two  
control registers (SSPCON1 and SSPCON2). 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.  
Shift  
Clock  
bit 0  
RC5/SDO/SEG12  
RF7/SS/  
SEG25  
Control  
Enable  
SS  
Additional details are provided under the individual  
sections.  
Edge  
Select  
2
Clock Select  
SSPM3:SSPM0  
SMP:CKE  
2
4
TMR2 Output  
RC3/SCK/  
SCL  
(
)
2
Edge  
Select  
TOSC  
Prescaler  
4, 16, 64  
Data to TXx/RXx in SSPSR  
TRIS bit  
© 2007 Microchip Technology Inc.  
DS39629C-page 157  
PIC18F6390/6490/8390/8490  
SSPSR is the shift register used for shifting data in or  
out. SSPBUF is the buffer register to which data bytes  
are written to or read from.  
15.3.1  
REGISTERS  
The MSSP module has four registers for SPI mode  
operation. These are:  
In receive operations, SSPSR and SSPBUF together  
create a double-buffered receiver. When SSPSR  
receives a complete byte, it is transferred to SSPBUF  
and the SSPIF interrupt is set.  
• MSSP Control Register 1 (SSPCON1)  
• MSSP Status Register (SSPSTAT)  
• Serial Receive/Transmit Buffer Register (SSPBUF)  
• MSSP Shift Register (SSPSR) – Not directly  
accessible  
During transmission, the SSPBUF is not double-  
buffered. A write to SSPBUF will write to both SSPBUF  
and SSPSR.  
SSPCON1 and SSPSTAT are the control and status  
registers in SPI mode operation. The SSPCON1  
register is readable and writable. The lower 6 bits of  
the SSPSTAT are read-only. The upper 2 bits of the  
SSPSTAT are read/write.  
REGISTER 15-1: SSPSTAT: MSSP 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  
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.  
bit 6  
CKE: SPI Clock Edge Select bit  
When CKP = 0:  
1= Data transmitted on rising edge of SCK  
0= Data transmitted on falling edge of SCK  
When CKP = 1:  
1= Data transmitted on falling edge of SCK  
0= Data transmitted on rising edge of SCK  
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, SSPBUF is full  
0= Receive not complete, SSPBUF is empty  
DS39629C-page 158  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
REGISTER 15-2: SSPCON1: MSSP 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  
-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 (Transmit mode only)  
1= The SSPBUF register is written while it is still transmitting the previous word (must be cleared in  
software)  
0= No collision  
bit 6  
SSPOV: Receive Overflow Indicator bit(1)  
SPI Slave mode:  
1= A new byte is received while the SSPBUF register is still holding the previous data. In case of over-  
flow, the data in SSPSR is lost. Overflow can only occur in Slave mode. The user must read the  
SSPBUF, even if only transmitting data, to avoid setting overflow (must be cleared in software).  
0= No overflow  
bit 5  
SSPEN: Synchronous Serial Port Enable bit(2)  
1= Enables serial port and configures SCK, SDO, SDI and SS 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  
SSPM3:SSPM0: Master Synchronous Serial Port Mode Select bits(3)  
0101= SPI Slave mode, clock = SCK pin, SS pin control disabled, SS can be used as I/O pin  
0100= SPI Slave mode, clock = SCK pin, SS 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 SSPBUF register.  
2: When enabled, these pins must be properly configured as inputs or outputs.  
3: Bit combinations not specifically listed here are either reserved or implemented in I2C™ mode only.  
© 2007 Microchip Technology Inc.  
DS39629C-page 159  
PIC18F6390/6490/8390/8490  
reading the data that was just received. Any write to the  
SSPBUF register during transmission/reception of data  
will be ignored and the Write Collision Detect bit,  
WCOL (SSPCON1<7>), will be set. User software  
must clear the WCOL bit so that it can be determined if  
the following write(s) to the SSPBUF register  
completed successfully.  
15.3.2  
OPERATION  
When initializing the SPI, several options need to be  
specified. This is done by programming the appropriate  
control bits (SSPCON1<5:0> and SSPSTAT<7:6>).  
These control bits allow the following to be specified:  
• Master mode (SCK is the clock output)  
• Slave mode (SCK is the clock input)  
• Clock Polarity (Idle state of SCK)  
When the application software is expecting to receive  
valid data, the SSPBUF should be read before the next  
byte of data to transfer is written to the SSPBUF. The  
Buffer Full bit, BF (SSPSTAT<0>), indicates when  
SSPBUF has been loaded with the received data  
(transmission is complete). When the SSPBUF 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 transmission/reception  
has completed. The SSPBUF must be read and/or  
written. 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 15-1 shows the  
loading of the SSPBUF (SSPSR) for data transmission.  
• Data Input Sample Phase (middle or end of data  
output time)  
• Clock Edge (output data on rising/falling edge of  
SCK)  
• Clock Rate (Master mode only)  
• Slave Select mode (Slave mode only)  
The MSSP consists of a Transmit/Receive Shift regis-  
ter (SSPSR) and a Buffer register (SSPBUF). The  
SSPSR shifts the data in and out of the device, MSb  
first. The SSPBUF holds the data that was written to the  
SSPSR until the received data is ready. Once the 8 bits  
of data have been received, that byte is moved to the  
SSPBUF register. Then, the Buffer Full detect bit, BF  
(SSPSTAT<0>), and the interrupt flag bit, SSPIF, are  
set. This double-buffering of the received data  
(SSPBUF) allows the next byte to start reception before  
The SSPSR is not directly readable or writable and can  
only be accessed by addressing the SSPBUF register.  
Additionally, the MSSP Status register (SSPSTAT)  
indicates the various status conditions.  
EXAMPLE 15-1:  
LOADING THE SSPBUF (SSPSR) REGISTER  
LOOP  
BTFSS  
BRA  
SSPSTAT, BF  
LOOP  
;Has data been received (transmit complete)?  
;No  
MOVF  
SSPBUF, W  
;WREG reg = contents of SSPBUF  
MOVWF  
RXDATA  
;Save in user RAM, if data is meaningful  
MOVF  
MOVWF  
TXDATA, W  
SSPBUF  
;W reg = contents of TXDATA  
;New data to xmit  
DS39629C-page 160  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
15.3.3  
ENABLING SPI I/O  
15.3.4  
TYPICAL CONNECTION  
To enable the serial port, MSSP Enable bit, SSPEN  
(SSPCON1<5>), must be set. To reset or reconfigure  
SPI mode, clear the SSPEN bit, reinitialize the  
SSPCONx registers and then set the SSPEN bit. This  
configures the SDI, SDO, SCK and SS pins as serial  
port pins. For the pins to behave as the serial port func-  
tion, some must have their data direction bits (in the  
TRIS register) appropriately programmed as follows:  
Figure 15-2 shows a typical connection between two  
microcontrollers. The master controller (Processor 1)  
initiates the data transfer by sending the SCK signal.  
Data is shifted out of both shift registers on their  
programmed 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:  
• SDI is automatically controlled by the SPI module  
• SDO must have TRISC<5> bit cleared  
• SCK (Master mode) must have TRISC<3> bit  
cleared  
• Master sends data – Slave sends dummy data  
• Master sends data – Slave sends data  
• SCK (Slave mode) must have TRISC<3> bit set  
• SS must have TRISF<7> bit set  
• Master sends dummy data – Slave sends data  
Any serial port function that is not desired may be  
overridden by programming the corresponding Data  
Direction (TRIS) register to the opposite value.  
FIGURE 15-2:  
SPI MASTER/SLAVE CONNECTION  
SPI Master (SSPM3:SSPM0 = 00xx)  
SPI Slave (SSPM3:SSPM0 = 010x)  
SDO  
SDI  
Serial Input Buffer  
(SSPBUF)  
Serial Input Buffer  
(SSPBUF)  
SDI  
SDO  
Shift Register  
(SSPSR)  
Shift Register  
(SSPSR)  
LSb  
MSb  
MSb  
LSb  
Serial Clock  
SCK  
SCK  
PROCESSOR 1  
PROCESSOR 2  
© 2007 Microchip Technology Inc.  
DS39629C-page 161  
PIC18F6390/6490/8390/8490  
The clock polarity is selected by appropriately  
programming the CKP bit (SSPCON1<4>). This then,  
would give waveforms for SPI communication, as  
shown in Figure 15-3, Figure 15-5 and Figure 15-6,  
where the MSB is transmitted first. In Master mode, the  
SPI clock rate (bit rate) is user programmable to be one  
of the following:  
15.3.5  
MASTER MODE  
The master can initiate the data transfer at any time  
because it controls the SCK. The master determines  
when the slave (Processor 2, Figure 15-2) is to  
broadcast data by the software protocol.  
In Master mode, the data is transmitted/received as  
soon as the SSPBUF register is written to. If the SPI is  
only going to receive, the SDO output could be  
disabled (programmed as an input). The SSPSR regis-  
ter will continue to shift in the signal present on the SDI  
pin at the programmed clock rate. As each byte is  
received, it will be loaded into the SSPBUF 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.  
• FOSC/4 (or TCY)  
• FOSC/16 (or 4 • TCY)  
• FOSC/64 (or 16 • TCY)  
• Timer2 output/2  
This allows a maximum data rate (at 40 MHz) of  
10.00 Mbps.  
Figure 15-3 shows the waveforms for Master mode.  
When the CKE bit is set, the SDO data is valid before  
there is a clock edge on SCK. The change of the input  
sample is shown based on the state of the SMP bit. The  
time when the SSPBUF is loaded with the received  
data is shown.  
FIGURE 15-3:  
SPI MODE WAVEFORM (MASTER MODE)  
Write to  
SSPBUF  
SCK  
(CKP = 0  
CKE = 0)  
SCK  
(CKP = 1  
CKE = 0)  
4 Clock  
Modes  
SCK  
(CKP = 0  
CKE = 1)  
SCK  
(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  
SDO  
(CKE = 0)  
bit 7  
bit 7  
bit 3  
bit 3  
SDO  
(CKE = 1)  
SDI  
(SMP = 0)  
bit 0  
bit 7  
Input  
Sample  
(SMP = 0)  
SDI  
(SMP = 1)  
bit 0  
bit 7  
Input  
Sample  
(SMP = 1)  
SSPIF  
Next Q4 Cycle  
after Q2↓  
SSPSR to  
SSPBUF  
DS39629C-page 162  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
even if in the middle of a transmitted byte and becomes  
a floating output. External pull-up/pull-down resistors  
may be desirable depending on the application.  
15.3.6  
SLAVE MODE  
In Slave mode, the data is transmitted and received as  
the external clock pulses appear on SCK. When the  
last bit is latched, the SSPIF interrupt flag bit is set.  
Note 1: When the SPI is in Slave mode with SS pin  
control enabled (SSPCON<3:0> = 0100),  
the SPI module will reset if the SS pin is set  
to VDD.  
While in Slave mode, the external clock is supplied by  
the external clock source on the SCK pin. This external  
clock must meet the minimum high and low times as  
specified in the electrical specifications.  
2: If the SPI is used in Slave mode with CKE  
set, then the SS pin control must be  
enabled.  
While in Sleep mode, the slave can transmit/receive  
data. When a byte is received, the device will wake-up  
from Sleep.  
When the SPI module resets, the bit counter is forced  
to ‘0’. This can be done by either forcing the SS pin to  
a high level or clearing the SSPEN bit.  
15.3.7  
SLAVE SELECT  
SYNCHRONIZATION  
To emulate two-wire communication, the SDO pin can  
be connected to the SDI pin. When the SPI needs to  
operate as a receiver, the SDO pin can be configured  
as an input. This disables transmissions from the SDO.  
The SDI can always be left as an input (SDI function)  
since it cannot create a bus conflict.  
The SS pin allows a Synchronous Slave mode. The  
SPI must be in Slave mode with SS pin control enabled  
(SSPCON1<3:0> = 04h). The pin must not be driven  
low for the SS pin to function as an input. The data latch  
must be high. When the SS pin is low, transmission and  
reception are enabled and the SDO pin is driven. When  
the SS pin goes high, the SDO pin is no longer driven,  
FIGURE 15-4:  
SLAVE SYNCHRONIZATION WAVEFORM  
SS  
SCK  
(CKP = 0  
CKE = 0)  
SCK  
(CKP = 1  
CKE = 0)  
Write to  
SSPBUF  
bit 6  
bit 7  
bit 7  
bit 0  
SDO  
bit 7  
SDI  
(SMP = 0)  
bit 0  
bit 7  
Input  
Sample  
(SMP = 0)  
SSPIF  
Interrupt  
Flag  
Next Q4 Cycle  
SSPSR to  
SSPBUF  
after Q2↓  
© 2007 Microchip Technology Inc.  
DS39629C-page 163  
PIC18F6390/6490/8390/8490  
FIGURE 15-5:  
SPI MODE WAVEFORM (SLAVE MODE WITH CKE = 0)  
SS  
Optional  
SCK  
(CKP = 0  
CKE = 0)  
SCK  
(CKP = 1  
CKE = 0)  
Write to  
SSPBUF  
bit 6  
bit 2  
bit 5  
bit 4  
bit 3  
bit 1  
bit 0  
SDO  
bit 7  
SDI  
(SMP = 0)  
bit 0  
bit 7  
Input  
Sample  
(SMP = 0)  
SSPIF  
Interrupt  
Flag  
Next Q4 Cycle  
after Q2↓  
SSPSR to  
SSPBUF  
FIGURE 15-6:  
SPI MODE WAVEFORM (SLAVE MODE WITH CKE = 1)  
SS  
Not Optional  
SCK  
(CKP = 0  
CKE = 1)  
SCK  
(CKP = 1  
CKE = 1)  
Write to  
SSPBUF  
bit 6  
bit 2  
bit 5  
bit 4  
bit 1  
bit 0  
SDO  
bit 7  
bit 7  
bit 3  
SDI  
(SMP = 0)  
bit 0  
Input  
Sample  
(SMP = 0)  
SSPIF  
Interrupt  
Flag  
Next Q4 Cycle  
after Q2↓  
SSPSR to  
SSPBUF  
DS39629C-page 164  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
15.3.8  
SLEEP OPERATION  
15.3.9  
EFFECTS OF A RESET  
In SPI Master mode, module clocks may be operating  
at a different speed than when in Full-Power mode; in  
the case of Sleep mode, all clocks are halted.  
A Reset disables the MSSP module and terminates the  
current transfer.  
15.3.10 BUS MODE COMPATIBILITY  
In most power-managed modes, a clock is provided to  
the peripherals. That clock should be from the primary  
clock source, the secondary clock (Timer1 oscillator at  
32.768 kHz) or the INTOSC source. See Section 2.7  
“Clock Sources and Oscillator Switching” for  
additional information.  
Table 15-1 shows the compatibility between the  
standard SPI modes and the states of the CKP and  
CKE control bits.  
TABLE 15-1: SPI BUS MODES  
In most cases, the speed that the master clocks SPI  
data is not important; however, this should be  
evaluated for each system.  
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
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.  
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.  
There is also an SMP bit which controls when the data  
is sampled.  
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 Transmit/  
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.  
TABLE 15-2: 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  
TX1IE  
TX1IP  
RBIE  
SSPIF  
SSPIE  
SSPIP  
TMR0IF  
CCP1IF  
CCP1IE  
CCP1IP  
INT0IF  
RBIF  
59  
61  
61  
61  
62  
62  
60  
60  
60  
ADIF  
ADIE  
ADIP  
RC1IF  
RC1IE  
RC1IP  
TMR2IF  
TMR1IF  
PIE1  
TMR2IE TMR1IE  
TMR2IP TMR1IP  
IPR1  
TRISC  
TRISF  
PORTC Data Direction Register  
PORTF Data Direction Register  
SSPBUF  
SSPCON1  
SSPSTAT  
MSSP Receive Buffer/Transmit Register  
WCOL  
SMP  
SSPOV  
CKE  
SSPEN  
D/A  
CKP  
P
SSPM3  
S
SSPM2  
R/W  
SSPM1  
UA  
SSPM0  
BF  
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by the MSSP in SPI mode.  
© 2007 Microchip Technology Inc.  
DS39629C-page 165  
PIC18F6390/6490/8390/8490  
2
15.4.1  
REGISTERS  
15.4 I C Mode  
The MSSP module has six registers for I2C operation.  
These are:  
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.  
• MSSP Control Register 1 (SSPCON1)  
• MSSP Control Register 2 (SSPCON2)  
• MSSP Status Register (SSPSTAT)  
• Serial Receive/Transmit Buffer Register  
(SSPBUF)  
Two pins are used for data transfer:  
• MSSP Shift Register (SSPSR) – Not directly  
accessible  
• Serial clock (SCL) – RC3/SCK/SCL  
• Serial data (SDA) – RC4/SDI/SDA  
• MSSP Address Register (SSPADD)  
The user must configure these pins as inputs by setting  
the TRISC<4:3> bits.  
SSPCON1, SSPCON2 and SSPSTAT are the control  
and status registers in I2C mode operation. The  
SSPCON1 and SSPCON2 registers are readable and  
writable. The lower 6 bits of the SSPSTAT are read-only.  
The upper 2 bits of the SSPSTAT are read/write.  
FIGURE 15-7:  
MSSP BLOCK DIAGRAM  
(I2C™ MODE)  
SSPSR is the shift register used for shifting data in or  
out. SSPBUF is the buffer register to which data bytes  
are written to, or read from.  
Internal  
Data Bus  
Read  
Write  
SSPADD register holds the slave device address  
when the MSSP is configured in I2C Slave mode.  
When the MSSP is configured in Master mode, the  
lower 7 bits of SSPADD act as the Baud Rate  
Generator reload value.  
SSPBUF reg  
RC3/SCK/SCL  
Shift  
Clock  
In receive operations, SSPSR and SSPBUF together  
create a double-buffered receiver. When SSPSR  
receives a complete byte, it is transferred to SSPBUF  
and the SSPIF interrupt is set.  
SSPSR reg  
RC4/  
SDI/  
SDA  
MSb  
LSb  
Addr Match  
Match Detect  
During transmission, the SSPBUF is not double-  
buffered. A write to SSPBUF will write to both SSPBUF  
and SSPSR.  
SSPADD reg  
Set, Reset  
S, P bits  
(SSPSTAT reg)  
Start and  
Stop bit Detect  
DS39629C-page 166  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
REGISTER 15-3: SSPSTAT: MSSP 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 SSPADD register  
0= Address does not need to be updated  
BF: Buffer Full Status bit  
In Transmit mode:  
1= Receive complete, SSPBUF is full  
0= Receive not complete, SSPBUF is empty  
In Receive mode:  
1= Data transmit in progress (does not include the ACK and Stop bits), SSPBUF is full  
0= Data transmit complete (does not include the ACK and Stop bits), SSPBUF is empty  
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 Idle mode.  
© 2007 Microchip Technology Inc.  
DS39629C-page 167  
PIC18F6390/6490/8390/8490  
REGISTER 15-4: SSPCON1: MSSP CONTROL REGISTER 1 (I2C™ MODE)  
R/W-0  
WCOL  
R/W-0  
R/W-0  
SSPEN(1)  
R/W-0  
CKP  
R/W-0  
SSPM3(2)  
R/W-0  
SSPM2(2)  
R/W-0  
SSPM1(2)  
R/W-0  
SSPM0(2)  
SSPOV  
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  
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 SDA and SCL pins as the serial port pins  
0= Disables serial port and configures these pins as I/O port pins  
CKP: SCK Release Control bit  
In Slave mode:  
1= Releases clock  
0= Holds clock low (clock stretch), used to ensure data setup time  
In Master mode:  
Unused in this mode.  
bit 3-0  
SSPM3:SSPM0: Synchronous Serial Port Mode Select bits(2)  
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 * (SSPADD + 1))  
0111= I2C Slave mode, 10-bit address  
0110= I2C Slave mode, 7-bit address  
Note 1: When enabled, the SDA and SCL pins must be configured as inputs.  
2: Bit combinations not specifically listed here are either reserved or implemented in SPI mode only.  
DS39629C-page 168  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
REGISTER 15-5: SSPCON2: MSSP 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  
-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  
GCEN: General Call Enable bit (Slave mode only)  
1= Enable interrupt when a general call address (0000h) is received in the SSPSR  
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 SDA and SCL 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 SDA and SCL 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 SDA and SCL 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 SDA and SCL 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: If the I2C module is not in the Idle mode, these bits may not be set (no spooling) and the SSPBUF may not  
be written (or writes to the SSPBUF are disabled).  
© 2007 Microchip Technology Inc.  
DS39629C-page 169  
PIC18F6390/6490/8390/8490  
15.4.2  
OPERATION  
15.4.3.1  
Addressing  
The MSSP module functions are enabled by setting  
MSSP Enable bit, SSPEN (SSPCON1<5>).  
The SSPCON1 register allows control of the I2C  
operation. Four mode selection bits (SSPCON1<3:0>)  
allow one of the following I2C modes to be selected:  
• I2C Master mode, clock = (FOSC/4) x (SSPADD + 1)  
• I2C Slave mode (7-bit address)  
• I2C Slave mode (10-bit address)  
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 SSPSR register. All  
incoming bits are sampled with the rising edge of the  
clock (SCL) line. The value of register SSPSR<7:1> is  
compared to the value of the SSPADD register. The  
address is compared on the falling edge of the eighth  
clock (SCL) pulse. If the addresses match and the BF  
and SSPOV bits are clear, the following events occur:  
• I2C Slave mode (7-bit address) with Start and  
Stop bit interrupts enabled  
• 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 SCL and SDA pins to be open-drain,  
provided these pins are programmed to inputs by  
setting the appropriate TRISC bits. To ensure proper  
operation of the module, pull-up resistors must be  
provided externally to the SCL and SDA pins.  
1. The SSPSR register value is loaded into the  
SSPBUF register.  
2. The Buffer Full bit, BF, is set.  
3. An ACK pulse is generated.  
4. MSSP Interrupt Flag bit, SSPIF (PIR1<3>), is  
set (interrupt is generated, if enabled) on the  
falling edge of the ninth SCL 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 (SSPSTAT<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 Addressing mode is as follows, with steps 7  
through 9 for the slave-transmitter:  
15.4.3  
SLAVE MODE  
In Slave mode, the SCL and SDA pins must be config-  
ured 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 SSPIF,  
BF and UA (SSPSTAT<1>) are set).  
2. Update the SSPADD register with second (low)  
byte of address (clears bit UA and releases the  
SCL 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 SSPBUF register with the received value  
currently in the SSPSR register.  
3. Read the SSPBUF register (clears bit, BF) and  
clear flag bit, SSPIF.  
4. Receive second (low) byte of address (bits  
SSPIF, BF and UA are set).  
5. Update the SSPADD register with the first (high)  
byte of address. If match releases SCL line, this  
will clear bit, UA.  
Any combination of the following conditions will cause  
the MSSP module not to give this ACK pulse:  
6. Read the SSPBUF register (clears bit, BF) and  
clear flag bit, SSPIF.  
• The Buffer Full bit, BF (SSPSTAT<0>), was set  
before the transfer was received.  
7. Receive Repeated Start condition.  
• The overflow bit, SSPOV (SSPCON1<6>), was  
set before the transfer was received.  
8. Receive first (high) byte of address (SSPIF and  
BF bits are set).  
In this case, the SSPSR register value is not loaded  
into the SSPBUF, but the SSPIF bit (PIR1<3>) is set.  
The BF bit is cleared by reading the SSPBUF register,  
while bit SSPOV is cleared through software.  
9. Read the SSPBUF register (clears bit, BF) and  
clear flag bit, SSPIF.  
The SCL clock input must have a minimum high and  
low time 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.  
DS39629C-page 170  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
15.4.3.2  
Reception  
15.4.3.3  
Transmission  
When the R/W bit of the address byte is clear and an  
address match occurs, the R/W bit of the SSPSTAT  
register is cleared. The received address is loaded into  
the SSPBUF register and the SDA 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  
SSPSTAT register is set. The received address is  
loaded into the SSPBUF register. The ACK pulse will  
be sent on the ninth bit and pin RC3/SCK/SCL is held  
low regardless of SEN (see Section 15.4.4 “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 SSPBUF register  
which also loads the SSPSR register. Then, pin RC3/  
SCK/SCL should be enabled by setting bit, CKP  
(SSPCON1<4>). The 8 data bits are shifted out on the  
falling edge of the SCL input. This ensures that the  
SDA signal is valid during the SCL high time  
(Figure 15-9).  
When the address byte overflow condition exists, then  
the no Acknowledge (ACK) pulse is given. An overflow  
condition is defined as either bit BF (SSPSTAT<0>) is  
set, or bit SSPOV (SSPCON1<6>) is set.  
An MSSP interrupt is generated for each data transfer  
byte. Flag bit, SSPIF (PIR1<3>), must be cleared in  
software. The SSPSTAT register is used to determine  
the status of the byte.  
If SEN is enabled (SSPCON2<0> = 1), RC3/SCK/SCL  
will be held low (clock stretch) following each data  
transfer. The clock must be released by setting bit  
CKP (SSPCON1<4>). See Section 15.4.4 “Clock  
Stretching” for more detail.  
The ACK pulse from the master-receiver is latched on  
the rising edge of the ninth SCL input pulse. If the SDA  
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 and the slave monitors for  
another occurrence of the Start bit. If the SDA line was  
low (ACK), the next transmit data must be loaded into  
the SSPBUF register. Again, pin RC3/SCK/SCL must  
be enabled by setting bit CKP.  
An MSSP interrupt is generated for each data transfer  
byte. The SSPIF bit must be cleared in software and  
the SSPSTAT register is used to determine the status  
of the byte. The SSPIF bit is set on the falling edge of  
the ninth clock pulse.  
© 2007 Microchip Technology Inc.  
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2
FIGURE 15-8:  
I C™ SLAVE MODE TIMING WITH SEN = 0(RECEPTION, 7-BIT ADDRESS)  
DS39629C-page 172  
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2
FIGURE 15-9:  
I C™ SLAVE MODE TIMING (TRANSMISSION, 7-BIT ADDRESS)  
© 2007 Microchip Technology Inc.  
DS39629C-page 173  
PIC18F6390/6490/8390/8490  
FIGURE 15-10:  
I2C™ SLAVE MODE TIMING WITH SEN = 0(RECEPTION, 10-BIT ADDRESS)  
DS39629C-page 174  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
2
FIGURE 15-11:  
I C™ SLAVE MODE TIMING (TRANSMISSION, 10-BIT ADDRESS)  
© 2007 Microchip Technology Inc.  
DS39629C-page 175  
PIC18F6390/6490/8390/8490  
15.4.4  
CLOCK STRETCHING  
15.4.4.3  
Clock Stretching for 7-Bit Slave  
Transmit Mode  
Both 7 and 10-Bit Slave modes implement automatic  
clock stretching during a transmit sequence.  
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 (SSPCON2<0>) allows clock stretching to  
be enabled during receives. Setting SEN will cause  
the SCL 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 SCL line  
low, the user has time to service the ISR and load the  
contents of the SSPBUF before the master device can  
initiate another transmit sequence (see Figure 15-9).  
15.4.4.1  
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 SSPCON1 register is  
automatically cleared, forcing the SCL output to be  
held low. The CKP being cleared to ‘0’ will assert the  
SCL line low. The CKP bit must be set in the user’s  
ISR before reception is allowed to continue. By holding  
the SCL line low, the user has time to service the ISR  
and read the contents of the SSPBUF before the  
master device can initiate another receive sequence.  
This will prevent buffer overruns from occurring (see  
Figure 15-13).  
Note 1: If the user loads the contents of SSPBUF,  
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.  
15.4.4.4  
Clock Stretching for 10-Bit Slave  
Transmit Mode  
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 15-11).  
Note 1: If the user reads the contents of the  
SSPBUF 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.  
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.  
15.4.4.2  
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  
SSPADD. 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 SSPADD register before the  
falling edge of the ninth clock occurs and if  
the user hasn’t cleared the BF bit by read-  
ing the SSPBUF 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.  
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already asserted the SCL line. The SCL output will  
remain low until the CKP bit is set and all other  
devices on the I2C bus have deasserted SCL. This  
ensures that a write to the CKP bit will not violate the  
minimum high time requirement for SCL (see  
Figure 15-12).  
15.4.4.5  
Clock Synchronization and  
the CKP bit  
When the CKP bit is cleared, the SCL output is forced  
to ‘0’. However, setting the CKP bit will not assert the  
SCL output low until the SCL output is already sam-  
pled low. Therefore, the CKP bit will not assert the  
SCL line until an external I2C master device has  
FIGURE 15-12:  
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  
SDA  
SCL  
DX  
DX – 1  
Master device  
asserts clock  
CKP  
Master device  
deasserts clock  
WR  
SSPCON  
© 2007 Microchip Technology Inc.  
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2
FIGURE 15-13:  
I C™ SLAVE MODE TIMING WITH SEN = 1(RECEPTION, 7-BIT ADDRESS)  
DS39629C-page 178  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
FIGURE 15-14:  
I2C™ SLAVE MODE TIMING WITH SEN = 1(RECEPTION, 10-BIT ADDRESS)  
© 2007 Microchip Technology Inc.  
DS39629C-page 179  
PIC18F6390/6490/8390/8490  
If the general call address matches, the SSPSR is  
transferred to the SSPBUF, the BF flag bit is set (eighth  
bit) and on the falling edge of the ninth bit (ACK bit), the  
SSPIF interrupt flag bit is set.  
15.4.5  
GENERAL CALL ADDRESS  
SUPPORT  
The addressing procedure for the I2C bus is such that  
the first byte after the Start condition usually deter-  
mines 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 inter-  
rupt can be checked by reading the contents of the  
SSPBUF. The value can be used to determine if the  
address was device specific or a general call address.  
In 10-bit mode, the SSPADD is required to be updated  
for the second half of the address to match and the UA  
bit is set (SSPSTAT<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 15-15).  
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  
(SSPCON2<7> set). Following a Start bit detect, 8 bits  
are shifted into the SSPSR and the address is  
compared against the SSPADD. It is also compared to  
the general call address and fixed in hardware.  
FIGURE 15-15:  
SLAVE MODE GENERAL CALL ADDRESS SEQUENCE  
(7 OR 10-BIT ADDRESSING MODE)  
Address is compared to General Call Address  
after ACK, set interrupt  
Receiving Data  
D5 D4 D3 D2 D1  
ACK  
R/W = 0  
General Call Address  
ACK  
SDA  
SCL  
D7 D6  
D0  
8
1
2
3
4
5
6
7
8
9
1
2
3
4
5
6
7
9
S
SSPIF  
BF (SSPSTAT<0>)  
Cleared in software  
SSPBUF is read  
SSPOV (SSPCON1<6>)  
GCEN (SSPCON2<7>)  
0’  
1’  
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15.4.6  
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 SSPBUF register to  
initiate transmission before the Start condi-  
tion is complete. In this case, the SSPBUF  
will not be written to and the WCOL bit will  
be set, indicating that a write to the  
SSPBUF did not occur.  
Master mode is enabled by setting and clearing the  
appropriate SSPM bits in SSPCON1 and by setting the  
SSPEN bit. In Master mode, the SCL and SDA lines  
are manipulated by the MSSP hardware.  
Master mode of operation is supported by interrupt  
generation on the detection of the Start and Stop  
conditions. 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 MSSP Interrupt  
Flag bit, SSPIF, to be set (MSSP 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  
Once Master mode is enabled, the user has six  
options.  
• Data transfer byte transmitted/received  
• Acknowledge transmit  
• Repeated Start  
1. Assert a Start condition on SDA and SCL.  
2. Assert a Repeated Start condition on SDA and  
SCL.  
3. Write to the SSPBUF 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 SDA and SCL.  
2
FIGURE 15-16:  
MSSP BLOCK DIAGRAM (I C™ MASTER MODE)  
Internal  
Data Bus  
SSPM3:SSPM0  
SSPADD<6:0>  
Read  
Write  
SSPBUF  
SSPSR  
Baud  
Rate  
Generator  
SDA  
Shift  
Clock  
SDA In  
MSb  
LSb  
Start bit, Stop bit,  
Acknowledge  
Generate  
SCL  
Start bit Detect  
Stop bit Detect  
Write Collision Detect  
Clock Arbitration  
State Counter for  
end of XMIT/RCV  
SCL In  
Bus Collision  
Set/Reset, S, P, WCOL (SSPSTAT),  
Set SSPIF, BCLIF,  
Reset ACKSTAT, PEN (SSPCON2)  
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I2C Master Mode Operation  
A typical transmit sequence would go as follows:  
15.4.6.1  
1. The user generates a Start condition by setting  
the Start Enable bit, SEN (SSPCON2<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. SSPIF is set. The MSSP module will wait the  
required start time before any other operation  
takes place.  
3. The user loads the SSPBUF with the slave  
address to transmit.  
In Master Transmitter mode, serial data is output  
through SDA, while SCL 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 SDA 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  
SSPCON2 register (SSPCON2<6>).  
6. The MSSP module generates an interrupt at the  
end of the ninth clock cycle by setting the SSPIF  
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 SDA, while SCL outputs the  
serial clock. Serial data is received 8 bits at a time. After  
each byte is received, an Acknowledge bit is transmit-  
ted. Start and Stop conditions indicate the beginning  
and end of transmission.  
7. The user loads the SSPBUF with 8 bits of data.  
8. Data is shifted out the SDA 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  
SSPCON2 register (SSPCON2<6>).  
10. The MSSP module generates an interrupt at the  
end of the ninth clock cycle by setting the SSPIF  
bit.  
11. The user generates a Stop condition by setting  
the Stop Enable bit, PEN (SSPCON2<2>).  
The Baud Rate Generator used for the SPI mode  
operation is used to set the SCL clock frequency for  
either 100 kHz, 400 kHz or 1 MHz I2C operation. See  
Section 15.4.7 “Baud Rate” for more detail.  
12. Interrupt is generated once the Stop condition is  
complete.  
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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 SCL pin  
will remain in its last state.  
15.4.7  
BAUD RATE  
In I2C Master mode, the Baud Rate Generator (BRG)  
reload value is placed in the lower 7 bits of the  
SSPADD register (Figure 15-17). When a write occurs  
to SSPBUF, 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.  
Table 15-3 demonstrates clock rates based on  
instruction cycles and the BRG value loaded into  
SSPADD.  
FIGURE 15-17:  
BAUD RATE GENERATOR BLOCK DIAGRAM  
SSPM3:SSPM0  
SSPADD<6:0>  
SSPM3:SSPM0  
SCL  
Reload  
Control  
Reload  
BRG Down Counter  
CLKO  
FOSC/4  
TABLE 15-3: I2C™ CLOCK RATE w/BRG  
FSCL  
FCY  
FCY * 2  
BRG Value  
(2 Rollovers of BRG)  
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  
19h  
20h  
3Fh  
0Ah  
0Dh  
28h  
03h  
0Ah  
00h  
400 kHz(1)  
312.5 kHz  
100 kHz  
400 kHz(1)  
308 kHz  
100 kHz  
333 kHz(1)  
100 kHz  
1 MHz(1)  
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.  
© 2007 Microchip Technology Inc.  
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SCL pin is sampled high, the Baud Rate Generator is  
reloaded with the contents of SSPADD<6:0> and  
begins counting. This ensures that the SCL 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 15-18).  
15.4.7.1  
Clock Arbitration  
Clock arbitration occurs when the master, during any  
receive, transmit or Repeated Start/Stop condition,  
deasserts the SCL pin (SCL allowed to float high).  
When the SCL pin is allowed to float high, the Baud  
Rate Generator (BRG) is suspended from counting  
until the SCL pin is actually sampled high. When the  
FIGURE 15-18:  
BAUD RATE GENERATOR TIMING WITH CLOCK ARBITRATION  
SDA  
DX  
DX – 1  
SCL allowed to transition high  
SCL deasserted but slave holds  
SCL low (clock arbitration)  
SCL  
BRG decrements on  
Q2 and Q4 cycles  
BRG  
Value  
03h  
02h  
01h  
00h (hold off)  
03h  
02h  
SCL is sampled high, reload takes  
place and BRG starts its count  
BRG  
Reload  
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15.4.8  
I2C MASTER MODE START  
CONDITION TIMING  
Note:  
If at the beginning of the Start condition,  
the SDA and SCL pins are already sam-  
pled low, or if during the Start condition, the  
SCL line is sampled low before the SDA  
line is driven low, a bus collision occurs,  
the Bus Collision Interrupt Flag, BCLIF, 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  
Condition Enable bit, SEN (SSPCON2<0>). If the SDA  
and SCL pins are sampled high, the Baud Rate Gener-  
ator is reloaded with the contents of SSPADD<6:0>  
and starts its count. If SCL and SDA are both sampled  
high when the Baud Rate Generator times out (TBRG),  
the SDA pin is driven low. The action of the SDA being  
driven low while SCL is high is the Start condition and  
causes the S bit (SSPSTAT<3>) to be set. Following  
this, the Baud Rate Generator is reloaded with the  
contents of SSPADD<6:0> and resumes its count.  
When the Baud Rate Generator times out (TBRG), the  
SEN bit (SSPCON2<0>) will be automatically cleared  
by hardware, the Baud Rate Generator is suspended,  
leaving the SDA line held low and the Start condition is  
complete.  
15.4.8.1  
WCOL Status Flag  
If the user writes the SSPBUF when a 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 to the lower 5 bits of  
SSPCON2 is disabled until the Start  
condition is complete.  
FIGURE 15-19:  
FIRST START BIT TIMING  
Set S bit (SSPSTAT<3>)  
At completion of Start bit,  
Write to SEN bit occurs here  
SDA = 1,  
SCL = 1  
hardware clears SEN bit  
and sets SSPIF bit  
TBRG  
TBRG  
Write to SSPBUF occurs here  
2nd bit  
1st bit  
SDA  
TBRG  
SCL  
TBRG  
S
© 2007 Microchip Technology Inc.  
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15.4.9  
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  
(SSPCON2<1>) is programmed high and the I2C logic  
module is in the Idle state. When the RSEN bit is set,  
the SCL pin is asserted low. When the SCL pin is  
sampled low, the Baud Rate Generator is loaded with  
the contents of SSPADD<5:0> and begins counting.  
The SDA pin is released (brought high) for one Baud  
Rate Generator count (TBRG). When the Baud Rate  
Generator times out, if SDA is sampled high, the SCL  
pin will be deasserted (brought high). When SCL is  
sampled high, the Baud Rate Generator is reloaded  
with the contents of SSPADD<6:0> and begins count-  
ing. SDA and SCL must be sampled high for one TBRG.  
This action is then followed by assertion of the SDA pin  
(SDA = 0) for one TBRG while SCL is high. Following  
this, the RSEN bit (SSPCON2<1>) will be automatically  
cleared and the Baud Rate Generator will not be  
reloaded, leaving the SDA pin held low. As soon as a  
Start condition is detected on the SDA and SCL pins,  
the S bit (SSPSTAT<3>) will be set. The SSPIF bit will  
not be set until the Baud Rate Generator has timed out.  
2: A bus collision during the Repeated Start  
condition occurs if:  
• SDA is sampled low when SCL goes  
from low-to-high.  
• SCL goes low before SDA is  
asserted low. This may indicate that  
another master is attempting to  
transmit a data ‘1’.  
Immediately following the SSPIF bit getting set, the user  
may write the SSPBUF with the 7-bit address in 7-bit  
mode, or the default first address in 10-bit mode. After  
the first 8 bits are transmitted and an ACK is received,  
the user may then transmit an additional eight bits of  
address (10-bit mode) or 8 bits of data (7-bit mode).  
15.4.9.1  
WCOL Status Flag  
If the user writes the SSPBUF 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  
SSPCON2 is disabled until the Repeated  
Start condition is complete.  
FIGURE 15-20:  
REPEAT START CONDITION WAVEFORM  
Set S (SSPSTAT<3>)  
Write to SSPCON2  
SDA = 1,  
occurs here.  
At completion of Start bit,  
hardware clears RSEN bit  
and sets SSPIF  
SCL = 1  
SDA = 1,  
SCL (no change).  
TBRG  
TBRG  
TBRG  
1st bit  
SDA  
Write to SSPBUF occurs here  
TBRG  
Falling edge of ninth clock,  
end of Xmit  
SCL  
TBRG  
Sr = Repeated Start  
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15.4.10 I2C MASTER MODE  
TRANSMISSION  
15.4.10.3 ACKSTAT Status Flag  
In Transmit mode, the ACKSTAT bit (SSPCON2<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.  
Transmission of a data byte, a 7-bit address or the  
other half of a 10-bit address is accomplished by simply  
writing a value to the SSPBUF register. This action will  
set the Buffer Full flag bit, BF, and allow the Baud Rate  
Generator to begin counting and start the next trans-  
mission. Each bit of address/data will be shifted out  
onto the SDA pin after the falling edge of SCL is  
asserted (see data hold time specification parameter  
#106). SCL is held low for one Baud Rate Generator  
rollover count (TBRG). Data should be valid before SCL  
is released high (see data setup time specification  
parameter #107). When the SCL pin is released high, it  
is held that way for TBRG. The data on the SDA pin  
must remain stable for that duration and some hold  
time after the next falling edge of SCL. After the eighth  
bit is shifted out (the falling edge of the eighth clock),  
the BF flag is cleared and the master releases SDA.  
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 SSPIF bit is set and the master clock (Baud  
Rate Generator) is suspended until the next data byte  
is loaded into the SSPBUF, leaving SCL low and SDA  
unchanged (Figure 15-21).  
15.4.11 I2C MASTER MODE RECEPTION  
Master mode reception is enabled by programming the  
Receive Enable bit, RCEN (SSPCON2<3>).  
Note:  
The MSSP module must be in an Idle 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 SCL pin changes (high-to-low/  
low-to-high) and data is shifted into the SSPSR. After  
the falling edge of the eighth clock, the receive enable  
flag is automatically cleared, the contents of the  
SSPSR are loaded into the SSPBUF, the BF flag bit is  
set, the SSPIF flag bit is set and the Baud Rate  
Generator is suspended from counting, holding SCL  
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  
(SSPCON2<4>).  
15.4.11.1 BF Status Flag  
After the write to the SSPBUF, each bit of address will  
be shifted out on the falling edge of SCL until all  
7 address bits and the R/W bit are completed. On the  
falling edge of the eighth clock, the master will deassert  
the SDA pin, allowing the slave to respond with an  
Acknowledge. On the falling edge of the ninth clock, the  
master will sample the SDA pin to see if the address  
was recognized by a slave. The status of the ACK bit is  
loaded into the ACKSTAT status bit (SSPCON2<6>).  
Following the falling edge of the ninth clock transmis-  
sion of the address, the SSPIF is set, the BF flag is  
cleared and the Baud Rate Generator is turned off until  
another write to the SSPBUF takes place, holding SCL  
low and allowing SDA to float.  
In receive operation, the BF bit is set when an address  
or data byte is loaded into SSPBUF from SSPSR. It is  
cleared when the SSPBUF register is read.  
15.4.11.2 SSPOV Status Flag  
In receive operation, the SSPOV bit is set when 8 bits  
are received into the SSPSR and the BF flag bit is  
already set from a previous reception.  
15.4.11.3 WCOL Status Flag  
If the user writes the SSPBUF when a receive is  
already in progress (i.e., SSPSR 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).  
15.4.10.1 BF Status Flag  
In Transmit mode, the BF bit (SSPSTAT<0>) is set  
when the CPU writes to SSPBUF and is cleared when  
all 8 bits are shifted out.  
15.4.10.2 WCOL Status Flag  
If the user writes the SSPBUF when a transmit is  
already in progress (i.e., SSPSR is still shifting out a  
data byte), the WCOL is set and the contents of the  
buffer are unchanged (the write doesn’t occur).  
WCOL must be cleared in software.  
© 2007 Microchip Technology Inc.  
DS39629C-page 187  
PIC18F6390/6490/8390/8490  
2
FIGURE 15-21:  
I C™ MASTER MODE WAVEFORM (TRANSMISSION, 7 OR 10-BIT ADDRESS)  
DS39629C-page 188  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
2
FIGURE 15-22:  
I C™ MASTER MODE WAVEFORM (RECEPTION, 7-BIT ADDRESS)  
© 2007 Microchip Technology Inc.  
DS39629C-page 189  
PIC18F6390/6490/8390/8490  
15.4.12 ACKNOWLEDGE SEQUENCE  
TIMING  
15.4.13 STOP CONDITION TIMING  
A Stop bit is asserted on the SDA pin at the end of a  
receive/transmit by setting the Stop Sequence Enable  
bit, PEN (SSPCON2<2>). At the end of a receive/  
transmit, the SCL line is held low after the falling edge  
of the ninth clock. When the PEN bit is set, the master  
will assert the SDA line low. When the SDA line is  
sampled low, the Baud Rate Generator is reloaded and  
counts down to ‘0’. When the Baud Rate Generator  
times out, the SCL pin will be brought high and one  
TBRG (Baud Rate Generator rollover count) later, the  
SDA pin will be deasserted. When the SDA pin is sam-  
pled high while SCL is high, the P bit (SSPSTAT<4>) is  
set. A TBRG later, the PEN bit is cleared and the SSPIF  
bit is set (Figure 15-24).  
An Acknowledge sequence is enabled by setting the  
Acknowledge Sequence Enable bit, ACKEN  
(SSPCON2<4>). When this bit is set, the SCL pin is  
pulled low and the contents of the Acknowledge data bit  
are presented on the SDA pin. If the user wishes to gen-  
erate 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 SCL pin is deasserted (pulled high). When the  
SCL pin is sampled high (clock arbitration), the Baud  
Rate Generator counts for TBRG. The SCL pin is then  
pulled low. Following this, the ACKEN bit is automatically  
cleared, the Baud Rate Generator is turned off and the  
MSSP module then goes into Idle mode (Figure 15-23).  
15.4.13.1 WCOL Status Flag  
If the user writes the SSPBUF 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).  
15.4.12.1 WCOL Status Flag  
If the user writes the SSPBUF 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 15-23:  
ACKNOWLEDGE SEQUENCE WAVEFORM  
Acknowledge sequence starts here,  
write to SSPCON2  
ACKEN automatically cleared  
ACKEN = 1, ACKDT = 0  
TBRG  
TBRG  
ACK  
SDA  
SCL  
D0  
8
9
SSPIF  
Cleared in  
Set SSPIF at the end  
of receive  
software  
Cleared in  
software  
Set SSPIF at the end  
of Acknowledge sequence  
Note: TBRG = one Baud Rate Generator period.  
FIGURE 15-24:  
STOP CONDITION RECEIVE OR TRANSMIT MODE  
SCL = 1for TBRG, followed by SDA = 1for TBRG  
after SDA sampled high. P bit (SSPSTAT<4>) is set.  
Write to SSPCON2,  
set PEN  
PEN bit (SSPCON2<2>) is cleared by  
hardware and the SSPIF bit is set  
Falling edge of  
9th clock  
TBRG  
SCL  
SDA  
ACK  
P
TBRG  
TBRG  
TBRG  
SCL brought high after TBRG  
SDA asserted low before rising edge of clock  
to setup Stop condition  
Note: TBRG = one Baud Rate Generator period.  
DS39629C-page 190  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
15.4.14 SLEEP OPERATION  
15.4.17 MULTI-MASTER COMMUNICATION,  
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).  
BUS COLLISION AND BUS  
ARBITRATION  
Multi-Master mode support is achieved by bus arbitra-  
tion. When the master outputs address/data bits onto  
the SDA pin, arbitration takes place when the master  
outputs a ‘1’ on SDA, by letting SDA float high and  
another master asserts a ‘0’. When the SCL pin floats  
high, data should be stable. If the expected data on  
SDA is a ‘1’ and the data sampled on the SDA pin = 0,  
then a bus collision has taken place. The master will set  
the Bus Collision Interrupt Flag, BCLIF and reset the  
I2C port to its Idle state (Figure 15-25).  
15.4.15 EFFECT OF A RESET  
A Reset disables the MSSP module and terminates the  
current transfer.  
15.4.16 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 (SSPSTAT<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 SDA and SCL lines are deasserted and the  
SSPBUF 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 SDA 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 BCLIF bit.  
If a Start, Repeated Start, Stop or Acknowledge  
condition was in progress when the bus collision  
occurred, the condition is aborted, the SDA and SCL  
lines are deasserted and the respective control bits in  
the SSPCON2 register are cleared. When the user ser-  
vices 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  
The master will continue to monitor the SDA and SCL  
pins. If a Stop condition occurs, the SSPIF bit will be set.  
• A Repeated Start Condition  
• An Acknowledge Condition  
A write to the SSPBUF 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 SSPSTAT  
register, or the bus is Idle and the S and P bits are  
cleared.  
FIGURE 15-25:  
BUS COLLISION TIMING FOR TRANSMIT AND ACKNOWLEDGE  
Sample SDA. While SCL is high,  
data doesn’t match what is driven  
by the master.  
Data changes  
while SCL = 0  
SDA line pulled low  
by another source  
Bus collision has occurred.  
SDA released  
by master  
SDA  
SCL  
Set bus collision  
interrupt (BCLIF)  
BCLIF  
© 2007 Microchip Technology Inc.  
DS39629C-page 191  
PIC18F6390/6490/8390/8490  
If the SDA pin is sampled low during this count, the  
15.4.17.1 Bus Collision During a Start  
Condition  
BRG is reset and the SDA line is asserted early  
(Figure 15-28). If, however, a ‘1’ is sampled on the SDA  
pin, the SDA pin is asserted low at the end of the BRG  
count. The Baud Rate Generator is then reloaded and  
counts down to 0 and during this time, if the SCL pins  
are sampled as ‘0’, a bus collision does not occur. At  
the end of the BRG count, the SCLpin is asserted low.  
During a Start condition, a bus collision occurs if:  
a) SDA or SCL are sampled low at the beginning of  
the Start condition (Figure 15-26).  
b) SCL is sampled low before SDA is asserted low  
(Figure 15-27).  
During a Start condition, both the SDA and the SCL  
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 SDA before the other.  
This condition does not cause a bus  
collision because the two masters must be  
allowed to arbitrate the first address follow-  
ing 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 SDA pin is already low, or the SCL pin is already  
low, then all of the following occur:  
• the Start condition is aborted,  
• the BCLIF flag is set and  
• the MSSP module is reset to its Idle state  
(Figure 15-26).  
The Start condition begins with the SDA and SCL pins  
deasserted. When the SDA pin is sampled high, the  
Baud Rate Generator is loaded from SSPADD<6:0>  
and counts down to ‘0’. If the SCL pin is sampled low  
while SDA 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 15-26:  
BUS COLLISION DURING START CONDITION (SDA ONLY)  
SDA goes low before the SEN bit is set.  
Set BCLIF,  
S bit and SSPIF set because  
SDA = 0, SCL = 1.  
SDA  
SCL  
SEN  
Set SEN, enable Start  
condition if SDA = 1, SCL = 1  
SEN cleared automatically because of bus collision.  
MSSP module reset into Idle state.  
SDA sampled low before  
Start condition. Set BCLIF.  
S bit and SSPIF set because  
SDA = 0, SCL = 1.  
BCLIF  
SSPIF and BCLIF are  
cleared in software  
S
SSPIF  
SSPIF and BCLIF are  
cleared in software  
DS39629C-page 192  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
FIGURE 15-27:  
BUS COLLISION DURING START CONDITION (SCL = 0)  
SDA = 0, SCL = 1  
TBRG  
TBRG  
SDA  
Set SEN, enable Start  
sequence if SDA = 1, SCL = 1  
SCL  
SEN  
SCL = 0before SDA = 0,  
bus collision occurs. Set BCLIF.  
SCL = 0before BRG time-out,  
bus collision occurs. Set BCLIF.  
BCLIF  
Interrupt cleared  
in software  
S
0’  
0’  
0’  
0’  
SSPIF  
FIGURE 15-28:  
BRG RESET DUE TO SDA ARBITRATION DURING START CONDITION  
SDA = 0, SCL = 1  
Set S  
Set SSPIF  
Less than TBRG  
TBRG  
SDA pulled low by other master.  
Reset BRG and assert SDA.  
SDA  
SCL  
S
SCL pulled low after BRG  
time-out  
SEN  
Set SEN, enable START  
sequence if SDA = 1, SCL = 1  
0’  
BCLIF  
S
SSPIF  
Interrupts cleared  
in software  
SDA = 0, SCL = 1,  
set SSPIF  
© 2007 Microchip Technology Inc.  
DS39629C-page 193  
PIC18F6390/6490/8390/8490  
If SDA is low, a bus collision has occurred (i.e., another  
15.4.17.2 Bus Collision During a Repeated  
Start Condition  
master is attempting to transmit a data ‘0’, Figure 15-29).  
If SDA is sampled high, the BRG is reloaded and begins  
counting. If SDA goes from high-to-low before the BRG  
times out, no bus collision occurs because no two  
masters can assert SDA at exactly the same time.  
During a Repeated Start condition, a bus collision  
occurs if:  
a) A low level is sampled on SDA when SCL goes  
from low level to high level.  
If SCL goes from high-to-low before the BRG times out  
and SDA 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 15-30).  
b) SCL goes low before SDA is asserted low,  
indicating that another master is attempting to  
transmit a data ‘1’.  
When the user deasserts SDA and the pin is allowed to  
float high, the BRG is loaded with SSPADD<6:0> and  
counts down to 0. The SCL pin is then deasserted and  
when sampled high, the SDA pin is sampled.  
If, at the end of the BRG time-out, both SCL and SDA  
are still high, the SDA pin is driven low and the BRG is  
reloaded and begins counting. At the end of the count,  
regardless of the status of the SCL pin, the SCL pin is  
driven low and the Repeated Start condition is  
complete.  
FIGURE 15-29:  
BUS COLLISION DURING A REPEATED START CONDITION (CASE 1)  
SDA  
SCL  
Sample SDA when SCL goes high.  
If SDA = 0, set BCLIF and release SDA and SCL.  
RSEN  
BCLIF  
Cleared in software  
0’  
S
0’  
SSPIF  
FIGURE 15-30:  
BUS COLLISION DURING REPEATED START CONDITION (CASE 2)  
TBRG  
TBRG  
SDA  
SCL  
SCL goes low before SDA,  
set BCLIF. Release SDA and SCL.  
BCLIF  
RSEN  
Interrupt cleared  
in software  
0’  
S
SSPIF  
DS39629C-page 194  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
The Stop condition begins with SDA asserted low.  
When SDA is sampled low, the SCL pin is allowed to  
float. When the pin is sampled high (clock arbitration),  
the Baud Rate Generator is loaded with SSPADD<6:0>  
and counts down to 0. After the BRG times out, SDA is  
sampled. If SDA is sampled low, a bus collision has  
occurred. This is due to another master attempting to  
drive a data ‘0’ (Figure 15-31). If the SCL pin is  
sampled low before SDA is allowed to float high, a bus  
collision occurs. This is another case of another master  
attempting to drive a data ‘0’ (Figure 15-32).  
15.4.17.3 Bus Collision During a Stop  
Condition  
Bus collision occurs during a Stop condition if:  
a) After the SDA pin has been deasserted and  
allowed to float high, SDA is sampled low after  
the BRG has timed out.  
b) After the SCL pin is deasserted, SCL is sampled  
low before SDA goes high.  
FIGURE 15-31:  
BUS COLLISION DURING A STOP CONDITION (CASE 1)  
SDA sampled  
low after TBRG,  
set BCLIF  
TBRG  
TBRG  
TBRG  
SDA  
SDA asserted low  
SCL  
PEN  
BCLIF  
P
0’  
0’  
SSPIF  
FIGURE 15-32:  
BUS COLLISION DURING A STOP CONDITION (CASE 2)  
TBRG  
TBRG  
TBRG  
SDA  
SCL goes low before SDA goes high,  
set BCLIF  
Assert SDA  
SCL  
PEN  
BCLIF  
P
0’  
0’  
SSPIF  
© 2007 Microchip Technology Inc.  
DS39629C-page 195  
PIC18F6390/6490/8390/8490  
TABLE 15-4: 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  
RBIE  
SSPIF  
SSPIE  
SSPIP  
TMR0IF  
CCP1IF  
CCP1IE  
CCP1IP  
INT0IF  
TMR2IF  
TMR2IE  
TMR2IP  
RBIF  
59  
61  
61  
61  
62  
60  
60  
60  
60  
60  
ADIF  
ADIE  
ADIP  
RC1IF  
RC1IE  
RC1IP  
TMR1IF  
TMR1IE  
TMR1IP  
PIE1  
IPR1  
TRISC  
PORTC Data Direction Register  
SSPBUF  
SSPADD  
SSPCON1  
SSPCON2  
SSPSTAT  
MSSP Receive Buffer/Transmit Register  
2
2
MSSP Address Register in I C Slave Mode. MSSP Baud Rate Reload Register in I C Slave Mode.  
WCOL  
GCEN  
SMP  
SSPOV  
ACKSTAT  
CKE  
SSPEN  
ACKDT  
D/A  
CKP  
ACKEN  
P
SSPM3  
RCEN  
S
SSPM2  
PEN  
SSPM1  
RSEN  
UA  
SSPM0  
SEN  
BF  
R/W  
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by the MSSP in SPI mode.  
DS39629C-page 196  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
The pins of the EUSART are multiplexed with the  
16.0 ENHANCED UNIVERSAL  
SYNCHRONOUS  
functions  
of  
PORTC  
(RC6/TX1/CK1  
and  
RC7/RX1/DT1). In order to configure these pins as an  
EUSART:  
ASYNCHRONOUS RECEIVER  
TRANSMITTER (EUSART)  
• bit SPEN (RCSTA1<7>) must be set (= 1)  
• bit TRISC<7> must be set (= 1)  
PIC18F6390/6490/8390/8490 devices have three  
serial I/O modules: the MSSP module, discussed in the  
previous chapter and two Universal Synchronous  
Asynchronous Receiver Transmitter (USART) mod-  
ules. (Generically, the USART is also known as a Serial  
Communications Interface or SCI.) The USART 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.  
• bit TRISC<6> must be set (= 1)  
Note:  
The USART control will automatically  
reconfigure the pin from input to output as  
needed.  
The operation of the Enhanced USART module is  
controlled through three registers:  
• Transmit Status and Control Register 1 (TXSTA1)  
• Receive Status and Control Register 1 (RCSTA1)  
• Baud Rate Control Register 1 (BAUDCON1)  
The registers are described in Register 16-1,  
Register 16-2 and Register 16-3.  
There are two distinct implementations of the USART  
module in these devices: the Enhanced USART  
(EUSART) discussed here and the Addressable  
USART discussed in the next chapter. For this device  
family, USART1 always refers to the EUSART, while  
USART2 is always the AUSART.  
The EUSART and AUSART modules implement the  
same core features for serial communications; their  
basic operation is essentially the same. The EUSART  
module provides additional features, including  
Automatic Baud Rate Detection (ABD) and calibration,  
automatic wake-up on Sync Break reception and 12-bit  
Break character transmit. These features make it  
ideally suited for use in Local Interconnect Network bus  
(LIN bus) systems.  
The EUSART can be configured in the following  
modes:  
• Asynchronous (full-duplex) with:  
- Auto-wake-up on character reception  
- Auto-baud calibration  
- 12-bit Break character transmission  
• Synchronous – Master (half-duplex) with  
selectable clock polarity  
• Synchronous – Slave (half-duplex) with selectable  
clock polarity  
© 2007 Microchip Technology Inc.  
DS39629C-page 197  
PIC18F6390/6490/8390/8490  
REGISTER 16-1: TXSTA1: EUSART TRANSMIT STATUS AND CONTROL REGISTER  
R/W-0  
CSRC  
R/W-0  
TX9  
R/W-0  
TXEN(1)  
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)  
1= Transmit enabled  
0= Transmit disabled  
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= TSR empty  
0= TSR full  
TX9D: 9th bit of Transmit Data  
Can be address/data bit or a parity bit.  
Note 1: SREN/CREN overrides TXEN in Sync mode.  
DS39629C-page 198  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
REGISTER 16-2: RCSTA1: EUSART 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 RX1/DT1 and TX1/CK1 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 RSR<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 RCREG1 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.  
© 2007 Microchip Technology Inc.  
DS39629C-page 199  
PIC18F6390/6490/8390/8490  
REGISTER 16-3: BAUDCON1: BAUD RATE CONTROL REGISTER 1  
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 Idle  
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 (CK1) is a high level  
0= Idle state for clock (CK1) is a low level  
bit 3  
BRG16: 16-Bit Baud Rate Register Enable bit  
1= 16-bit Baud Rate Generator – SPBRGH1 and SPBRG1  
0= 8-bit Baud Rate Generator – SPBRG1 only (Compatible mode), SPBRGH1 value ignored  
bit 2  
bit 1  
Unimplemented: Read as ‘0’  
WUE: Wake-up Enable bit  
Asynchronous mode:  
1= EUSART will continue to sample the RX1 pin – interrupt generated on falling edge; bit cleared in  
hardware on following rising edge  
0= RX1 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.  
DS39629C-page 200  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
geous 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.  
16.1 EUSART 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 (BAUDCON1<3>)  
selects 16-bit mode.  
Writing a new value to the SPBRGH1:SPBRG1 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 SPBRGH1:SPBRG1 register pair controls the period  
of a free-running timer. In Asynchronous mode, the  
BRGH (TXSTA1<2>) and BRG16 (BAUDCON1<3>) bits  
also control the baud rate. In Synchronous mode, BRGH  
is ignored. Table 16-1 shows the formula for computation  
of the baud rate for different EUSART modes that only  
apply in Master mode (internally generated clock).  
16.1.1  
OPERATION IN POWER-MANAGED  
MODES  
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 SPBRG1 register pair.  
Given the desired baud rate and FOSC, the nearest  
integer value for the SPBRGH1:SPBRG1 registers can  
be calculated using the formulas in Table 16-1. From  
this, the error in baud rate can be determined. An exam-  
ple calculation is shown in Example 16-1. Typical baud  
rates and error values for the various Asynchronous  
modes are shown in Table 16-3. It may be advanta-  
16.1.2  
SAMPLING  
The data on the RX1 pin is sampled three times by a  
majority detect circuit to determine if a high or a low  
level is present at the RX1 pin.  
TABLE 16-1: BAUD RATE FORMULAS  
Configuration Bits  
BRG/EUSART Mode  
Baud Rate Formula  
FOSC/[64 (n + 1)]  
FOSC/[16 (n + 1)]  
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/[4 (n + 1)]  
Legend: x= Don’t care, n = Value of SPBRGH1:SPBRG1 register pair  
EXAMPLE 16-1: 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 ([SPBRGH1:SPBRG1] + 1))  
Solving for SPBRGH1:SPBRG1:  
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 16-2: REGISTERS ASSOCIATED WITH THE BAUD RATE GENERATOR  
Reset Values  
on Page  
Name  
Bit 7  
Bit 6  
Bit 5  
Bit 4  
Bit 3  
Bit 2  
Bit 1  
Bit 0  
TXSTA1  
RCSTA1  
CSRC  
SPEN  
TX9  
RX9  
TXEN  
SREN  
SYNC  
CREN  
SCKP  
SENDB  
ADDEN  
BRG16  
BRGH  
FERR  
TRMT  
OERR  
WUE  
TX9D  
RX9D  
61  
61  
62  
62  
61  
BAUDCON1 ABDOVF RCIDL  
ABDEN  
SPBRGH1  
SPBRG1  
EUSART1 Baud Rate Generator Register High Byte  
EUSART1 Baud Rate Generator Register Low Byte  
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by the BRG.  
© 2007 Microchip Technology Inc.  
DS39629C-page 201  
PIC18F6390/6490/8390/8490  
TABLE 16-3: 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  
value  
(decimal)  
SPBRG Actual  
value  
(decimal)  
SPBRG  
value  
(decimal)  
%
Error  
%
Error  
%
Error  
%
Error  
Rate (K)  
Rate (K)  
Rate (K)  
(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  
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  
19.531  
62.500  
104.167  
2
115.2 125.000  
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  
%
Error  
Rate (K)  
Rate (K)  
(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  
SPBRG Actual  
value  
(decimal)  
SPBRG Actual  
value  
(decimal)  
SPBRG  
value  
%
Error  
%
Error  
%
Error  
%
Error  
Rate (K)  
Rate (K)  
Rate (K)  
(decimal)  
(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  
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  
115.2 113.636  
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  
%
Error  
Rate (K)  
Rate (K)  
(decimal)  
0.3  
1.2  
207  
103  
25  
12  
3
1.201  
2.403  
9615  
-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  
2.404  
9.615  
19.231  
62.500  
0.16  
0.16  
0.16  
0.16  
8.51  
8.51  
2.4  
9.6  
19.2  
57.6  
115.2 125.000  
1
DS39629C-page 202  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
TABLE 16-3: 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  
SPBRG Actual  
value  
(decimal)  
SPBRG  
value  
(decimal)  
%
Error  
%
Error  
%
Error  
%
Error  
Rate (K)  
value  
Rate (K)  
Rate (K)  
(decimal)  
(decimal)  
0.3  
1.2  
0.300  
1.200  
2.402  
9.615  
19.231  
58.140  
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  
2.399  
2.404  
9.6  
9.615  
9.615  
19.2  
57.6  
19.231  
56.818  
113.636  
0.16  
19.531  
56.818  
125.000  
31  
25  
-1.36  
-1.36  
21  
10  
8
115.2 113.636  
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  
%
Error  
Rate (K)  
Rate (K)  
(decimal)  
0.3  
1.2  
0.300  
1.202  
2.404  
9.615  
19.231  
62.500  
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  
0.300  
1.201  
2.403  
-0.16  
-0.16  
-0.16  
207  
51  
25  
2.4  
9.6  
12  
19.2  
57.6  
115.2 125.000  
1
SYNC = 0, BRGH = 1, BRG16 = 1or 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  
%
Error  
%
Error  
value  
(decimal)  
Rate (K)  
value  
Rate (K)  
Rate (K)  
(decimal)  
(decimal)  
0.3  
1.2  
0.300  
1.200  
2.400  
9.606  
19.193  
57.803  
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  
2.402  
2.400  
9.6  
9.596  
9.615  
9.615  
19.2  
57.6  
19.231  
57.471  
116.279  
19.231  
58.140  
113.636  
19.230  
57.142  
117.647  
172  
115.2 114.943  
86  
42  
21  
-2.12  
16  
SYNC = 0, BRGH = 1, BRG16 = 1or SYNC = 1, BRG16 = 1  
FOSC = 4.000 MHz FOSC = 2.000 MHz FOSC = 1.000 MHz  
BAUD  
RATE  
Actual  
(K)  
SPBRG Actual  
SPBRG Actual  
SPBRG  
value  
%
Error  
%
Error  
%
Error  
Rate (K)  
value  
Rate (K)  
value  
Rate (K)  
(decimal)  
(decimal)  
(decimal)  
0.3  
1.2  
0.300  
1.200  
2.404  
9.615  
19.231  
58.824  
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  
2403  
9.615  
19.230  
-0.04  
-0.16  
-0.16  
-0.16  
-0.16  
832  
207  
103  
25  
2.4  
9.6  
19.2  
57.6  
25  
12  
16  
8
115.2 111.111  
8
© 2007 Microchip Technology Inc.  
DS39629C-page 203  
PIC18F6390/6490/8390/8490  
16.1.3  
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 16-1) 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 RX1 signal, the RX1 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.  
3: When the auto-baud feature is enabled,  
the BRG16 bit (BAUDCON<3>) must be  
set.  
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 SPBRG1 begins  
counting up, using the preselected clock source on the  
first rising edge of RX1. After eight bits on the RX1 pin  
or the fifth rising edge, an accumulated value totalling  
TABLE 16-4: BRG COUNTER CLOCK  
RATES  
BRG16 BRGH  
BRG Counter Clock  
0
0
1
1
0
1
0
1
FOSC/512  
FOSC/128  
FOSC/128  
FOSC/32  
the  
proper  
BRG  
period  
is  
left  
in  
the  
SPBRGH1:SPBRG1 register pair. Once the 5th edge is  
seen (this should correspond to the Stop bit), the  
ABDEN bit is automatically cleared.  
16.1.3.1  
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,  
TXREG1 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  
(BAUDCON1<7>). It is set in hardware by BRG rollovers  
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 16-2).  
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. This allows the user to verify  
that no carry occurred for 8-bit modes by checking for  
00h in the SPBRGH1 register. Refer to Table 16-4 for  
counter clock rates to the BRG.  
While the ABD sequence takes place, the EUSART  
state machine is held in Idle. The RC1IF interrupt is set  
once the fifth rising edge on RX1 is detected. The value  
in the RCREG1 needs to be read to clear the RC1IF  
interrupt. The contents of RCREG1 should be  
discarded.  
DS39629C-page 204  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
FIGURE 16-1:  
AUTOMATIC BAUD RATE CALCULATION  
BRG Value  
XXXXh  
0000h  
001Ch  
Edge #5  
Stop Bit  
Edge #1  
Edge #2  
Bit 3  
Edge #3  
Bit 5  
Edge #4  
Bit 7  
Bit 6  
Start  
RX1 pin  
Bit 1  
Bit 0  
Bit 2  
Bit 4  
BRG Clock  
Auto-Cleared  
Set by User  
ABDEN bit  
RC1IF bit  
(Interrupt)  
Read  
RCREG1  
XXXXh  
XXXXh  
1Ch  
00h  
SPBRG1  
SPBRGH1  
Note: The ABD sequence requires the EUSART module to be configured in Asynchronous mode and WUE = 0.  
FIGURE 16-2:  
BRG OVERFLOW SEQUENCE  
BRG Clock  
ABDEN bit  
RX1 pin  
Start  
Bit 0  
ABDOVF bit  
BRG Value  
FFFFh  
XXXXh  
0000h  
0000h  
© 2007 Microchip Technology Inc.  
DS39629C-page 205  
PIC18F6390/6490/8390/8490  
Once the TXREG1 register transfers the data to the  
16.2 EUSART Asynchronous Mode  
TSR register (occurs in one TCY), the TXREG1 register  
is empty and the TX1IF flag bit (PIR1<4>) is set. This  
interrupt can be enabled or disabled by setting or clear-  
ing the interrupt enable bit, TX1IE (PIE1<4>). TX1IF  
will be set regardless of the state of TX1IE; it cannot be  
cleared in software. TX1IF is also not cleared immedi-  
ately upon loading TXREG1, but becomes valid in the  
second instruction cycle following the load instruction.  
Polling TX1IF immediately following a load of TXREG1  
will return invalid results.  
The Asynchronous mode of operation is selected by  
clearing the SYNC bit (TXSTA1<4>). In this mode, the  
EUSART uses standard Non-Return-to-Zero (NRZ) for-  
mat (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 (TXSTA1<2> and BAUDCON1<3>).  
Parity is not supported by the hardware but can be  
implemented in software and stored as the 9th data bit.  
While TX1IF indicates the status of the TXREG1 regis-  
ter, another bit, TRMT (TXSTA1<1>), shows the status  
of the TSR register. TRMT is a read-only bit which is set  
when the TSR 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 TSR register is empty.  
Note 1: The TSR register is not mapped in data  
When operating in Asynchronous mode, the EUSART  
module consists of the following important elements:  
memory so it is not available to the user.  
2: Flag bit, TX1IF, is set when enable bit  
• Baud Rate Generator  
TXEN is set.  
• Sampling Circuit  
To set up an Asynchronous Transmission:  
• Asynchronous Transmitter  
• Asynchronous Receiver  
1. Initialize the SPBRGH1:SPBRG1 registers for  
the appropriate baud rate. Set or clear the  
BRGH and BRG16 bits, as required, to achieve  
the desired baud rate.  
• Auto-Wake-up on Sync Break Character  
• 12-Bit Break Character Transmit  
• Auto-Baud Rate Detection  
2. Enable the asynchronous serial port by clearing  
bit, SYNC, and setting bit, SPEN.  
16.2.1  
EUSART ASYNCHRONOUS  
TRANSMITTER  
3. If interrupts are desired, set enable bit, TX1IE.  
4. If 9-bit transmission is desired, set transmit bit,  
TX9; can be used as address/data bit.  
The EUSART transmitter block diagram is shown in  
Figure 16-3. The heart of the transmitter is the Transmit  
(Serial) Shift Register (TSR). The Shift register obtains  
its data from the Read/Write Transmit Buffer register,  
TXREG1. The TXREG1 register is loaded with data in  
software. The TSR register is not loaded until the Stop  
bit has been transmitted from the previous load. As  
soon as the Stop bit is transmitted, the TSR is loaded  
with new data from the TXREG1 register (if available).  
5. Enable the transmission by setting bit, TXEN,  
which will also set bit, TX1IF.  
6. If 9-bit transmission is selected, the ninth bit  
should be loaded in bit, TX9D.  
7. Load data to the TXREG1 register (starts  
transmission).  
8. If using interrupts, ensure that the GIE and PEIE  
bits in the INTCON register (INTCON<7:6>) are  
set.  
FIGURE 16-3:  
EUSART TRANSMIT BLOCK DIAGRAM  
Data Bus  
TX1IF  
TXREG1 Register  
8
TX1IE  
MSb  
(8)  
LSb  
0
Pin Buffer  
and Control  
• •  
TSR Register  
TX1 pin  
Interrupt  
Baud Rate CLK  
TXEN  
TRMT  
SPEN  
BRG16  
SPBRGH1 SPBRG1  
Baud Rate Generator  
TX9  
TX9D  
DS39629C-page 206  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
FIGURE 16-4:  
ASYNCHRONOUS TRANSMISSION  
Write to TXREG1  
Word 1  
BRG Output  
(Shift Clock)  
TX1 (pin)  
Start bit  
bit 0  
bit 1  
Word 1  
bit 7/8  
Stop bit  
TX1IF bit  
(Transmit Buffer  
Reg. Empty Flag)  
1 TCY  
Word 1  
Transmit Shift Reg  
TRMT bit  
(Transmit Shift  
Reg. Empty Flag)  
FIGURE 16-5:  
ASYNCHRONOUS TRANSMISSION (BACK-TO-BACK)  
Write to TXREG1  
Word 2  
Start bit  
Word 1  
BRG Output  
(Shift Clock)  
TX1 (pin)  
Start bit  
Word 2  
bit 0  
bit 1  
bit 7/8  
bit 0  
Stop bit  
1 TCY  
Word 1  
TX1IF 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.  
TABLE 16-5: 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  
TX1IE  
TX1IP  
CREN  
RBIE  
SSPIF  
SSPIE  
SSPIP  
ADDEN  
TMR0IF  
CCP1IF  
INT0IF  
RBIF  
59  
61  
61  
61  
61  
61  
61  
62  
62  
61  
ADIF  
ADIE  
ADIP  
RX9  
RC1IF  
RC1IE  
RC1IP  
SREN  
TMR2IF  
TMR1IF  
PIE1  
CCP1IE TMR2IE TMR1IE  
CCP1IP TMR2IP TMR1IP  
IPR1  
RCSTA1  
TXREG1  
TXSTA1  
SPEN  
FERR  
OERR  
RX9D  
EUSART1 Transmit Register  
CSRC  
TX9  
TXEN  
SYNC  
SCKP  
SENDB  
BRG16  
BRGH  
TRMT  
WUE  
TX9D  
BAUDCON1 ABDOVF  
RCIDL  
ABDEN  
SPBRGH1  
SPBRG1  
EUSART1 Baud Rate Generator Register High Byte  
EUSART1 Baud Rate Generator Register Low Byte  
Legend: — = unimplemented locations read as ‘0’. Shaded cells are not used for asynchronous transmission.  
© 2007 Microchip Technology Inc.  
DS39629C-page 207  
PIC18F6390/6490/8390/8490  
16.2.2  
EUSART ASYNCHRONOUS  
RECEIVER  
16.2.3  
SETTING UP 9-BIT MODE WITH  
ADDRESS DETECT  
The receiver block diagram is shown in Figure 16-6.  
The data is received on the RX1 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 SPBRGH1:SPBRG1 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 SPBRGH1:SPBRG1 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 RC1IP  
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, RC1IE.  
4. If 9-bit reception is desired, set bit, RX9.  
5. Enable the reception by setting bit, CREN.  
7. The RC1IF bit will be set when reception is  
complete. The interrupt will be Acknowledged if  
the RC1IE and GIE bits are set.  
6. Flag bit, RC1IF, will be set when reception is  
complete and an interrupt will be generated if  
enable bit, RC1IE, was set.  
8. Read the RCSTA1 register to determine if any  
error occurred during reception, as well as read  
bit 9 of data (if applicable).  
7. Read the RCSTA1 register to get the 9th bit (if  
enabled) and determine if any error occurred  
during reception.  
9. Read RCREG1 to determine if the device is  
being addressed.  
8. Read the 8-bit received data by reading the  
RCREG1 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 16-6:  
EUSART RECEIVE BLOCK DIAGRAM  
CREN  
OERR  
FERR  
x64 Baud Rate CLK  
÷ 64  
RSR Register  
• • •  
MSb  
Stop  
LSb  
Start  
BRG16  
SPBRGH1 SPBRG1  
or  
÷ 16  
(8)  
7
1
0
or  
Baud Rate Generator  
÷ 4  
RX9  
Pin Buffer  
and Control  
Data  
Recovery  
RX1  
RX9D  
RCREG1 Register  
FIFO  
SPEN  
8
Interrupt  
RC1IF  
RC1IE  
Data Bus  
DS39629C-page 208  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
FIGURE 16-7:  
ASYNCHRONOUS RECEPTION  
Start  
bit  
Start  
bit  
Start  
bit  
RX1 (pin)  
bit 0 bit 1  
bit 7/8  
Stop  
bit  
Stop  
bit  
Stop  
bit  
bit 0  
bit 7/8  
bit 7/8  
Rcv Shift Reg  
Rcv Buffer Reg  
Word 2  
RCREG1  
Word 1  
RCREG1  
RCREG1  
Read Rcv  
Buffer Reg  
RC1IF  
(Interrupt Flag)  
OERR bit  
CREN bit  
Note: This timing diagram shows three words appearing on the RX1 input. The RCREG1 (Receive Buffer register) is read after the third word  
causing the OERR (Overrun) bit to be set.  
TABLE 16-6: 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  
TX1IE  
TX1IP  
CREN  
RBIE  
SSPIF  
SSPIE  
SSPIP  
ADDEN  
TMR0IF  
CCP1IF  
INT0IF  
RBIF  
59  
61  
61  
61  
61  
61  
61  
62  
62  
61  
ADIF  
ADIE  
ADIP  
RX9  
RC1IF  
RC1IE  
RC1IP  
SREN  
TMR2IF TMR1IF  
PIE1  
CCP1IE TMR2IE TMR1IE  
CCP1IP TMR2IP TMR1IP  
IPR1  
RCSTA1  
RCREG1  
TXSTA1  
SPEN  
FERR  
OERR  
RX9D  
EUSART1 Receive Register  
CSRC  
TX9  
TXEN  
SYNC  
SCKP  
SENDB  
BRG16  
BRGH  
TRMT  
WUE  
TX9D  
BAUDCON1 ABDOVF  
RCIDL  
ABDEN  
SPBRGH1  
SPBRG1  
EUSART1 Baud Rate Generator Register High Byte  
EUSART1 Baud Rate Generator Register Low Byte  
Legend: — = unimplemented locations read as ‘0’. Shaded cells are not used for asynchronous reception.  
© 2007 Microchip Technology Inc.  
DS39629C-page 209  
PIC18F6390/6490/8390/8490  
End-Of-Character (EOC) and cause data or framing  
errors. Therefore, to work properly, the initial character  
in the transmission must be all ‘0’s. This can be 00h  
(8 bytes) for standard RS-232 devices, or 000h  
(12 bits) for LIN bus.  
16.2.4  
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 per-  
formed. The auto-wake-up feature allows the controller  
to wake-up, due to activity on the RX1/DT1 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 (BAUDCON<1>). Once set, the typical receive  
sequence on RX1/DT1 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 RX1/DT1  
line. (This coincides with the start of a Sync Break or a  
Wake-up Signal character for the LIN protocol.)  
16.2.4.2  
Special Considerations Using  
the WUE Bit  
The timing of WUE and RC1IF 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 Idle mode. The wake-up event causes  
a receive interrupt by setting the RC1IF bit. The WUE  
bit is cleared after this when a rising edge is seen on  
RX1/DT1. The interrupt condition is then cleared by  
reading the RCREG1 register. Ordinarily, the data in  
RCREG1 will be dummy data and should be discarded.  
Following a wake-up event, the module generates an  
RC1IF interrupt. The interrupt is generated synchro-  
nously to the Q clocks in normal operating modes  
(Figure 16-8) and asynchronously, if the device is in  
Sleep mode (Figure 16-9). The interrupt condition is  
cleared by reading the RCREG1 register.  
The WUE bit is automatically cleared once a low-to-high  
transition is observed on the RX1 line following the  
wake-up event. At this point, the EUSART module is in  
Idle mode 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 RC1IF flag is set, should not be used as  
an indicator of the integrity of the data in RCREG1.  
Users should consider implementing a parallel method  
in firmware to verify received data integrity.  
16.2.4.1  
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 RX1/DT1, information with any state  
changes before the Stop bit may signal a false  
FIGURE 16-8:  
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  
Bit set by user  
Auto-Cleared  
RX1/DT1 Line  
RC1IF  
Cleared due to user read of RCREG1  
Note: The EUSART remains in Idle while the WUE bit is set.  
FIGURE 16-9:  
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  
Bit set by user  
Auto-Cleared  
RX1/DT1 Line  
RC1IF  
Note 1  
Cleared due to user read of RCREG1  
Sleep Ends  
SLEEPCommand Executed  
Note 1: If the wake-up event requires long oscillator warm-up time, the auto-clear of the WUE bit can occur while the stposc signal is still active.  
This sequence should not depend on the presence of Q clocks.  
2: The EUSART remains in Idle while the WUE bit is set.  
DS39629C-page 210  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
3. Load the TXREG1 with a dummy character to  
initiate transmission (the value is ignored).  
16.2.5  
BREAK CHARACTER SEQUENCE  
The Enhanced USART 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 (TXSTA<3> and  
TXSTA<5>) are set while the Transmit Shift Register is  
loaded with data. Note that the value of data written to  
TXREG1 will be ignored and all ‘0’s will be transmitted.  
4. Write ‘55h’ to TXREG1 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.  
When the TXREG1 becomes empty, as indicated by the  
TX1IF, the next data byte can be written to TXREG1.  
16.2.6  
RECEIVING A BREAK CHARACTER  
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).  
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  
location (13 bits for Break versus Start bit and 8 data  
bits for typical data).  
Note that the data value written to the TXREG1 for the  
Break character is ignored. The write simply serves the  
purpose of initiating the proper sequence.  
The TRMT bit indicates when the transmit operation is  
active or Idle, just as it does during normal transmis-  
sion. See Figure 16-10 for the timing of the Break  
character sequence.  
The second method uses the auto-wake-up feature  
described in Section 16.2.4 “Auto-Wake-up on Sync  
Break Character”. By enabling this feature, the  
EUSART will sample the next two transitions on  
RX1/DT1, cause an RC1IF interrupt and receive the  
next data byte followed by another interrupt.  
16.2.5.1  
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 TX1IF interrupt is observed.  
1. Configure the EUSART for the desired mode.  
2. Set the TXEN and SENDB bits to set up the  
Break character.  
FIGURE 16-10:  
SEND BREAK CHARACTER SEQUENCE  
Write to TXREG1  
Dummy Write  
BRG Output  
(Shift Clock)  
TX1 (pin)  
Start bit  
bit 0  
bit 1  
Break  
bit 11  
Stop bit  
TX1IF bit  
(Transmit Buffer  
Reg. Empty Flag)  
TRMT bit  
(Transmit Shift  
Reg. Empty Flag)  
SENDB sampled here  
Auto-Cleared  
SENDB  
(Transmit Shift  
Reg. Empty Flag)  
© 2007 Microchip Technology Inc.  
DS39629C-page 211  
PIC18F6390/6490/8390/8490  
Once the TXREG1 register transfers the data to the  
16.3 EUSART Synchronous  
Master Mode  
TSR register (occurs in one TCYCLE), the TXREG1 is  
empty and the TX1IF flag bit (PIR1<4>) is set. The  
interrupt can be enabled or disabled by setting or clear-  
ing the interrupt enable bit, TX1IE (PIE1<4>). TX1IF is  
set regardless of the state of enable bit, TX1IE; it  
cannot be cleared in software. It will reset only when  
new data is loaded into the TXREG1 register.  
The Synchronous Master mode is entered by setting  
the CSRC bit (TXSTA<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 (TXSTA<4>). In addition, enable bit, SPEN  
(RCSTA1<7>), is set in order to configure the TX1 and  
RX1 pins to CK1 (clock) and DT1 (data) lines,  
respectively.  
While flag bit, TX1IF, indicates the status of the TXREG1  
register, another bit, TRMT (TXSTA<1>), shows the  
status of the TSR register. TRMT is a read-only bit which  
is set when the TSR is empty. No interrupt logic is tied to  
this bit so the user has to poll this bit in order to deter-  
mine if the TSR register is empty. The TSR 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 CK1 line. Clock polarity is  
selected with the SCKP bit (BAUDCON<4>); setting  
SCKP sets the Idle state on CK1 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 SPBRGH1:SPBRG1 registers for  
the appropriate baud rate. Set or clear the  
BRG16 bit, as required, to achieve the desired  
baud rate.  
16.3.1  
EUSART SYNCHRONOUS MASTER  
TRANSMISSION  
2. Enable the synchronous master serial port by  
setting bits, SYNC, SPEN and CSRC.  
The EUSART transmitter block diagram is shown in  
Figure 16-3. The heart of the transmitter is the Transmit  
(Serial) Shift Register (TSR). The Shift register obtains  
its data from the Read/Write Transmit Buffer register,  
TXREG1. The TXREG1 register is loaded with data in  
software. The TSR register is not loaded until the last  
bit has been transmitted from the previous load. As  
soon as the last bit is transmitted, the TSR is loaded  
with new data from the TXREG1 (if available).  
3. If interrupts are desired, set enable bit, TX1IE.  
4. If 9-bit transmission is desired, set bit, TX9.  
5. Enable the transmission by setting bit, TXEN.  
6. If 9-bit transmission is selected, the ninth bit  
should be loaded in bit, TX9D.  
7. Start transmission by loading data to the  
TXREG1 register.  
8. If using interrupts, ensure that the GIE and PEIE  
bits in the INTCON register (INTCON<7:6>) are  
set.  
FIGURE 16-11:  
SYNCHRONOUS TRANSMISSION  
Q1 Q2 Q3 Q4 Q1Q2 Q3 Q4 Q1Q2 Q3 Q4 Q1Q2 Q3 Q4 Q1Q2 Q3 Q4  
Q3 Q4 Q1 Q2 Q3Q4 Q1Q2 Q3Q4 Q1Q2 Q3 Q4 Q1Q2Q3 Q4 Q1Q2 Q3 Q4 Q1 Q2 Q3 Q4  
RC7/RX1/DT1  
pin  
bit 0  
bit 1  
bit 2  
bit 7  
bit 0  
bit 1  
bit 7  
Word 2  
Word 1  
RC6/TX1/CK1 pin  
(SCKP = 0)  
RC6/TX1/CK1 pin  
(SCKP = 1)  
Write to  
TXREG1 Reg  
Write Word 1  
Write Word 2  
TX1IF bit  
(Interrupt Flag)  
TRMT bit  
1’  
1’  
TXEN bit  
Note: Sync Master mode, SPBRG1 = 0, continuous transmission of two 8-bit words.  
DS39629C-page 212  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
FIGURE 16-12:  
SYNCHRONOUS TRANSMISSION (THROUGH TXEN)  
RC7/RX1/DT1 pin  
bit 0  
bit 2  
bit 1  
bit 6  
bit 7  
RC6/TX1/CK1 pin  
Write to  
TXREG1 Reg  
TX1IF bit  
TRMT bit  
TXEN bit  
TABLE 16-7: 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  
TX1IE  
TX1IP  
CREN  
RBIE  
SSPIF  
SSPIE  
SSPIP  
ADDEN  
TMR0IF  
INT0IF  
RBIF  
59  
61  
61  
61  
61  
61  
61  
62  
62  
61  
ADIF  
ADIE  
ADIP  
RX9  
RC1IF  
RC1IE  
RC1IP  
SREN  
CCP1IF TMR2IF TMR1IF  
CCP1IE TMR2IE TMR1IE  
CCP1IP TMR2IP TMR1IP  
PIE1  
IPR1  
RCSTA1  
TXREG1  
TXSTA1  
SPEN  
FERR  
OERR  
RX9D  
EUSART1 Transmit Register  
CSRC  
TX9  
TXEN  
SYNC  
SCKP  
SENDB  
BRG16  
BRGH  
TRMT  
WUE  
TX9D  
BAUDCON1 ABDOVF  
RCIDL  
ABDEN  
SPBRGH1 EUSART1 Baud Rate Generator Register High Byte  
SPBRG1 EUSART1 Baud Rate Generator Register Low Byte  
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used for synchronous master transmission.  
© 2007 Microchip Technology Inc.  
DS39629C-page 213  
PIC18F6390/6490/8390/8490  
3. Ensure bits, CREN and SREN, are clear.  
4. If interrupts are desired, set enable bit, RC1IE.  
5. If 9-bit reception is desired, set bit, RX9.  
16.3.2  
EUSART SYNCHRONOUS  
MASTER RECEPTION  
Once Synchronous mode is selected, reception is  
enabled by setting either the Single Receive Enable bit,  
SREN (RCSTA1<5>), or the Continuous Receive  
Enable bit, CREN (RCSTA1<4>). Data is sampled on  
the RX1 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, RC1IF, will be set when recep-  
tion is complete and an interrupt will be generated  
if the enable bit, RC1IE, 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 RCSTA1 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  
RCREG1 register.  
To set up a Synchronous Master Reception:  
1. Initialize the SPBRGH1:SPBRG1 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 16-13:  
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 Q4Q1 Q2 Q3 Q4 Q1Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4  
RC7/RX1/DT1  
pin  
bit 0  
bit 1  
bit 2  
bit 3  
bit 4  
bit 5  
bit 6  
bit 7  
RC6/TX1/CK1 pin  
(SCKP = 0)  
RC6/TX1/CK1 pin  
(SCKP = 1)  
Write to  
SREN bit  
SREN bit  
CREN bit  
0’  
0’  
RC1IF bit  
(Interrupt)  
Read  
RCREG1  
Note: Timing diagram demonstrates Sync Master mode with SREN bit = 1and BRGH bit = 0.  
TABLE 16-8: 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  
TX1IE  
TX1IP  
CREN  
RBIE  
SSPIF  
SSPIE  
SSPIP  
ADDEN  
TMR0IF  
CCP1IF  
CCP1IE  
CCP1IP  
FERR  
INT0IF  
RBIF  
59  
61  
61  
61  
61  
61  
61  
62  
62  
61  
ADIF  
ADIE  
ADIP  
RX9  
RC1IF  
RC1IE  
RC1IP  
SREN  
TMR2IF TMR1IF  
TMR2IE TMR1IE  
TMR2IP TMR1IP  
PIE1  
IPR1  
RCSTA1  
RCREG1  
TXSTA1  
SPEN  
OERR  
RX9D  
EUSART1 Receive Register  
CSRC  
TX9  
TXEN  
SYNC  
SCKP  
SENDB  
BRG16  
BRGH  
TRMT  
WUE  
TX9D  
BAUDCON1 ABDOVF  
RCIDL  
ABDEN  
SPBRGH1 EUSART1 Baud Rate Generator Register High Byte  
SPBRG1 EUSART1 Baud Rate Generator Register Low Byte  
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used for synchronous master reception.  
DS39629C-page 214  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
To set up a Synchronous Slave Transmission:  
16.4 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 (TXSTA1<7>). This mode differs from the  
Synchronous Master mode in that the shift clock is  
supplied externally at the CK1 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, TX1IE.  
4. If 9-bit transmission is desired, set bit, TX9.  
5. Enable the transmission by setting enable bit,  
TXEN.  
16.4.1  
EUSART SYNCHRONOUS SLAVE  
TRANSMIT  
6. If 9-bit transmission is selected, the ninth bit  
should be loaded in bit, TX9D.  
The operation of the Synchronous Master and Slave  
modes are identical except in the case of the Sleep  
mode.  
7. Start transmission by loading data to the  
TXREG1 register.  
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 TXREG1, and then the  
SLEEPinstruction is executed, the following will occur:  
a) The first word will immediately transfer to the  
TSR register and transmit.  
b) The second word will remain in the TXREG1  
register.  
c) Flag bit, TX1IF, will not be set.  
d) When the first word has been shifted out of TSR,  
the TXREG1 register will transfer the second  
word to the TSR and flag bit, TX1IF, will now be  
set.  
e) If enable bit, TX1IE, 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 16-9: 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  
CREN  
RBIE  
SSPIF  
SSPIE  
SSPIP  
ADDEN  
TMR0IF  
CCP1IF  
CCP1IE  
CCP1IP  
FERR  
INT0IF  
RBIF  
59  
61  
61  
61  
61  
61  
61  
62  
62  
61  
ADIF  
ADIE  
ADIP  
RX9  
RC1IF  
RC1IE  
RC1IP  
SREN  
TMR2IF TMR1IF  
TMR2IE TMR1IE  
TMR2IP TMR1IP  
PIE1  
IPR1  
RCSTA1  
TXREG1  
TXSTA1  
SPEN  
OERR  
RX9D  
EUSART1 Transmit Register  
CSRC  
TX9  
TXEN  
SYNC  
SCKP  
SENDB  
BRG16  
BRGH  
TRMT  
WUE  
TX9D  
BAUDCON1 ABDOVF  
RCIDL  
ABDEN  
SPBRGH1 EUSART1 Baud Rate Generator Register High Byte  
SPBRG1 EUSART1 Baud Rate Generator Register Low Byte  
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used for synchronous slave transmission.  
© 2007 Microchip Technology Inc.  
DS39629C-page 215  
PIC18F6390/6490/8390/8490  
To set up a Synchronous Slave Reception:  
16.4.2  
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, RC1IE.  
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 RSR register will transfer the data to the  
RCREG1 register. If the RC1IE 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, RC1IF, will be set when reception is  
complete. An interrupt will be generated if  
enable bit, RC1IE, was set.  
6. Read the RCSTA1 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  
RCREG1 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 16-10: 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  
TX1IE  
TX1IP  
CREN  
RBIE  
SSPIF  
SSPIE  
SSPIP  
ADDEN  
TMR0IF  
CCP1IF  
INT0IF  
RBIF  
59  
61  
61  
61  
61  
61  
61  
62  
62  
61  
ADIF  
ADIE  
ADIP  
RX9  
RC1IF  
RC1IE  
RC1IP  
SREN  
TMR2IF TMR1IF  
PIE1  
CCP1IE TMR2IE TMR1IE  
CCP1IP TMR2IP TMR1IP  
IPR1  
RCSTA1  
RCREG1  
TXSTA1  
SPEN  
FERR  
OERR  
RX9D  
EUSART1 Receive Register  
CSRC  
TX9  
TXEN  
SYNC  
SCKP  
SENDB  
BRG16  
BRGH  
TRMT  
WUE  
TX9D  
BAUDCON1 ABDOVF  
RCIDL  
ABDEN  
SPBRGH1 EUSART1 Baud Rate Generator Register High Byte  
SPBRG1 EUSART1 Baud Rate Generator Register Low Byte  
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used for synchronous slave reception.  
DS39629C-page 216  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
The pins of the AUSART module are multiplexed with  
17.0 ADDRESSABLE UNIVERSAL  
the functions of PORTG (RG1/TX2/CK2/SEG29 and  
RG2/RX2/DT2/SEG28, respectively). In order to  
configure these pins as an AUSART:  
SYNCHRONOUS  
ASYNCHRONOUS RECEIVER  
TRANSMITTER (AUSART)  
• SPEN bit (RCSTA2<7>) must be set (= 1)  
• TRISG<2> bit must be set (= 1)  
The Addressable Universal Synchronous Asynchro-  
nous Receiver Transmitter (AUSART) module is very  
similar in function to the Enhanced USART module,  
discussed in the previous chapter. It is provided as an  
additional channel for serial communication, with  
external devices, for those situations that do not require  
Auto-Baud Detection or LIN bus support.  
• TRISG<1> bit must be cleared (= 0) for  
Asynchronous and Synchronous Master modes  
• TRISG<1> bit must be set (= 1) for Synchronous  
Slave mode  
Note:  
The AUSART control will automatically  
reconfigure the pin from input to output as  
needed.  
The AUSART can be configured in the following modes:  
• Asynchronous (full-duplex)  
The operation of the Addressable USART module is  
controlled through two registers, TXSTA2 and  
RXSTA2. These are detailed in Register 17-1 and  
Register 17-2 respectively.  
• Synchronous – Master (half-duplex)  
• Synchronous – Slave (half-duplex)  
© 2007 Microchip Technology Inc.  
DS39629C-page 217  
PIC18F6390/6490/8390/8490  
REGISTER 17-1: TXSTA2: AUSART TRANSMIT STATUS AND CONTROL REGISTER  
R/W-0  
CSRC  
R/W-0  
TX9  
R/W-0  
TXEN(1)  
R/W-0  
SYNC  
U-0  
R/W-0  
BRGH  
R-1  
R/W-0  
TX9D  
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)  
1= Transmit enabled  
0= Transmit disabled  
bit 4  
SYNC: AUSART Mode Select bit  
1= Synchronous mode  
0= Asynchronous mode  
bit 3  
bit 2  
Unimplemented: Read as ‘0’  
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= TSR empty  
0= TSR full  
TX9D: 9th bit of Transmit Data  
Can be address/data bit or a parity bit.  
Note 1: SREN/CREN overrides TXEN in Sync mode.  
DS39629C-page 218  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
REGISTER 17-2: RCSTA2: AUSART 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 RX2/DT2 and TX2/CK2 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 RSR<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 RCREG2 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.  
© 2007 Microchip Technology Inc.  
DS39629C-page 219  
PIC18F6390/6490/8390/8490  
geous to use the high baud rate (BRGH = 1) to reduce  
the baud rate error, or achieve a slow baud rate for a  
fast oscillator frequency.  
17.1 AUSART Baud Rate Generator  
(BRG)  
The BRG is a dedicated 8-bit generator that supports  
both the Asynchronous and Synchronous modes of the  
AUSART.  
Writing a new value to the SPBRG2 register 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 SPBRG2 register controls the period of a  
free-running timer. In Asynchronous mode, bit BRGH  
(TXSTA<2>) also controls the baud rate. In Synchro-  
nous mode, BRGH is ignored. Table 17-1 shows the  
formula for computation of the baud rate for different  
AUSART modes, which only apply in Master mode  
(internally generated clock).  
17.1.1  
OPERATION IN POWER-MANAGED  
MODES  
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 SPBRG2 register.  
Given the desired baud rate and FOSC, the nearest  
integer value for the SPBRG2 register can be calcu-  
lated using the formulas in Table 17-1. From this, the  
error in baud rate can be determined. An example  
calculation is shown in Example 17-1. Typical baud  
rates and error values for the various Asynchronous  
modes are shown in Table 17-3. It may be advanta-  
17.1.2  
SAMPLING  
The data on the RX2 pin is sampled three times by a  
majority detect circuit to determine if a high or a low  
level is present at the RX2 pin.  
TABLE 17-1: BAUD RATE FORMULAS  
Configuration Bits  
BRG/AUSART Mode  
Baud Rate Formula  
SYNC  
BRGH  
0
0
1
0
1
x
Asynchronous  
Asynchronous  
Synchronous  
FOSC/[64 (n + 1)]  
FOSC/[16 (n + 1)]  
FOSC/[4 (n + 1)]  
Legend: x= Don’t care, n = Value of SPBRG2 register  
EXAMPLE 17-1: CALCULATING BAUD RATE ERROR  
For a device with FOSC of 16 MHz, desired baud rate of 9600, Asynchronous mode, BRGH = 0:  
Desired Baud Rate  
Solving for SPBRG2:  
X
=
FOSC/(64 ([SPBRG2] + 1))  
=
=
=
((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 17-2: REGISTERS ASSOCIATED WITH THE BAUD RATE GENERATOR  
Reset  
Values on  
Page  
Name  
Bit 7  
Bit 6  
Bit 5  
Bit 4  
Bit 3  
Bit 2  
Bit 1  
Bit 0  
TXSTA2  
RCSTA2  
SPBRG2  
CSRC  
SPEN  
TX9  
RX9  
TXEN  
SREN  
SYNC  
CREN  
BRGH  
FERR  
TRMT  
OERR  
TX9D  
RX9D  
63  
63  
63  
ADDEN  
AUSART2 Baud Rate Generator Register  
Legend: Shaded cells are not used by the BRG.  
DS39629C-page 220  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
TABLE 17-3: BAUD RATES FOR ASYNCHRONOUS MODES  
BRGH = 0  
FOSC = 20.000 MHz  
FOSC = 40.000 MHz  
FOSC = 10.000 MHz  
FOSC = 8.000 MHz  
BAUD Actual  
RATE Rate (K)  
(K)  
SPBRG Actual  
SPBRG Actual  
SPBRG Actual  
SPBRG  
value  
(decimal)  
%
Error  
%
Error  
%
Error  
%
Error  
value  
Rate (K)  
value  
Rate (K)  
value  
Rate (K)  
(decimal)  
(decimal)  
(decimal)  
0.3  
1.2  
255  
129  
31  
15  
4
0.16  
0.16  
1.73  
1.73  
-9.58  
-32.18  
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  
2.4  
2.441  
9.615  
19.531  
56.818  
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  
19.531  
62.500  
104.167  
2
115.2 125.000  
2
1
BRGH = 0  
FOSC = 4.000 MHz  
FOSC = 2.000 MHz  
FOSC = 1.000 MHz  
BAUD Actual  
RATE Rate (K)  
(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  
1.202  
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
BRGH = 1  
FOSC = 20.000 MHz  
BAUD  
RATE  
(K)  
FOSC = 40.000 MHz  
FOSC = 10.000 MHz  
FOSC = 8.000 MHz  
Actual  
Rate (K)  
SPBRG Actual  
SPBRG Actual  
SPBRG Actual  
value  
SPBRG  
value  
(decimal)  
%
Error  
%
Error  
%
Error  
%
Error  
value  
(decimal)  
Rate (K)  
value  
Rate (K)  
Rate (K)  
(decimal)  
(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  
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  
115.2 113.636  
21  
BRGH = 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  
%
Error  
Rate (K)  
Rate (K)  
(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  
2.404  
9.615  
19.231  
62.500  
0.16  
0.16  
0.16  
0.16  
8.51  
8.51  
2.4  
9.6  
19.2  
57.6  
115.2 125.000  
1
© 2007 Microchip Technology Inc.  
DS39629C-page 221  
PIC18F6390/6490/8390/8490  
Once the TXREG2 register transfers the data to the  
17.2 AUSART Asynchronous Mode  
TSR register (occurs in one TCY), the TXREG2 register  
is empty and the TX2IF flag bit (PIR3<4>) is set. This  
interrupt can be enabled or disabled by setting or  
clearing the interrupt enable bit, TX2IE (PIE3<4>).  
TX2IF will be set regardless of the state of TX2IE; it  
cannot be cleared in software. TX2IF is also not  
cleared immediately upon loading TXREG2, but  
becomes valid in the second instruction cycle following  
the load instruction. Polling TX2IF immediately  
following a load of TXREG2 will return invalid results.  
The Asynchronous mode of operation is selected by  
clearing the SYNC bit (TXSTA2<4>). In this mode, the  
AUSART 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 Baud Rate Generator can be  
used to derive standard baud rate frequencies from the  
oscillator.  
The AUSART transmits and receives the LSb first. The  
AUSART’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 bit (TXSTA2<2>). Parity is not supported by the  
hardware but can be implemented in software and  
stored as the 9th data bit.  
While TX2IF indicates the status of the TXREG2  
register, another bit, TRMT (TXSTA2<1>), shows the  
status of the TSR register. TRMT is a read-only bit  
which is set when the TSR register is empty. No inter-  
rupt logic is tied to this bit, so the user has to poll this  
bit in order to determine if the TSR register is empty.  
Note 1: The TSR register is not mapped in data  
When operating in Asynchronous mode, the AUSART  
module consists of the following important elements:  
memory, so it is not available to the user.  
2: Flag bit, TX2IF, is set when enable bit,  
• Baud Rate Generator  
• Sampling Circuit  
TXEN is set.  
To set up an Asynchronous Transmission:  
• Asynchronous Transmitter  
• Asynchronous Receiver  
1. Initialize the SPBRG2 register for the appropriate  
baud rate. Set or clear the BRGH bit, as required,  
to achieve the desired baud rate.  
17.2.1  
AUSART ASYNCHRONOUS  
TRANSMITTER  
2. Enable the asynchronous serial port by clearing  
bit, SYNC, and setting bit, SPEN.  
The AUSART transmitter block diagram is shown in  
Figure 17-1. The heart of the transmitter is the Transmit  
(Serial) Shift Register (TSR). The Shift register obtains  
its data from the Read/Write Transmit Buffer register,  
TXREG2. The TXREG2 register is loaded with data in  
software. The TSR register is not loaded until the Stop  
bit has been transmitted from the previous load. As  
soon as the Stop bit is transmitted, the TSR is loaded  
with new data from the TXREG2 register (if available).  
3. If interrupts are desired, set enable bit, TX2IE.  
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, TX2IF.  
6. If 9-bit transmission is selected, the ninth bit  
should be loaded in bit, TX9D.  
7. Load data to the TXREG2 register (starts  
transmission).  
8. If using interrupts, ensure that the GIE and PEIE  
bits in the INTCON register (INTCON<7:6>) are  
set.  
FIGURE 17-1:  
AUSART TRANSMIT BLOCK DIAGRAM  
Data Bus  
TX2IF  
TXREG2 Register  
8
TX2IE  
MSb  
(8)  
LSb  
0
Pin Buffer  
and Control  
• •  
TSR Register  
TX2 pin  
Interrupt  
Baud Rate CLK  
TXEN  
TRMT  
SPEN  
SPBRG2  
Baud Rate Generator  
TX9  
TX9D  
DS39629C-page 222  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
FIGURE 17-2:  
ASYNCHRONOUS TRANSMISSION  
Write to TXREG2  
Word 1  
BRG Output  
(Shift Clock)  
TX2 (pin)  
Start bit  
bit 0  
bit 1  
Word 1  
bit 7/8  
Stop bit  
TX2IF bit  
(Transmit Buffer  
Reg. Empty Flag)  
1 TCY  
Word 1  
Transmit Shift Reg  
TRMT bit  
(Transmit Shift  
Reg. Empty Flag)  
FIGURE 17-3:  
ASYNCHRONOUS TRANSMISSION (BACK-TO-BACK)  
Write to TXREG2  
Word 2  
Start bit  
Word 1  
BRG Output  
(Shift Clock)  
TX2 (pin)  
Start bit  
Word 2  
bit 0  
bit 1  
bit 7/8  
bit 0  
Stop bit  
1 TCY  
Word 1  
TX2IF 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.  
TABLE 17-4: 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  
PIR3  
GIE/GIEH PEIE/GIEL TMR0IE  
INT0IE  
TX2IF  
TX2IE  
TX2IP  
CREN  
RBIE  
TMR0IF  
INT0IF  
RBIF  
59  
61  
61  
61  
63  
63  
63  
63  
LCDIF  
LCDIE  
LCDIP  
RX9  
RC2IF  
RC2IE  
RC2IP  
SREN  
PIE3  
IPR3  
RCSTA2  
TXREG2  
TXSTA2  
SPBRG2  
SPEN  
ADDEN  
FERR  
OERR  
RX9D  
AUSART2 Transmit Register  
CSRC TX9 TXEN  
SYNC  
BRGH  
TRMT  
TX9D  
AUSART2 Baud Rate Generator Register  
Legend: — = unimplemented locations read as ‘0’. Shaded cells are not used for asynchronous transmission.  
© 2007 Microchip Technology Inc.  
DS39629C-page 223  
PIC18F6390/6490/8390/8490  
17.2.2  
AUSART ASYNCHRONOUS  
RECEIVER  
17.2.3  
SETTING UP 9-BIT MODE WITH  
ADDRESS DETECT  
The receiver block diagram is shown in Figure 17-4.  
The data is received on the RX2 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 SPBRG2 register 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 SPBRG2 register for the appropriate  
baud rate. Set or clear the BRGH bit, 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 RC2IP  
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, RC2IE.  
4. If 9-bit reception is desired, set bit, RX9.  
5. Enable the reception by setting bit, CREN.  
7. The RC2IF bit will be set when reception is  
complete. The interrupt will be Acknowledged if  
the RC2IE and GIE bits are set.  
6. Flag bit, RC2IF, will be set when reception is  
complete and an interrupt will be generated if  
enable bit, RC2IE, was set.  
8. Read the RCSTA2 register to determine if any  
error occurred during reception, as well as read  
bit 9 of data (if applicable).  
7. Read the RCSTA2 register to get the 9th bit (if  
enabled) and determine if any error occurred  
during reception.  
9. Read RCREG2 to determine if the device is  
being addressed.  
8. Read the 8-bit received data by reading the  
RCREG2 register.  
10. If any error occurred, clear the CREN bit.  
9. If any error occurred, clear the error by clearing  
enable bit, CREN.  
11. If the device has been addressed, clear the  
ADDEN bit to allow all received data into the  
receive buffer and interrupt the CPU.  
10. If using interrupts, ensure that the GIE and PEIE  
bits in the INTCON register (INTCON<7:6>) are  
set.  
FIGURE 17-4:  
AUSART RECEIVE BLOCK DIAGRAM  
CREN  
OERR  
FERR  
x64 Baud Rate CLK  
SPBRG2  
÷ 64  
or  
MSb  
Stop  
RSR Register  
• • •  
LSb  
Start  
÷ 16  
(8)  
7
1
0
or  
÷ 4  
Baud Rate Generator  
RX9  
Pin Buffer  
and Control  
Data  
Recovery  
RX2  
RX9D  
RCREG2 Register  
FIFO  
SPEN  
8
Interrupt  
RC2IF  
RC2IE  
Data Bus  
DS39629C-page 224  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
FIGURE 17-5:  
ASYNCHRONOUS RECEPTION  
Start  
bit  
Start  
bit  
Start  
bit  
RX2 (pin)  
bit 0 bit 1  
bit 7/8  
Stop  
bit  
Stop  
bit  
Stop  
bit  
bit 0  
bit 7/8  
bit 7/8  
Rcv Shift Reg  
Rcv Buffer Reg  
Word 2  
RCREG2  
Word 1  
RCREG2  
Read Rcv  
Buffer Reg  
RCREG2  
RC2IF  
(Interrupt Flag)  
OERR bit  
CREN  
Note: This timing diagram shows three words appearing on the RX2 input. The RCREG2 (Receive Buffer register) is read after the third  
word causing the OERR (Overrun) bit to be set.  
TABLE 17-5: 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  
PIR3  
GIE/GIEH PEIE/GIEL TMR0IE  
INT0IE  
TX2IF  
TX2IE  
TX2IP  
CREN  
RBIE  
TMR0IF  
INT0IF  
RBIF  
59  
61  
61  
61  
63  
63  
63  
63  
LCDIF  
LCDIE  
LCDIP  
RX9  
RC2IF  
RC2IE  
RC2IP  
SREN  
PIE3  
IPR3  
RCSTA2  
RCREG2  
TXSTA2  
SPBRG2  
SPEN  
ADDEN  
FERR  
OERR  
RX9D  
AUSART2 Receive Register  
CSRC TX9 TXEN  
SYNC  
BRGH  
TRMT  
TX9D  
AUSART2 Baud Rate Generator Register  
Legend: — = unimplemented locations read as ‘0’. Shaded cells are not used for asynchronous reception.  
© 2007 Microchip Technology Inc.  
DS39629C-page 225  
PIC18F6390/6490/8390/8490  
Once the TXREG2 register transfers the data to the  
17.3 AUSART Synchronous  
Master Mode  
TSR register (occurs in one TCYCLE), the TXREG2 is  
empty and the TX2IF flag bit (PIR3<4>) is set. The  
interrupt can be enabled or disabled by setting or clear-  
ing the interrupt enable bit, TX2IE (PIE3<4>). TX2IF is  
set regardless of the state of enable bit, TX2IE; it  
cannot be cleared in software. It will reset only when  
new data is loaded into the TXREG2 register.  
The Synchronous Master mode is entered by setting  
the CSRC bit (TXSTA2<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 (TXSTA2<4>). In addition, enable bit, SPEN  
(RCSTA2<7>), is set in order to configure the TX2 and  
RX2 pins to CK2 (clock) and DT2 (data) lines,  
respectively.  
While flag bit, TX2IF, indicates the status of the TXREG2  
register, another bit, TRMT (TXSTA2<1>), shows the  
status of the TSR register. TRMT is a read-only bit which  
is set when the TSR is empty. No interrupt logic is tied to  
this bit so the user has to poll this bit in order to deter-  
mine if the TSR register is empty. The TSR is not  
mapped in data memory so it is not available to the user.  
The Master mode indicates that the processor transmits  
the master clock on the CK2 line.  
To set up a Synchronous Master Transmission:  
17.3.1  
AUSART SYNCHRONOUS MASTER  
TRANSMISSION  
1. Initialize the SPBRG2 register for the appropriate  
baud rate.  
The AUSART transmitter block diagram is shown in  
Figure 17-1. The heart of the transmitter is the Transmit  
(Serial) Shift Register (TSR). The Shift register obtains  
its data from the Read/Write Transmit Buffer register,  
TXREG2. The TXREG2 register is loaded with data in  
software. The TSR register is not loaded until the last  
bit has been transmitted from the previous load. As  
soon as the last bit is transmitted, the TSR is loaded  
with new data from the TXREG2 (if available).  
2. Enable the synchronous master serial port by  
setting bits, SYNC, SPEN and CSRC.  
3. If interrupts are desired, set enable bit, TX2IE.  
4. If 9-bit transmission is desired, set bit, TX9.  
5. Enable the transmission by setting bit, TXEN.  
6. If 9-bit transmission is selected, the ninth bit  
should be loaded in bit, TX9D.  
7. Start transmission by loading data to the  
TXREG2 register.  
8. If using interrupts, ensure that the GIE and PEIE  
bits in the INTCON register (INTCON<7:6>) are  
set.  
FIGURE 17-6:  
SYNCHRONOUS TRANSMISSION  
Q1 Q2 Q3Q4 Q1 Q2 Q3 Q4 Q1Q2 Q3 Q4 Q1Q2 Q3 Q4 Q1Q2 Q3 Q4  
Q3 Q4 Q1 Q2 Q3Q4 Q1Q2 Q3Q4 Q1 Q2Q3Q4 Q1 Q2Q3 Q4Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4  
RX2/DT2 pin  
TX2/CK2 pin  
bit 0  
bit 1  
bit 2  
bit 7  
bit 0  
bit 1  
bit 7  
Word 2  
Word 1  
Write to  
TXREG2 Reg  
Write Word 1  
Write Word 2  
TX2IF bit  
(Interrupt Flag)  
TRMT bit  
TXEN bit  
1’  
1’  
Note: Sync Master mode, SPBRG2 = 0, continuous transmission of two 8-bit words.  
DS39629C-page 226  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
FIGURE 17-7:  
SYNCHRONOUS TRANSMISSION (THROUGH TXEN)  
RX2/DT2 pin  
bit 0  
bit 2  
bit 1  
bit 6  
bit 7  
TX2/CK2 pin  
Write to  
TXREG2 Reg  
TX2IF bit  
TRMT bit  
TXEN bit  
TABLE 17-6: 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  
PIR3  
GIE/GIEH PEIE/GIEL TMR0IE  
INT0IE  
TX2IF  
TX2IE  
TX2IP  
CREN  
RBIE  
TMR0IF  
INT0IF  
RBIF  
59  
61  
61  
61  
63  
63  
63  
63  
LCDIF  
LCDIE  
LCDIP  
RX9  
RC2IF  
RC2IE  
RC2IP  
SREN  
PIE3  
IPR3  
RCSTA2  
TXREG2  
TXSTA2  
SPBRG2  
SPEN  
ADDEN  
FERR  
OERR  
RX9D  
AUSART2 Transmit Register  
CSRC TX9 TXEN  
SYNC  
BRGH  
TRMT  
TX9D  
AUSART2 Baud Rate Generator Register  
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used for synchronous master transmission.  
© 2007 Microchip Technology Inc.  
DS39629C-page 227  
PIC18F6390/6490/8390/8490  
4. If interrupts are desired, set enable bit, RC2IE.  
5. If 9-bit reception is desired, set bit, RX9.  
17.3.2  
AUSART SYNCHRONOUS  
MASTER RECEPTION  
6. If a single reception is required, set bit, SREN.  
For continuous reception, set bit, CREN.  
Once Synchronous mode is selected, reception is  
enabled by setting either the Single Receive Enable bit,  
SREN (RCSTA2<5>), or the Continuous Receive  
Enable bit, CREN (RCSTA2<4>). Data is sampled on  
the RX2 pin on the falling edge of the clock.  
7. Interrupt flag bit, RC2IF, will be set when recep-  
tion is complete and an interrupt will be generated  
if the enable bit, RC2IE, was set.  
8. Read the RCSTA2 register to get the 9th bit (if  
enabled) and determine if any error occurred  
during reception.  
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.  
9. Read the 8-bit received data by reading the  
RCREG2 register.  
To set up a Synchronous Master Reception:  
10. If any error occurred, clear the error by clearing  
bit, CREN.  
1. Initialize the SPBRG2 register for the appropriate  
baud rate.  
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.  
3. Ensure bits, CREN and SREN, are clear.  
FIGURE 17-8:  
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 Q4Q1 Q2 Q3 Q4 Q1Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4  
RX2/DT2 pin  
TX2/CK2 pin  
bit 0  
bit 1  
bit 2  
bit 3  
bit 4  
bit 5  
bit 6  
bit 7  
Write to  
SREN bit  
SREN bit  
CREN bit  
0’  
0’  
RC2IF bit  
(Interrupt)  
Read  
RCREG2  
Note: Timing diagram demonstrates Sync Master mode with bit SREN = 1and bit BRGH = 0.  
TABLE 17-7: 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  
PIR3  
GIE/GIEH PEIE/GIEL TMR0IE  
INT0IE  
TX2IF  
TX2IE  
TX2IP  
CREN  
RBIE  
TMR0IF  
INT0IF  
RBIF  
59  
61  
61  
61  
63  
63  
63  
63  
LCDIF  
LCDIE  
LCDIP  
RX9  
RC2IF  
RC2IE  
RC2IP  
SREN  
PIE3  
IPR3  
RCSTA2  
SPEN  
ADDEN  
FERR  
OERR  
RX9D  
RCREG2 AUSART2 Receive Register  
TXSTA2 CSRC TX9 TXEN  
SYNC  
BRGH  
TRMT  
TX9D  
SPBRG2 AUSART2 Baud Rate Generator Register  
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used for synchronous master reception.  
DS39629C-page 228  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
To set up a Synchronous Slave Transmission:  
17.4 AUSART 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 (TXSTA2<7>). This mode differs from the  
Synchronous Master mode in that the shift clock is  
supplied externally at the CK2 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, TX2IE.  
4. If 9-bit transmission is desired, set bit, TX9.  
5. Enable the transmission by setting enable bit,  
TXEN.  
17.4.1  
AUSART SYNCHRONOUS  
SLAVE TRANSMIT  
6. If 9-bit transmission is selected, the ninth bit  
should be loaded in bit, TX9D.  
The operation of the Synchronous Master and Slave  
modes are identical except in the case of the Sleep  
mode.  
7. Start transmission by loading data to the  
TXREG2 register.  
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 TXREG2 and then the  
SLEEPinstruction is executed, the following will occur:  
a) The first word will immediately transfer to the  
TSR register and transmit.  
b) The second word will remain in the TXREG2  
register.  
c) Flag bit, TX2IF, will not be set.  
d) When the first word has been shifted out of TSR,  
the TXREG2 register will transfer the second  
word to the TSR and flag bit, TX2IF, will now be  
set.  
e) If enable bit, TX2IE, 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 17-8: 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  
PIR3  
GIE/GIEH PEIE/GIEL TMR0IE  
INT0IE  
TX2IF  
TX2IE  
TX2IP  
CREN  
RBIE  
TMR0IF  
INT0IF  
RBIF  
59  
61  
61  
61  
63  
63  
63  
63  
LCDIF  
LCDIE  
LCDIP  
RX9  
RC2IF  
RC2IE  
RC2IP  
SREN  
PIE3  
IPR3  
RCSTA2  
TXREG2  
TXSTA2  
SPBRG2  
SPEN  
ADDEN  
FERR  
OERR  
RX9D  
AUSART2 Transmit Register  
CSRC TX9 TXEN  
SYNC  
BRGH  
TRMT  
TX9D  
AUSART2 Baud Rate Generator Register  
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used for synchronous slave transmission.  
© 2007 Microchip Technology Inc.  
DS39629C-page 229  
PIC18F6390/6490/8390/8490  
To set up a Synchronous Slave Reception:  
17.4.2  
AUSART 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, RC2IE.  
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 RSR register will transfer the data to the  
RCREG2 register; if the RC2IE enable bit is set, the  
interrupt generated will wake the chip from low-power  
mode. If the global interrupt is enabled, the program will  
branch to the interrupt vector.  
5. Flag bit, RC2IF, will be set when reception is  
complete. An interrupt will be generated if  
enable bit, RC2IE, was set.  
6. Read the RCSTA2 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  
RCREG2 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 17-9: 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  
PIR3  
GIE/GIEH PEIE/GIEL TMR0IE  
INT0IE  
TX2IF  
TX2IE  
TX2IP  
CREN  
RBIE  
TMR0IF  
INT0IF  
RBIF  
59  
61  
61  
61  
63  
63  
63  
63  
LCDIF  
LCDIE  
LCDIP  
RX9  
RC2IF  
RC2IE  
RC2IP  
SREN  
PIE3  
IPR3  
RCSTA2  
RCREG2  
TXSTA2  
SPBRG2  
SPEN  
ADDEN  
FERR  
OERR  
RX9D  
AUSART2 Receive Register  
CSRC TX9 TXEN  
SYNC  
BRGH  
TRMT  
TX9D  
AUSART2 Baud Rate Generator Register  
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used for synchronous slave reception.  
DS39629C-page 230  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
The module has five registers:  
18.0 10-BIT ANALOG-TO-DIGITAL  
• 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)  
CONVERTER (A/D) MODULE  
The Analog-to-Digital (A/D) converter module has  
12 inputs for the PIC18F6X90/8X90 devices. This  
module allows conversion of an analog input signal to  
a corresponding 10-bit digital number.  
The ADCON0 register, shown in Register 18-1,  
controls the operation of the A/D module. The  
ADCON1 register, shown in Register 18-2, configures  
the functions of the port pins. The ADCON2 register,  
shown in Register 18-3, configures the A/D clock  
source, programmed acquisition time and justification.  
REGISTER 18-1: ADCON0: A/D CONTROL REGISTER 0  
U-0  
U-0  
R/W-0  
CHS3  
R/W-0  
CHS2  
R/W-0  
CHS1  
R/W-0  
CHS0  
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’  
CHS3:CHS0: Analog Channel Select bits  
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= Unimplemented(1)  
1101= Unimplemented(1)  
1110= Unimplemented(1)  
1111= Unimplemented(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: Performing a conversion on unimplemented channels will return a floating input measurement.  
© 2007 Microchip Technology Inc.  
DS39629C-page 231  
PIC18F6390/6490/8390/8490  
REGISTER 18-2: ADCON1: A/D CONTROL REGISTER 1  
U-0  
U-0  
R/W-0  
R/W-0  
R/W-q  
R/W-q  
R/W-q  
R/W-q  
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  
Unimplemented: Read as ‘0’  
VCFG1: Voltage Reference Configuration bit (VREF- source)  
1= VREF- (AN2)  
0= AVSS  
bit 4  
VCFG0: Voltage Reference Configuration bit (VREF+ source)  
1= VREF+ (AN3)  
0= AVDD  
bit 3-0  
PCFG3:PCFG0: A/D Port Configuration Control bits:  
PCFG3:  
PCFG0  
0000  
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
0001  
0010  
0011  
0100  
0101  
0110  
0111  
1000  
1001  
1010  
1011  
1100  
1101  
1110  
1111  
A = Analog input  
D = Digital I/O  
DS39629C-page 232  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
REGISTER 18-3: 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  
ACQT2:ACQT0: 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  
ADCS2:ADCS0: 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.  
© 2007 Microchip Technology Inc.  
DS39629C-page 233  
PIC18F6390/6490/8390/8490  
The analog reference voltage is software selectable to  
either the device’s positive and negative supply voltage  
(AVDD and AVSS), or the voltage level on the  
RA3/AN3/VREF+/SEG17 and RA2/AN2/VREF-/SEG16  
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  
registers, the GO/DONE bit (ADCON0<1>) is cleared  
and the A/D Interrupt Flag bit, ADIF, is set. The block  
diagram of the A/D module is shown in Figure 18-1.  
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 18-1:  
A/D BLOCK DIAGRAM  
CHS3:CHS0  
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  
VCFG1:VCFG0  
AN1  
(1)  
0000  
AVDD  
AN0  
X0  
X1  
1X  
VREF+  
VREF-  
Reference  
Voltage  
0X  
(1)  
AVSS  
Note 1: I/O pins have diode protection to VDD and VSS.  
DS39629C-page 234  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
The value in the ADRESH:ADRESL registers is not  
5. Wait for A/D conversion to complete, by either:  
• Polling for the GO/DONE bit to be cleared  
modified for a Power-on Reset. The ADRESH:ADRESL  
registers will contain unknown data after a Power-on  
Reset.  
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 con-  
version is started. The analog input channels must  
have their corresponding TRIS bits selected as an  
input. To determine acquisition time, see Section 18.1  
“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 ADIF bit, 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 3 TAD is  
required before the next acquisition starts.  
FIGURE 18-2:  
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<1>)  
FIGURE 18-3:  
ANALOG INPUT MODEL  
VDD  
Sampling  
Switch  
VT = 0.6V  
ANx  
SS  
RIC 1k  
RSS  
Rs  
CPIN  
VAIN  
ILEAKAGE  
±100 nA  
CHOLD = 25 pF  
VSS  
VT = 0.6V  
5 pF  
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
Sampling Switch (kΩ)  
© 2007 Microchip Technology Inc.  
DS39629C-page 235  
PIC18F6390/6490/8390/8490  
To calculate the minimum acquisition time,  
18.1 A/D Acquisition Requirements  
Equation 18-1 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.  
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 18-3. 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 18-3 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 18-1: ACQUISITION TIME  
TACQ  
=
=
Amplifier Settling Time + Holding Capacitor Charging Time + Temperature Coefficient  
TAMP + TC + TCOFF  
EQUATION 18-2: 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 18-3: CALCULATING THE MINIMUM REQUIRED ACQUISITION TIME  
TACQ  
TAMP  
TCOFF  
=
=
=
TAMP + TC + TCOFF  
0.2 μs  
(Temp – 25°C)(0.02 μs/°C)  
(50°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  
5.03 μs  
TACQ  
=
0.2 μs + 5 μs + 1.2 μs  
6.4 μs  
DS39629C-page 236  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
18.2 Selecting and Configuring  
Automatic Acquisition Time  
18.3 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.  
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:  
When the GO/DONE bit is set, sampling is stopped and  
a conversion begins. The user is responsible for ensur-  
ing the required acquisition time has passed between  
selecting the desired input channel and setting the  
GO/DONE bit. This occurs when the ACQT2:ACQT0  
bits (ADCON2<5:3>) remain in their Reset state (‘000’)  
and is compatible with devices that do not offer  
programmable acquisition times.  
• 2 TOSC  
• 4 TOSC  
• 8 TOSC  
• 16 TOSC  
• 32 TOSC  
• 64 TOSC  
• Internal RC Oscillator  
If desired, the ACQT bits can be set to select a  
programmable acquisition time for the A/D module.  
When the GO/DONE bit is set, the A/D module contin-  
ues to sample the input for the selected acquisition  
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.  
For correct A/D conversions, the A/D conversion clock  
(TAD) must be as short as possible, but greater than the  
minimum TAD (approximately 2 μs, see parameter 130  
for more information).  
Table 18-1 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 18-1: TAD vs. DEVICE OPERATING FREQUENCIES  
AD Clock Source (TAD)  
Maximum Device Frequency  
Operation  
ADCS2:ADCS0  
PIC18F6X90/8X90  
PIC18LF6X90/8X90(4)  
2 TOSC  
4 TOSC  
8 TOSC  
16 TOSC  
32 TOSC  
64 TOSC  
RC(3)  
000  
100  
001  
101  
010  
110  
x11  
1.25 MHz  
2.50 MHz  
5.00 MHz  
10.0 MHz  
20.0 MHz  
40.0 MHz  
1.00 MHz(1)  
666 kHz  
1.33 MHz  
2.66 MHz  
5.33 MHz  
10.65 MHz  
21.33 MHz  
1.00 MHz(2)  
Note 1: The RC source has a typical TAD time of 4 μs.  
2: The RC source has a typical TAD time of 6 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.  
© 2007 Microchip Technology Inc.  
DS39629C-page 237  
PIC18F6390/6490/8390/8490  
18.4 Operation in Power-Managed  
Modes  
18.5 Configuring Analog Port Pins  
The ADCON1, TRISA and TRISF 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.  
The A/D operation is independent of the state of the  
CHS3:CHS0 bits and the TRIS bits.  
If the A/D is expected to operate while the device is in  
a power-managed mode, the ACQT2:ACQT0 and  
ADCS2:ADCS0 bits in ADCON2 should be updated in  
accordance with the power-managed mode clock that  
will be used. After the power-managed mode is  
entered, an A/D acquisition or conversion may be  
started. Once an acquisition or conversion is started,  
the device should continue to be clocked by the same  
power-managed mode clock source until the conver-  
sion has been completed. If desired, the device may be  
placed into the corresponding power-managed Idle  
mode during the conversion.  
Note 1: When reading the PORT register, all pins  
configured as analog input channels will  
read as cleared (a low level). Pins config-  
ured as digital inputs will convert an  
analog input. Analog levels on a digitally  
configured input will be accurately  
converted.  
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.  
If the power-managed mode clock frequency is less  
than 1 MHz, the A/D RC clock source should be  
selected.  
Operation in the Sleep mode requires the A/D FRC  
clock to be selected. If bits, ACQT2:ACQT0, 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  
and SCS bits in the OSCCON register must have  
already been cleared prior to starting the conversion.  
DS39629C-page 238  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
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.  
18.6 A/D Conversions  
Figure 18-4 shows the operation of the A/D converter  
after the GO/DONE bit has been set and the  
ACQT2:ACQT0 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 18-5 shows the operation of the A/D converter  
after the GO/DONE bit has been set, the  
ACQT2:ACQT0 bits are set to ‘010’ and a 4 TAD acqui-  
sition time has been selected before the conversion  
starts.  
18.7 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  
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  
charge  
the  
capacitor  
array,  
rather  
than  
charge/discharge based on previous measure values.  
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 18-4:  
A/D CONVERSION TAD CYCLES (ACQT<2:0> = 000, TACQ = 0)  
TCY - TAD  
TAD8 TAD9 TAD10 TAD11  
TAD1  
TAD1 TAD2 TAD3 TAD4 TAD5 TAD6 TAD7  
b4  
b1  
b0  
b9  
b8  
b7  
b6  
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 is loaded, GO/DONE bit is cleared,  
ADIF bit is set, holding capacitor is connected to analog input.  
FIGURE 18-5:  
A/D CONVERSION TAD CYCLES (ACQT<2:0> = 010, TACQ = 4 TAD)  
TAD Cycles  
TACQT Cycles  
6
7
8
9
10  
b1  
11 TAD1  
b0  
1
2
3
4
1
2
3
4
5
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 is loaded, GO/DONE bit is cleared,  
ADIF bit is set, holding capacitor is connected to analog input.  
© 2007 Microchip Technology Inc.  
DS39629C-page 239  
PIC18F6390/6490/8390/8490  
software overhead (moving ADRESH/ADRESL to the  
18.8 Use of the CCP2 Trigger  
desired location). The appropriate analog input chan-  
nel 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).  
An A/D conversion can be started by the “Special Event  
Trigger” of the CCP2 module. This requires that the  
CCP2M3:CCP2M0 bits (CCP2CON<3:0>) be pro-  
grammed 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 automat-  
ically repeat the A/D acquisition period with minimal  
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 18-2: 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  
RBIE  
SSPIF  
SSPIE  
SSPIP  
BCLIF  
BCLIE  
BCLIP  
TMR0IF  
CCP1IF  
CCP1IE  
CCP1IP  
HLVDIF  
HLVDIE  
HLVDIP  
INT0IF  
TMR2IF  
TMR2IE  
TMR2IP  
TMR3IF  
TMR3IE  
TMR3IP  
RBIF  
59  
61  
61  
61  
61  
61  
61  
61  
61  
61  
61  
61  
62  
62  
62  
62  
62  
ADIF  
ADIE  
ADIP  
CMIF  
CMIE  
CMIP  
RC1IF  
RC1IE  
RC1IP  
TMR1IF  
TMR1IE  
TMR1IP  
CCP2IF  
CCP2IE  
CCP2IP  
IPR1  
PIR2  
PIE2  
OSCFIF  
OSCFIE  
OSCFIP  
IPR2  
ADRESH A/D Result Register High Byte  
ADRESL A/D Result Register Low Byte  
ADCON0  
ADCON1  
ADCON2  
PORTA  
TRISA  
CHS3  
VCFG1  
ACQT2  
RA5  
CHS2  
VCFG0  
ACQT1  
RA4  
CHS1  
PCFG3  
ACQT0  
RA3  
CHS0 GO/DONE ADON  
PCFG2  
ADCS2  
RA2  
PCFG1  
ADCS1  
RA1  
PCFG0  
ADCS0  
RA0  
ADFM  
RA7(1)  
RA6(1)  
TRISA7(1) TRISA6(1) PORTA Data Direction Register  
Read PORTF pins, Write LATF Latch  
PORTF Data Direction Register  
PORTF  
TRISF  
LATF  
LATF Data Output Register  
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used for A/D conversion.  
Note 1: These pins may be configured as port pins depending on the oscillator mode selected.  
DS39629C-page 240  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
The CMCON register (Register 19-1) selects the  
comparator input and output configuration. Block  
diagrams of the various comparator configurations are  
shown in Figure 19-1.  
19.0 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 20.0  
“Comparator Voltage Reference Module”). The digi-  
tal outputs (normal or inverted) are available at the pin  
level and can also be read through the control register.  
REGISTER 19-1: CMCON: COMPARATOR 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  
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  
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  
C2 VIN- connects to RF3/AN8  
0= C1 VIN- connects to RF6/AN11  
C2 VIN- connects to RF4/AN9  
bit 2-0  
CM2:CM0: Comparator Mode bits  
Figure 19-1 shows the Comparator modes and the CM2:CM0 bit settings.  
© 2007 Microchip Technology Inc.  
DS39629C-page 241  
PIC18F6390/6490/8390/8490  
mode is changed, the comparator output level may not  
be valid for the specified mode change delay shown in  
19.1 Comparator Configuration  
There are eight modes of operation for the compara-  
tors, shown in Figure 19-1. Bits, CM2:CM0 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  
Section 26.0 “Electrical Characteristics”.  
Note: Comparator interrupts should be disabled  
during  
a
Comparator mode change;  
otherwise, a false interrupt may occur.  
FIGURE 19-1:  
COMPARATOR I/O OPERATING MODES  
Comparators Reset (POR Default Value)  
CM2:CM0 = 000  
Comparators Off  
CM2:CM0 = 111  
RF6/AN11/  
SEG24  
RF5/AN10/  
CVREF/SEG23  
RF6/AN11/  
SEG24  
RF5/AN10/  
CVREF/SEG23  
A
D
VIN-  
VIN-  
Off (Read as ‘0’)  
Off (Read as ‘0’)  
Off (Read as ‘0’)  
Off (Read as ‘0’)  
C1  
C2  
C1  
C2  
VIN+  
VIN+  
A
D
RF4/AN9/  
SEG22  
RF3/AN8/  
SEG21  
RF4/AN9/  
SEG22  
RF3/AN8/  
SEG21  
A
A
D
D
VIN-  
VIN-  
VIN+  
VIN+  
Two Independent Comparators  
Two Independent Comparators with Outputs  
CM2:CM0 = 010  
CM2:CM0 = 011  
RF6/AN11/  
SEG24  
RF5/AN10/  
CVREF/SEG23  
RF6/AN11/  
SEG24  
RF5/AN10/  
CVREF/SEG23  
A
A
VIN-  
VIN-  
C1OUT  
C2OUT  
C1OUT  
C2OUT  
C1  
C2  
C1  
C2  
VIN+  
VIN+  
A
A
RF2/AN7/C1OUT*/SEG20  
RF4/AN9/  
SEG22  
RF3/AN8/  
SEG21  
RF4/AN9/  
SEG22  
RF3/AN8/  
SEG21  
A
A
VIN-  
A
A
VIN-  
VIN+  
VIN+  
RF1/AN6/C2OUT*/SEG19  
Two Common Reference Comparators  
Two Common Reference Comparators with Outputs  
CM2:CM0 = 100  
CM2:CM0 = 101  
RF6/AN11/  
SEG24  
RF5/AN10/  
CVREF/SEG23  
A
RF6/AN11/  
SEG24  
RF5/AN10/  
CVREF/SEG23  
A
A
VIN-  
VIN-  
C1OUT  
C2OUT  
C1OUT  
C1  
C2  
C1  
C2  
VIN+  
VIN+  
A
RF2/AN7/C1OUT*/SEG20  
RF4/AN9/  
SEG22  
RF3/AN8/  
SEG21  
A
D
VIN-  
RF4/AN9/  
SEG22  
RF3/AN8/  
SEG21  
A
D
VIN-  
VIN+  
C2OUT  
VIN+  
RF1/AN6/C2OUT*/SEG19  
Four Inputs Multiplexed to Two Comparators  
One Independent Comparator with Output  
CM2:CM0 = 110  
CM2:CM0 = 001  
RF6/AN11/  
SEG24  
RF5/AN10/  
CVREF/SEG23  
A
RF6/AN11/  
SEG24  
RF5/AN10/  
CVREF/SEG23  
A
VIN-  
CIS = 0  
CIS = 1  
VIN-  
A
C1OUT  
C1  
VIN+  
A
C1OUT  
C1  
C2  
VIN+  
RF4/AN9/  
SEG22  
RF3/AN8/  
SEG21  
A
A
RF2/AN7/C1OUT*/SEG20  
VIN-  
CIS = 0  
CIS = 1  
C2OUT  
RF4/AN9/  
VIN+  
D
D
VIN-  
SEG22  
Off (Read as ‘0’)  
C2  
RF3/AN8/  
SEG21  
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.  
DS39629C-page 242  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
19.3.2  
INTERNAL REFERENCE SIGNAL  
19.2 Comparator Operation  
The comparator module also allows the selection of an  
internally generated voltage reference from the com-  
parator voltage reference module. This module is  
described in more detail in Section 20.0 “Comparator  
Voltage Reference Module”.  
A single comparator is shown in Figure 19-2, 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 19-2 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  
(CM2:CM0 = 110). In this mode, the internal voltage  
reference is applied to the VIN+ pin of both comparators.  
19.3 Comparator Reference  
19.4 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 19-2).  
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 ref-  
erence 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 26.0  
“Electrical Characteristics”).  
FIGURE 19-2:  
SINGLE COMPARATOR  
19.5 Comparator Outputs  
VIN+  
VIN-  
+
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 RF2 and RF1  
I/O pins. When enabled, multiplexers in the output path  
of the RF2 and RF1 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 19-3 shows the comparator output block  
diagram.  
VIN-  
VIN+  
The TRISF bits will still function as an output enable/  
disable for the RF2 and RF1 pins while in this mode.  
Output  
The polarity of the comparator outputs can be changed  
using the C2INV and C1INV bits (CMCON<5:4>).  
19.3.1  
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.  
© 2007 Microchip Technology Inc.  
DS39629C-page 243  
PIC18F6390/6490/8390/8490  
FIGURE 19-3:  
COMPARATOR OUTPUT BLOCK DIAGRAM  
Port pins  
To RF2 or  
RF1 pin  
D
Q
Bus  
Data  
CxINV  
EN  
Read CMCON  
D
Q
Set  
CMIF  
bit  
EN  
CL  
From  
Other  
Comparator  
Reset  
19.6 Comparator Interrupts  
19.7 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.  
While the comparator is powered up, higher Sleep  
currents than shown in the power-down current  
specification will occur. 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 (CM2:CM0 = 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.  
19.8 Effects of a Reset  
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<6>)  
interrupt flag may not get set.  
A device Reset forces the CMCON register to its Reset  
state, causing the comparator module to be in the  
Comparator Reset mode (CM2:CM0 = 000). This  
ensures that all potential inputs are analog inputs.  
Device current is minimized when analog inputs are  
present at Reset time. The comparators are powered  
down during the Reset interval.  
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.  
DS39629C-page 244  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
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.  
19.9 Analog Input Connection  
Considerations  
A simplified circuit for an analog input is shown in  
Figure 19-4. 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 19-4:  
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 19-1: 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  
CIS  
CM2  
CM1  
CVR1  
INT0IF  
CM0  
CVR0  
RBIF  
61  
61  
59  
61  
61  
61  
62  
62  
62  
CVR3  
RBIE  
CVR2  
GIE/GIEH PEIE/GIEL TMR0IE  
TMR0IF  
HLVDIF  
OSCFIF  
OSCFIE  
OSCFIP  
CMIF  
CMIE  
CMIP  
BCLIF  
BCLIE  
BCLIP  
TMR3IF CCP2IF  
PIE2  
HLVDIE TMR3IE CCP2IE  
HLVDIP TMR3IP CCP2IP  
IPR2  
PORTF  
LATF  
Read PORTF pins, Write LATF Latch  
LATF Data Output Register  
TRISF  
PORTF Data Direction Register  
Legend: — = unimplemented, read as ‘0’. Shaded cells are unused by the comparator module.  
© 2007 Microchip Technology Inc.  
DS39629C-page 245  
PIC18F6390/6490/8390/8490  
NOTES:  
DS39629C-page 246  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
used is selected by the CVRR bit (CVRCON<5>). The  
primary difference between the ranges is the size of the  
steps selected by the CVREF selection bits  
20.0 COMPARATOR VOLTAGE  
REFERENCE MODULE  
(CVR3:CVR0), with one range offering finer resolution.  
The equations used to calculate the output of the  
comparator voltage reference are as follows:  
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  
A block diagram of the module is shown in Figure 20-1.  
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.  
If CVRR = 0:  
CVREF = (CVDD x 1/4) + (((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>).  
20.1 Configuring the Comparator  
Voltage Reference  
The settling time of the comparator voltage reference  
must be considered when changing the CVREF  
output (see Table 26-3 in Section 26.0 “Electrical  
Characteristics”).  
The voltage reference module is controlled through the  
CVRCON register (Register 20-1). The comparator  
voltage reference provides two ranges of output  
voltage, each with 16 distinct levels. The range to be  
REGISTER 20-1: 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  
-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  
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/SEG23 pin  
0= CVREF voltage is disconnected from the RF5/AN10/CVREF/SEG23 pin  
CVRR: Comparator VREF Range Selection bit  
1= 0.00 CVRSRC to 0.75 CVRSRC, with CVRSRC/24 step size  
0= 0.25 CVRSRC to 0.75 CVRSRC, with CVRSRC/32 step size  
CVRSS: Comparator VREF Source Selection bit  
1= Comparator reference source, CVRSRC = (VREF+) – (VREF-)  
0= Comparator reference source, CVRSRC = VDD – VSS  
CVR3:CVR0: Comparator VREF Value Selection bits (0 (CVR3:CVR0) 15)  
When CVRR = 1:  
CVREF = ((CVR3:CVR0)/24) (CVRSRC)  
When CVRR = 0:  
CVREF = (CVRSRC/4) + ((CVR3:CVR0)/32) (CVRSRC)  
Note 1: CVROE overrides the TRISF<5> bit setting if enabled for output; RF5 must also be configured as an input  
by setting TRISF<5> to ‘1’.  
© 2007 Microchip Technology Inc.  
DS39629C-page 247  
PIC18F6390/6490/8390/8490  
FIGURE 20-1:  
COMPARATOR VOLTAGE REFERENCE BLOCK DIAGRAM  
CVRSS = 1  
CVRSS = 0  
VREF+  
VDD  
8R  
CVR3:CVR0  
R
CVREN  
R
R
R
16 Steps  
CVREF  
R
R
R
CVRR  
VREF-  
8R  
CVRSS = 1  
CVRSS = 0  
20.2 Voltage Reference Accuracy/Error  
20.4 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 20-1) 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 26.0 “Electrical Characteristics”.  
A device Reset disables the voltage reference by  
clearing bit, CVREN (CVRCON<7>). This Reset also dis-  
connects the reference from the RA2 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.  
20.5 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  
TRISF<5> bit and the CVROE bit are both set.  
Enabling the voltage reference output onto the RF5 pin,  
with an input signal present, will increase current  
consumption. Connecting RF5 as a digital output with  
CVRSS enabled will also increase current  
consumption.  
20.3 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 20-2 shows an example buffering technique.  
DS39629C-page 248  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
FIGURE 20-2:  
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 20-1: REGISTERS ASSOCIATED WITH THE COMPARATOR VOLTAGE REFERENCE  
Reset  
Name  
Bit 7  
Bit 6  
Bit 5  
Bit 4  
Bit 3  
Bit 2  
Bit 1  
Bit 0  
Values  
on Page  
CVRCON  
CMCON  
TRISF  
CVREN  
C2OUT  
CVROE  
C1OUT  
CVRR  
C2INV  
CVRSS  
C1INV  
CVR3  
CIS  
CVR2  
CM2  
CVR1  
CM1  
CVR0  
CM0  
61  
61  
62  
PORTF Data Direction Register  
Legend: Shaded cells are not used with the comparator voltage reference.  
© 2007 Microchip Technology Inc.  
DS39629C-page 249  
PIC18F6390/6490/8390/8490  
NOTES:  
DS39629C-page 250  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
The High/Low-Voltage Detect Control register  
(Register 21-1) completely controls the operation of the  
HLVD module. This allows the circuitry to be “turned  
21.0 HIGH/LOW-VOLTAGE  
DETECT (HLVD)  
off” by the user under software control, which  
minimizes the current consumption for the device.  
PIC18F6390/6490/8390/8490  
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 21-1.  
REGISTER 21-1: 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 (HLVDL3:HLVDL0)  
0= Event occurs when voltage equals or falls below trip point (HLVDL3:HLVDL0)  
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  
HLVDL3:HLVDL0: Voltage Detection Limit bits(1)  
1111= External analog input is used (input comes from the HLVDIN pin)  
1110= 4.41V-4.87V  
1101= 4.11V-4.55V  
1100= 3.92V-4.34V  
1011= 3.72V-4.12V  
1010= 3.53V-3.91V  
1001= 3.43V-3.79V  
1000= 3.24V-3.58V  
0111= 2.95V-3.26V  
0110= 2.75V-3.03V  
0101= 2.64V-2.92V  
0100= 2.43V-2.69V  
0011= 2.35V-2.59V  
0010= 2.16V-2.38V  
0001= 1.96V-2.16V  
0000= Reserved  
Note 1: HLVDL3:HLVDL0 modes that result in a trip point below the valid operating voltage of the device are not  
tested.  
© 2007 Microchip Technology Inc.  
DS39629C-page 251  
PIC18F6390/6490/8390/8490  
The module is enabled by setting the HLVDEN bit.  
Each time that the HLVD module is enabled, the cir-  
cuitry 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  
HLVDL3:HLVDL0  
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,  
HLVDL3:HLVDL0, 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.  
21.1 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 21-1:  
HLVD MODULE BLOCK DIAGRAM (WITH EXTERNAL INPUT)  
Externally Generated  
Trip Point  
VDD  
VDD  
HLVDL3:HLVDL0  
HLVDCON  
Register  
HLVDIN  
VDIRMAG  
HLVDEN  
HLVDIN  
Set  
HLVDIF  
HLVDEN  
BOREN  
Internal Voltage  
Reference  
DS39629C-page 252  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
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.  
21.2 HLVD Setup  
The following steps are needed to set up the HLVD  
module:  
1. Disable the module by clearing the HLVDEN bit  
(HLVDCON<4>).  
2. Write the value to the HLVDL3:HLVDL0 bits that  
selects the desired HLVD trip point.  
21.4 HLVD Start-up Time  
3. Set the VDIRMAG bit to detect high voltage  
The internal reference voltage of the HLVD module,  
specified in electrical specification parameter #D423,  
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 26-10).  
(VDIRMAG = 1) or low voltage (VDIRMAG = 0).  
4. Enable the HLVD module by setting the  
HLVDEN bit.  
5. Clear the HLVD interrupt flag (PIR2<2>), which  
may have been set from a previous interrupt.  
6. Enable the HLVD interrupt, if interrupts are  
desired, by setting the HLVDIE and GIE bits  
(PIE<2> and INTCON<7>). An interrupt will not  
be generated until the IRVST bit is set.  
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 21-2 or Figure 21-3.  
21.3 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.  
FIGURE 21-2:  
LOW-VOLTAGE DETECT OPERATION (VDIRMAG = 0)  
CASE 1:  
HLVDIF may not be set  
VDD  
VLVD  
HLVDIF  
Enable HLVD  
IRVST  
TIRVST  
HLVDIF cleared in software  
Internal Reference is stable  
CASE 2:  
VDD  
VLVD  
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  
© 2007 Microchip Technology Inc.  
DS39629C-page 253  
PIC18F6390/6490/8390/8490  
FIGURE 21-3:  
HIGH-VOLTAGE DETECT OPERATION (VDIRMAG = 1)  
CASE 1:  
HLVDIF may not be set  
VLVD  
VDD  
HLVDIF  
Enable HLVD  
IRVST  
TIRVST  
HLVDIF cleared in software  
Internal Reference is stable  
CASE 2:  
VLVD  
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 21-4:  
TYPICAL LOW-VOLTAGE  
DETECT APPLICATION  
21.5 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 USB attach or detach. This assumes  
the device is powered by a lower voltage source than  
the Universal Serial Bus 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 21-4 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  
TB  
VA = HLVD trip point  
VB = Minimum valid device  
operating voltage  
TA  
Time  
Legend:  
application  
a time window, represented by the  
difference between TA and TB, to safely exit.  
DS39629C-page 254  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
21.6 Operation During Sleep  
21.7 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 21-1: 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  
60  
59  
61  
61  
61  
INTCON  
PIR2  
GIE/GIEH PEIE/GIEL TMR0IE  
INT0IE  
RBIE  
BCLIF  
BCLIE  
BCLIP  
TMR0IF  
HLVDIF  
INT0IF  
RBIF  
OSCFIF  
OSCFIE  
OSCFIP  
CMIF  
CMIE  
CMIP  
TMR3IF CCP2IF  
PIE2  
HLVDIE TMR3IE CCP2IE  
HLVDIP TMR3IP CCP2IP  
IPR2  
Legend: — = unimplemented, read as ‘0’. Shaded cells are unused by the HLVD module.  
© 2007 Microchip Technology Inc.  
DS39629C-page 255  
PIC18F6390/6490/8390/8490  
NOTES:  
DS39629C-page 256  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
The LCD driver module supports:  
22.0 LIQUID CRYSTAL DISPLAY  
• Direct driving of LCD panel  
• Three LCD clock sources with selectable prescaler  
• Up to four commons:  
- Static  
(LCD) DRIVER MODULE  
The Liquid Crystal Display (LCD) driver module  
generates the timing control to drive a static or  
multiplexed LCD panel. In the 80-pin devices  
(PIC18F8390/8490), the module drives the panels of  
up to four commons and up to 48 segments and in the  
64-pin devices (PIC18F6390/6490), the module drives  
the panels of up to four commons and up to  
32 segments. It also provides control of the LCD pixel  
data.  
- 1/2 multiplex  
- 1/3 multiplex  
- 1/4 multiplex  
• Up to 48 (in 80-pin devices)/32 (in 64-pin devices)  
segments  
• Static, 1/2 or 1/3 LCD bias  
A simplified block diagram of the module is shown in  
Figure 22-1.  
FIGURE 22-1:  
LCD DRIVER MODULE BLOCK DIAGRAM  
LCDDATAx  
Registers  
24 x 8  
SE<47:0>  
Data Bus  
192-to-48  
MUX  
To I/O Pads  
(= 4 x 48)  
Timing Control  
COM3:COM0  
LCDCON  
LCDPS  
To I/O Pads  
LCDSEx  
FOSC/4  
T13CKI  
Clock Source  
Select and  
Prescaler  
INTRC Oscillator  
© 2007 Microchip Technology Inc.  
DS39629C-page 257  
PIC18F6390/6490/8390/8490  
used to enable or disable the LCD module. The LCD  
panel can also operate during Sleep by clearing the  
SLPEN (LCDCON<6>) bit.  
22.1 LCD Registers  
The LCD driver module has 32 registers:  
• LCD Control Register (LCDCON)  
• LCD Phase Register (LCDPS)  
The LCDPS register, shown in Register 22-2,  
configures the LCD clock source prescaler and the type  
of waveform, Type-A or Type-B. Details on these  
features are provided in Section 22.2 “LCD Clock  
Source Selection”, Section 22.3 “LCD Bias Types”  
and Section 22.8 “LCD Waveform Generation”.  
• Six LCD Segment Enable Registers  
(LCDSE5:LCDSE0)  
• 24 LCD Data Registers  
(LCDDATA23:LCDDATA0)  
The LCDCON register, shown in Register 22-1,  
controls the overall operation of the module. Once the  
module is configured, the LCDEN (LCDCON<7>) bit is  
REGISTER 22-1: LCDCON: LCD CONTROL REGISTER  
R/W-0  
R/W-0  
R/C-0  
U-0  
R/W-0  
CS1  
R/W-0  
CS0  
R/W-0  
R/W-0  
LCDEN  
SLPEN  
WERR  
LMUX1  
LMUX0  
bit 7  
bit 0  
Legend:  
C = Clearable Only bit  
W = Writable bit  
‘1’ = Bit is set  
R = Readable bit  
U = Unimplemented bit, read as ‘0’  
‘0’ = Bit is cleared x = Bit is unknown  
-n = Value at POR  
bit 7  
bit 6  
bit 5  
LCDEN: LCD Driver Enable bit  
1= LCD driver module is enabled  
0= LCD driver module is disabled  
SLPEN: LCD Driver Enable in Sleep mode bit  
1= LCD driver module is disabled in Sleep mode  
0= LCD driver module is enabled in Sleep mode  
WERR: LCD Write Failed Error bit  
1= LCDDATAx register written while LCDPS<WA> = 0(must be cleared in software)  
0= No LCD write error  
bit 4  
Unimplemented: Read as ‘0’  
bit 3-2  
CS1:CS0: Clock Source Select bits  
00= (FOSC/4)/8192  
01= T13CKI (Timer1)/32  
1x= INTRC (31.25 kHz)/32  
bit 1-0  
LMUX1:LMUX0: Commons Select bits  
Maximum  
Number of  
Pixels  
Maximum  
Number of  
Pixels  
LMUX1:LMUX0  
Multiplex  
Bias  
(PIC18F6X90) (PIC18F8X90)  
00  
01  
10  
11  
Static (COM0)  
32  
64  
48  
96  
Static  
1/2 or 1/3  
1/2 or 1/3  
1/3  
1/2 (COM1:COM0)  
1/3 (COM2:COM0)  
1/4 (COM3:COM0)  
96  
144  
192  
128  
DS39629C-page 258  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
REGISTER 22-2: LCDPS: LCD PHASE REGISTER  
R/W-0  
WFT  
R/W-0  
R-0  
R-0  
WA  
R/W-0  
LP3  
R/W-0  
LP2  
R/W-0  
LP1  
R/W-0  
LP0  
BIASMD  
LCDA  
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  
WFT: Waveform Type Select bit  
1= Type-B waveform (phase changes on each frame boundary)  
0= Type-A waveform (phase changes within each common type)  
BIASMD: Bias Mode Select bit  
When LMUX1:LMUX0 = 00:  
0= Static Bias mode (do not set this bit to ‘1’)  
When LMUX1:LMUX0 = 01:  
1= 1/2 Bias mode  
0= 1/3 Bias mode  
When LMUX1:LMUX0 = 10:  
1= 1/2 Bias mode  
0= 1/3 Bias mode  
When LMUX1:LMUX0 = 11:  
0= 1/3 Bias mode (do not set this bit to ‘1’)  
bit 5  
LCDA: LCD Active Status bit  
1= LCD driver module is active  
0= LCD driver module is inactive  
bit 4  
WA: LCD Write Allow Status bit  
1= Write into the LCDDATAx registers is allowed  
0= Write into the LCDDATAx registers is not allowed  
bit 3-0  
LP3:LP0: LCD Prescaler Select bits  
1111= 1:16  
1110= 1:15  
1101= 1:14  
1100= 1:13  
1011= 1:12  
1010= 1:11  
1001= 1:10  
1000= 1:9  
0111= 1:8  
0110= 1:7  
0101= 1:6  
0100= 1:5  
0011= 1:4  
0010= 1:3  
0001= 1:2  
0000= 1:1  
© 2007 Microchip Technology Inc.  
DS39629C-page 259  
PIC18F6390/6490/8390/8490  
The LCDSE5:LCDSE0 registers configure the  
functions of the port pins. Setting the segment enable  
bit for a particular segment configures that pin as an  
LCD driver. There are six LCD Segment Enable  
registers listed in Table 22-1. The prototype LCDSEx  
register is shown in Register 22-3.  
Once the module is initialized for the LCD panel, the  
individual bits of the LCDDATA23:LCDDATA0 registers  
are cleared or set to represent a clear or dark pixel,  
respectively. Specific sets of LCDDATA registers are  
used with specific segments and common signals.  
Each bit represents a unique combination of a specific  
segment connected to a specific common. Individual  
LCDDATA bits are named by the convention “SxxCy”,  
with “xx” as the segment number and “y” as the  
common number. The relationship is summarized in  
Table 22-2. The prototype LCDDATAx register is  
shown in Register 22-4.  
TABLE 22-1: LCDSE REGISTERS AND  
ASSOCIATED SEGMENTS  
Register  
Segments  
LCDSE0  
LCDSE1  
LCDSE2  
LCDSE3  
LCDSE4  
LCDSE5  
7:0  
15:8  
Note:  
Writing into the registers, LCDDATA4,  
LCDDATA5, LCDDATA10, LCDDATA11,  
LCDDATA16, LCDDATA17, LCDDATA22  
and LCDDATA23, in PIC18F6X90 devices  
will not affect the status of any pixel and  
these registers can be used as General  
Purpose Registers.  
23:16  
31:24  
39:32  
47:40  
.
Note:  
The LCDSE5:LCDSE4 registers are not  
implemented in PIC18F6X90 devices.  
REGISTER 22-3: LCDSEx: LCD SEGMENTx ENABLE 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  
SE(n)  
SE(n + 7)  
SE(n + 6)  
SE(n + 5)  
SE(n + 4)  
SE(n + 3)  
SE(n + 2)  
SE(n + 1)  
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 7-0  
SE(n + 7):SE(n): Segment Enable bits  
For LCDSE0: n = 0  
For LCDSE1: n = 8  
For LCDSE2: n = 16  
For LCDSE3: n = 24  
For LCDSE4: n = 32  
For LCDSE5: n = 40  
1= Segment function of the pin is enabled, digital I/O is disabled  
0= I/O function of the pin is enabled  
DS39629C-page 260  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
TABLE 22-2: LCDDATA REGISTERS AND BITS FOR SEGMENT AND COM COMBINATIONS  
COM Lines  
Segments  
0
1
2
3
LCDDATA0  
S00C0:S07C0  
LCDDATA1  
LCDDATA6  
S00C1:S07C1  
LCDDATA7  
LCDDATA12  
S00C2:S07C2  
LCDDATA13  
LCDDATA18  
S00C3:S07C3  
LCDDATA19  
0 through 7  
8 through 15  
16 through 23  
24 through 31  
32 through 39  
40 through 47  
S08C0:S15C0  
LCDDATA2  
S08C1:S15C1  
LCDDATA8  
S08C2:S15C2  
LCDDATA14  
S08C0:S15C3  
LCDDATA20  
S16C0:S23C0  
LCDDATA3  
S16C1:S23C1  
LCDDATA9  
S16C2:S23C2  
LCDDATA15  
S16C3:S23C3  
LCDDATA21  
S24C0:S31C0  
LCDDATA4(1)  
S32C0:S39C0  
LCDDATA5(1)  
S40C0:S47C0  
S24C1:S31C1  
LCDDATA10(1)  
S32C1:S39C1  
LCDDATA11(1)  
S40C1:S47C1  
S24C2:S31C2  
LCDDATA16(1)  
S32C2:S39C2  
LCDDATA17(1)  
S40C2:S47C2  
S24C3:S31C3  
LCDDATA22(1)  
S32C3:S39C3  
LCDDATA23(1)  
S40C3:S47C3  
Note 1: These registers are implemented but not used as LCD data registers in 64-pin devices. They may be used  
as general purpose data memory.  
REGISTER 22-4: LCDDATAx: LCD DATAx 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  
S(n + 7)Cy  
S(n + 6)Cy  
S(n + 5)Cy  
S(n + 4)Cy  
S(n + 3)Cy  
S(n + 2)Cy  
S(n + 1)Cy  
S(n)Cy  
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  
S(n + 7)Cy:S(n)Cy: Pixel On bits  
For LCDDATA0 through LCDDATA5: n = (8x), y = 0  
For LCDDATA6 through LCDDATA11: n = (8(x – 6)), y = 1  
For LCDDATA12 through LCDDATA17: n = (8(x – 12)), y = 2  
For LCDDATA18 through LCDDATA23: n = (8(x – 18)), y = 3  
1= Pixel on (dark)  
0= Pixel off (clear)  
© 2007 Microchip Technology Inc.  
DS39629C-page 261  
PIC18F6390/6490/8390/8490  
The third clock source is a 31.25 kHz internal RC  
oscillator/32, which provides approximately 1 kHz  
output.  
22.2  
LCD Clock Source Selection  
The LCD driver module has 3 possible clock sources:  
• (FOSC/4)/8192  
• T13CKI Clock/32  
• INTRC/32  
The second and third clock sources may be used to  
continue running the LCD while the processor is in  
Sleep.  
Using the bits, CS1:CS0 (LCDCON<3:2>), any of these  
clock sources can be selected.  
The first clock source is the system clock divided by  
8192 ((FOSC/4)/8192). This divider ratio is chosen to  
provide about 1 kHz output when the system clock is  
8 MHz. The divider is not programmable. Instead, the  
LCD prescaler bits, LCDPS<3:0>, are used to set the  
LCD frame clock rate.  
22.2.1  
LCD PRESCALER  
A 16-bit counter is available as a prescaler for the LCD  
clock. The prescaler is not directly readable or writable;  
its value is set by the LP3:LP0 bits (LCDPS<3:0>), which  
determine the prescaler assignment and prescale ratio.  
The second clock source is the Timer1 oscillator/32.  
This also gives about 1 kHz when a 32.768 kHz crystal  
is used with the Timer1 oscillator. To use the Timer1  
The prescale values from 1:1 through 1:32768 in  
power-of-2 increments are selectable.  
oscillator as  
a
clock source, the T1OSCEN  
(T1CON<3>) bit should be set.  
FIGURE 22-2:  
LCD CLOCK GENERATION  
System Clock  
(FOSC/4)  
÷8192  
÷32  
STAT  
÷4  
÷2  
TMR1 32 kHz  
Crystal Oscillator  
÷1, 2, 3, 4  
Ring Counter  
DUP  
4-Bit Prog Prescaler  
TRIP  
QUAD  
Internal RC Oscillator  
Nom FRC = 31.25 kHz  
÷32  
LP3:LP0  
(LCDPS<3:0>)  
LMUX1:LMUX0  
(LCDCON<1:0>)  
CS1:CS0  
(LCDCON<3:2>)  
LMUX1:LMUX0  
(LCDCON<1:0>)  
DS39629C-page 262  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
If the pin is a digital I/O, the corresponding TRIS bit  
controls the data direction. If the pin is a COM drive,  
then the TRIS setting of that pin is overridden.  
22.3 LCD Bias Types  
The LCD driver module can be configured into three  
bias types:  
Note:  
On a Power-on Reset, the LMUX1:LMUX0  
• Static Bias (2 voltage levels: AVSS and AVDD)  
bits are ‘00’.  
• 1/2 Bias (3 voltage levels: AVSS, 1/2 AVDD and  
AVDD)  
TABLE 22-3: PORTE<6:4> FUNCTION  
• 1/3 Bias (4 voltage levels: AVSS, 1/3 AVDD, 2/3 AVDD  
and AVDD)  
LMUX1:  
PORTE<6> PORTE<5> PORTE<4>  
LMUX0  
This module uses an external resistor ladder to  
generate the LCD bias voltages.  
00  
01  
10  
11  
Digital I/O  
Digital I/O  
Digital I/O  
Digital I/O  
Digital I/O COM1 Driver  
The external resistor ladder should be connected to the  
Bias 1 pin, Bias 2 pin, Bias 3 pin and VSS. The Bias 3  
pin should also be connected to AVDD.  
Digital I/O COM2 Driver COM1 Driver  
COM3 Driver COM2 Driver COM1 Driver  
Figure 22-3 shows the proper way to connect the  
resistor ladder to the Bias pins.  
22.5 Segment Enables  
The LCDSEx registers are used to select the pin  
function for each segment pin. The selection allows  
each pin to operate as either an LCD segment driver or  
a digital only pin. To configure the pin as a segment pin,  
the corresponding bits in the LCDSEx registers must  
be set to ‘1’.  
22.4 LCD Multiplex Types  
The LCD driver module can be configured into four  
multiplex types:  
• Static (only COM0 used)  
• 1/2 multiplex (COM0 and COM1 are used)  
• 1/3 multiplex (COM0, COM1 and COM2 are used)  
If the pin is a digital I/O, the corresponding TRIS bit  
controls the data direction. Any bit set in the LCDSEx  
registers overrides any bit settings in the corresponding  
TRIS register.  
• 1/4 multiplex (all COM0, COM1, COM2 and COM3  
are used)  
The LMUX1:LMUX0 setting decides the function of the  
PORTE<6:4> bits (see Table 22-3 for details).  
Note:  
On a Power-on Reset, these pins are  
configured as digital I/O.  
FIGURE 22-3:  
LCD BIAS RESISTOR LADDER CONNECTION DIAGRAM  
Static  
1/2 Bias 1/3 Bias  
AVSS AVSS  
Bias  
VLCD 0  
VLCD 1  
VLCD 2  
VLCD 3  
AVSS  
VLCD 3  
VLCD 2  
VLCD 1  
VLCD 0  
1/2 AVDD 1/3 AVDD  
1/2 AVDD 2/3 AVDD  
To  
LCD  
Driver  
AVDD  
AVDD  
AVDD  
LCD Bias 3  
LCD Bias 2 LCD Bias 1  
Connections for External R-ladder  
Static Bias  
AVDD*  
AVDD*  
1/2 Bias  
10 kΩ*  
10 kΩ*  
10 kΩ*  
AVSS  
1/3 Bias  
10 kΩ*  
10 kΩ*  
AVDD*  
AVSS  
* These values are provided for design guidance only and should be optimized for the application by the designer.  
© 2007 Microchip Technology Inc.  
DS39629C-page 263  
PIC18F6390/6490/8390/8490  
22.6 Pixel Control  
22.8 LCD Waveform Generation  
The LCDDATAx registers contain bits which define the  
state of each pixel. Each bit defines one unique pixel.  
LCD waveform generation is based on the philosophy  
that the net AC voltage across the dark pixel should be  
maximized and the net AC voltage across the clear  
pixel should be minimized. The net DC voltage across  
any pixel should be zero.  
Table 22-2 shows the correlation of each bit in the  
LCDDATAx registers to the respective common and  
segment signals.  
The COM signal represents the time slice for each  
common, while the SEG contains the pixel data.  
Any LCD pixel location not being used for display can  
be used as general purpose RAM.  
The pixel signal (COM-SEG) will have no DC com-  
ponent and it can take only one of the two rms values.  
The higher rms value will create a dark pixel and a  
lower rms value will create a clear pixel.  
22.7 LCD Frame Frequency  
The rate at which the COM and SEG outputs changes  
is called the LCD frame frequency  
As the number of commons increases, the delta  
between the two rms values decreases. The delta  
represents the maximum contrast that the display can  
have.  
TABLE 22-4: FRAME FREQUENCY  
FORMULAS  
Multiplex  
Frame Frequency =  
The LCDs can be driven by two types of waveform:  
Type-A and Type-B. In Type-A waveform, the phase  
changes within each common type, whereas in Type-B  
waveform, the phase changes on each frame  
boundary. Thus, Type-A waveform maintains 0 VDC  
over a single frame, whereas Type-B waveform takes  
two frames.  
Static  
1/2  
Clock Source/(4 x 1 x (LP3:LP0 + 1))  
Clock Source/(2 x 2 x (LP3:LP0 + 1))  
Clock Source/(1 x 3 x (LP3:LP0 + 1))  
Clock Source/(1 x 4 x (LP3:LP0 + 1))  
1/3  
1/4  
Note:  
Clock source is (FOSC/4)/8192,  
Timer1 Osc/32 or INTRC/32.  
Note 1: If Sleep has to be executed with LCD  
Sleep enabled (LCDCON<SLPEN> is  
1’), then care must be taken to execute  
Sleep only when VDC on all the pixels is  
0’.  
TABLE 22-5: APPROXIMATE FRAME  
FREQUENCY (IN Hz) USING  
FOSC @ 32 MHz,  
2: When the LCD clock source is  
(FOSC/4)/8192, if Sleep is executed  
irrespective of the LCDCON<SLPEN>  
setting, the LCD goes into Sleep. Thus,  
take care to see that VDC on all pixels is ‘0’  
when Sleep is executed.  
TIMER1 @ 32.768 kHz OR  
INTRC OSCILLATOR  
LP3:LP0  
Static  
1/2  
1/3  
1/4  
1
2
3
4
5
6
7
125  
83  
62  
50  
42  
36  
31  
125  
83  
62  
50  
42  
36  
31  
167  
111  
83  
125  
83  
62  
50  
42  
36  
31  
Figure 22-4 through Figure 22-14 provide waveforms  
for static, half-multiplex, one-third-multiplex and  
quarter-multiplex drives for Type-A and Type-B  
waveforms.  
67  
56  
48  
42  
DS39629C-page 264  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
FIGURE 22-4:  
TYPE-A/TYPE-B WAVEFORMS IN STATIC DRIVE  
V
V
1
COM0  
0
COM0  
V
1
SEG0  
V
0
V
1
SEG1  
V
0
V
V
1
COM0-SEG0  
0
-V  
1
COM0-SEG1  
V
0
1 Frame  
© 2007 Microchip Technology Inc.  
DS39629C-page 265  
PIC18F6390/6490/8390/8490  
FIGURE 22-5:  
TYPE-A WAVEFORMS IN 1/2 MUX, 1/2 BIAS DRIVE  
V
V
V
2
1
0
COM0  
COM1  
COM0  
V
V
V
2
1
0
COM1  
SEG0  
SEG1  
V
V
V
2
1
0
V
V
V
2
1
0
V
V
V
2
1
0
COM0-SEG0  
-V  
-V  
1
2
V
V
V
2
1
0
COM0-SEG1  
-V  
-V  
1
2
1 Frame  
DS39629C-page 266  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
FIGURE 22-6:  
TYPE-B WAVEFORMS IN 1/2 MUX, 1/2 BIAS DRIVE  
V
V
V
2
1
0
COM0  
COM1  
COM0  
V
V
V
2
1
0
COM1  
SEG0  
V
V
V
2
1
0
V
V
V
2
1
0
SEG1  
V
V
V
2
1
0
COM0-SEG0  
-V  
-V  
1
2
V
V
V
2
1
0
COM0-SEG1  
-V  
-V  
1
2
2 Frames  
© 2007 Microchip Technology Inc.  
DS39629C-page 267  
PIC18F6390/6490/8390/8490  
FIGURE 22-7:  
TYPE-A WAVEFORMS IN 1/2 MUX, 1/3 BIAS DRIVE  
V
V
V
V
V
V
V
V
V
V
V
V
3
2
1
0
3
2
1
0
3
2
1
0
COM0  
COM1  
COM0  
COM1  
SEG0  
SEG1  
V
V
V
V
3
2
1
0
V
V
V
V
3
2
1
0
COM0-SEG0  
-V  
-V  
-V  
1
2
3
V
V
V
V
3
2
1
0
COM0-SEG1  
-V  
-V  
-V  
1
2
3
1 Frame  
DS39629C-page 268  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
FIGURE 22-8:  
TYPE-B WAVEFORMS IN 1/2 MUX, 1/3 BIAS DRIVE  
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
3
2
1
0
3
2
1
0
3
2
1
0
COM0  
COM1  
COM0  
COM1  
SEG0  
3
2
1
0
SEG1  
V
V
V
V
3
2
1
0
COM0-SEG0  
-V  
-V  
-V  
1
2
3
V
V
V
V
3
2
1
0
COM0-SEG1  
-V  
-V  
-V  
1
2
3
2 Frames  
© 2007 Microchip Technology Inc.  
DS39629C-page 269  
PIC18F6390/6490/8390/8490  
FIGURE 22-9:  
TYPE-A WAVEFORMS IN 1/3 MUX, 1/2 BIAS DRIVE  
V
V
V
2
1
0
COM0  
COM2  
V
V
V
2
1
0
COM1  
COM2  
COM1  
COM0  
V
V
V
2
1
0
V
V
V
2
1
0
SEG0  
SEG2  
V
V
V
2
1
0
SEG1  
V
V
V
2
1
0
COM0-SEG0  
-V  
-V  
1
2
V
V
V
2
1
0
COM0-SEG1  
-V  
-V  
1
2
1 Frame  
DS39629C-page 270  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
FIGURE 22-10:  
TYPE-B WAVEFORMS IN 1/3 MUX, 1/2 BIAS DRIVE  
V
V
V
2
1
0
COM0  
COM1  
COM2  
SEG0  
SEG1  
COM2  
V
V
V
2
1
0
COM1  
COM0  
V
V
V
2
1
0
V
V
V
2
1
0
V
V
V
2
1
0
V
V
V
2
1
0
COM0-SEG0  
-V  
-V  
1
2
V
V
V
2
1
0
COM0-SEG1  
-V  
-V  
1
2
2 Frames  
© 2007 Microchip Technology Inc.  
DS39629C-page 271  
PIC18F6390/6490/8390/8490  
FIGURE 22-11:  
TYPE-A WAVEFORMS IN 1/3 MUX, 1/3 BIAS DRIVE  
V
V
V
V
V
V
V
V
3
2
1
0
3
2
1
0
COM0  
COM2  
COM1  
COM2  
COM1  
COM0  
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
3
2
1
0
3
2
1
0
3
2
1
0
3
2
1
0
SEG0  
SEG2  
SEG1  
COM0-SEG0  
-V  
-V  
-V  
1
2
3
V
V
V
V
3
2
1
0
COM0-SEG1  
-V  
-V  
-V  
1
2
3
1 Frame  
DS39629C-page 272  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
FIGURE 22-12:  
TYPE-B WAVEFORMS IN 1/3 MUX, 1/3 BIAS DRIVE  
V
V
V
V
V
V
V
V
3
2
1
0
3
2
1
0
COM0  
COM1  
COM2  
SEG0  
SEG1  
COM2  
COM1  
COM0  
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
3
2
1
0
3
2
1
0
3
2
1
0
3
2
1
0
COM0-SEG0  
-V  
-V  
-V  
1
2
3
V
V
V
V
3
2
1
0
COM0-SEG1  
-V  
-V  
-V  
1
2
3
2 Frames  
© 2007 Microchip Technology Inc.  
DS39629C-page 273  
PIC18F6390/6490/8390/8490  
FIGURE 22-13:  
TYPE-A WAVEFORMS IN 1/4 MUX, 1/3 BIAS DRIVE  
COM3  
COM2  
V
V
V
V
3
2
1
0
COM0  
COM1  
V
V
V
V
3
2
1
0
COM1  
COM0  
V
V
V
V
3
2
1
0
COM2  
COM3  
SEG0  
SEG1  
V
V
V
V
3
2
1
0
V
V
V
V
3
2
1
0
V
V
V
V
3
2
1
0
V
V
V
V
-V  
-V  
-V  
3
2
1
0
COM0-SEG0  
1
2
3
V
V
V
V
-V  
-V  
-V  
3
2
1
0
COM0-SEG1  
1
2
3
1 Frame  
DS39629C-page 274  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
FIGURE 22-14:  
TYPE-B WAVEFORMS IN 1/4 MUX, 1/3 BIAS DRIVE  
COM3  
COM2  
V
V
V
V
3
2
1
0
COM0  
COM1  
V
V
V
V
3
2
1
0
COM1  
COM0  
V
V
V
V
3
2
1
0
COM2  
COM3  
SEG0  
SEG1  
V
V
V
V
3
2
1
0
V
V
V
V
3
2
1
0
V
V
V
V
3
2
1
0
V
V
V
V
-V  
-V  
-V  
3
2
1
0
COM0-SEG0  
COM0-SEG1  
1
2
3
V
V
V
V
3
2
1
0
-V  
-V  
-V  
1
2
3
2 Frames  
© 2007 Microchip Technology Inc.  
DS39629C-page 275  
PIC18F6390/6490/8390/8490  
When the LCD driver is running with Type-B waveforms  
22.9 LCD Interrupts  
and the LMUX1:LMUX0 bits are not equal to ‘00’, there  
are some additional issues that must be addressed.  
Since the DC voltage on the pixel takes two frames to  
maintain zero volts, the pixel data must not change  
between subsequent frames. If the pixel data were  
allowed to change, the waveform for the odd frames  
would not necessarily be the complement of the  
waveform generated in the even frames and a DC  
component would be introduced into the panel. There-  
fore, when using Type-B waveforms, the user must  
synchronize the LCD pixel updates to occur within a  
subframe after the frame interrupt.  
The LCD timing generation provides an interrupt that  
defines the LCD frame timing. This interrupt can be  
used to coordinate the writing of the pixel data with the  
start of a new frame. Writing pixel data at the frame  
boundary allows a visually crisp transition of the image.  
This interrupt can also be used to synchronize external  
events to the LCD. For example, the interface to an  
external segment driver can be synchronized for  
segment data update to the LCD frame.  
A new frame is defined to begin at the leading edge of  
the COM0 common signal. The interrupt will be set  
immediately after the LCD controller completes  
accessing all pixel data required for a frame. This will  
occur at a fixed interval before the frame boundary  
(TFINT), as shown in Figure 22-15. The LCD controller  
will begin to access data for the next frame within the  
interval from the interrupt to when the controller begins  
to access data after the interrupt (TFWR). New data  
must be written within TFWR, as this is when the LCD  
controller will begin to access the data for the next  
frame.  
To correctly sequence writing while in Type-B, the  
interrupt will only occur on complete phase intervals. If  
the user attempts to write when the write is disabled,  
the WERR (LCDCON<5>) bit is set.  
Note: The interrupt is not generated when the  
Type-A waveform is selected and when the  
Type-B with no multiplex (static) is  
selected.  
FIGURE 22-15:  
EXAMPLE WAVEFORMS AND INTERRUPT TIMING IN QUARTER-DUTY  
CYCLE DRIVE  
LCD  
Interrupt  
Occurs  
Controller Accesses  
Next Frame Data  
V
V
V
V
3
2
1
0
COM0  
COM1  
V
V
V
V
3
2
1
0
V
V
V
V
3
2
1
0
COM2  
COM3  
V
V
V
V
3
2
1
0
2 Frames  
Frame  
TFINT  
TFWR  
Frame  
Boundary  
Frame  
Boundary  
Boundary  
TFWR = TFRAME/2*(LMUX1:LMUX0 + 1) + TCY/2  
TFINT = (TFWR/2 – (2 TCY + 40 ns)) minimum = 1.5(TFRAME/4) – (2 TCY + 40 ns)  
(TFWR/2 – (1 TCY + 40 ns)) maximum = 1.5(TFRAME/4) – (1 TCY + 40 ns)  
DS39629C-page 276  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
If a SLEEPinstruction is executed and SLPEN = 0, the  
module will continue to display the current contents of  
22.10 Operation During Sleep  
The LCD module can operate during Sleep. The selec-  
tion is controlled by bit, SLPEN (LCDCON<6>). Setting  
the SLPEN bit allows the LCD module to go to Sleep.  
Clearing the SLPEN bit allows the module to continue  
to operate during Sleep.  
the LCDDATA registers. To allow the module to  
continue operation while in Sleep, the clock source  
must be either the internal RC oscillator or Timer1  
external oscillator. While in Sleep, the LCD data cannot  
be changed. The LCD module current consumption will  
not decrease in this mode, however, the overall  
consumption of the device will be lower due to shut  
down of the core and other peripheral functions.  
If a SLEEPinstruction is executed and SLPEN = 1, the  
LCD module will cease all functions and go into a very  
low-current consumption mode. The module will stop  
operation immediately and drive the minimum LCD  
voltage on both segment and common lines.  
Figure 22-16 shows this operation.  
If the system clock is selected and the module is  
programmed to not Sleep, the module will ignore the  
SLPEN bit and stop operation immediately. The  
minimum LCD voltage will then be driven onto the  
segments and commons.  
To ensure that no DC component is introduced on the  
panel, the SLEEP instruction should be executed  
immediately after a LCD frame boundary. The LCD  
interrupt can be used to determine the frame boundary.  
See Section 22.9 “LCD Interrupts” for the formulas to  
calculate the delay.  
Note:  
The internal RC oscillator or external  
Timer1 oscillator must be used to operate  
the LCD module during Sleep.  
FIGURE 22-16:  
SLEEP ENTRY/EXIT WHEN SLPEN = 1OR CS1:CS0 = 00  
V
V
V
V
3
2
1
0
COM0  
V
V
V
V
3
2
1
0
COM1  
V
V
V
V
3
2
1
0
COM2  
SEG0  
V
V
V
V
3
2
1
0
2 Frames  
Wake-up  
SLEEPInstruction Execution  
© 2007 Microchip Technology Inc.  
DS39629C-page 277  
PIC18F6390/6490/8390/8490  
4. Write initial values to Pixel Data registers,  
22.11 Configuring the LCD Module  
LCDDATA0 through LCDDATA23.  
The following is the sequence of steps to configure the  
LCD module.  
5. Clear LCD Interrupt Flag, LCDIF (PIR3<6>),  
and if desired, enable the interrupt by setting bit,  
LCDIE (PIE3<6>).  
1. Select the frame clock prescale using bits,  
LP3:LP0 (LCDPS<3:0>).  
6. Enable the LCD module by setting bit, LCDEN  
(LCDCON<7>).  
2. Configure the appropriate pins to function as  
segment drivers using the LCDSEx registers.  
3. Configure the LCD module for the following  
using the LCDCON register:  
- Multiplex and Bias mode, LMUX1:LMUX0  
bits  
- Timing source, CS1:CS0 bits  
- Sleep mode, SLPEN bit  
DS39629C-page 278  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
TABLE 22-6: REGISTERS ASSOCIATED WITH LCD OPERATION  
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  
TX2IF  
TX2IE  
TX2IP  
RI  
RBIE  
TMR0IF  
INT0IF  
RBIF  
59  
61  
61  
61  
60  
63  
63  
63  
63  
63  
63  
63  
63  
63  
63  
63  
63  
63  
63  
63  
63  
63  
63  
63  
63  
63  
63  
63  
63  
64  
64  
64  
64  
64  
64  
64  
64  
PIR3  
PIE3  
LCDIF  
LCDIE  
LCDIP  
SBOREN  
S46C3  
S38C3  
S30C3  
S22C3  
S14C3  
S06C3  
S46C2  
S38C2  
S30C2  
S22C2  
S14C2  
S06C2  
S46C1  
S38C1  
S30C1  
S22C1  
S14C1  
S06C1  
S46C0  
S38C0  
S30C0  
S22C0  
S14C0  
S06C0  
SE46  
RC2IF  
RC2IE  
RC2IP  
IPR3  
RCON  
IPEN  
TO  
PD  
POR  
BOR  
LCDDATA23(1) S47C3  
LCDDATA22(1) S39C3  
S45C3  
S37C3  
S29C3  
S21C3  
S13C3  
S05C3  
S45C2  
S37C2  
S29C2  
S21C2  
S13C2  
S05C2  
S45C1  
S37C1  
S29C1  
S21C1  
S13C1  
S05C1  
S45C0  
S37C0  
S29C0  
S21C0  
S13C0  
S05C0  
SE45  
S44C3  
S36C3  
S28C3  
S20C3  
S12C3  
S04C3  
S44C2  
S36C2  
S28C2  
S20C2  
S12C2  
S04C2  
S44C1  
S36C1  
S28C1  
S20C1  
S12C1  
S04C1  
S44C0  
S36C0  
S28C0  
S20C0  
S12C0  
S04C0  
SE44  
S43C3  
S35C3  
S27C3  
S19C3  
S11C3  
S03C3  
S43C2  
S35C2  
S27C2  
S19C2  
S11C2  
S03C2  
S43C1  
S35C1  
S27C1  
S19C1  
S11C1  
S03C1  
S43C0  
S35C0  
S27C0  
S19C0  
S11C0  
S03C0  
SE43  
SE35  
SE27  
SE19  
SE11  
S42C3  
S34C3  
S26C3  
S18C3  
S10C3  
S02C3  
S42C2  
S34C2  
S26C2  
S18C2  
S10C2  
S02C2  
S42C1  
S34C1  
S26C1  
S18C1  
S10C1  
S02C1  
S42C0  
S34C0  
S26C0  
S18C0  
S10C0  
S02C0  
SE42  
SE34  
SE26  
SE18  
SE10  
SE2  
S41C3  
S33C3  
S25C3  
S17C3  
S09C3  
S01C3  
S41C2  
S33C2  
S25C2  
S17C2  
S09C2  
S01C2  
S41C1  
S33C1  
S25C1  
S17C1  
S09C1  
S01C1  
S41C0  
S33C0  
S25C0  
S17C0  
S09C0  
S01C0  
SE41  
S40C3  
S32C3  
S24C3  
S16C3  
S08C3  
S00C3  
S40C2  
S32C2  
S24C2  
S16C2  
S08C2  
S00C2  
S40C1  
S32C1  
S24C1  
S16C1  
S08C1  
S00C1  
S40C0  
S32C0  
S24C0  
S16C0  
S08C0  
S00C0  
SE40  
LCDDATA21  
LCDDATA20  
LCDDATA19  
LCDDATA18  
LCDDATA17(1) S47C2  
LCDDATA16(1) S39C2  
S31C3  
S23C3  
S15C3  
S07C3  
LCDDATA15  
LCDDATA14  
LCDDATA13  
LCDDATA12  
LCDDATA11(1)  
S31C2  
S23C2  
S15C2  
S07C2  
S47C1  
LCDDATA10(1) S39C1  
LCDDATA9  
LCDDATA8  
LCDDATA7  
LCDDATA6  
LCDDATA5(1)  
LCDDATA4(1)  
LCDDATA3  
LCDDATA2  
LCDDATA1  
LCDDATA0  
LCDSE5(2)  
LCDSE4(2)  
LCDSE3  
S31C1  
S23C1  
S15C1  
S07C1  
S47C0  
S39C0  
S31C0  
S23C0  
S15C0  
S07C0  
SE47  
SE39  
SE38  
SE37  
SE36  
SE33  
SE32  
SE31  
SE30  
SE29  
SE28  
SE25  
SE24  
LCDSE2  
SE23  
SE22  
SE21  
SE20  
SE17  
SE16  
LCDSE1  
SE15  
SE14  
SE13  
SE12  
SE9  
SE8  
LCDSE0  
SE7  
SE6  
SE5  
SE4  
SE3  
SE1  
SE0  
LCDCON  
LCDEN  
WFT  
SLPEN  
BIASMD  
WERR  
LCDA  
CS1  
CS0  
LMUX1 LMUX0  
LP1 LP0  
LCDPS  
WA  
LP3  
LP2  
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used for A/D conversion.  
Note 1: These registers are implemented but unused on 64-pin devices and may be used as general purpose data  
RAM.  
2: These registers are unimplemented on 64-pin devices.  
© 2007 Microchip Technology Inc.  
DS39629C-page 279  
PIC18F6390/6490/8390/8490  
NOTES:  
DS39629C-page 280  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
A complete discussion of device Resets and interrupts  
is available in previous sections of this data sheet.  
23.0 SPECIAL FEATURES  
OF THE CPU  
In addition to their Power-up and Oscillator Start-up  
PIC18F6390/6490/8390/8490 devices include several  
features intended to maximize reliability and minimize  
cost through elimination of external components.  
These are:  
Timers provided for Resets, PIC18F6390/6490/8390/  
8490 devices have a Watchdog Timer, which is either  
permanently enabled via the Configuration bits, or  
software controlled (if configured as disabled).  
• Oscillator Selection  
• Resets:  
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.  
- 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  
All of these features are enabled and configured by  
setting the appropriate Configuration register bits.  
23.1 Configuration Bits  
• ID Locations  
The Configuration bits can be programmed (read as  
0’), or left unprogrammed (read as ‘1’), to select vari-  
ous device configurations. These bits are mapped  
starting at program memory location 300000h.  
• In-Circuit Serial Programming™ (ICSP™)  
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”.  
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.  
TABLE 23-1: 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  
FOSC2  
FOSC1  
FOSC0  
00-- 0111  
---1 1111  
---1 1111  
1--- -0-1  
10-- ---1  
---- ---1  
BORV1  
BORV0 BOREN1 BOREN0 PWRTEN  
WDTPS3 WDTPS2 WDTPS1 WDTPS0 WDTEN  
300005h CONFIG3H MCLRE  
LPT1OSC  
CCP2MX  
STVREN  
CP  
300006h CONFIG4L DEBUG XINST  
300008h CONFIG5L  
3FFFFEh DEVID1  
3FFFFFh DEVID2  
(1)  
DEV2  
DEV10  
DEV1  
DEV9  
DEV0  
DEV8  
REV4  
DEV7  
REV3  
DEV6  
REV2  
DEV5  
REV1  
DEV4  
REV0  
xxxx xxxx  
(1)  
DEV3  
0000 xxxx  
Legend:  
x= unknown, u= unchanged, -= unimplemented, q= value depends on condition.  
Shaded cells are unimplemented, read as ‘0’.  
Note 1: See Register 23-7 for DEVID values. DEVID registers are read-only and cannot be programmed by the user.  
© 2007 Microchip Technology Inc.  
DS39629C-page 281  
PIC18F6390/6490/8390/8490  
REGISTER 23-1: 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  
P = Programmable bit  
U = Unimplemented bit, read as ‘0’  
-n = Value when device is unprogrammed  
u = Unchanged from programmed state  
bit 7  
bit 6  
IESO: Internal/External Oscillator Switchover bit  
1= Oscillator Switchover mode enabled  
0= Oscillator Switchover mode 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’  
FOSC3:FOSC0: 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  
DS39629C-page 282  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
REGISTER 23-2: CONFIG2L: CONFIGURATION REGISTER 2 LOW (BYTE ADDRESS 300002h)  
U-0  
U-0  
U-0  
R/P-1  
R/P-1  
R/P-1  
R/P-1  
R/P-1  
BORV1  
BORV0  
BOREN1(1) BOREN0(1) PWRTEN(1)  
bit 7  
bit 0  
Legend:  
R = Readable bit  
P = Programmable bit  
U = Unimplemented bit, read as ‘0’  
-n = Value when device is unprogrammed  
u = Unchanged from programmed state  
bit 7-5  
bit 4-3  
Unimplemented: Read as ‘0’  
BORV1:BORV0: Brown-out Reset Voltage bits  
11= VBOR set to 2.1V  
10= VBOR set to 2.8V  
01= VBOR set to 4.3V  
00= VBOR set to 4.6V  
bit 2-1  
bit 0  
BOREN1:BOREN0 Brown-out Reset Enable bits(1)  
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)  
10= Brown-out Reset enabled and controlled by software (SBOREN is enabled)  
10= Brown-out Reset disabled in hardware and software  
PWRTEN: Power-up Timer Enable bit(1)  
1= PWRT disabled  
0= PWRT enabled  
Note 1: The Power-up Timer is decoupled from Brown-out Reset, allowing these features to be independently  
controlled.  
© 2007 Microchip Technology Inc.  
DS39629C-page 283  
PIC18F6390/6490/8390/8490  
REGISTER 23-3: 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  
P = Programmable bit  
U = Unimplemented bit, read as ‘0’  
-n = Value when device is unprogrammed  
u = Unchanged from programmed state  
bit 7-5  
bit 4-1  
Unimplemented: Read as ‘0’  
WDTPS3:WDTPS0: 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)  
REGISTER 23-4: CONFIG3H: CONFIGURATION REGISTER 3 HIGH (BYTE ADDRESS 300005h)  
R/P-1  
U-0  
U-0  
U-0  
U-0  
R/P-0  
U-0  
R/P-1  
MCLRE  
LPT1OSC  
CCP2MX  
bit 7  
bit 0  
Legend:  
R = Readable bit  
P = Programmable bit  
U = Unimplemented bit, read as ‘0’  
-n = Value when device is unprogrammed  
u = Unchanged from programmed state  
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 Timer 1 Oscillator Enable bit  
1= Timer1 configured for low-power operation  
0= Timer1 configured for higher power operation  
bit 1  
bit 0  
Unimplemented: Read as ‘0’  
CCP2MX: CCP2 MUX bit  
1= CCP2 input/output is multiplexed with RC1  
0= CCP2 input/output is multiplexed with RE7  
DS39629C-page 284  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
REGISTER 23-5: CONFIG4L: CONFIGURATION REGISTER 4 LOW (BYTE ADDRESS 300006h)  
R/P-1  
R/P-0  
U-0  
U-0  
U-0  
U-0  
U-0  
R/P-1  
DEBUG  
XINST  
STVREN  
bit 7  
bit 0  
Legend:  
R = Readable bit  
P = Programmable bit  
U = Unimplemented bit, read as ‘0’  
-n = Value when device is unprogrammed  
u = Unchanged from programmed state  
bit 7  
bit 6  
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  
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 5-1  
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  
REGISTER 23-6: CONFIG5L: CONFIGURATION REGISTER 5 LOW (BYTE ADDRESS 300008h)  
U-0  
U-0  
U-0  
U-0  
U-0  
U-0  
U-0  
R/C-1  
CP  
bit 7  
bit 0  
Legend:  
R = Readable bit  
C = Clearable bit  
U = Unimplemented bit, read as ‘0’  
-n = Value when device is unprogrammed  
u = Unchanged from programmed state  
bit 7-1  
bit 0  
Unimplemented: Read as ‘0’  
CP: Code Protection bit  
1= Program memory block (000000-003FFFh) not code-protected  
0= Program memory block (000000-003FFFh) code-protected  
© 2007 Microchip Technology Inc.  
DS39629C-page 285  
PIC18F6390/6490/8390/8490  
REGISTER 23-7: DEVID1: DEVICE ID REGISTER 1 FOR PIC18F6390/6490/8390/8490 DEVICES  
R
R
R
R
R
R
R
R
DEV2  
DEV1  
DEV0  
REV4  
REV3  
REV2  
REV1  
REV0  
bit 7  
bit 0  
Legend:  
R = Readable bit  
P = Programmable bit  
U = Unimplemented bit, read as ‘0’  
-n = Value when device is unprogrammed  
u = Unchanged from programmed state  
bit 7-5  
bit 4-0  
DEV2:DEV0: Device ID bits  
100= PIC18F8390/8490  
101= PIC18F6390/6490  
REV4:REV0: Revision ID bits  
These bits are used to indicate the device revision.  
REGISTER 23-8: DEVID2: DEVICE ID REGISTER 2 FOR PIC18F6390/6490/8390/8490 DEVICES  
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  
P = Programmable bit  
U = Unimplemented bit, read as ‘0’  
-n = Value when device is unprogrammed  
u = Unchanged from programmed state  
bit 7-0  
DEV10:DEV3: Device ID bits(1)  
These bits are used with the DEV2:DEV0 bits in the Device ID Register 1 to identify the part number.  
0000 0110= PIC18F6490/8490 devices  
0000 1011= PIC18F6390/8390 devices  
Note 1: These values for DEV10:DEV3 may be shared with other devices. The specific device is always identified  
by using the entire DEV10:DEV0 bit sequence.  
DS39629C-page 286  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
23.2 Watchdog Timer (WDT)  
Note 1: The CLRWDT and SLEEP instructions  
clear the WDT and postscaler counts  
when executed.  
For PIC18F6390/6490/8390/8490 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 multiplexer, controlled by bits in Configu-  
ration Register 2H. Available periods range from 4 ms  
to 134.2 seconds (2.24 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.  
23.2.1  
CONTROL REGISTER  
Register 23-9 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 23-1:  
WDT BLOCK DIAGRAM  
Enable WDT  
SWDTEN  
WDTEN  
INTRC Control  
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  
WDT  
4
WDTPS<3:0>  
Sleep  
© 2007 Microchip Technology Inc.  
DS39629C-page 287  
PIC18F6390/6490/8390/8490  
REGISTER 23-9: 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 23-2: 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  
60  
SWDTEN  
60  
Legend: — = unimplemented, read as ‘0’. Shaded cells are not used by the Watchdog Timer.  
DS39629C-page 288  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
Reset. For wake-ups from Sleep, the INTOSC or  
postscaler clock sources can be selected by setting the  
IRCF2:IRCF0 bits prior to entering Sleep mode.  
23.3 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 INTRC  
oscillator as a clock source until the primary clock  
source is available. It is enabled by setting the IESO  
Configuration bit.  
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.  
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 a  
OST start-up delay; for these, Two-Speed Start-up  
should be disabled.  
23.3.1  
SPECIAL CONSIDERATIONS FOR  
USING TWO-SPEED START-UP  
While using the INTRC oscillator in Two-Speed  
Start-up, the device still obeys the normal command  
sequences for entering power-managed modes,  
including serial SLEEP instructions (refer to  
Section 3.1.2 “Entering Power-Managed Modes”).  
In practice, this means that user code can change  
the SCS1:SCS0 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.  
Because the OSCCON register is cleared on Reset  
events, the INTOSC (or postscaler) clock source is not  
initially available after a Reset event; the INTRC clock  
is used directly at its base frequency. 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, IRCF2:IRCF0, immediately after  
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.  
FIGURE 23-2:  
TIMING TRANSITION FOR TWO-SPEED START-UP (INTOSC TO HSPLL)  
Q3  
Q4  
Q1  
Q2 Q3 Q4 Q1 Q2 Q3  
Q1  
Q2  
INTOSC  
Multiplexer  
OSC1  
(1)  
(1)  
TOST  
TPLL  
1
2
n-1 n  
PLL Clock  
Output  
Clock  
Transition  
CPU Clock  
Peripheral  
Clock  
Program  
Counter  
PC + 4  
PC + 6  
PC  
PC + 2  
OSTS bit Set  
Wake from Interrupt Event  
Note 1: TOST = 1024 TOSC; TPLL = 2 ms (approx). These intervals are not shown to scale.  
© 2007 Microchip Technology Inc.  
DS39629C-page 289  
PIC18F6390/6490/8390/8490  
To use a higher clock speed on wake-up, the INTOSC  
23.4 Fail-Safe Clock Monitor  
or postscaler clock sources can be selected to provide  
a higher clock speed by setting bits, IRCF2:IRCF0,  
immediately after Reset. For wake-ups from Sleep, the  
INTOSC or postscaler clock sources can be selected  
by setting the IRCF2:IRCF0 bits prior to entering Sleep  
mode.  
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 23-3) 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.  
23.4.1  
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  
IRCF2:IRCF0 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 Monitor  
events also reset the WDT and postscaler, allowing  
them to start timing from when execution speed was  
changed and decreasing the likelihood of an erroneous  
time-out.  
FIGURE 23-3:  
FSCM BLOCK DIAGRAM  
Clock Monitor  
Latch (CM)  
(edge-triggered)  
Peripheral  
Clock  
S
C
Q
Q
INTRC  
Source  
÷ 64  
(32 μs)  
488 Hz  
(2.048 ms)  
23.4.2  
EXITING FAIL-SAFE OPERATION  
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 oscil-  
lator mode, such as the OST or PLL timer). The  
INTOSC multiplexer 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 23-4). 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 multiplexer. 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 3.1.2 “Entering Power-Managed  
Modes” and Section 23.3.1 “Special Considerations  
for Using Two-Speed Start-up” for more details.  
DS39629C-page 290  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
FIGURE 23-4:  
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.  
23.4.3  
FSCM INTERRUPTS IN  
23.4.4  
POR OR WAKE FROM SLEEP  
POWER-MANAGED MODES  
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.  
By entering a power-managed mode, the clock  
multiplexer selects the clock source selected by the  
OSCCON register. Fail-Safe Clock Monitoring of  
the power-managed clock source resumes in the  
power-managed mode.  
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 con-  
figured 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.  
If an oscillator failure occurs during power-managed  
operation, the subsequent events depend on whether  
or not the Oscillator Failure Interrupt Flag 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.  
If the interrupt is disabled, the device will not exit the  
power-managed mode on oscillator failure. Instead, the  
device will continue to operate as before, but clocked  
by the INTOSC multiplexer. While in Idle mode, sub-  
sequent interrupts will cause the CPU to begin  
executing instructions while being clocked by the  
INTOSC multiplexer.  
Note:  
The same logic that prevents false  
oscillator failure interrupts on POR, or  
wake from Sleep, will also prevent the  
detection of the oscillator’s failure to start  
at all following 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.  
As noted in Section 23.3.1 “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.  
© 2007 Microchip Technology Inc.  
DS39629C-page 291  
PIC18F6390/6490/8390/8490  
23.5.1  
READING PROGRAM MEMORY  
AND OTHER LOCATIONS  
23.5 Program Verification and  
Code Protection  
The program memory may be read to any location  
using the table read instructions. The Device ID and the  
Configuration registers may be read with the table read  
instructions.  
The overall structure of the code protection on the  
PIC18F6390/6490/8390/8490 Flash devices differs  
from previous PIC18 devices.  
For all devices in the PIC18F6X90/8X90 family, the  
user program memory is made of a single block.  
Figure 23-5 shows the program memory organization  
for individual devices. Code protection for this block is  
controlled by a single bit, CP (CONFIG5L<0>). The CP  
bit inhibits external reads from and writes to the entire  
program memory space. It has no direct effect in  
normal execution mode.  
23.5.2  
CONFIGURATION REGISTER  
PROTECTION  
The Configuration registers can only be written via  
ICSP using an external programmer. No separate  
protection bit is associated with them.  
FIGURE 23-5:  
CODE-PROTECTED PROGRAM MEMORY FOR PIC18F6390/6490/8390/8490  
MEMORY SIZE/DEVICE  
Block Code Protection  
8 Kbytes  
Address  
16 Kbytes  
Address  
Controlled By:  
(PIC18F6390/8390) Range (PIC18F6490/8490) Range  
Program Memory 000000h Program Memory 000000h  
CP, EBTR  
Block  
001FFFh  
Block  
003FFFh  
002000h  
004000h  
Unimplemented  
Unimplemented  
Read ‘0’s  
Read ‘0’s  
(Unimplemented Memory Space)  
1FFFFFh  
1FFFFFh  
TABLE 23-3: SUMMARY OF CODE PROTECTION REGISTERS  
File Name  
300008h CONFIG5L  
Bit 7  
Bit 6  
Bit 5  
Bit 4  
Bit 3  
Bit 2  
Bit 1  
Bit 0  
CP  
Legend: Shaded cells are unimplemented.  
DS39629C-page 292  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
23.6 ID Locations  
23.8 In-Circuit Debugger  
Eight memory locations (200000h-200007h) are  
designated as ID locations, where the user can store  
checksum or other code identification numbers. These  
locations are readable during normal execution through  
the TBLRD instruction. During program/verify, these  
locations are readable and writable. The ID locations  
can be read when the device is code-protected.  
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 23-4 shows which resources are  
required by the background debugger.  
TABLE 23-4: DEBUGGER RESOURCES  
23.7  
In-Circuit Serial Programming  
I/O pins:  
RB6, RB7  
2 levels  
PIC18F6390/6490/8390/8490 microcontrollers 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.  
Stack:  
Program Memory:  
Data Memory:  
512 bytes  
10 bytes  
To use the In-Circuit Debugger function of the micro-  
controller, the design must implement In-Circuit Serial  
Programming connections to 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.  
© 2007 Microchip Technology Inc.  
DS39629C-page 293  
PIC18F6390/6490/8390/8490  
NOTES:  
DS39629C-page 294  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
The literal instructions may use some of the following  
operands:  
24.0 INSTRUCTION SET SUMMARY  
PIC18FXX90 devices incorporate the standard set of  
seventy-five PIC18 core instructions, as well as an  
extended set of 8 new instructions for the optimization  
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 ‘—’)  
24.1 Standard Instruction Set  
The control instructions may use some of the following  
operands:  
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 24-2 lists  
byte-oriented, bit-oriented, literal and control  
operations. Table 24-1 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  
register is to be used by the instruction. The destination  
designator, ‘d’, specifies where the result of the opera-  
tion 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 24-1 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 24-2,  
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 24.1.1 “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 desig-  
nator, ‘f’, represents the number of the file in which the  
bit is located.  
© 2007 Microchip Technology Inc.  
DS39629C-page 295  
PIC18F6390/6490/8390/8490  
TABLE 24-1: 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  
BSR  
Bit address within an 8-bit file register (0 to 7).  
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
}
[text]  
(text)  
[expr]<n>  
Indicates an indexed address.  
The contents of text.  
Specifies bit nof the register indicated by the pointer expr.  
Assigned to.  
< >  
Register bit field.  
In the set of.  
italics  
User-defined term (font is Courier New).  
DS39629C-page 296  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
FIGURE 24-1:  
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
MOVFF MYREG1, MYREG2  
OPCODE  
f (Source FILE #)  
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, GOTOand 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  
15  
11 10  
0
0
BRA MYFUNC  
BC MYFUNC  
OPCODE  
n<10:0> (literal)  
n<7:0> (literal)  
8 7  
OPCODE  
© 2007 Microchip Technology Inc.  
DS39629C-page 297  
PIC18F6390/6490/8390/8490  
TABLE 24-2: PIC18FXXXX INSTRUCTION SET  
16-Bit Instruction Word  
MSb LSb  
Mnemonic,  
Operands  
Status  
Affected  
Description  
Cycles  
Notes  
BYTE-ORIENTED OPERATIONS  
ADDWF f, d, a Add WREG and f  
ADDWFC f, d, a Add WREG and Carry bit to f  
1
0010 01da ffff ffff C, DC, Z, OV, N 1, 2  
0010 00da ffff ffff C, DC, Z, OV, N 1, 2  
1
1
1
1
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 an 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 the 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.  
5: If the table write starts the write cycle to internal memory, the write will continue until terminated.  
DS39629C-page 298  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
TABLE 24-2: 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, d, 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 an 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 the 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.  
5: If the table write starts the write cycle to internal memory, the write will continue until terminated.  
© 2007 Microchip Technology Inc.  
DS39629C-page 299  
PIC18F6390/6490/8390/8490  
TABLE 24-2: 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 an 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 the 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.  
5: If the table write starts the write cycle to internal memory, the write will continue until terminated.  
DS39629C-page 300  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
24.1.1  
STANDARD INSTRUCTION SET  
ADD Literal to W  
ADDLW  
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.  
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 24.2.3 “Byte-Oriented and  
Bit-Oriented Instructions in Indexed  
Literal Offset Mode” for details.  
Example:  
ADDLW  
15h  
Before Instruction  
10h  
After Instruction  
25h  
W
=
Words:  
Cycles:  
1
1
W
=
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).  
© 2007 Microchip Technology Inc.  
DS39629C-page 301  
PIC18F6390/6490/8390/8490  
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  
Words:  
1
1
Cycles:  
Q Cycle Activity:  
Q1  
location ‘f’.  
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.  
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 24.2.3 “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
=
=
DS39629C-page 302  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
ANDWF  
AND W with f  
BC  
Branch if Carry  
Syntax:  
ANDWF  
f {,d {,a}}  
Syntax:  
BC  
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.  
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 24.2.3 “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:  
1
1
Cycles:  
No  
No  
No  
No  
operation  
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
=
17h  
C2h  
PC  
=
address (HERE)  
REG  
=
After Instruction  
After Instruction  
If Carry  
PC  
If Carry  
PC  
=
=
=
=
1;  
W
REG  
=
=
02h  
C2h  
address (HERE + 12)  
0;  
address (HERE + 2)  
© 2007 Microchip Technology Inc.  
DS39629C-page 303  
PIC18F6390/6490/8390/8490  
BCF  
Bit Clear f  
BN  
Branch if Negative  
Syntax:  
BCF f, b {,a}  
Syntax:  
BN  
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.  
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 24.2.3 “Byte-Oriented and  
Bit-Oriented Instructions in Indexed  
Literal Offset Mode” for details.  
Words:  
Cycles:  
1
1(2)  
Q Cycle Activity:  
If Jump:  
Q1  
Words:  
Cycles:  
1
1
Q2  
Q3  
Q4  
Decode  
Read literal  
‘n’  
Process  
Data  
Write to PC  
Q Cycle Activity:  
Q1  
Q2  
Q3  
Q4  
No  
No  
No  
No  
Decode  
Read  
register ‘f’  
Process  
Data  
Write  
register ‘f’  
operation  
operation  
operation  
operation  
If No Jump:  
Q1  
Q2  
Q3  
Q4  
Example:  
BCF  
FLAG_REG, 7, 0  
Decode  
Read literal  
‘n’  
Process  
Data  
No  
operation  
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)  
DS39629C-page 304  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
BNC  
Branch if Not Carry  
BNN  
Branch if Not Negative  
Syntax:  
BNC  
n
Syntax:  
BNN  
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  
instruction, the new address will be  
PC + 2 + 2n. This instruction is then a  
two-cycle instruction.  
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.  
Words:  
Cycles:  
1
Words:  
Cycles:  
1
1(2)  
1(2)  
Q Cycle Activity:  
If Jump:  
Q1  
Q Cycle Activity:  
If Jump:  
Q1  
Q2  
Q3  
Q4  
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)  
© 2007 Microchip Technology Inc.  
DS39629C-page 305  
PIC18F6390/6490/8390/8490  
BNOV  
Branch if Not Overflow  
BNZ  
Branch if Not Zero  
Syntax:  
BNOV  
n
Syntax:  
BNZ  
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:  
Q1  
Q Cycle Activity:  
If Jump:  
Q1  
Q2  
Q3  
Q4  
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)  
DS39629C-page 306  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
BRA  
Unconditional Branch  
BSF  
Bit Set f  
Syntax:  
BRA  
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.  
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 24.2.3 “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  
Words:  
Cycles:  
1
1
No  
operation  
No  
operation  
No  
operation  
No  
operation  
Q Cycle Activity:  
Q1  
Example:  
HERE  
BRA Jump  
Q2  
Q3  
Q4  
Decode  
Read  
register ‘f’  
Process  
Data  
Write  
register ‘f’  
Before Instruction  
PC  
=
=
address (HERE)  
address (Jump)  
After Instruction  
PC  
Example:  
BSF  
FLAG_REG, 7, 1  
0Ah  
8Ah  
Before Instruction  
FLAG_REG  
After Instruction  
FLAG_REG  
=
=
© 2007 Microchip Technology Inc.  
DS39629C-page 307  
PIC18F6390/6490/8390/8490  
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.  
If ‘a’ is ‘0’, the Access Bank is selected. If  
‘a’ is ‘1’, the BSR is used to select the  
GPR bank.  
If ‘a’ is ‘0’ and the extended instruction set  
is enabled, this instruction operates in  
Indexed Literal Offset Addressing  
mode whenever f 95 (5Fh).  
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 24.2.3 “Byte-Oriented and  
Bit-Oriented Instructions in Indexed  
Literal Offset Mode” for details.  
See Section 24.2.3 “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  
Note: 3 cycles if skip and followed  
by a 2-word instruction.  
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)  
DS39629C-page 308  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
BTG  
Bit Toggle f  
BOV  
Branch if Overflow  
Syntax:  
BTG f, b {,a}  
Syntax:  
BOV  
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.  
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 24.2.3 “Byte-Oriented and  
Bit-Oriented Instructions in Indexed  
Literal Offset Mode” for details.  
Words:  
Cycles:  
1
1(2)  
Q Cycle Activity:  
If Jump:  
Q1  
Words:  
Cycles:  
1
1
Q2  
Q3  
Q4  
Decode  
Read literal  
‘n’  
Process  
Data  
Write to PC  
Q Cycle Activity:  
Q1  
No  
No  
No  
No  
operation  
Q2  
Q3  
Q4  
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:  
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)  
© 2007 Microchip Technology Inc.  
DS39629C-page 309  
PIC18F6390/6490/8390/8490  
BZ  
Branch if Zero  
CALL  
Subroutine Call  
Syntax:  
BZ  
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.  
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.  
Status Affected:  
None  
Encoding:  
1st word (k<7:0>)  
2nd word(k<19:8>)  
1110  
1111  
110s  
k kkk  
kkkk  
kkkk  
7
0
8
k
kkk kkkk  
19  
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  
Words:  
Cycles:  
1
1(2)  
Q Cycle Activity:  
If Jump:  
Q1  
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.  
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  
Q2  
Q3  
Q4  
Q Cycle Activity:  
Q1  
Decode  
Read literal  
‘n’  
Process  
Data  
No  
operation  
Q2  
Q3  
Q4  
Decode  
Read literal Push PC to Read literal  
‘k’<7:0>,  
stack  
‘k’<19:8>,  
Write to PC  
Example:  
HERE  
BZ Jump  
No  
operation  
No  
operation  
No  
operation  
No  
operation  
Before Instruction  
PC  
=
address (HERE)  
After Instruction  
If Zero  
PC  
If Zero  
PC  
=
=
=
=
1;  
Example:  
HERE  
CALL THERE,1  
address (Jump)  
Before Instruction  
PC  
After Instruction  
0;  
address (HERE + 2)  
=
address (HERE)  
PC  
=
address (THERE)  
TOS  
WS  
=
=
=
address (HERE + 4)  
W
BSR  
STATUS  
BSRS  
STATUSS=  
DS39629C-page 310  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
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  
postscaler 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.  
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 24.2.3 “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  
No  
Process  
Data  
No  
operation  
operation  
Words:  
Cycles:  
1
1
Example:  
CLRWDT  
Q Cycle Activity:  
Q1  
Before Instruction  
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  
© 2007 Microchip Technology Inc.  
DS39629C-page 311  
PIC18F6390/6490/8390/8490  
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 ‘1’, the result is  
stored in W. If ‘d’ is ‘0’, 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.  
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 24.2.3 “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 ‘0’, the BSR is used to select the  
GPR bank.  
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 24.2.3 “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:  
REG  
W
=
=
13h  
ECh  
Q1  
No  
Q2  
No  
Q3  
No  
Q4  
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)  
DS39629C-page 312  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
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.  
If ‘a’ is ‘0’, the Access Bank is selected.  
If ‘a’ is ‘1’, the BSR is used to select the  
GPR bank.  
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 24.2.3 “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  
register ‘f’  
Process  
Data  
No  
operation  
1(2)  
Note: 3 cycles if skip and followed  
If skip:  
Q1  
by a 2-word instruction.  
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  
Q2  
No  
Q3  
No  
Q4  
No  
No  
operation  
No  
operation  
No  
operation  
No  
operation  
No  
operation  
operation  
operation  
operation  
No  
No  
No  
No  
If skip and followed by 2-word instruction:  
operation  
operation  
operation  
operation  
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  
NGREATER  
GREATER  
CPFSGT REG, 0  
:
:
?
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)  
© 2007 Microchip Technology Inc.  
DS39629C-page 313  
PIC18F6390/6490/8390/8490  
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.  
0000  
0000  
0000  
0111  
Description:  
DAWadjusts 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 24.2.3 “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  
Q2  
Q3  
Q4  
Decode  
Read  
register W  
Process  
Data  
Write  
W
Q Cycle Activity:  
Q1  
Q2  
Q3  
Q4  
Example 1:  
Decode  
Read  
register ‘f’  
Process  
Data  
Write to  
destination  
DAW  
Before Instruction  
W
=
=
=
A5h  
0
0
Example:  
DECF  
CNT,  
1, 0  
C
Before Instruction  
DC  
CNT  
Z
After Instruction  
=
01h  
0
After Instruction  
=
W
=
=
=
05h  
1
0
C
DC  
CNT  
Z
=
=
00h  
1
Example 2:  
Before Instruction  
W
=
=
=
CEh  
0
0
C
DC  
After Instruction  
W
=
=
=
34h  
1
0
C
DC  
DS39629C-page 314  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
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.  
If ‘a’ is ‘0’, the Access Bank is selected.  
If ‘a’ is ‘1’, the BSR is used to select the  
GPR bank.  
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 24.2.3 “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 24.2.3 “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  
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;  
Address (CONTINUE)  
0;  
Address (HERE + 2)  
If CNT  
=
=
=
TEMP  
If TEMP  
PC  
If TEMP  
PC  
=
=
=
=
TEMP – 1,  
0;  
Address (ZERO)  
0;  
Address (NZERO)  
PC  
If CNT  
PC  
© 2007 Microchip Technology Inc.  
DS39629C-page 315  
PIC18F6390/6490/8390/8490  
GOTO  
Unconditional Branch  
INCF  
Increment f  
Syntax:  
GOTO  
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:  
Status Affected:  
Encoding:  
C, DC, N, OV, Z  
1st word (k<7:0>)  
2nd word(k<19:8>)  
1110  
1111  
1111  
kkk  
k kkk  
kkkk  
kkkk  
kkkk  
7
0
8
0010  
10da  
ffff  
ffff  
k
19  
Description:  
The contents of register ‘f’ are  
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.  
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.  
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 24.2.3 “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  
Words:  
Cycles:  
1
1
No  
operation  
No  
No  
No  
operation  
operation  
operation  
Q Cycle Activity:  
Q1  
Example:  
GOTO THERE  
Q2  
Q3  
Q4  
Decode  
Read  
register ‘f’  
Process  
Data  
Write to  
destination  
After Instruction  
PC  
=
Address (THERE)  
Example:  
INCF  
CNT, 1, 0  
Before Instruction  
CNT  
Z
=
FFh  
0
=
=
=
C
?
DC  
?
After Instruction  
CNT  
Z
=
00h  
1
=
=
=
C
1
DC  
1
DS39629C-page 316  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
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.  
If ‘a’ is ‘0’, the Access Bank is selected.  
If ‘a’ is ‘1’, the BSR is used to select the  
GPR bank.  
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 24.2.3 “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 24.2.3 “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  
Note: 3 cycles if skip and followed  
by a 2-word instruction.  
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)  
© 2007 Microchip Technology Inc.  
DS39629C-page 317  
PIC18F6390/6490/8390/8490  
IORLW  
Inclusive OR Literal with W  
IORWF  
Inclusive OR W with f  
Syntax:  
IORLW  
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.  
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 24.2.3 “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
=
DS39629C-page 318  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
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  
k kkk  
k kkk  
11  
kkkk  
0101  
00da  
ffff  
ffff  
7
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.  
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 24.2.3 “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  
© 2007 Microchip Technology Inc.  
DS39629C-page 319  
PIC18F6390/6490/8390/8490  
MOVFF  
Move f to f  
MOVLB  
Move Literal to Low Nibble in BSR  
Syntax:  
MOVFF f ,f  
Syntax:  
MOVLW 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:  
The eight-bit literal ‘k’ is loaded into the  
Bank Select Register (BSR). The value  
of BSR<7:4> always remains ‘0’,  
1st word (source)  
2nd word (destin.)  
1100  
1111  
ffff  
ffff  
ffff  
ffff  
ffffs  
ffffd  
regardless of the value of k :k .  
7
4
Description:  
The contents of source register ‘f ’ are  
s
moved to destination register ‘f ’.  
Words:  
Cycles:  
1
1
d
Location of source ‘f ’ can be anywhere  
s
in the 4096-byte data space (000h to  
Q Cycle Activity:  
Q1  
FFFh) and location of destination ‘f ’  
can also be anywhere from 000h to  
FFFh.  
d
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  
DS39629C-page 320  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
MOVLW  
Move Literal to W  
MOVWF  
Move W to f  
Syntax:  
MOVLW  
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.  
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 24.2.3 “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  
© 2007 Microchip Technology Inc.  
DS39629C-page 321  
PIC18F6390/6490/8390/8490  
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 the 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  
W is unchanged.  
None of the Status flags are affected.  
unchanged.  
Note that neither Overflow nor Carry is  
possible in this operation. A Zero result  
is possible but not detected.  
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.  
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.  
Q Cycle Activity:  
Q1  
Q2  
Q3  
Q4  
If ‘a’ is ‘0’ and the extended  
Decode  
Read  
literal ‘k’  
Process  
Data  
Write  
instruction set is enabled, this  
instruction operates in Indexed Literal  
Offset Addressing mode whenever  
f 95 (5Fh). See Section 24.2.3  
“Byte-Oriented and Bit-Oriented  
Instructions in Indexed Literal Offset  
Mode” for details.  
registers  
PRODH:  
PRODL  
Example:  
MULLW  
0C4h  
E2h  
?
?
Before Instruction  
W
PRODH  
PRODL  
=
=
=
Words:  
Cycles:  
1
1
After Instruction  
Q Cycle Activity:  
Q1  
W
PRODH  
PRODL  
=
=
=
E2h  
ADh  
08h  
Q2  
Q3  
Q4  
Decode  
Read  
register ‘f’  
Process  
Data  
Write  
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  
DS39629C-page 322  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
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.  
Q Cycle Activity:  
Q1  
Q2  
Q3  
No  
operation  
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 24.2.3 “Byte-Oriented and  
Bit-Oriented Instructions in Indexed  
Literal Offset Mode” for details.  
Decode  
No  
operation  
No  
operation  
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]  
=
© 2007 Microchip Technology Inc.  
DS39629C-page 323  
PIC18F6390/6490/8390/8490  
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.  
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.  
This instruction is provided to enable  
the user to properly manage the return  
stack to incorporate a software 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)  
DS39629C-page 324  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
RCALL  
Relative Call  
RESET  
Reset  
Syntax:  
RCALL  
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  
No  
No  
Reset  
operation  
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)  
© 2007 Microchip Technology Inc.  
DS39629C-page 325  
PIC18F6390/6490/8390/8490  
RETFIE  
Return from Interrupt  
RETLW  
Return Literal to W  
Syntax:  
RETFIE {s}  
Syntax:  
RETLW 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  
operation  
No  
operation  
No  
operation  
Words:  
Cycles:  
1
2
Q Cycle Activity:  
Q1  
Example:  
Q2  
Q3  
Q4  
CALL TABLE ; W contains table  
; offset value  
Decode  
No  
No  
POP PC  
; W now has  
operation  
operation  
from stack  
; table value  
Set GIEH or  
GIEL  
:
TABLE  
ADDWF PCL  
No  
No  
No  
No  
operation  
; W = offset  
; Begin table  
;
operation  
operation  
operation  
RETLW k0  
RETLW k1  
Example:  
RETFIE  
1
:
:
After Interrupt  
RETLW kn  
; End of table  
PC  
=
=
=
=
=
TOS  
WS  
W
Before Instruction  
BSR  
STATUS  
GIE/GIEH, PEIE/GIEL  
BSRS  
W
=
07h  
STATUSS  
1
After Instruction  
W
=
value of kn  
DS39629C-page 326  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
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.  
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 24.2.3  
“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  
from stack  
register f  
C
No  
No  
No  
No  
operation  
operation  
operation  
operation  
Words:  
Cycles:  
1
1
Q Cycle Activity:  
Q1  
Example:  
RETURN  
Q2  
Read  
register ‘f’  
Q3  
Q4  
After Interrupt  
Decode  
Process  
Data  
Write to  
destination  
PC = TOS  
Example:  
RLCF  
REG, 0, 0  
Before Instruction  
REG  
C
=
=
1110 0110  
0
After Instruction  
REG  
W
C
=
=
=
1110 0110  
1100 1100  
1
© 2007 Microchip Technology Inc.  
DS39629C-page 327  
PIC18F6390/6490/8390/8490  
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.  
If ‘a’ is ‘0’, the Access Bank is selected.  
If ‘a’ is ‘1’, the BSR is used to select the  
GPR bank.  
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 24.2.3 “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 24.2.3 “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
DS39629C-page 328  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
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.  
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 24.2.3 “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.  
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 24.2.3 “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  
© 2007 Microchip Technology Inc.  
DS39629C-page 329  
PIC18F6390/6490/8390/8490  
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. 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.  
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 24.2.3 “Byte-Oriented and  
Bit-Oriented Instructions in Indexed  
Literal Offset Mode” for details.  
Q Cycle Activity:  
Q1  
Q2  
Q3  
Q4  
Decode  
No  
operation  
Process  
Data  
Go to  
Sleep  
Words:  
Cycles:  
1
1
Example:  
SLEEP  
Before Instruction  
Q Cycle Activity:  
Q1  
TO  
PD  
=
=
?
?
Q2  
Q3  
Q4  
After Instruction  
Decode  
Read  
register ‘f’  
Process  
Data  
Write to  
destination  
TO  
PD  
=
=
1 †  
0
Example 1:  
SUBFWB  
REG, 1, 0  
Before Instruction  
If WDT causes wake-up, this bit is cleared.  
REG  
W
=
=
=
3
2
1
C
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
DS39629C-page 330  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
SUBLW  
Subtract W from Literal  
SUBWF  
Subtract W from f  
Syntax:  
SUBLW  
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  
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).  
Words:  
Cycles:  
1
1
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.  
Decode  
Read  
literal ‘k’  
Process  
Data  
Write to W  
Example 1:  
SUBLW 02h  
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 24.2.3 “Byte-Oriented and  
Bit-Oriented Instructions in Indexed  
Literal Offset Mode” for details.  
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  
W
C
=
=
02h  
?
Q2  
Q3  
Q4  
Decode  
Read  
register ‘f’  
Process  
Data  
Write to  
destination  
After Instruction  
W
C
Z
=
00h  
=
=
=
1
1
0
; result is zero  
Example 1:  
SUBWF  
REG, 1, 0  
Before Instruction  
N
REG  
W
=
=
=
3
2
?
Example 3:  
Before Instruction  
SUBLW 02h  
C
After Instruction  
W
C
=
=
03h  
?
REG  
W
C
Z
N
=
1
2
1
0
0
=
=
=
=
After Instruction  
; result is positive  
W
C
Z
=
FFh; (2’s complement)  
=
=
=
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
© 2007 Microchip Technology Inc.  
DS39629C-page 331  
PIC18F6390/6490/8390/8490  
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.  
If ‘a’ is ‘0’, the Access Bank is selected.  
If ‘a’ is ‘1’, the BSR is used to select the  
GPR bank.  
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 24.2.3 “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 24.2.3 “Byte-Oriented and  
Bit-Oriented Instructions in Indexed  
Literal Offset Mode” for details.  
Words:  
Cycles:  
1
1
Words:  
1
1
Cycles:  
Q Cycle Activity:  
Q1  
Q Cycle Activity:  
Q1  
Q2  
Read  
register ‘f’  
Q3  
Process  
Data  
Q4  
Decode  
Write to  
Q2  
Q3  
Q4  
destination  
Decode  
Read  
register ‘f’  
Process  
Data  
Write to  
Example 1:  
SUBWFB REG, 1, 0  
destination  
Before Instruction  
REG  
W
C
=
=
=
19h  
0Dh  
1
(0001 1001)  
(0000 1101)  
Example:  
SWAPF  
REG, 1, 0  
Before Instruction  
After Instruction  
REG  
After Instruction  
=
53h  
35h  
REG  
W
C
=
0Ch  
0Dh  
1
(0000 1011)  
(0000 1101)  
=
=
=
=
REG  
=
Z
0
N
0
; result is positive  
Example 2:  
SUBWFB REG, 0, 0  
Before Instruction  
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  
DS39629C-page 332  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
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  
=
=
=
=
0AAh  
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)  
© 2007 Microchip Technology Inc.  
DS39629C-page 333  
PIC18F6390/6490/8390/8490  
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+*,  
=
FFh  
After Instructions (table write completion)  
TABLAT  
TBLPTR  
HOLDING REGISTER  
(00A356h)  
=
=
55h  
00A357h  
=
55h  
Example 2:  
TBLWT +*;  
Before Instruction  
(TBLPTR) + 1 TBLPTR,  
TABLAT  
TBLPTR  
=
=
34h  
01389Ah  
(TABLAT) Holding Register  
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 the  
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 6.0 “Flash Program  
Memory” for additional details on  
=
=
FFh  
34h  
Note:  
The table write (TBLWT) instructions are  
not available in user mode in  
PIC18F6X90/8X90 devices, as these  
devices are standard Flash parts without  
an external bus interface.  
programming Flash memory.)  
The TBLPTR (a 21-bit pointer) points to  
each byte in the program memory. TBLPTR  
has a 2-MBtye 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 )  
DS39629C-page 334  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
TSTFSZ  
Test f, Skip if 0  
XORLW  
Exclusive OR Literal with W  
Syntax:  
TSTFSZ f {,a}  
Syntax:  
XORLW 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.  
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 24.2.3 “Byte-Oriented and  
Bit-Oriented Instructions in Indexed  
Literal Offset Mode” for details.  
Decode  
Read  
literal ‘k’  
Process  
Data  
Write to W  
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)  
© 2007 Microchip Technology Inc.  
DS39629C-page 335  
PIC18F6390/6490/8390/8490  
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.  
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 24.2.3 “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  
DS39629C-page 336  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
A summary of the instructions in the extended instruc-  
tion set is provided in Table 24-3. Detailed descriptions  
are provided in Section 24.2.2 “Extended Instruction  
Set”. The opcode field descriptions in Table 24-1 apply  
to both the standard and extended PIC18 instruction  
sets.  
24.2 Extended Instruction Set  
In addition to the standard 75 instructions of the PIC18  
instruction set, PIC18FXX90 devices also provide an  
optional extension to the core CPU functionality. The  
added features include eight additional instructions that  
augment Indirect and Indexed Addressing operations  
and the implementation of Indexed Literal Offset  
Addressing mode 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 pro-  
vided as a reference for users who may be  
reviewing code that has been generated  
by a compiler.  
The additional features are disabled 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.  
24.2.1  
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. 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 24.2.3.1 “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 24-3: 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  
© 2007 Microchip Technology Inc.  
DS39629C-page 337  
PIC18F6390/6490/8390/8490  
24.2.2  
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,  
PC = (TOS)  
Operation:  
FSR(f) + k FSR(f)  
Status Affected:  
Encoding:  
None  
Status Affected: None  
1110  
1000  
ffkk  
kkkk  
Encoding:  
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:  
The instruction takes two cycles to  
execute; a NOPis performed during the  
second cycle.  
Q Cycle Activity:  
Q1  
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.  
Words:  
Cycles:  
1
2
Example:  
ADDFSR 2, 23h  
Before Instruction  
FSR2  
After Instruction  
FSR2  
=
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 syntax then becomes: {label} instruction argument(s).  
DS39629C-page 338  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
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:  
Status Affected:  
Encoding:  
None  
1st word (source)  
2nd word (destin.)  
1110  
1111  
1011  
ffff  
0zzz  
ffff  
zzzz  
ffff  
s
0000  
0000  
0001  
0100  
d
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 of  
s
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  
© 2007 Microchip Technology Inc.  
DS39629C-page 339  
PIC18F6390/6490/8390/8490  
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 – 1FSR2  
Operation:  
((FSR2) + z ) ((FSR2) + z )  
s d  
Status Affected:  
Encoding:  
None  
Status Affected: None  
Encoding:  
1111  
1010  
kkkk  
kkkk  
1st word (source)  
2nd word (dest.)  
Description  
1110  
1111  
1011  
xxxx  
1zzz  
xzzz  
zzzz  
zzzz  
s
d
Description:  
The 8-bit literal ‘k’ is written to the data  
memory address specified by FSR2. FSR2 is  
decremented by 1 after the operation.  
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.  
Words:  
Cycles:  
1
1
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).  
Q Cycle Activity:  
Q1  
Q2  
Q3  
Q4  
Decode  
Read ‘k’  
Process  
data  
Write to  
destination  
The MOVSSinstruction cannot use the  
PCL, TOSU, TOSH or TOSL as the  
destination register.  
If the resultant source address points to  
an Indirect Addressing register, the  
value returned will be 00h. If the  
Example:  
PUSHL 08h  
Before Instruction  
resultant destination address points to  
an Indirect Addressing register, the  
instruction will execute as a NOP.  
FSR2H:FSR2L  
=
=
01ECh  
Memory (01ECh)  
00h  
After Instruction  
Words:  
2
2
FSR2H:FSR2L  
Memory (01ECh)  
=
=
01EBh  
08h  
Cycles:  
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  
Contents  
of 85h  
Contents  
of 86h  
=
=
=
80h  
33h  
11h  
After Instruction  
FSR2  
=
=
=
80h  
33h  
33h  
Contents  
of 85h  
Contents  
of 86h  
DS39629C-page 340  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
SUBFSR  
Subtract Literal from FSR  
SUBULNK  
Subtract Literal from FSR2 and Return  
Syntax:  
SUBFSR f, k  
Syntax:  
SUBULNK k  
Operands:  
0 k 63  
Operands:  
Operation:  
0 k 63  
f [ 0, 1, 2 ]  
FSR2 – k FSR2,  
(TOS) PC  
Operation:  
FSRf – k FSRf  
Status Affected:  
Encoding:  
None  
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
The instruction takes two cycles to execute;  
a NOPis performed during the second cycle.  
Cycles:  
This may be thought of as a special case of  
the SUBFSRinstruction, where f = 3 (binary  
11’); it operates only on FSR2.  
Q Cycle Activity:  
Q1  
Q2  
Q3  
Q4  
Decode  
Read  
register ‘f’  
Process  
Data  
Write to  
destination  
Words:  
1
2
Cycles:  
Q Cycle Activity:  
Q1  
Example:  
SUBFSR 2, 23h  
03FFh  
Q2  
Q3  
Q4  
Before Instruction  
FSR2  
After Instruction  
FSR2  
Decode  
Read  
register ‘f’  
Process  
Data  
Write to  
destination  
=
No  
Operation  
No  
Operation  
No  
Operation  
No  
Operation  
=
03DCh  
Example:  
SUBULNK 23h  
Before Instruction  
FSR2  
PC  
=
=
03FFh  
0100h  
After Instruction  
FSR2  
PC  
=
=
03DCh  
(TOS)  
© 2007 Microchip Technology Inc.  
DS39629C-page 341  
PIC18F6390/6490/8390/8490  
24.2.3  
BYTE-ORIENTED AND  
BIT-ORIENTED INSTRUCTIONS IN  
INDEXED LITERAL OFFSET MODE  
24.2.3.1  
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 brackets, will generate an  
error in the MPASM™ Assembler.  
Note:  
Enabling the PIC18 instruction set  
extension 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 mode (Section 5.6.1  
“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 instructions  
– 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 24.2.3.1  
“Extended Instruction Syntax with Standard PIC18  
Commands”).  
24.2.4  
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.  
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.  
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  
programming 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.  
When porting an application to the PIC18FXX90, 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 applications that  
heavily use the Access Bank will most likely not benefit  
from using the extended instruction set.  
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  
conditions shown in the examples are applicable to all  
instructions of these types.  
DS39629C-page 342  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
ADD W to Indexed  
(Indexed Literal Offset mode)  
Bit Set Indexed  
BSF  
ADDWF  
(Indexed Literal Offset mode)  
Syntax:  
ADDWF  
[k] {,d}  
Syntax:  
BSF [k], b  
Operands:  
0 k 95  
d [0,1]  
a = 0  
Operands:  
0 f 95  
0 b 7  
a = 0  
Operation:  
(W) + ((FSR2) + k) dest  
Operation:  
1 ((FSR2 + k))<b>  
Status Affected: N, OV, C, DC, Z  
Status Affected:  
Encoding:  
None  
Encoding:  
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  
Words:  
Cycles:  
1
1
Q2  
Q3  
Q4  
Decode  
Read  
register ‘f’  
Process  
Data  
Write to  
destination  
Q Cycle Activity:  
Q1  
Q2  
Q3  
Q4  
Example:  
BSF  
[FLAG_OFST], 7  
Decode  
Read ‘k’  
Process  
Data  
Write to  
destination  
Before Instruction  
FLAG_OFST  
FSR2  
=
=
0Ah  
0A00h  
Example:  
ADDWF  
[OFST],0  
Contents  
of 0A0Ah  
Before Instruction  
=
55h  
D5h  
W
OFST  
FSR2  
=
=
=
17h  
After Instruction  
Contents  
2Ch  
0A00h  
of 0A0Ah  
=
Contents  
of 0A2Ch  
=
20h  
After Instruction  
W
=
=
37h  
20h  
Contents  
of 0A2Ch  
Set Indexed  
(Indexed Literal Offset mode)  
SETF  
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  
© 2007 Microchip Technology Inc.  
DS39629C-page 343  
PIC18F6390/6490/8390/8490  
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:  
24.2.5  
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 of the PIC18FXX90 family of devices. 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 develop-  
ment, MPLAB IDE will automatically set default Config-  
uration bits for that device. The default setting for the  
XINST Configuration bit 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.  
• A directive in the source code  
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.  
DS39629C-page 344  
© 2007 Microchip Technology Inc.  
PIC18FXX90  
25.1 MPLAB Integrated Development  
Environment Software  
25.0 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  
• A single graphical interface to all debugging tools  
- Simulator  
- MPLAB C18 and MPLAB C30 C Compilers  
- MPLINKTM Object Linker/  
MPLIBTM Object Librarian  
- Programmer (sold separately)  
- Emulator (sold separately)  
- In-Circuit Debugger (sold separately)  
• A full-featured editor with color-coded context  
• A multiple project manager  
- MPLAB ASM30 Assembler/Linker/Library  
• Simulators  
- MPLAB SIM Software Simulator  
• Emulators  
• Customizable data windows with direct edit of  
contents  
- MPLAB ICE 2000 In-Circuit Emulator  
- MPLAB REAL ICE™ In-Circuit Emulator  
• In-Circuit Debugger  
• High-level source code debugging  
• Visual device initializer for easy register  
initialization  
- MPLAB ICD 2  
• Mouse over variable inspection  
• Device Programmers  
• Drag and drop variables from source to watch  
windows  
- PICSTART® Plus Development Programmer  
- MPLAB PM3 Device Programmer  
- PICkit™ 2 Development Programmer  
• Extensive on-line help  
• Integration of select third party tools, such as  
HI-TECH Software C Compilers and IAR  
C Compilers  
• Low-Cost Demonstration and Development  
Boards and Evaluation Kits  
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.  
© 2007 Microchip Technology Inc.  
DS39629C-page 345  
PIC18FXX90  
25.2 MPASM Assembler  
25.5 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:  
• Integration into MPLAB IDE projects  
• Support for the entire dsPIC30F instruction set  
• Support for fixed-point and floating-point data  
• Command line interface  
• User-defined macros to streamline  
assembly code  
• Rich directive set  
• Conditional assembly for multi-purpose  
source files  
• Flexible macro language  
• MPLAB IDE compatibility  
• Directives that allow complete control over the  
assembly process  
25.6 MPLAB SIM Software Simulator  
25.3 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 microcontrol-  
lers and the dsPIC30 and dsPIC33 family of digital sig-  
nal 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.  
25.4 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  
DS39629C-page 346  
© 2007 Microchip Technology Inc.  
PIC18FXX90  
25.7 MPLAB ICE 2000  
High-Performance  
25.9 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.  
25.10 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.  
25.8 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.  
© 2007 Microchip Technology Inc.  
DS39629C-page 347  
PIC18FXX90  
25.11 PICSTART Plus Development  
Programmer  
25.13 Demonstration, Development and  
Evaluation Boards  
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.  
25.12 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.  
DS39629C-page 348  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
26.0 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 MCLR/VPP/RG5 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 MCLR/VPP/  
RG5 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.  
© 2007 Microchip Technology Inc.  
DS39629C-page 349  
PIC18F6390/6490/8390/8490  
FIGURE 26-1:  
PIC18F6390/6490/8390/8490 VOLTAGE-FREQUENCY GRAPH (INDUSTRIAL)  
6.0V  
5.5V  
5.0V  
4.5V  
4.0V  
PIC18FX390/X490  
4.2V  
3.5V  
3.0V  
2.5V  
2.0V  
40 MHz  
Frequency  
FIGURE 26-2:  
PIC18LF6390/6490/8390/8490 VOLTAGE-FREQUENCY GRAPH (INDUSTRIAL)  
6.0V  
5.5V  
5.0V  
4.5V  
4.0V  
PIC18LFX390/X490  
4.2V  
3.5V  
3.0V  
2.5V  
2.0V  
40 MHz  
4 MHz  
Frequency  
FMAX = (16.36 MHz/V) (VDDAPPMIN – 2.0V) + 4 MHz  
Note: VDDAPPMIN is the minimum voltage of the PIC® device in the application.  
DS39629C-page 350  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
26.1 DC Characteristics: Supply Voltage  
PIC18F6390/6490/8390/8490 (Industrial)  
PIC18LF6390/6490/8390/8490 (Industrial)  
PIC18LF6390/6490/8390/8490  
Standard Operating Conditions (unless otherwise stated)  
Operating temperature -40°C TA +85°C for industrial  
(Industrial)  
PIC18F6390/6490/8390/8490  
Standard Operating Conditions (unless otherwise stated)  
(Industrial)  
Operating temperature  
-40°C TA +85°C for industrial  
Param  
No.  
Symbol  
Characteristic  
Supply Voltage  
Min Typ Max Units  
Conditions  
D001  
VDD  
PIC18LF6390/6490/8390/8490 2.0  
PIC18F6390/6490/8390/8490 4.2  
5.5  
5.5  
V
V
V
HS, XT, RC and LP Oscillator modes  
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 on Power-on Reset for  
details  
D004  
SVDD  
VBOR  
VDD Rise Rate  
to Ensure Internal Power-on  
Reset Signal  
0.05  
V/ms See section on Power-on Reset for  
details  
Brown-out Reset Voltage  
PIC18LF6390/6490/8390/8490  
BORV1:BORV0 = 11  
BORV1:BORV0 = 10  
All devices  
D005  
D005  
2.00 2.05 2.16  
2.65 2.79 2.93  
V
V
BORV1:BORV0 = 01  
BORV1:BORV0 = 00  
4.11 4.33 4.55  
4.36 4.59 4.82  
V
V
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.  
© 2007 Microchip Technology Inc.  
DS39629C-page 351  
PIC18F6390/6490/8390/8490  
26.2 DC Characteristics: Power-Down and Supply Current  
PIC18F6390/6490/8390/8490 (Industrial)  
PIC18LF6390/6490/8390/8490 (Industrial)  
PIC18LF6390/6490/8390/8490  
Standard Operating Conditions (unless otherwise stated)  
Operating temperature -40°C TA +85°C for industrial  
(Industrial)  
PIC18F6390/6490/8390/8490  
Standard Operating Conditions (unless otherwise stated)  
(Industrial)  
Operating temperature  
-40°C TA +85°C for industrial  
Param  
Device  
No.  
Typ Max Units  
Conditions  
(1)  
Power-Down Current (IPD)  
PIC18LF6390/6490/8390/8490 0.1  
1
1
μA  
μA  
μA  
μA  
μA  
μA  
μA  
μA  
μA  
-40°C  
+25°C  
VDD = 2.0V  
(Sleep mode)  
0.1  
0.2  
5
+85°C  
-40°C  
+25°C  
+85°C  
-40°C  
+25°C  
+85°C  
PIC18LF6390/6490/8390/8490 0.1  
2
VDD = 3.0V  
(Sleep mode)  
0.1  
2
0.3  
8
All devices 0.1  
2.0  
2.0  
15  
VDD = 5.0V  
(Sleep mode)  
0.1  
0.4  
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: Low-power Timer1 oscillator 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.  
DS39629C-page 352  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
26.2 DC Characteristics: Power-Down and Supply Current  
PIC18F6390/6490/8390/8490 (Industrial)  
PIC18LF6390/6490/8390/8490 (Industrial) (Continued)  
PIC18LF6390/6490/8390/8490  
Standard Operating Conditions (unless otherwise stated)  
(Industrial)  
Operating temperature  
-40°C TA +85°C for industrial  
PIC18F6390/6490/8390/8490  
Standard Operating Conditions (unless otherwise stated)  
(Industrial)  
Operating temperature  
Typ Max Units  
-40°C TA +85°C for industrial  
Param  
Device  
No.  
Conditions  
(2)  
Supply Current (IDD)  
PIC18LF6390/6490/8390/8490 12  
26  
24  
μA  
μA  
-40°C  
12  
+25°C  
+85°C  
-40°C  
+25°C  
+85°C  
-40°C  
+25°C  
+85°C  
-40°C  
+25°C  
+85°C  
-40°C  
+25°C  
+85°C  
-40°C  
+25°C  
+85°C  
VDD = 2.0V  
VDD = 3.0V  
VDD = 5.0V  
VDD = 2.0V  
VDD = 3.0V  
VDD = 5.0V  
12  
23  
μA  
PIC18LF6390/6490/8390/8490 32  
50  
μA  
FOSC = 31 kHz  
(RC_RUN mode,  
INTRC source)  
27  
48  
μA  
22  
46  
μA  
All devices 84  
134  
128  
128  
.8  
μA  
82  
μA  
72  
μA  
PIC18LF6390/6490/8390/8490 .26  
mA  
mA  
mA  
mA  
mA  
mA  
mA  
mA  
mA  
.26  
.8  
.26  
.8  
PIC18LF6390/6490/8390/8490 .48  
1.04  
.96  
.88  
1.84  
1.76  
1.68  
FOSC = 1 MHz  
(RC_RUN mode,  
INTOSC source)  
.44  
.48  
All devices .88  
.88  
.8  
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: Low-power Timer1 oscillator 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.  
© 2007 Microchip Technology Inc.  
DS39629C-page 353  
PIC18F6390/6490/8390/8490  
26.2 DC Characteristics: Power-Down and Supply Current  
PIC18F6390/6490/8390/8490 (Industrial)  
PIC18LF6390/6490/8390/8490 (Industrial) (Continued)  
PIC18LF6390/6490/8390/8490  
Standard Operating Conditions (unless otherwise stated)  
Operating temperature -40°C TA +85°C for industrial  
(Industrial)  
PIC18F6390/6490/8390/8490  
Standard Operating Conditions (unless otherwise stated)  
(Industrial)  
Operating temperature  
-40°C TA +85°C for industrial  
Param  
Device  
No.  
Typ Max Units  
Conditions  
(2)  
Supply Current (IDD)  
PIC18LF6390/6490/8390/8490 0.6  
1.7  
1.6  
1.5  
2.4  
2.4  
2.4  
4.2  
4
mA  
mA  
mA  
mA  
mA  
mA  
mA  
mA  
mA  
μA  
-40°C  
0.6  
+25°C  
+85°C  
-40°C  
+25°C  
+85°C  
-40°C  
+25°C  
+85°C  
-40°C  
+25°C  
+85°C  
-40°C  
+25°C  
+85°C  
-40°C  
+25°C  
+85°C  
VDD = 2.0V  
VDD = 3.0V  
VDD = 5.0V  
VDD = 2.0V  
VDD = 3.0V  
VDD = 5.0V  
0.6  
PIC18LF6390/6490/8390/8490 1.0  
FOSC = 4 MHz  
(RC_RUN mode,  
INTOSC source)  
1.0  
1.0  
All devices 2.0  
2.0  
2.0  
3.8  
6.4  
6.4  
8.8  
8.8  
8.8  
12  
PIC18LF6390/6490/8390/8490 2.3  
2.5  
μA  
2.9  
μA  
PIC18LF6390/6490/8390/8490 3.6  
μA  
FOSC = 31 kHz  
(RC_IDLE mode,  
INTRC source)  
3.8  
μA  
4.6  
μA  
All devices 7.4  
16  
μA  
7.8  
9.1  
16  
μA  
29  
μA  
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: Low-power Timer1 oscillator 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.  
DS39629C-page 354  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
26.2 DC Characteristics: Power-Down and Supply Current  
PIC18F6390/6490/8390/8490 (Industrial)  
PIC18LF6390/6490/8390/8490 (Industrial) (Continued)  
PIC18LF6390/6490/8390/8490  
Standard Operating Conditions (unless otherwise stated)  
(Industrial)  
Operating temperature  
-40°C TA +85°C for industrial  
PIC18F6390/6490/8390/8490  
Standard Operating Conditions (unless otherwise stated)  
(Industrial)  
Operating temperature  
Typ Max Units  
-40°C TA +85°C for industrial  
Param  
Device  
No.  
Conditions  
(2)  
Supply Current (IDD)  
PIC18LF6390/6490/8390/8490 132  
400  
400  
400  
600  
600  
600  
1
μA  
μA  
-40°C  
140  
+25°C  
+85°C  
-40°C  
+25°C  
+85°C  
-40°C  
+25°C  
+85°C  
-40°C  
+25°C  
+85°C  
-40°C  
+25°C  
+85°C  
-40°C  
+25°C  
+85°C  
VDD = 2.0V  
VDD = 3.0V  
VDD = 5.0V  
VDD = 2.0V  
VDD = 3.0V  
VDD = 5.0V  
152  
μA  
PIC18LF6390/6490/8390/8490 200  
μA  
FOSC = 1 MHz  
(RC_IDLE mode,  
INTOSC source)  
216  
μA  
252  
μA  
All devices 0.40  
mA  
mA  
mA  
μA  
0.42  
1
0.44  
1
PIC18LF6390/6490/8390/8490 272  
700  
700  
700  
1
280  
μA  
288  
μA  
PIC18LF6390/6490/8390/8490 0.416  
mA  
mA  
mA  
mA  
mA  
mA  
FOSC = 4 MHz  
(RC_IDLE mode,  
INTOSC source)  
0.432  
0.464  
1
1
All devices  
.8  
.9  
.9  
1.6  
1.6  
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: Low-power Timer1 oscillator 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.  
© 2007 Microchip Technology Inc.  
DS39629C-page 355  
PIC18F6390/6490/8390/8490  
26.2 DC Characteristics: Power-Down and Supply Current  
PIC18F6390/6490/8390/8490 (Industrial)  
PIC18LF6390/6490/8390/8490 (Industrial) (Continued)  
PIC18LF6390/6490/8390/8490  
Standard Operating Conditions (unless otherwise stated)  
Operating temperature -40°C TA +85°C for industrial  
(Industrial)  
PIC18F6390/6490/8390/8490  
Standard Operating Conditions (unless otherwise stated)  
(Industrial)  
Operating temperature  
-40°C TA +85°C for industrial  
Param  
Device  
No.  
Typ Max Units  
Conditions  
(2)  
Supply Current (IDD)  
PIC18LF6390/6490/8390/8490 250  
500  
500  
500  
650  
650  
650  
1.6  
1.5  
1.4  
2.0  
2.0  
2.0  
3.0  
3.0  
3.0  
6.0  
6.0  
6.0  
35  
μA  
μA  
-40°C  
260  
+25°C  
+85°C  
-40°C  
+25°C  
+85°C  
-40°C  
+25°C  
+85°C  
-40°C  
+25°C  
+85°C  
-40°C  
+25°C  
+85°C  
-40°C  
+25°C  
+85°C  
-40°C  
+25°C  
+85°C  
-40°C  
+25°C  
+85°C  
VDD = 2.0V  
VDD = 3.0V  
VDD = 5.0V  
VDD = 2.0V  
VDD = 3.0V  
VDD = 5.0V  
VDD = 4.2V  
VDD = 5.0V  
250  
μA  
PIC18LF6390/6490/8390/8490 550  
μA  
FOSC = 1 MHZ  
(PRI_RUN,  
EC oscillator)  
480  
μA  
460  
μA  
All devices 1.2  
mA  
mA  
mA  
mA  
mA  
mA  
mA  
mA  
mA  
mA  
mA  
mA  
mA  
mA  
mA  
mA  
mA  
mA  
1.1  
1.0  
PIC18LF6390/6490/8390/8490 0.72  
0.74  
0.74  
PIC18LF6390/6490/8390/8490 1.3  
FOSC = 4 MHz  
(PRI_RUN,  
EC oscillator)  
1.3  
1.3  
All devices 2.7  
2.6  
2.5  
All devices 15  
16  
35  
FOSC = 40 MHZ  
(PRI_RUN,  
EC oscillator)  
16  
35  
All devices 21  
40  
21  
21  
40  
40  
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: Low-power Timer1 oscillator 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.  
DS39629C-page 356  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
26.2 DC Characteristics: Power-Down and Supply Current  
PIC18F6390/6490/8390/8490 (Industrial)  
PIC18LF6390/6490/8390/8490 (Industrial) (Continued)  
PIC18LF6390/6490/8390/8490  
Standard Operating Conditions (unless otherwise stated)  
(Industrial)  
Operating temperature  
-40°C TA +85°C for industrial  
PIC18F6390/6490/8390/8490  
Standard Operating Conditions (unless otherwise stated)  
(Industrial)  
Operating temperature  
Typ Max Units  
-40°C TA +85°C for industrial  
Param  
Device  
No.  
Conditions  
(2)  
Supply Current (IDD)  
All devices 7.5  
16  
15  
14  
21  
20  
19  
35  
35  
35  
40  
40  
40  
mA  
mA  
mA  
mA  
mA  
mA  
mA  
mA  
mA  
mA  
mA  
mA  
-40°C  
FOSC = 4 MHZ.  
16 MHz internal  
(PRI_RUN HS+PLL)  
7.4  
+25°C  
+85°C  
-40°C  
+25°C  
+85°C  
-40°C  
+25°C  
+85°C  
-40°C  
+25°C  
+85°C  
VDD = 4.2V  
VDD = 5.0V  
VDD = 4.2V  
VDD = 5.0V  
7.3  
All devices 10  
FOSC = 4 MHZ,  
16 MHz internal  
(PRI_RUN HS+PLL)  
10  
9.7  
All devices 17  
FOSC = 10 MHZ,  
40 MHz internal  
(PRI_RUN HS+PLL)  
17  
17  
All devices 23  
FOSC = 10 MHZ,  
40 MHz internal  
(PRI_RUN HS+PLL)  
23  
23  
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: Low-power Timer1 oscillator 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.  
© 2007 Microchip Technology Inc.  
DS39629C-page 357  
PIC18F6390/6490/8390/8490  
26.2 DC Characteristics: Power-Down and Supply Current  
PIC18F6390/6490/8390/8490 (Industrial)  
PIC18LF6390/6490/8390/8490 (Industrial) (Continued)  
PIC18LF6390/6490/8390/8490  
Standard Operating Conditions (unless otherwise stated)  
Operating temperature -40°C TA +85°C for industrial  
(Industrial)  
PIC18F6390/6490/8390/8490  
Standard Operating Conditions (unless otherwise stated)  
(Industrial)  
Operating temperature  
-40°C TA +85°C for industrial  
Param  
Device  
No.  
Typ Max Units  
Conditions  
(2)  
Supply Current (IDD)  
PIC18LF6390/6490/8390/8490 59  
117  
108  
104  
243  
225  
216  
432  
405  
387  
428  
405  
387  
810  
765  
729  
1.35  
1.26  
1.17  
14.4  
14.4  
14.4  
16.2  
16.2  
16.2  
μA  
μA  
μA  
μA  
μA  
μA  
μA  
μA  
μA  
μA  
μA  
μA  
μA  
μA  
μA  
mA  
mA  
mA  
mA  
mA  
mA  
mA  
mA  
mA  
-40°C  
59  
+25°C  
+85°C  
-40°C  
+25°C  
+85°C  
-40°C  
+25°C  
+85°C  
-40°C  
+25°C  
+85°C  
-40°C  
+25°C  
+85°C  
-40°C  
+25°C  
+85°C  
-40°C  
+25°C  
+85°C  
-40°C  
+25°C  
+85°C  
VDD = 2.0V  
VDD = 3.0V  
VDD = 5.0V  
VDD = 2.0V  
VDD = 3.0V  
VDD = 5.0V  
VDD = 4.2V  
VDD = 5.0V  
63  
PIC18LF6390/6490/8390/8490 108  
FOSC = 1 MHz  
(PRI_IDLE mode,  
EC oscillator)  
108  
117  
All devices 270  
216  
270  
PIC18LF6390/6490/8390/8490 234  
230  
243  
PIC18LF6390/6490/8390/8490 378  
FOSC = 4 MHz  
(PRI_IDLE mode,  
EC oscillator)  
387  
405  
All devices  
.8  
.8  
.8  
All devices 5.4  
5.6  
FOSC = 40 MHz  
(PRI_IDLE mode,  
EC oscillator)  
5.9  
All devices 7.3  
8.2  
7.5  
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: Low-power Timer1 oscillator 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.  
DS39629C-page 358  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
26.2 DC Characteristics: Power-Down and Supply Current  
PIC18F6390/6490/8390/8490 (Industrial)  
PIC18LF6390/6490/8390/8490 (Industrial) (Continued)  
PIC18LF6390/6490/8390/8490  
Standard Operating Conditions (unless otherwise stated)  
(Industrial)  
Operating temperature  
-40°C TA +85°C for industrial  
PIC18F6390/6490/8390/8490  
Standard Operating Conditions (unless otherwise stated)  
(Industrial)  
Operating temperature  
Typ Max Units  
-40°C TA +85°C for industrial  
Param  
Device  
No.  
Conditions  
(2)  
Supply Current (IDD)  
PIC18LF6390/6490/8390/8490 13  
40  
40  
40  
70  
70  
70  
150  
150  
150  
15  
15  
18  
30  
30  
35  
80  
80  
85  
μA  
μA  
μA  
μA  
μA  
μA  
μA  
μA  
μA  
μA  
μA  
μA  
μA  
μA  
μA  
μA  
μA  
μA  
-40°C  
14  
+25°C  
+80°C  
-40°C  
+25°C  
+80°C  
-40°C  
+25°C  
+80°C  
-40°C  
+25°C  
+80°C  
-40°C  
+25°C  
+80°C  
-40°C  
+25°C  
+80°C  
VDD = 2.0V  
VDD = 3.0V  
VDD = 5.0V  
VDD = 2.0V  
VDD = 3.0V  
VDD = 5.0V  
16  
PIC18LF6390/6490/8390/8490 34  
FOSC = 32 kHz  
31  
(SEC_RUN mode,  
(4)  
Timer1 as clock)  
28  
All devices 72  
65  
59  
PIC18LF6390/6490/8390/8490 5.5  
5.8  
6.1  
PIC18LF6390/6490/8390/8490 8.2  
FOSC = 32 kHz  
8.6  
(SEC_IDLE mode,  
(4)  
Timer1 as clock)  
8.8  
All devices 13  
13  
13  
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: Low-power Timer1 oscillator 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.  
© 2007 Microchip Technology Inc.  
DS39629C-page 359  
PIC18F6390/6490/8390/8490  
26.2 DC Characteristics: Power-Down and Supply Current  
PIC18F6390/6490/8390/8490 (Industrial)  
PIC18LF6390/6490/8390/8490 (Industrial) (Continued)  
PIC18LF6390/6490/8390/8490  
Standard Operating Conditions (unless otherwise stated)  
Operating temperature -40°C TA +85°C for industrial  
(Industrial)  
PIC18F6390/6490/8390/8490  
Standard Operating Conditions (unless otherwise stated)  
(Industrial)  
Operating temperature  
-40°C TA +85°C for industrial  
Param  
Device  
No.  
Typ Max Units  
Conditions  
Module Differential Currents (ΔIWDT, ΔIBOR, ΔILVD, ΔILCD, ΔIOSCB, ΔIAD)  
D022  
(ΔIWDT)  
Watchdog Timer 1.7  
4
4
μA  
μA  
μA  
μA  
μA  
μA  
μA  
μA  
μA  
μA  
-40°C  
+25°C  
+85°C  
-40°C  
+25°C  
+85°C  
-40°C  
+25°C  
+85°C  
2.1  
VDD = 2.0V  
VDD = 3.0V  
VDD = 5.0V  
2.6  
5
2.2  
6
2.4  
6
2.8  
7
2.9  
10  
10  
13  
50  
3.1  
3.3  
D022A  
(ΔIBOR)  
Brown-out Reset 17  
-40°C to  
+85°C  
VDD = 3.0V  
VDD = 5.0V  
VDD = 2.0V  
VDD = 3.0V  
VDD = 5.0V  
42  
60  
38  
40  
45  
μA  
μA  
μA  
μA  
-40°C to  
+85°C  
D022B  
(ΔILVD)  
High/Low-Voltage Detect 14  
-40°C to  
+85°C  
18  
21  
-40°C to  
+85°C  
-40°C to  
+85°C  
D024  
(ΔILCD)  
LCD Module 1.5  
3
3
μA  
μA  
μA  
μA  
μA  
μA  
μA  
μA  
μA  
-40°C  
+25°C  
+85°C  
-40°C  
+25°C  
+85°C  
-40°C  
+25°C  
+85°C  
LCD on INTRC clock,  
LCD segments enabled.  
1.5  
1.7  
2.2  
2.5  
2.7  
6.1  
6.5  
7.2  
VDD = 2.0V  
VDD = 3.0V  
VDD = 5.0V  
4
5
LCD on INTRC clock,  
LCD segments enabled.  
5
6
10  
10  
10  
LCD on INTRC clock,  
LCD segments enabled.  
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: Low-power Timer1 oscillator 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.  
DS39629C-page 360  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
26.2 DC Characteristics: Power-Down and Supply Current  
PIC18F6390/6490/8390/8490 (Industrial)  
PIC18LF6390/6490/8390/8490 (Industrial) (Continued)  
PIC18LF6390/6490/8390/8490  
Standard Operating Conditions (unless otherwise stated)  
(Industrial)  
Operating temperature  
-40°C TA +85°C for industrial  
PIC18F6390/6490/8390/8490  
Standard Operating Conditions (unless otherwise stated)  
(Industrial)  
Operating temperature  
Typ Max Units  
-40°C TA +85°C for industrial  
Param  
Device  
No.  
Conditions  
Module Differential Currents (ΔIWDT, ΔIBOR, ΔILVD, ΔILCD, ΔIOSCB, ΔIAD)  
D025  
(ΔIOSCB)  
Timer1 Oscillator 1.0  
3.5  
3.5  
4.5  
4.5  
4.5  
5.5  
6.0  
6.0  
7.0  
3.0  
4.0  
8.0  
μA  
μA  
μA  
μA  
μA  
μA  
μA  
μA  
μA  
μA  
μA  
μA  
-10°C  
+25°C  
+70°C  
-10°C  
+25°C  
+70°C  
-10°C  
+25°C  
+70°C  
(4)  
(4)  
(4)  
1.1  
VDD = 2.0V  
VDD = 3.0V  
VDD = 5.0V  
32 kHz on Timer1  
32 kHz on Timer1  
32 kHz on Timer1  
1.1  
1.2  
1.3  
1.2  
1.8  
1.9  
1.9  
D026  
(ΔIAD)  
A/D Converter 1.0  
VDD = 2.0V  
VDD = 3.0V  
VDD = 5.0V  
A/D on, not converting  
1.0  
1.0  
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: Low-power Timer1 oscillator 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.  
© 2007 Microchip Technology Inc.  
DS39629C-page 361  
PIC18F6390/6490/8390/8490  
26.3 DC Characteristics: PIC18F6390/6490/8390/8490 (Industrial)  
PIC18LF6390/6490/8390/8490 (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  
VIH  
IIL  
Input Low Voltage  
I/O Ports:  
with TTL Buffer  
D030  
D030A  
D031  
VSS  
0.15 VDD  
0.8  
V
V
VDD < 4.5V  
4.5V VDD 5.5V  
with Schmitt Trigger Buffer  
RC3 and RC4  
VSS  
VSS  
0.2 VDD  
0.3 VDD  
V
V
D032  
MCLR  
VSS  
VSS  
0.2 VDD  
0.3 VDD  
V
V
D032A  
OSC1 and T1OSI  
LP, XT, HS, HSPLL  
modes(1)  
EC mode(1)  
D033  
OSC1  
VSS  
0.2 VDD  
V
Input High Voltage  
I/O Ports:  
D040  
D040A  
D041  
with TTL Buffer  
0.25 VDD + 0.8V  
2.0  
VDD  
VDD  
V
V
VDD < 4.5V  
4.5V VDD 5.5V  
with Schmitt Trigger Buffer  
RC3 and RC4  
0.8 VDD  
0.7 VDD  
VDD  
VDD  
V
V
D042  
MCLR  
0.8 VDD  
0.7 VDD  
VDD  
VDD  
V
V
D042A  
OSC1 and T1OSI  
LP, XT, HS, HSPLL  
modes(1)  
EC mode(1)  
D043  
D060  
OSC1  
0.8 VDD  
VDD  
V
Input Leakage Current(2,3)  
I/O Ports  
±1  
μA VSS VPIN VDD,  
Pin at hi-impedance  
D061  
D063  
MCLR  
±5  
±5  
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.  
4: Parameter is characterized but not tested.  
DS39629C-page 362  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
26.3 DC Characteristics: PIC18F6390/6490/8390/8490 (Industrial)  
PIC18LF6390/6490/8390/8490 (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  
VOH  
VOD  
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  
(RC, RCIO, EC, ECIO modes)  
Output High Voltage(3)  
IOL = 1.6 mA, VDD = 4.5V,  
-40°C to +85°C  
D090  
D092  
D150  
I/O Ports  
VDD – 0.7  
VDD – 0.7  
V
V
V
IOH = -3.0 mA, VDD = 4.5V,  
-40°C to +85°C  
OSC2/CLKO  
(RC, RCIO, EC, ECIO modes)  
IOH = -1.3 mA, VDD = 4.5V,  
-40°C to +85°C  
Open-Drain High Voltage  
8.5  
RA4 pin  
Capacitive Loading Specs  
on Output Pins  
D100(4) 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  
SCL, SDA  
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.  
4: Parameter is characterized but not tested.  
© 2007 Microchip Technology Inc.  
DS39629C-page 363  
PIC18F6390/6490/8390/8490  
TABLE 26-1: 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  
Program Flash Memory  
D110  
D113  
VPP  
Voltage on MCLR/VPP pin  
10.0  
12.0  
1
V
IDDP  
Supply Current during  
Programming  
mA  
D130  
D131  
EP  
Cell Endurance  
VDD for Read  
1K  
E/W -40°C to +85°C  
VPR  
VMIN  
5.5  
V
VMIN = Minimum operating  
voltage  
D132  
VIE  
VDD for Block Erase  
2.75  
2.75  
5.5  
5.5  
V
V
Using ICSP™ port  
Using ICSP port  
D132A VIW  
VDD for Externally Timed Erase  
or Write  
D132B VPEW VDD for Self-Timed Write  
VMIN  
5.5  
V
VMIN = Minimum operating  
voltage  
D133  
TIE  
ICSP Block Erase Cycle Time  
2
4
ms VDD > 4.5V  
ms VDD > 4.5V  
D133A TIW  
ICSP Erase or Write Cycle Time  
(externally timed)  
D133A TIW  
Self-Timed Write Cycle Time  
2
ms  
D134 TRETD Characteristic Retention  
40  
100  
Year Provided no other  
specifications are violated  
Data in “Typ” column is at 5.0V, 25°C unless otherwise stated. These parameters are for design guidance  
only and are not tested.  
DS39629C-page 364  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
TABLE 26-2: 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  
*
These parameters are characterized but not tested.  
Note 1: Response time measured with one comparator input at (VDD – 1.5)/2, while the other input transitions  
from VSS to VDD.  
TABLE 26-3: 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 CVR3:CVR0 transitions from ‘0000’ to ‘1111’.  
© 2007 Microchip Technology Inc.  
DS39629C-page 365  
PIC18F6390/6490/8390/8490  
FIGURE 26-3:  
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 26-4: 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  
Transition High-to-Low  
HLVDL<3:0> = 0000  
HLVDL<3:0> = 0001  
HLVDL<3:0> = 0010  
HLVDL<3:0> = 0011  
HLVDL<3:0> = 0100  
HLVDL<3:0> = 0101  
HLVDL<3:0> = 0110  
HLVDL<3:0> = 0111  
HLVDL<3:0> = 1000  
HLVDL<3:0> = 1001  
HLVDL<3:0> = 1010  
HLVDL<3:0> = 1011  
HLVDL<3:0> = 1100  
HLVDL<3:0> = 1101  
HLVDL<3:0> = 1110  
HLVDL<3:0> = 1111  
2.06  
2.12  
2.24  
2.32  
2.47  
2.65  
2.74  
2.96  
3.22  
3.37  
3.52  
3.70  
3.90  
4.11  
4.36  
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  
1.2  
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
V
D423 VBG Band Gap Reference  
Voltage Value  
HLVD input external.  
Production tested at TAMB = 25°C. Specifications over temperature limits ensured by characterization.  
DS39629C-page 366  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
26.4 AC (Timing) Characteristics  
26.4.1 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  
© 2007 Microchip Technology Inc.  
DS39629C-page 367  
PIC18F6390/6490/8390/8490  
26.4.2  
TIMING CONDITIONS  
Note:  
Because of space limitations, the generic  
terms “PIC18FXXXX” and “PIC18LFXXXX”  
are used throughout this section to refer to  
the PIC18F6390/6490/8390/8490 and  
PIC18LF6390/6490/8390/8490 families of  
devices specifically and only those devices.  
The temperature and voltages specified in Table 26-5  
apply to all timing specifications unless otherwise  
noted. Figure 26-4 specifies the load conditions for the  
timing specifications.  
TABLE 26-5: TEMPERATURE AND VOLTAGE SPECIFICATIONS – AC  
Standard Operating Conditions (unless otherwise stated)  
Operating temperature  
-40°C TA +85°C for industrial  
AC CHARACTERISTICS  
Operating voltage VDD range as described in DC spec Section 26.1 and  
Section 26.3.  
LF parts operate for industrial temperatures only.  
FIGURE 26-4:  
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  
DS39629C-page 368  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
26.4.3  
TIMING DIAGRAMS AND SPECIFICATIONS  
FIGURE 26-5:  
EXTERNAL CLOCK TIMING (ALL MODES EXCEPT PLL)  
Q4  
Q1  
1
Q2  
Q3  
Q4  
Q1  
OSC1  
CLKO  
3
4
3
4
2
TABLE 26-6: EXTERNAL CLOCK TIMING REQUIREMENTS  
Param.  
Symbol  
Characteristic  
Min  
Max  
Units  
Conditions  
No.  
1A  
FOSC  
External CLKI Frequency(1)  
DC  
DC  
DC  
DC  
0.1  
4
1
20  
31.25  
4
MHz XT, RC Oscillator mode  
MHz HS Oscillator mode  
kHz LP Oscillator mode  
MHz RC Oscillator mode  
MHz XT Oscillator mode  
MHz HS Oscillator mode  
kHz LP Oscillator mode  
Oscillator Frequency(1)  
4
20  
200  
5
1
TOSC  
External CLKI Period(1)  
Oscillator Period(1)  
1000  
50  
ns  
ns  
μs  
ns  
μs  
ns  
ns  
μs  
ns  
ns  
μs  
ns  
ns  
ns  
ns  
XT, RC Oscillator mode  
HS Oscillator mode  
LP Oscillator mode  
RC Oscillator mode  
XT Oscillator mode  
HS Oscillator mode  
HS Oscillator mode  
LP Oscillator mode  
TCY = 4/FOSC  
32  
250  
250  
100  
50  
1
250  
250  
5
2
3
TCY  
Instruction Cycle Time(1)  
100  
30  
TOSL,  
TOSH  
External Clock in (OSC1)  
High or Low Time  
XT Oscillator mode  
LP Oscillator mode  
HS Oscillator mode  
XT Oscillator mode  
LP Oscillator mode  
HS Oscillator mode  
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.  
© 2007 Microchip Technology Inc.  
DS39629C-page 369  
PIC18F6390/6490/8390/8490  
TABLE 26-7: PLL CLOCK TIMING SPECIFICATIONS (VDD = 4.2V TO 5.5V)  
Param  
Sym  
Characteristic  
Min  
Typ†  
Max  
Units Conditions  
No.  
F10  
FOSC Oscillator Frequency Range  
4
10  
40  
2
MHz HS mode only  
F11  
F12  
F13  
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 26-8: AC CHARACTERISTICS: INTERNAL RC ACCURACY  
PIC18LF6390/6490/8390/8490 (INDUSTRIAL)  
PIC18F6390/6490/8390/8490 (INDUSTRIAL)  
PIC18LF6390/6490/8390/8490  
Standard Operating Conditions (unless otherwise stated)  
(Industrial)  
Operating temperature  
-40°C TA +85°C for industrial  
PIC18F6390/6490/8390/8490  
Standard Operating Conditions (unless otherwise stated)  
(Industrial)  
Operating temperature -40°C TA +85°C for industrial  
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  
PIC18LF6390/6490/8390/8490  
PIC18F6390/6490/8390/8490  
INTRC Accuracy @ Freq = 31 kHz  
-2  
-5  
+/-1  
2
5
%
%
%
%
%
%
+25°C  
VDD = 2.7-3.3V  
-10°C to +85°C VDD = 2.7-3.3V  
-40°C to +85°C VDD = 2.7-3.3V  
-10  
-2  
+/-1  
+/-1  
10  
2
+25°C  
VDD = 4.5-5.5V  
-5  
5
-10°C to +85°C VDD = 4.5-5.5V  
-40°C to +85°C VDD = 4.5-5.5V  
-10  
(2)  
+/-1  
10  
PIC18LF6390/6490/8390/8490 26.562  
35.938  
35.938  
kHz  
kHz  
-40°C to +85°C VDD = 2.7-3.3V  
-40°C to +85°C VDD = 4.5-5.5V  
PIC18F6390/6490/8390/8490 26.562  
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.  
2: INTRC frequency after calibration.  
DS39629C-page 370  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
FIGURE 26-6:  
CLKO AND I/O TIMING  
Q1  
Q2  
Q3  
Q4  
OSC1  
11  
10  
CLKO  
13  
12  
19  
18  
14  
16  
I/O pin  
(Input)  
15  
17  
I/O pin  
(Output)  
New Value  
Old Value  
20, 21  
Refer to Figure 26-4 for load conditions.  
Note:  
TABLE 26-9: 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 (Note 1)  
ns (Note 1)  
ns (Note 1)  
ns (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 (Note 1)  
0.25 TCY + 25  
ns (Note 1)  
ns (Note 1)  
ns  
0
150  
TOSH2IOI OSC1(Q2 cycle) to  
Port Input Invalid  
PIC18FXXXX  
PIC18LFXXXX  
100  
200  
ns  
ns VDD = 2.0V  
(I/O in hold time)  
19  
TIOV2OSH Port Input Valid to OSC1(I/O in setup time)  
0
10  
10  
25  
60  
25  
60  
ns  
20  
TIOR  
Port Output Rise Time  
Port Output Fall Time  
PIC18FXXXX  
PIC18LFXXXX  
PIC18FXXXX  
PIC18LFXXXX  
ns  
20A  
21  
ns VDD = 2.0V  
TIOF  
ns  
21A  
22†  
23†  
ns VDD = 2.0V  
TINP  
INTx pin High or Low Time  
TCY  
TCY  
ns  
ns  
TRBP  
RB7:RB4 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.  
© 2007 Microchip Technology Inc.  
DS39629C-page 371  
PIC18F6390/6490/8390/8490  
FIGURE 26-7:  
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 26-4 for load conditions.  
FIGURE 26-8:  
BROWN-OUT RESET TIMING  
BVDD  
VDD  
35  
VBGAP = 1.2V  
VIRVST  
Enable Internal  
Reference Voltage  
Internal Reference  
Voltage Stable  
36  
TABLE 26-10: 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  
Oscillator Start-up Timer Period  
1024 TOSC  
55.5  
65.5  
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  
Low-Voltage Detect Pulse Width  
CPU Start-up Time  
200  
10  
1
μs  
μs  
VDD VLVD  
TIOBST Time for INTRC Block to Stabilize  
ms  
DS39629C-page 372  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
FIGURE 26-9:  
TIMER0 AND TIMER1 EXTERNAL CLOCK TIMINGS  
T0CKI  
41  
40  
42  
T1OSO/T13CKI  
46  
45  
47  
48  
TMR0 or  
TMR1  
Note:  
Refer to Figure 26-4 for load conditions.  
TABLE 26-11: 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  
© 2007 Microchip Technology Inc.  
DS39629C-page 373  
PIC18F6390/6490/8390/8490  
FIGURE 26-10:  
CAPTURE/COMPARE/PWM TIMINGS (ALL CCP MODULES)  
CCPx  
(Capture Mode)  
50  
51  
52  
54  
CCPx  
(Compare or PWM Mode)  
53  
Refer to Figure 26-4 for load conditions.  
Note:  
TABLE 26-12: CAPTURE/COMPARE/PWM REQUIREMENTS (ALL 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  
DS39629C-page 374  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
FIGURE 26-11:  
EXAMPLE SPI MASTER MODE TIMING (CKE = 0)  
SS  
70  
SCK  
(CKP = 0)  
71  
72  
78  
79  
79  
SCK  
(CKP = 1)  
78  
80  
MSb  
bit 6 - - - - - - 1  
LSb  
SDO  
SDI  
75, 76  
MSb In  
74  
bit 6 - - - - 1  
LSb In  
73  
Note: Refer to Figure 26-4 for load conditions.  
TABLE 26-13: EXAMPLE SPI MODE REQUIREMENTS (MASTER MODE, CKE = 0)  
Param  
No.  
Symbol  
Characteristic  
Min  
Max Units Conditions  
70  
TSSL2SCH, SS to SCK or SCK Input  
TCY  
ns  
TSSL2SCL  
71  
TSCH  
SCK 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)  
TSCL  
SCK Input Low Time  
(Slave mode)  
ns  
72A  
73  
ns (Note 1)  
TDIV2SCH, Setup Time of SDI Data Input to SCK Edge  
TDIV2SCL  
100  
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 SDI Data Input to SCK Edge  
TSCL2DIL  
100  
ns  
75  
TDOR  
SDO Data Output Rise Time PIC18FXXXX  
PIC18LFXXXX  
25  
45  
25  
25  
45  
25  
50  
100  
ns  
ns VDD = 2.0V  
76  
78  
TDOF  
TSCR  
SDO Data Output Fall Time  
ns  
SCK Output Rise Time  
(Master mode)  
PIC18FXXXX  
PIC18LFXXXX  
ns  
ns VDD = 2.0V  
79  
80  
TSCF  
SCK Output Fall Time (Master mode)  
ns  
TSCH2DOV, SDO Data Output Valid after PIC18FXXXX  
TSCL2DOV SCK Edge  
ns  
PIC18LFXXXX  
ns VDD = 2.0V  
Note 1: Requires the use of Parameter #73A.  
2: Only if Parameter #71A and #72A are used.  
© 2007 Microchip Technology Inc.  
DS39629C-page 375  
PIC18F6390/6490/8390/8490  
FIGURE 26-12:  
EXAMPLE SPI MASTER MODE TIMING (CKE = 1)  
SS  
81  
SCK  
(CKP = 0)  
71  
72  
79  
78  
73  
SCK  
(CKP = 1)  
80  
LSb  
MSb  
bit 6 - - - - - - 1  
SDO  
SDI  
75, 76  
MSb In  
74  
bit 6 - - - - 1  
LSb In  
Note: Refer to Figure 26-4 for load conditions.  
TABLE 26-14: EXAMPLE SPI MODE REQUIREMENTS (MASTER MODE, CKE = 1)  
Param.  
No.  
Symbol  
TSCH  
Characteristic  
Min  
Max Units Conditions  
71  
SCK Input High Time  
Continuous  
Single Byte  
Continuous  
Single Byte  
1.25 TCY + 30  
ns  
(Slave mode)  
71A  
72  
40  
1.25 TCY + 30  
40  
ns (Note 1)  
TSCL  
SCK Input Low Time  
(Slave mode)  
ns  
72A  
73  
ns (Note 1)  
TDIV2SCH, Setup Time of SDI Data Input to SCK Edge  
TDIV2SCL  
100  
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 SDI Data Input to SCK Edge  
TSCL2DIL  
100  
ns  
75  
TDOR  
SDO Data Output Rise Time PIC18FXXXX  
PIC18LFXXXX  
25  
45  
25  
25  
45  
25  
50  
100  
ns  
ns VDD = 2.0V  
76  
78  
TDOF  
TSCR  
SDO Data Output Fall Time  
ns  
SCK Output Rise Time  
(Master mode)  
PIC18FXXXX  
ns  
PIC18LFXXXX  
ns VDD = 2.0V  
79  
80  
TSCF  
SCK Output Fall Time (Master mode)  
ns  
TSCH2DOV, SDO Data Output Valid after PIC18FXXXX  
TSCL2DOV SCK Edge  
ns  
PIC18LFXXXX  
ns VDD = 2.0V  
ns  
81  
TDOV2SCH, SDO Data Output Setup to SCK Edge  
TDOV2SCL  
TCY  
Note 1: Requires the use of Parameter #73A.  
2: Only if Parameter #71A and #72A are used.  
DS39629C-page 376  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
FIGURE 26-13:  
EXAMPLE SPI SLAVE MODE TIMING (CKE = 0)  
SS  
70  
SCK  
(CKP = 0)  
83  
71  
72  
78  
79  
79  
78  
SCK  
(CKP = 1)  
80  
MSb  
LSb  
SDO  
SDI  
bit 6 - - - - - - 1  
75, 76  
77  
MSb In  
74  
bit 6 - - - - 1  
LSb In  
73  
Note:  
Refer to Figure 26-4 for load conditions.  
TABLE 26-15: EXAMPLE SPI MODE REQUIREMENTS (SLAVE MODE TIMING, CKE = 0)  
Param  
No.  
Symbol  
Characteristic  
Min  
Max Units Conditions  
70  
TSSL2SCH, SS to SCK or SCK Input  
TCY  
ns  
TSSL2SCL  
71  
TSCH  
SCK 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)  
TSCL  
SCK Input Low Time  
(Slave mode)  
ns  
72A  
73  
ns (Note 1)  
TDIV2SCH, Setup Time of SDI Data Input to SCK Edge  
TDIV2SCL  
100  
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 SDI Data Input to SCK Edge  
TSCL2DIL  
100  
ns  
75  
TDOR  
SDO Data Output Rise Time  
PIC18FXXXX  
PIC18LFXXXX  
25  
45  
25  
50  
25  
45  
25  
50  
100  
ns  
ns VDD = 2.0V  
76  
77  
78  
TDOF  
SDO Data Output Fall Time  
ns  
TSSH2DOZ SS to SDO Output High-Impedance  
10  
ns  
TSCR  
SCK Output Rise Time (Master mode) PIC18FXXXX  
PIC18LFXXXX  
ns  
ns VDD = 2.0V  
79  
80  
TSCF  
SCK Output Fall Time (Master mode)  
ns  
TSCH2DOV, SDO Data Output Valid after SCK Edge PIC18FXXXX  
TSCL2DOV  
ns  
PIC18LFXXXX  
ns VDD = 2.0V  
ns  
83  
TSCH2SSH, SS after SCK Edge  
1.5 TCY + 40  
TSCL2SSH  
Note 1: Requires the use of Parameter #73A.  
2: Only if Parameter #71A and #72A are used.  
© 2007 Microchip Technology Inc.  
DS39629C-page 377  
PIC18F6390/6490/8390/8490  
FIGURE 26-14:  
EXAMPLE SPI SLAVE MODE TIMING (CKE = 1)  
82  
SS  
70  
SCK  
83  
(CKP = 0)  
71  
72  
SCK  
(CKP = 1)  
80  
MSb  
bit 6 - - - - - - 1  
LSb  
SDO  
SDI  
75, 76  
77  
MSb In  
74  
bit 6 - - - - 1  
LSb In  
Note: Refer to Figure 26-4 for load conditions.  
TABLE 26-16: EXAMPLE SPI SLAVE MODE REQUIREMENTS (CKE = 1)  
Param  
No.  
Symbol  
Characteristic  
Min  
Max Units Conditions  
70  
TSSL2SCH, SS to SCK or SCK Input  
TCY  
ns  
TSSL2SCL  
71  
TSCH  
TSCL  
TB2B  
SCK 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  
SCK 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 SDI Data Input to SCK Edge  
TSCL2DIL  
100  
75  
TDOR  
SDO 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  
SDO Data Output Fall Time  
ns  
TSSH2DOZ SS to SDO Output High-Impedance  
10  
ns  
TSCR  
SCK Output Rise Time  
(Master mode)  
PIC18FXXXX  
PIC18LFXXXX  
ns  
ns VDD = 2.0V  
79  
80  
TSCF  
SCK Output Fall Time (Master mode)  
ns  
TSCH2DOV, SDO Data Output Valid after SCK PIC18FXXXX  
TSCL2DOV Edge  
ns  
PIC18LFXXXX  
ns VDD = 2.0V  
82  
83  
TSSL2DOV SDO Data Output Valid after SS PIC18FXXXX  
ns  
Edge  
PIC18LFXXXX  
ns VDD = 2.0V  
ns  
TSCH2SSH, SS after SCK Edge  
1.5 TCY + 40  
TSCL2SSH  
Note 1: Requires the use of Parameter #73A.  
2: Only if Parameter #71A and #72A are used.  
DS39629C-page 378  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
FIGURE 26-15:  
I2C™ BUS START/STOP BITS TIMING  
SCL  
SDA  
91  
93  
90  
92  
Stop  
Condition  
Start  
Condition  
Note: Refer to Figure 26-4 for load conditions.  
TABLE 26-17: 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 26-16:  
I2C™ BUS DATA TIMING  
103  
102  
100  
101  
SCL  
90  
106  
107  
91  
92  
SDA  
In  
110  
109  
109  
SDA  
Out  
Note: Refer to Figure 26-4 for load conditions.  
© 2007 Microchip Technology Inc.  
DS39629C-page 379  
PIC18F6390/6490/8390/8490  
TABLE 26-18: 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  
MSSP module  
100 kHz mode  
1.5 TCY  
4.7  
101  
TLOW  
Clock Low Time  
μs  
μs  
PIC18FXXXX must operate at  
a minimum of 1.5 MHz  
400 kHz mode  
MSSP module  
1.3  
PIC18FXXXX must operate at  
a minimum of 10 MHz  
1.5 TCY  
102  
103  
TR  
SDA and SCL 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  
SDA and SCL 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 SCL 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 SCL signal. If  
such a device does stretch the LOW period of the SCL signal, it must output the next data bit to the SDA line,  
2
TR max. + TSU:DAT = 1000 + 250 = 1250 ns (according to the Standard mode I C bus specification), before the SCL line  
is released.  
DS39629C-page 380  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
FIGURE 26-17:  
MASTER SSP I2C™ BUS START/STOP BITS TIMING WAVEFORMS  
SCL  
SDA  
93  
91  
90  
92  
Stop  
Condition  
Start  
Condition  
Note: Refer to Figure 26-4 for load conditions.  
TABLE 26-19: 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  
400 kHz mode  
1 MHz mode(1) 2(TOSC)(BRG + 1)  
2(TOSC)(BRG + 1)  
ns After this period, the  
first clock pulse is  
generated  
2(TOSC)(BRG + 1)  
TSU:STO Stop Condition  
Setup Time  
100 kHz mode  
400 kHz mode  
1 MHz mode(1) 2(TOSC)(BRG + 1)  
2(TOSC)(BRG + 1)  
ns  
2(TOSC)(BRG + 1)  
THD:STO Stop Condition  
Hold Time  
100 kHz mode  
400 kHz mode  
2(TOSC)(BRG + 1)  
ns  
2(TOSC)(BRG + 1)  
1 MHz mode(1) 2(TOSC)(BRG + 1)  
Note 1: Maximum pin capacitance = 10 pF for all I2C™ pins.  
FIGURE 26-18:  
MASTER SSP I2C™ BUS DATA TIMING  
103  
102  
100  
101  
SCL  
90  
106  
91  
92  
107  
SDA  
In  
110  
109  
109  
SDA  
Out  
Note: Refer to Figure 26-4 for load conditions.  
© 2007 Microchip Technology Inc.  
DS39629C-page 381  
PIC18F6390/6490/8390/8490  
TABLE 26-20: 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)  
SDA and SCL  
Rise Time  
100 kHz mode  
400 kHz mode  
1 MHz mode(1)  
100 kHz mode  
400 kHz mode  
1 MHz mode(1)  
1000  
300  
300  
300  
300  
100  
CB is specified to be from  
10 to 400 pF  
20 + 0.1 CB  
ns  
ns  
TF  
SDA and SCL  
Fall Time  
ns  
CB is specified to be from  
10 to 400 pF  
20 + 0.1 CB  
ns  
ns  
TSU:STA Start Condition 100 kHz mode  
2(TOSC)(BRG + 1)  
2(TOSC)(BRG + 1)  
ms Only relevant for  
Setup Time  
Repeated Start  
400 kHz mode  
ms  
condition  
ms  
1 MHz mode(1) 2(TOSC)(BRG + 1)  
91  
THD:STA Start Condition 100 kHz mode  
2(TOSC)(BRG + 1)  
2(TOSC)(BRG + 1)  
ms After this period, the first  
Hold Time  
clock pulse is generated  
400 kHz mode  
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  
TSU:DAT Data Input  
Setup Time  
250  
100  
ns  
ns  
(Note 2)  
ns  
TSU:STO Stop Condition  
Setup Time  
2(TOSC)(BRG + 1)  
2(TOSC)(BRG + 1)  
ms  
ms  
ms  
ns  
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  
ms Time the bus must be free  
before a new transmission  
ms  
can start  
ms  
Bus Capacitive Loading  
400  
pF  
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  
SCL signal. If such a device does stretch the LOW period of the SCL signal, it must output the next data bit  
to the SDA line, parameter #102 + parameter #107 = 1000 + 250 = 1250 ns (for 100 kHz mode,) before the  
SCL line is released.  
DS39629C-page 382  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
FIGURE 26-19:  
USART SYNCHRONOUS TRANSMISSION (MASTER/SLAVE) TIMING  
RC6/TX1/CK1  
pin  
121  
121  
RC7/RX1/DT1  
pin  
120  
Note: Refer to Figure 26-4 for load conditions.  
122  
TABLE 26-21: USART 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 26-20:  
USART SYNCHRONOUS RECEIVE (MASTER/SLAVE) TIMING  
RC6/TX1/CK1  
pin  
125  
RC7/RX1/DT1  
pin  
126  
Note: Refer to Figure 26-4 for load conditions.  
TABLE 26-22: USART 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)  
© 2007 Microchip Technology Inc.  
DS39629C-page 383  
PIC18F6390/6490/8390/8490  
TABLE 26-23: A/D CONVERTER CHARACTERISTICS: PIC18F6390/6490/8390/8490 (INDUSTRIAL)  
PIC18LF6390/6490/8390/8490 (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  
<±1  
<±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)  
ΔVREF Reference Voltage Range  
3
AVDD – AVSS  
V
For 10-bit resolution  
(VREFH – VREFL)  
A21  
A22  
A25  
A30  
VREFH Reference Voltage High  
AVSS + 3.0V  
AVSS – 0.3V  
VREFL  
AVDD + 0.3V  
AVDD – 3.0V  
VREFH  
V
V
For 10-bit resolution  
For 10-bit resolution  
VREFL  
VAIN  
Reference Voltage Low  
Analog Input Voltage  
V
ZAIN  
Recommended Impedance of  
Analog Voltage Source  
2.5  
kΩ  
A50  
IREF  
VREF Input Current (Note 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+/SEG17 pin or AVDD, whichever is selected as the VREFH source.  
VREFL current is from RA2/AN2/VREF-/SEG16 pin or AVSS, whichever is selected as the VREFL source.  
DS39629C-page 384  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
FIGURE 26-21:  
A/D CONVERSION TIMING  
BSF ADCON0, GO  
(Note 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.  
TABLE 26-24: 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  
TBD  
TBD  
11  
1
3
μs A/D RC mode  
μs VDD = 2.0V; A/D RC mode  
TAD  
PIC18LFXXXX  
131  
132  
TCNV  
TACQ  
Conversion Time  
(not including acquisition time) (Note 2)  
Acquisition Time (Note 3)  
12  
1.4  
TBD  
μs -40°C to +85°C  
μs  
0°C to +85°C  
135  
TSWC  
TDIS  
Switching Time from Convert Sample  
(Note 4)  
TBD  
Discharge Time  
0.2  
μs  
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.  
© 2007 Microchip Technology Inc.  
DS39629C-page 385  
PIC18F6390/6490/8390/8490  
NOTES:  
DS39629C-page 386  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
27.0 DC AND AC  
CHARACTERISTICS GRAPHS  
AND TABLES  
Graphs and tables are not available at this time.  
© 2007 Microchip Technology Inc.  
DS39629C-page 387  
PIC18F6390/6490/8390/8490  
NOTES:  
DS39629C-page 388  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
28.0 PACKAGING INFORMATION  
28.1 Package Marking Information  
64-Lead TQFP  
Example  
XXXXXXXXXX  
XXXXXXXXXX  
XXXXXXXXXX  
YYWWNNN  
PIC18F6490  
e
3
-I/PT  
0710017  
80-Lead TQFP  
Example  
XXXXXXXXXXXX  
XXXXXXXXXXXX  
YYWWNNN  
PIC18F8490-E  
/PT  
e
3
0710017  
Legend: XX...X Customer-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.  
© 2007 Microchip Technology Inc.  
DS39629C-page 389  
PIC18F6390/6490/8390/8490  
28.2 Package Details  
The following sections give the technical details of the  
packages.  
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E
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E1  
N
b
1 2 3  
NOTE 1  
c
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β
L
L1  
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."/, .ꢌꢎꢌꢐꢌꢄꢖꢌꢅ!ꢃꢑꢌꢄꢇꢃꢕꢄꢓꢅꢈꢇꢈꢉꢊꢊꢒꢅꢗꢃꢏꢘꢕꢈꢏꢅꢏꢕꢊꢌꢐꢉꢄꢖꢌꢓꢅꢎꢕꢐꢅꢃꢄꢎꢕꢐꢑꢉꢏꢃꢕꢄꢅꢛꢈꢐꢛꢕꢇꢌꢇꢅꢕꢄꢊꢒꢁ  
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DS39629C-page 390  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
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© 2007 Microchip Technology Inc.  
DS39629C-page 391  
PIC18F6390/6490/8390/8490  
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D
D1  
E
e
E1  
N
b
NOTE 1  
12 3  
α
NOTE 2  
A
c
φ
A2  
β
A1  
L1  
L
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ꢙꢁ ꢚꢘꢉꢑꢎꢌꢐꢇꢅꢉꢏꢅꢖꢕꢐꢄꢌꢐꢇꢅꢉꢐꢌꢅꢕꢛꢏꢃꢕꢄꢉꢊꢜꢅꢇꢃꢝꢌꢅꢑꢉꢒꢅꢆꢉꢐꢒꢁ  
 ꢁ !ꢃꢑꢌꢄꢇꢃꢕꢄꢇꢅ!ꢀꢅꢉꢄꢋꢅ"ꢀꢅꢋꢕꢅꢄꢕꢏꢅꢃꢄꢖꢊꢈꢋꢌꢅꢑꢕꢊꢋꢅꢎꢊꢉꢇꢘꢅꢕꢐꢅꢛꢐꢕꢏꢐꢈꢇꢃꢕꢄꢇꢁꢅ#ꢕꢊꢋꢅꢎꢊꢉꢇꢘꢅꢕꢐꢅꢛꢐꢕꢏꢐꢈꢇꢃꢕꢄꢇꢅꢇꢘꢉꢊꢊꢅꢄꢕꢏꢅꢌꢍꢖꢌꢌꢋꢅ$ꢁꢙ%ꢅꢑꢑꢅꢛꢌꢐꢅꢇꢃꢋꢌꢁ  
&ꢁ !ꢃꢑꢌꢄꢇꢃꢕꢄꢃꢄ'ꢅꢉꢄꢋꢅꢏꢕꢊꢌꢐꢉꢄꢖꢃꢄ'ꢅꢛꢌꢐꢅ()#"ꢅ*ꢀ&ꢁ%#ꢁ  
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."/, .ꢌꢎꢌꢐꢌꢄꢖꢌꢅ!ꢃꢑꢌꢄꢇꢃꢕꢄꢓꢅꢈꢇꢈꢉꢊꢊꢒꢅꢗꢃꢏꢘꢕꢈꢏꢅꢏꢕꢊꢌꢐꢉꢄꢖꢌꢓꢅꢎꢕꢐꢅꢃꢄꢎꢕꢐꢑꢉꢏꢃꢕꢄꢅꢛꢈꢐꢛꢕꢇꢌꢇꢅꢕꢄꢊꢒꢁ  
#ꢃꢖꢐꢕꢖꢘꢃꢛ -ꢖꢘꢄꢕꢊꢕ'ꢒ !ꢐꢉꢗꢃꢄ' ꢚ$&?$;ꢙ+  
DS39629C-page 392  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
)ꢙꢂꢃꢄꢅꢆꢇꢈꢉꢅꢊꢋꢌꢍꢇꢎꢏꢌꢐꢇꢑꢒꢅꢆꢇꢓꢉꢅꢋꢔꢅꢍꢕꢇꢖꢈꢎꢗꢇMꢇꢘ#ꢚꢘ#ꢚꢘꢇꢛꢛꢇꢜ ꢆ!"ꢇ#$ꢙꢙꢇꢛꢛꢇ%ꢎꢑꢓꢈ&  
' ꢋꢄ( /ꢕꢐꢅꢏꢘꢌꢅꢑꢕꢇꢏꢅꢖꢈꢐꢐꢌꢄꢏꢅꢛꢉꢖ0ꢉ'ꢌꢅꢋꢐꢉꢗꢃꢄ'ꢇꢓꢅꢛꢊꢌꢉꢇꢌꢅꢇꢌꢌꢅꢏꢘꢌꢅ#ꢃꢖꢐꢕꢖꢘꢃꢛꢅꢂꢉꢖ0ꢉ'ꢃꢄ'ꢅ)ꢛꢌꢖꢃꢎꢃꢖꢉꢏꢃꢕꢄꢅꢊꢕꢖꢉꢏꢌꢋꢅꢉꢏꢅ  
ꢘꢏꢏꢛ,11ꢗꢗꢗꢁꢑꢃꢖꢐꢕꢖꢘꢃꢛꢁꢖꢕꢑ1ꢛꢉꢖ0ꢉ'ꢃꢄ'  
© 2007 Microchip Technology Inc.  
DS39629C-page 393  
PIC18F6390/6490/8390/8490  
NOTES:  
DS39629C-page 394  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
APPENDIX A: REVISION HISTORY  
APPENDIX B: DEVICE  
DIFFERENCES  
Revision A (July 2004)  
The differences between the devices listed in this data  
sheet are shown in Table B-1.  
Original data sheet for PIC18F6390/6490/8390/8490  
devices.  
Revision B (August 2004)  
Updated preliminary “electrical characteristics” data.  
Revision C (November 2007)  
Revised I2C™ Slave Mode Timing figure. Updated DC  
Power-Down and Supply Current table and package  
drawings.  
TABLE B-1:  
DEVICE DIFFERENCES  
Features  
PIC18F6390  
PIC18F6490  
PIC18F8390  
PIC18F8490  
Number of Pixels the LCD Driver  
can Drive  
128 (4 x 32)  
128 (4 x 32)  
192 (4 x 48)  
192 (4 x 48)  
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, H, J  
F, G, H, J  
Flash Program Memory  
Packages  
8 Kbytes  
16 Kbytes  
64-Pin TQFP  
8 Kbytes  
16 Kbytes  
64-Pin TQFP  
80-Pin TQFP  
80-Pin TQFP  
© 2007 Microchip Technology Inc.  
DS39629C-page 395  
PIC18F6390/6490/8390/8490  
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  
DS39629C-page 396  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
APPENDIX E: MIGRATION FROM  
APPENDIX F: MIGRATION FROM  
HIGH-END TO  
MID-RANGE 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 as Literature Number DS00726.  
This Application Note is available as Literature Number  
DS00716.  
© 2007 Microchip Technology Inc.  
DS39629C-page 397  
PIC18F6390/6490/8390/8490  
NOTES:  
DS39629C-page 398  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
Baud Rate Generator (BRG) ................................... 220  
Associated Registers ....................................... 220  
Baud Rate Error, Calculating ........................... 220  
Baud Rates, Asynchronous Modes ................. 221  
INDEX  
A
A/D ................................................................................... 231  
A/D Converter Interrupt, Configuring ....................... 235  
Acquisition Requirements ........................................ 236  
ADCON0 Register .................................................... 231  
ADCON1 Register .................................................... 231  
ADCON2 Register .................................................... 231  
ADRESH Register ............................................ 231, 234  
ADRESL Register .................................................... 231  
Analog Port Pins, Configuring .................................. 238  
Associated Registers ............................................... 240  
Automatic Acquisition Time ...................................... 237  
Configuring the Module ............................................ 235  
Conversion Clock (TAD) ........................................... 237  
Conversion Status (GO/DONE Bit) .......................... 234  
Conversions ............................................................. 239  
Converter Characteristics ........................................ 384  
Discharge ................................................................. 239  
Operation in Power-Managed Modes ...................... 238  
Special Event Trigger (CCP) .................................... 240  
Use of the CCP2 Trigger .......................................... 240  
Absolute Maximum Ratings ............................................. 349  
AC (Timing) Characteristics ............................................. 367  
Load Conditions for Device Timing  
High Baud Rate Select (BRGH Bit) ................. 220  
Operation in Power-Managed Modes .............. 220  
Sampling ......................................................... 220  
Synchronous Master Mode ...................................... 226  
Associated Registers, Receive ........................ 228  
Associated Registers, Transmit ....................... 227  
Reception ........................................................ 228  
Transmission ................................................... 226  
Synchronous Slave Mode ........................................ 229  
Associated Registers, Receive ........................ 230  
Associated Registers, Transmit ....................... 229  
Reception ........................................................ 230  
Transmission ................................................... 229  
Auto-Wake-up on Sync Break Character ......................... 210  
B
Bank Select Register (BSR) .............................................. 71  
Baud Rate Generator ...................................................... 183  
BC .................................................................................... 303  
BCF ................................................................................. 304  
BF .................................................................................... 187  
BF Status Flag ................................................................. 187  
Block Diagrams  
Specifications ................................................... 368  
Parameter Symbology ............................................. 367  
Temperature and Voltage Specifications ................. 368  
Timing Conditions .................................................... 368  
Access Bank ...................................................................... 73  
Mapping with Indexed Literal Offset Mode ................. 86  
ACKSTAT ........................................................................ 187  
ACKSTAT Status Flag ..................................................... 187  
ADCON0 Register ............................................................ 231  
GO/DONE Bit ........................................................... 234  
ADCON1 Register ............................................................ 231  
ADCON2 Register ............................................................ 231  
ADDFSR .......................................................................... 338  
ADDLW ............................................................................ 301  
Addressable Universal Synchronous Asynchronous  
Receiver Transmitter (AUSART). See AUSART.  
ADDULNK ........................................................................ 338  
ADDWF ............................................................................ 301  
ADDWFC ......................................................................... 302  
ADRESH Register ............................................................ 231  
ADRESL Register .................................................... 231, 234  
Analog-to-Digital Converter. See A/D.  
ANDLW ............................................................................ 302  
ANDWF ............................................................................ 303  
Assembler  
A/D ........................................................................... 234  
Analog Input Model .................................................. 235  
AUSART Receive .................................................... 224  
AUSART Transmit ................................................... 222  
Baud Rate Generator .............................................. 183  
Capture Mode Operation ......................................... 150  
Comparator Analog Input Model .............................. 245  
Comparator I/O Operating Modes ........................... 242  
Comparator Output .................................................. 244  
Comparator Voltage Reference ............................... 248  
Compare Mode Operation ....................................... 151  
Device Clock .............................................................. 36  
EUSART Receive .................................................... 208  
EUSART Transmit ................................................... 206  
External Power-on Reset Circuit  
(Slow VDD Power-up) ........................................ 53  
Fail-Safe Clock Monitor ........................................... 290  
Generic I/O Port Operation ...................................... 109  
HLVD Module (with External Input) ......................... 252  
Interrupt Logic ............................................................ 94  
LCD Clock Generation ............................................. 262  
LCD Driver Module .................................................. 257  
LCD Resistor Ladder Connection ............................ 263  
2
MSSP (I C Master Mode) ........................................ 181  
2
MSSP (I C Mode) .................................................... 166  
MPASM Assembler .................................................. 346  
AUSART  
MSSP (SPI Mode) ................................................... 157  
On-Chip Reset Circuit ................................................ 51  
PLL (HS Mode) .......................................................... 33  
PWM Operation (Simplified) .................................... 153  
Reads from Flash Program Memory ......................... 88  
Single Comparator ................................................... 243  
Table Read Operation ............................................... 87  
Timer0 in 16-Bit Mode ............................................. 132  
Asynchronous Mode ................................................ 222  
Associated Registers, Receive ........................ 225  
Associated Registers, Transmit ....................... 223  
Receiver ........................................................... 224  
Setting up 9-Bit Mode with  
Address Detect ........................................ 224  
Transmitter ....................................................... 222  
© 2007 Microchip Technology Inc.  
DS39629C-page 399  
PIC18F6390/6490/8390/8490  
Timer0 in 8-Bit Mode ................................................132  
Timer1 ......................................................................136  
Timer1 (16-Bit Read/Write Mode) ............................136  
Timer2 ......................................................................142  
Timer3 ......................................................................144  
Timer3 (16-Bit Read/Write Mode) ............................144  
Voltage Reference Output Buffer Example ..............249  
Watchdog Timer .......................................................287  
BN ....................................................................................304  
BNC ..................................................................................305  
BNN ..................................................................................305  
BNOV ...............................................................................306  
BNZ ..................................................................................306  
BOR. See Brown-out Reset.  
BOV ..................................................................................309  
BRA ..................................................................................307  
Break Character (12-Bit) Transmit and Receive ..............211  
BRG. See Baud Rate Generator.  
Brown-out Reset (BOR) .............................................54, 281  
Disabling in Sleep Mode ............................................54  
BSF ..................................................................................307  
BSR ....................................................................................86  
BTFSC .............................................................................308  
BTFSS ..............................................................................308  
BTG ..................................................................................309  
BZ .....................................................................................310  
Initializing PORTA .................................................... 109  
Initializing PORTB .................................................... 112  
Initializing PORTC ................................................... 115  
Initializing PORTD ................................................... 118  
Initializing PORTE .................................................... 120  
Initializing PORTF .................................................... 122  
Initializing PORTG ................................................... 125  
Initializing PORTH ................................................... 127  
Initializing PORTJ .................................................... 129  
Loading the SSPBUF (SSPSR) Register ................. 160  
Reading a Flash Program Memory Word .................. 89  
Saving STATUS, WREG and BSR  
Registers in RAM ............................................. 108  
Code Protection ............................................................... 281  
COMF .............................................................................. 312  
Comparator ...................................................................... 241  
Analog Input Connection Considerations ................ 245  
Associated Registers ............................................... 245  
Configuration ........................................................... 242  
Effects of a Reset .................................................... 244  
Interrupts ................................................................. 244  
Operation ................................................................. 243  
Operation During Sleep ........................................... 244  
Outputs .................................................................... 243  
Reference ................................................................ 243  
External Signal ................................................ 243  
Internal Signal .................................................. 243  
C
Response Time ........................................................ 243  
Comparator Specifications ............................................... 365  
Comparator Voltage Reference ....................................... 247  
Accuracy and Error .................................................. 248  
Associated Registers ............................................... 249  
Configuring .............................................................. 247  
Connection Considerations ...................................... 248  
Effects of a Reset .................................................... 248  
Operation During Sleep ........................................... 248  
Compare (CCP Module) .................................................. 151  
Associated Registers ............................................... 152  
CCP Pin Configuration ............................................. 151  
CCPR2 Register ...................................................... 151  
Software Interrupt .................................................... 151  
Special Event Trigger .............................. 145, 151, 240  
Timer1/Timer3 Mode Selection ................................ 151  
Computed GOTO ............................................................... 68  
Configuration Bits ............................................................ 281  
Configuration Register Protection .................................... 292  
Context Saving During Interrupts ..................................... 108  
Conversion Considerations .............................................. 396  
CPFSEQ .......................................................................... 312  
CPFSGT .......................................................................... 313  
CPFSLT ........................................................................... 313  
Crystal Oscillator/Ceramic Resonator ................................ 31  
Customer Change Notification Service ............................ 409  
Customer Notification Service ......................................... 409  
Customer Support ............................................................ 409  
C Compilers  
MPLAB C18 .............................................................346  
MPLAB C30 .............................................................346  
CALL ................................................................................310  
CALLW .............................................................................339  
Capture (CCP Module) .....................................................150  
Associated Registers ...............................................152  
CCP Pin Configuration .............................................150  
CCPR2H:CCPR2L Registers ...................................150  
Software Interrupt ....................................................150  
Timer1/Timer3 Mode Selection ................................150  
Capture/Compare/PWM (CCP) ........................................147  
Capture Mode. See Capture.  
CCP Mode and Timer Resources ............................148  
CCPRxH Register ....................................................148  
CCPRxL Register .....................................................148  
Compare Mode. See Compare.  
Interaction of CCP1 and CCP2 for  
Timer Resources ..............................................149  
Interconnect Configurations .....................................148  
Module Configuration ...............................................148  
Clock Sources ....................................................................36  
Selecting the 31 kHz Source ......................................37  
Selection Using OSCCON Register ...........................37  
CLRF ................................................................................311  
CLRWDT ..........................................................................311  
Code Examples  
16 x 16 Signed Multiply Routine ................................92  
16 x 16 Unsigned Multiply Routine ............................92  
8 x 8 Signed Multiply Routine ....................................91  
8 x 8 Unsigned Multiply Routine ................................91  
Changing Between Capture Prescalers ...................150  
Computed GOTO Using an Offset Value ...................68  
Fast Register Stack ....................................................68  
How to Clear RAM (Bank 1) Using  
D
Data Addressing Modes .................................................... 81  
Comparing Addressing Modes with the  
Extended Instruction Set Enabled ..................... 85  
Direct ......................................................................... 81  
Indexed Literal Offset ................................................ 84  
Indirect ....................................................................... 81  
Inherent and Literal .................................................... 81  
Indirect Addressing ............................................81  
Implementing a Real-Time Clock Using  
a Timer1 Interrupt Service ...............................139  
DS39629C-page 400  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
Data Memory ..................................................................... 71  
Extended Instruction Set  
Access Bank .............................................................. 73  
and the Extended Instruction Set ............................... 84  
Bank Select Register (BSR) ....................................... 71  
General Purpose Registers ........................................ 73  
Map for PIC18F6X90/8X90 Devices .......................... 72  
Special Function Registers ........................................ 74  
DAW ................................................................................. 314  
DC and AC Characteristics  
Graphs and Tables .................................................. 387  
DC Characteristics ........................................................... 362  
Power-Down and Supply Current ............................ 352  
Supply Voltage ......................................................... 351  
DCFSNZ .......................................................................... 315  
DECF ............................................................................... 314  
DECFSZ ........................................................................... 315  
Development Support ...................................................... 345  
Device Differences ........................................................... 395  
Device Overview .................................................................. 7  
Features (table) ............................................................ 9  
New Core Features ...................................................... 7  
Special Features .......................................................... 8  
Direct Addressing ............................................................... 82  
ADDFSR .................................................................. 338  
ADDULNK ............................................................... 338  
CALLW .................................................................... 339  
MOVSF .................................................................... 339  
MOVSS .................................................................... 340  
PUSHL ..................................................................... 340  
SUBFSR .................................................................. 341  
SUBULNK ................................................................ 341  
External Clock Input ........................................................... 32  
F
Fail-Safe Clock Monitor ........................................... 281, 290  
Interrupts in Power-Managed Modes ...................... 291  
POR or Wake from Sleep ........................................ 291  
WDT During Oscillator Failure ................................. 290  
Fast Register Stack ........................................................... 68  
Firmware Instructions ...................................................... 295  
Flash Program Memory ..................................................... 87  
Associated Registers ................................................. 89  
Control Registers ....................................................... 88  
TABLAT (Table Latch) Register ........................ 88  
TBLPTR (Table Pointer) Register ...................... 88  
Reading ..................................................................... 88  
Table Reads .............................................................. 87  
FSCM. See Fail-Safe Clock Monitor.  
E
Effect on Standard Instructions .......................................... 84  
Effect on Standard PIC MCU Instructions ........................ 342  
Electrical Characteristics .................................................. 349  
Enhanced Universal Synchronous Asynchronous  
Receiver Transmitter (EUSART). See EUSART.  
Equations  
G
GOTO .............................................................................. 316  
H
Hardware Multiplier ............................................................ 91  
Introduction ................................................................ 91  
Operation ................................................................... 91  
Performance Comparison .......................................... 91  
High/Low-Voltage Detect ................................................. 251  
Applications ............................................................. 254  
Typical Low-Voltage Detect (diagram) ............ 254  
A/D Acquisition Time ................................................ 236  
A/D Minimum Charging Time ................................... 236  
Calculating the Minimum Required  
Acquisition Time .............................................. 236  
Errata ................................................................................... 5  
EUSART  
Asynchronous Mode ................................................ 206  
12-Bit Break Transmit and Receive ................. 211  
Associated Registers, Receive ........................ 209  
Associated Registers, Transmit ....................... 207  
Auto-Wake-up on Sync Break ......................... 210  
Receiver ........................................................... 208  
Setting up 9-Bit Mode with  
Associated Registers ............................................... 255  
Characteristics ......................................................... 366  
Current Consumption .............................................. 253  
Effects of a Reset .................................................... 255  
Operation ................................................................. 252  
During Sleep .................................................... 255  
Setup ....................................................................... 253  
Start-up Time ........................................................... 253  
HLVD. See High/Low-Voltage Detect. ............................. 251  
Address Detect ........................................ 208  
Transmitter ....................................................... 206  
Baud Rate Generator (BRG) .................................... 201  
Associated Registers ....................................... 201  
Auto-Baud Rate Detect .................................... 204  
Baud Rate Error, Calculating ........................... 201  
Baud Rates, Asynchronous Modes ................. 202  
High Baud Rate Select (BRGH Bit) ................. 201  
Operation in Power-Managed Modes .............. 201  
Sampling .......................................................... 201  
Synchronous Master Mode ...................................... 212  
Associated Registers, Receive ........................ 214  
Associated Registers, Transmit ....................... 213  
Reception ......................................................... 214  
Transmission ................................................... 212  
Synchronous Slave Mode ........................................ 215  
Associated Registers, Receive ........................ 216  
Associated Registers, Transmit ....................... 215  
Reception ......................................................... 216  
Transmission ................................................... 215  
I
I/O Ports .......................................................................... 109  
2
I C Mode (MSSP)  
Acknowledge Sequence Timing .............................. 190  
Associated Registers ............................................... 196  
Baud Rate Generator .............................................. 183  
Bus Collision  
During a Repeated Start Condition .................. 194  
During a Start Condition .................................. 192  
During a Stop Condition .................................. 195  
Clock Arbitration ...................................................... 184  
Clock Stretching ...................................................... 176  
10-Bit Slave Receive Mode (SEN = 1) ............ 176  
10-Bit Slave Transmit Mode ............................ 176  
7-Bit Slave Receive Mode (SEN = 1) .............. 176  
7-Bit Slave Transmit Mode .............................. 176  
© 2007 Microchip Technology Inc.  
DS39629C-page 401  
PIC18F6390/6490/8390/8490  
Effect of a Reset ......................................................191  
General Call Address Support .................................180  
I C Clock Rate w/BRG .............................................183  
Master Mode ............................................................181  
Operation .........................................................182  
DAW ........................................................................ 314  
DCFSNZ .................................................................. 315  
DECF ....................................................................... 314  
DECFSZ .................................................................. 315  
Extended Instructions .............................................. 337  
and Using MPLAB IDE Tools .......................... 344  
Considerations when Enabling ........................ 342  
Syntax .............................................................. 337  
General Format ........................................................ 297  
GOTO ...................................................................... 316  
INCF ........................................................................ 316  
INCFSZ .................................................................... 317  
INFSNZ .................................................................... 317  
IORLW ..................................................................... 318  
IORWF ..................................................................... 318  
LFSR ....................................................................... 319  
MOVF ...................................................................... 319  
MOVFF .................................................................... 320  
MOVLB .................................................................... 320  
MOVLW ................................................................... 321  
MOVWF ................................................................... 321  
MULLW .................................................................... 322  
MULWF .................................................................... 322  
NEGF ....................................................................... 323  
NOP ......................................................................... 323  
POP ......................................................................... 324  
PUSH ....................................................................... 324  
RCALL ..................................................................... 325  
RESET ..................................................................... 325  
RETFIE .................................................................... 326  
RETLW .................................................................... 326  
RETURN .................................................................. 327  
RLCF ....................................................................... 327  
RLNCF ..................................................................... 328  
RRCF ....................................................................... 328  
RRNCF .................................................................... 329  
SETF ....................................................................... 329  
SETF (Indexed Literal Offset mode) ........................ 343  
SLEEP ..................................................................... 330  
Standard Instructions ............................................... 295  
SUBFWB ................................................................. 330  
SUBLW .................................................................... 331  
SUBWF .................................................................... 331  
SUBWFB ................................................................. 332  
SWAPF .................................................................... 332  
TBLRD ..................................................................... 333  
TBLWT .................................................................... 334  
TSTFSZ ................................................................... 335  
XORLW ................................................................... 335  
XORWF ................................................................... 336  
Summary Table ....................................................... 298  
2
Reception .........................................................187  
Repeated Start Condition Timing .....................186  
Start Condition .................................................185  
Transmission ....................................................187  
Transmit Sequence ..........................................182  
Multi-Master Communication, Bus Collision  
and Arbitration ..................................................191  
Multi-Master Mode ...................................................191  
Operation .................................................................170  
Read/Write Bit Information (R/W Bit) ............... 170, 171  
Registers ..................................................................166  
Serial Clock (RC3/SCK/SCL) ...................................171  
Slave Mode ..............................................................170  
Addressing .......................................................170  
Reception .........................................................171  
Sleep Operation .......................................................191  
Stop Condition Timing ..............................................190  
Transmission ............................................................171  
ID Locations ............................................................. 281, 293  
INCF .................................................................................316  
INCFSZ ............................................................................317  
In-Circuit Debugger ..........................................................293  
In-Circuit Serial Programming (ICSP) ......................281, 293  
Indexed Literal Offset Addressing Mode ..........................342  
and Standard PIC18 Instructions .............................342  
Indexed Literal Offset Mode ......................................... 84, 86  
Indirect Addressing ............................................................82  
INFSNZ ............................................................................317  
Initialization Conditions for all Registers ......................59–64  
Instruction Cycle .................................................................69  
Clocking Scheme .......................................................69  
Instruction Flow/Pipelining .................................................69  
Instruction Set ..................................................................295  
ADDLW ....................................................................301  
ADDWF ....................................................................301  
ADDWF (Indexed Literal Offset mode) ....................343  
ADDWFC .................................................................302  
ANDLW ....................................................................302  
ANDWF ....................................................................303  
BC ............................................................................303  
BCF ..........................................................................304  
BN ............................................................................304  
BNC .........................................................................305  
BNN .........................................................................305  
BNOV .......................................................................306  
BNZ ..........................................................................306  
BOV .........................................................................309  
BRA ..........................................................................307  
BSF ..........................................................................307  
BSF (Indexed Literal Offset mode) ..........................343  
BTFSC .....................................................................308  
BTFSS .....................................................................308  
BTG ..........................................................................309  
BZ ............................................................................310  
CALL ........................................................................310  
CLRF ........................................................................311  
CLRWDT ..................................................................311  
COMF ......................................................................312  
CPFSEQ ..................................................................312  
CPFSGT ..................................................................313  
CPFSLT ...................................................................313  
INTCON Register  
RBIF Bit ................................................................... 112  
INTCON Registers ............................................................. 95  
2
Inter-Integrated Circuit. See I C.  
Internal Oscillator Block ..................................................... 34  
Adjustment ................................................................. 34  
INTIO Modes ............................................................. 34  
INTOSC Output Frequency ....................................... 34  
OSCTUNE Register ................................................... 34  
Internal RC Oscillator  
Use with WDT .......................................................... 287  
Internet Address .............................................................. 409  
DS39629C-page 402  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
Interrupt Sources ............................................................. 281  
MOVWF ........................................................................... 321  
MPLAB ASM30 Assembler, Linker, Librarian .................. 346  
MPLAB ICD 2 In-Circuit Debugger .................................. 347  
MPLAB ICE 2000 High-Performance  
Universal In-Circuit Emulator ................................... 347  
MPLAB Integrated Development  
Environment Software ............................................. 345  
MPLAB PM3 Device Programmer ................................... 347  
MPLAB REAL ICE In-Circuit Emulator System ............... 347  
MPLINK Object Linker/MPLIB Object Librarian ............... 346  
MSSP  
A/D Conversion Complete ....................................... 235  
Capture Complete (CCP) ......................................... 150  
Compare Complete (CCP) ....................................... 151  
Interrupt-on-Change (RB7:RB4) .............................. 112  
INTx Pin ................................................................... 108  
PORTB, Interrupt-on-Change .................................. 108  
TMR0 ....................................................................... 108  
TMR0 Overflow ........................................................ 133  
TMR1 Overflow ........................................................ 135  
TMR2 to PR2 Match (PWM) .................................... 153  
TMR3 Overflow ................................................ 143, 145  
Interrupts ............................................................................ 93  
Interrupts, Flag Bits  
ACK Pulse ....................................................... 170, 171  
Control Registers (general) ..................................... 157  
2
2
I C Mode. See I C Mode.  
Interrupt-on-Change (RB7:RB4) Flag  
Module Overview ..................................................... 157  
SPI Master/Slave Connection .................................. 161  
SPI Mode. See SPI Mode.  
(RBIF Bit) ......................................................... 112  
INTOSC Frequency Drift .................................................... 34  
INTOSC, INTRC. See Internal Oscillator Block.  
IORLW ............................................................................. 318  
IORWF ............................................................................. 318  
IPR Registers ................................................................... 104  
SSPBUF .................................................................. 162  
SSPSR .................................................................... 162  
MULLW ............................................................................ 322  
MULWF ............................................................................ 322  
L
N
LCD  
NEGF ............................................................................... 323  
NOP ................................................................................. 323  
Associated Registers ............................................... 279  
Bias Types ............................................................... 263  
Clock Source Selection ............................................ 262  
Configuring the Module ............................................ 278  
Frame Frequency ..................................................... 264  
Interrupts .................................................................. 276  
LCDCON Register ................................................... 258  
LCDDATA Register .................................................. 258  
LCDPS Register ....................................................... 258  
LCDSE Register ....................................................... 258  
Multiplex Types ........................................................ 263  
Operation During Sleep ........................................... 277  
Pixel Control ............................................................. 264  
Prescaler .................................................................. 262  
Segment Enables ..................................................... 263  
Waveform Generation .............................................. 264  
LCDCON Register ........................................................... 258  
LCDDATA Register .......................................................... 258  
LCDPS Register ............................................................... 258  
LP3:LP0 Bits ............................................................ 262  
LCDSE Register ............................................................... 258  
LFSR ................................................................................ 319  
Liquid Crystal Display (LCD) Driver ................................. 257  
Look-up Tables .................................................................. 68  
O
Opcode Field Descriptions ............................................... 296  
Oscillator Configuration ..................................................... 31  
EC .............................................................................. 31  
ECIO .......................................................................... 31  
HS .............................................................................. 31  
HSPLL ....................................................................... 31  
Internal Oscillator Block ............................................. 34  
INTIO1 ....................................................................... 31  
INTIO2 ....................................................................... 31  
LP .............................................................................. 31  
RC ............................................................................. 31  
RCIO .......................................................................... 31  
XT .............................................................................. 31  
Oscillator Selection .......................................................... 281  
Oscillator Start-up Timer (OST) ........................... 39, 55, 281  
Oscillator Switching ........................................................... 36  
Oscillator Transitions ......................................................... 37  
Oscillator, Timer1 ..................................................... 135, 145  
Oscillator, Timer3 ............................................................. 143  
P
Packaging ........................................................................ 389  
Details ...................................................................... 390  
Marking .................................................................... 389  
PICSTART Plus Development Programmer .................... 348  
PIE Registers ................................................................... 101  
Pin Functions  
M
Master Clear (MCLR) ......................................................... 53  
Master Synchronous Serial Port (MSSP). See MSSP.  
Memory Organization ......................................................... 65  
Data Memory ............................................................. 71  
Program Memory ....................................................... 65  
Memory Programming Requirements .............................. 364  
Microchip Internet Web Site ............................................. 409  
Migration from Baseline to Enhanced Devices ................ 396  
Migration from High-End to Enhanced Devices ............... 397  
Migration from Mid-Range to Enhanced Devices ............ 397  
MOVF ............................................................................... 319  
MOVFF ............................................................................ 320  
MOVLB ............................................................................ 320  
MOVLW ........................................................................... 321  
MOVSF ............................................................................ 339  
MOVSS ............................................................................ 340  
AVDD .......................................................................... 29  
AVDD .......................................................................... 19  
AVSS .......................................................................... 29  
AVSS .......................................................................... 19  
COM0 .................................................................. 17, 25  
LCDBIAS1 ........................................................... 17, 25  
LCDBIAS2 ........................................................... 17, 25  
LCDBIAS3 ........................................................... 17, 25  
MCLR/VPP/RG5 ................................................... 12, 20  
OSC1/CLKI/RA7 .................................................. 12, 20  
OSC2/CLKO/RA6 ................................................ 12, 20  
RA0/AN0 .............................................................. 13, 21  
© 2007 Microchip Technology Inc.  
DS39629C-page 403  
PIC18F6390/6490/8390/8490  
RA1/AN1 .............................................................. 13, 21  
RA2/AN2/VREF-/SEG16 ....................................... 13, 21  
RA3/AN3/VREF+/SEG17 ...................................... 13, 21  
RA4/T0CKI/SEG14 .............................................. 13, 21  
RA5/AN4/HLVDIN/SEG15 ................................... 13, 21  
RB0/INT0 ............................................................. 14, 22  
RB1/INT1/SEG8 ................................................... 14, 22  
RB2/INT2/SEG9 ................................................... 14, 22  
RB3/INT3/SEG10 ................................................. 14, 22  
RB4/KBI0/SEG11 ................................................. 14, 22  
RB5/KBI1 ............................................................. 14, 22  
RB6/KBI2/PGC .................................................... 14, 22  
RB7/KBI3/PGD .................................................... 14, 22  
RC0/T1OSO/T13CKI ...........................................15, 23  
RC1/T1OSI/CCP2 ................................................ 15, 23  
RC2/CCP1/SEG13 ...............................................15, 23  
RC3/SCK/SCL ..................................................... 15, 23  
RC4/SDI/SDA ...................................................... 15, 23  
RC5/SDO/SEG12 ................................................ 15, 23  
RC6/TX1/CK1 ...................................................... 15, 23  
RC7/RX1/DT1 ...................................................... 15, 23  
RD0/SEG0 ........................................................... 16, 24  
RD1/SEG1 ........................................................... 16, 24  
RD2/SEG2 ........................................................... 16, 24  
RD3/SEG3 ........................................................... 16, 24  
RD4/SEG4 ........................................................... 16, 24  
RD5/SEG5 ........................................................... 16, 24  
RD6/SEG6 ........................................................... 16, 24  
RD7/SEG7 ........................................................... 16, 24  
RE4/COM1 ........................................................... 17, 25  
RE5/COM2 ........................................................... 17, 25  
RE6/COM3 ........................................................... 17, 25  
RE7/CCP2/SEG31 ...............................................17, 25  
RF0/AN5/SEG18 .................................................. 18, 26  
RF1/AN6/C2OUT/SEG19 .................................... 18, 26  
RF2/AN7/C1OUT/SEG20 .................................... 18, 26  
RF3/AN8/SEG21 .................................................. 18, 26  
RF4/AN9/SEG22 .................................................. 18, 26  
RF5/AN10/CVREF/SEG23 .................................... 18, 26  
RF6/AN11/SEG24 ................................................ 18, 26  
RF7/SS/SEG25 .................................................... 18, 26  
RG0/SEG30 ......................................................... 19, 27  
RG1/TX2/CK2/SEG29 ......................................... 19, 27  
RG2/RX2/DT2/SEG28 ......................................... 19, 27  
RG3/SEG27 ......................................................... 19, 27  
RG4/SEG26 ......................................................... 19, 27  
RG5 ...................................................................... 19, 27  
RH0/SEG47 ...............................................................28  
RH1/SEG46 ...............................................................28  
RH2/SEG45 ...............................................................28  
RH3/SEG44 ...............................................................28  
RH4/SEG40 ...............................................................28  
RH5/SEG41 ...............................................................28  
RH6/SEG42 ...............................................................28  
RH7/SEG43 ...............................................................28  
RJ0/SEG32 ................................................................29  
RJ1/SEG33 ................................................................29  
RJ2/SEG34 ................................................................29  
RJ3/SEG35 ................................................................29  
RJ4/SEG39 ................................................................29  
RJ5/SEG38 ................................................................29  
RJ6/SEG37 ................................................................29  
RJ7/SEG36 ................................................................29  
VDD .............................................................................29  
VDD .............................................................................19  
VSS ............................................................................ 29  
VSS ............................................................................ 19  
Pinout I/O Descriptions  
PIC18F6X90 .............................................................. 12  
PIC18F8X90 .............................................................. 20  
PIR Registers ..................................................................... 98  
PLL .................................................................................... 33  
HSPLL Oscillator Mode ............................................. 33  
Use with INTOSC ................................................ 33, 34  
PLL Lock Time-out ............................................................. 55  
POP ................................................................................. 324  
POR. See Power-on Reset.  
PORTA  
Associated Registers ............................................... 111  
LATA Register ......................................................... 109  
PORTA Register ...................................................... 109  
TRISA Register ........................................................ 109  
PORTB  
Associated Registers ............................................... 114  
LATB Register ......................................................... 112  
PORTB Register ...................................................... 112  
RB7:RB4 Interrupt-on-Change Flag  
(RBIF Bit) ......................................................... 112  
TRISB Register ........................................................ 112  
PORTC  
Associated Registers ............................................... 117  
LATC Register ......................................................... 115  
PORTC Register ...................................................... 115  
RC3/SCK/SCL Pin ................................................... 171  
TRISC Register ........................................................ 115  
PORTD  
Associated Registers ............................................... 119  
LATD Register ......................................................... 118  
PORTD Register ...................................................... 118  
TRISD Register ........................................................ 118  
PORTE  
Associated Registers ............................................... 121  
LATE Register ......................................................... 120  
PORTE Register ...................................................... 120  
TRISE Register ........................................................ 120  
PORTF  
Associated Registers ............................................... 124  
LATF Register .......................................................... 122  
PORTF Register ...................................................... 122  
TRISF Register ........................................................ 122  
PORTG  
Associated Registers ............................................... 126  
LATG Register ......................................................... 125  
PORTG Register ...................................................... 125  
TRISG Register ....................................................... 125  
PORTH  
Associated Registers ............................................... 128  
LATH Register ......................................................... 127  
PORTH Register ...................................................... 127  
TRISH Register ........................................................ 127  
PORTJ  
Associated Registers ............................................... 130  
LATJ Register .......................................................... 129  
PORTJ Register ....................................................... 129  
TRISJ Register ........................................................ 129  
Postscaler, WDT  
Assignment (PSA Bit) .............................................. 133  
Rate Select (T0PS2:T0PS0 Bits) ............................. 133  
Switching Between Timer0 and WDT ...................... 133  
DS39629C-page 404  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
Power-Managed Modes ..................................................... 41  
Reader Response ............................................................ 410  
Reading Program Memory and Other Locations ............. 292  
Register File ....................................................................... 73  
Register File Summary ................................................ 76–79  
Registers  
and Multiple Sleep Commands .................................. 42  
Effects on Clock Sources ........................................... 39  
Entering ...................................................................... 41  
Exiting Idle and Sleep Modes  
by Reset ............................................................. 48  
by WDT Time-out ............................................... 48  
Without a Start-up Delay .................................... 48  
Exiting Idle or Sleep Modes ....................................... 48  
by Interrupt ......................................................... 48  
Idle Modes ................................................................. 45  
PRI_IDLE ........................................................... 46  
Run Modes ................................................................. 42  
PRI_RUN ........................................................... 42  
RC_RUN ............................................................ 44  
SEC_RUN .......................................................... 42  
Selecting .................................................................... 41  
Sleep Mode ................................................................ 45  
Summary (table) ........................................................ 41  
Power-on Reset (POR) .............................................. 53, 281  
Oscillator Start-up Timer (OST) ................................. 55  
Power-up Timer (PWRT) ................................... 55, 281  
Time-out Sequence .................................................... 55  
Power-up Delays ................................................................ 39  
Power-up Timer (PWRT) ............................................. 39, 55  
Prescaler, Capture ........................................................... 150  
Prescaler, Timer0 ............................................................. 133  
Assignment (PSA Bit) .............................................. 133  
Rate Select (T0PS2:T0PS0 Bits) ............................. 133  
Switching Between Timer0 and WDT ...................... 133  
Prescaler, Timer2 ............................................................. 154  
Program Counter ............................................................... 66  
PCL, PCH and PCU Registers ................................... 66  
PCLATH and PCLATU Registers .............................. 66  
Program Memory  
and Extended Instruction Set ..................................... 84  
Instructions ................................................................. 70  
Two-Word .......................................................... 70  
Interrupt Vector .......................................................... 65  
Map and Stack (diagram) ........................................... 65  
Reset Vector .............................................................. 65  
Program Verification and Code Protection ....................... 292  
Associated Registers ............................................... 292  
Programming, Device Instructions ................................... 295  
Pulse-Width Modulation. See PWM (CCP Module).  
PUSH ............................................................................... 324  
PUSH and POP Instructions .............................................. 67  
PUSHL ............................................................................. 340  
PWM (CCP Module)  
ADCON0 (A/D Control 0) ......................................... 231  
ADCON1 (A/D Control 1) ......................................... 232  
ADCON2 (A/D Control 2) ......................................... 233  
BAUDCON1 (Baud Rate Control 1) ......................... 200  
CCPxCON (CCPx Control) ...................................... 147  
CMCON (Comparator Control) ................................ 241  
CONFIG1H (Configuration 1 High) .......................... 282  
CONFIG2H (Configuration 2 High) .......................... 284  
CONFIG2L (Configuration 2 Low) ........................... 283  
CONFIG3H (Configuration 3 High) .......................... 284  
CONFIG4L (Configuration 4 Low) ........................... 285  
CONFIG5L (Configuration 5 Low) ........................... 285  
CVRCON (Comparator Voltage  
Reference Control) .......................................... 247  
DEVID1 (Device ID 1) .............................................. 286  
DEVID2 (Device ID 2) .............................................. 286  
HLVDCON (High/Low-Voltage  
Detect Control) ................................................ 251  
INTCON (Interrupt Control) ....................................... 95  
INTCON2 (Interrupt Control 2) .................................. 96  
INTCON3 (Interrupt Control 3) .................................. 97  
IPR1 (Peripheral Interrupt Priority 1) ....................... 104  
IPR2 (Peripheral Interrupt Priority 2) ....................... 105  
IPR3 (Peripheral Interrupt Priority 3) ....................... 106  
LCDCON (LCD Control) .......................................... 258  
LCDDATAx (LCD Datax) ......................................... 261  
LCDPS (LCD Phase) ............................................... 259  
LCDSEx (LCD Segmentx Enable) ........................... 260  
OSCCON (Oscillator Control) .................................... 38  
OSCTUNE (Oscillator Tuning) ................................... 35  
PIE1 (Peripheral Interrupt Enable 1) ....................... 101  
PIE2 (Peripheral Interrupt Enable 2) ....................... 102  
PIE3 (Peripheral Interrupt Enable 3) ....................... 103  
PIR1 (Peripheral Interrupt Request (Flag) 1) ............. 98  
PIR2 (Peripheral Interrupt Request (Flag) 2) ............. 99  
PIR3 (Peripheral Interrupt Request (Flag) 3) ........... 100  
RCON (Reset Control) ....................................... 52, 107  
RCSTA1 (EUSART Receive  
Status and Control) .......................................... 199  
RCSTA2 (AUSART Receive  
Status and Control) .......................................... 219  
2
SSPCON1 (MSSP Control 1, I C Mode) ................. 168  
SSPCON1 (MSSP Control 1, SPI Mode) ................ 159  
SSPCON2 (MSSP Control 2,  
2
Associated Registers ............................................... 155  
Duty Cycle ................................................................ 154  
Example Frequencies/Resolutions .......................... 154  
Period ....................................................................... 153  
Setup for PWM Operation ........................................ 155  
TMR2 to PR2 Match ................................................ 153  
I C Master Mode) ............................................ 169  
2
SSPSTAT (MSSP Status, I C Mode) ...................... 167  
SSPSTAT (MSSP Status, SPI Mode) ...................... 158  
STATUS .................................................................... 80  
STKPTR (Stack Pointer) ............................................ 67  
T0CON (Timer0 Control) ......................................... 131  
T1CON (Timer1 Control) ......................................... 135  
T2CON (Timer2 Control) ......................................... 141  
T3CON (Timer3 Control) ......................................... 143  
TXSTA1 (EUSART Transmit  
Q
Q Clock ............................................................................ 154  
R
Status and Control) .......................................... 198  
TXSTA2 (AUSART Transmit  
RAM. See Data Memory.  
RC Oscillator ...................................................................... 33  
RCIO Oscillator Mode ................................................ 33  
RCALL ............................................................................. 325  
RCON Register  
Status and Control) .......................................... 218  
WDTCON (Watchdog Timer Control) ...................... 288  
RESET ............................................................................. 325  
Bit Status During Initialization .................................... 58  
© 2007 Microchip Technology Inc.  
DS39629C-page 405  
PIC18F6390/6490/8390/8490  
Reset ..................................................................................51  
MCLR Reset, during Power-Managed Modes ...........51  
MCLR Reset, Normal Operation ................................51  
Power-on Reset (POR) ..............................................51  
Programmable Brown-out Reset (BOR) ....................51  
Stack Full Reset .........................................................51  
Stack Underflow Reset ..............................................51  
Watchdog Timer (WDT) Reset ...................................51  
Resets ..............................................................................281  
RETFIE ............................................................................326  
RETLW .............................................................................326  
RETURN ..........................................................................327  
Return Address Stack ........................................................66  
Return Stack Pointer (STKPTR) ........................................67  
Revision History ...............................................................395  
RLCF ................................................................................327  
RLNCF .............................................................................328  
RRCF ...............................................................................328  
RRNCF .............................................................................329  
SUBULNK ........................................................................ 341  
SUBWF ............................................................................ 331  
SUBWFB ......................................................................... 332  
SWAPF ............................................................................ 332  
T
T0CON Register  
PSA Bit .................................................................... 133  
T0CS Bit .................................................................. 132  
T0PS2:T0PS0 Bits ................................................... 133  
T0SE Bit .................................................................. 132  
Table Pointer Operations (table) ........................................ 88  
Table Reads ...................................................................... 68  
TBLRD ............................................................................. 333  
TBLWT ............................................................................. 334  
Time-out in Various Situations (table) ................................ 55  
Timer0 .............................................................................. 131  
16-Bit Mode Timer Reads and Writes ...................... 132  
Associated Registers ............................................... 133  
Clock Source Edge Select (T0SE Bit) ..................... 132  
Clock Source Select (T0CS Bit) ............................... 132  
Operation ................................................................. 132  
Overflow Interrupt .................................................... 133  
Prescaler. See Prescaler, Timer0.  
Timer1 .............................................................................. 135  
16-Bit Read/Write Mode .......................................... 137  
Associated Registers ............................................... 139  
Interrupt ................................................................... 138  
Operation ................................................................. 136  
Oscillator .......................................................... 135, 137  
Layout Considerations ..................................... 138  
Overflow Interrupt .................................................... 135  
Resetting, Using a Special Event Trigger  
Output (CCP) ................................................... 138  
TMR1H Register ...................................................... 135  
TMR1L Register ....................................................... 135  
Use as a Real-Time Clock ....................................... 138  
Timer2 .............................................................................. 141  
Associated Registers ............................................... 142  
Interrupt ................................................................... 142  
Operation ................................................................. 141  
Output ...................................................................... 142  
PR2 Register ........................................................... 153  
TMR2 to PR2 Match Interrupt .................................. 153  
Timer3 .............................................................................. 143  
16-Bit Read/Write Mode .......................................... 145  
Associated Registers ............................................... 145  
Operation ................................................................. 144  
Oscillator .......................................................... 143, 145  
Overflow Interrupt ............................................ 143, 145  
Special Event Trigger (CCP) ................................... 145  
TMR3H Register ...................................................... 143  
TMR3L Register ....................................................... 143  
Timing Diagrams  
S
SCK ..................................................................................157  
SDI ...................................................................................157  
SDO .................................................................................157  
Serial Clock, SCK .............................................................157  
Serial Data In (SDI) ..........................................................157  
Serial Data Out (SDO) .....................................................157  
Serial Peripheral Interface. See SPI Mode.  
SETF ................................................................................329  
Slave Select (SS) .............................................................157  
SLEEP ..............................................................................330  
Sleep  
OSC1 and OSC2 Pin States ......................................39  
Software Enabled BOR ......................................................54  
Software Simulator (MPLAB SIM) ....................................346  
Special Event Trigger. See Compare (CCP Module).  
Special Features of the CPU ............................................281  
Special Function Registers ................................................74  
Map ...................................................................... 74–75  
SPI Mode (MSSP)  
Associated Registers ...............................................165  
Bus Mode Compatibility ...........................................165  
Effects of a Reset .....................................................165  
Enabling SPI I/O ......................................................161  
Master Mode ............................................................162  
Master/Slave Connection .........................................161  
Operation .................................................................160  
Serial Clock ..............................................................157  
Serial Data In ...........................................................157  
Serial Data Out ........................................................157  
Slave Mode ..............................................................163  
Slave Select .............................................................157  
Slave Select Synchronization ..................................163  
Sleep Operation .......................................................165  
SPI Clock .................................................................162  
Typical Connection ..................................................161  
SS ....................................................................................157  
SSPOV .............................................................................187  
SSPOV Status Flag ..........................................................187  
SSPSTAT Register  
A/D Conversion ........................................................ 385  
Acknowledge Sequence .......................................... 190  
Asynchronous Reception ................................. 209, 225  
Asynchronous Transmission ............................ 207, 223  
Asynchronous Transmission  
(Back-to-Back) ......................................... 207, 223  
Automatic Baud Rate Calculation ............................ 205  
Auto-Wake-up Bit (WUE) During  
Normal Operation ............................................ 210  
Auto-Wake-up Bit (WUE) During Sleep ................... 210  
Baud Rate Generator with Clock Arbitration ............ 184  
BRG Overflow Sequence ......................................... 205  
R/W Bit ............................................................. 170, 171  
Stack Full/Underflow Resets ..............................................68  
STATUS Register ...............................................................80  
SUBFSR ...........................................................................341  
SUBFWB ..........................................................................330  
SUBLW ............................................................................331  
DS39629C-page 406  
© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
BRG Reset Due to SDA Arbitration  
Time-out Sequence on POR w/PLL Enabled  
During Start Condition ..................................... 193  
Brown-out Reset (BOR) ........................................... 372  
Bus Collision During a Repeated  
Start Condition (Case 1) .................................. 194  
Bus Collision During a Repeated  
Start Condition (Case 2) .................................. 194  
Bus Collision During a Start  
Condition (SCL = 0) ......................................... 193  
Bus Collision During a Start  
Condition (SDA Only) ...................................... 192  
Bus Collision During a Stop  
Condition (Case 1) ........................................... 195  
Bus Collision During a Stop  
(MCLR Tied to VDD) .......................................... 57  
Time-out Sequence on Power-up  
MCLR Not Tied to VDD, Case 1 ......................... 56  
MCLR Not Tied to VDD, Case 2 ......................... 56  
MCLR Tied to VDD, VDD Rise < TPWRT ............. 56  
Timer0 and Timer1 External Clock .......................... 373  
Transition for Entry to PRI_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) ........................................ 289  
Transition for Wake from Idle to Run Mode ............... 46  
Transition for Wake from Sleep (HSPLL) .................. 45  
Transition from RC_RUN Mode to  
Condition (Case 2) ........................................... 195  
Bus Collision for Transmit and Acknowledge ........... 191  
Capture/Compare/PWM (All CCP Modules) ............ 374  
CLKO and I/O .......................................................... 371  
Clock Synchronization ............................................. 177  
Clock/Instruction Cycle .............................................. 69  
Example SPI Master Mode (CKE = 0) ..................... 375  
Example SPI Master Mode (CKE = 1) ..................... 376  
Example SPI Slave Mode (CKE = 0) ....................... 377  
Example SPI Slave Mode (CKE = 1) ....................... 378  
External Clock (All Modes Except PLL) ................... 369  
Fail-Safe Clock Monitor ............................................ 291  
High/Low-Voltage Detect Characteristics ................ 366  
High-Voltage Detect Operation (VDIRMAG = 1) ...... 254  
PRI_RUN Mode ................................................. 44  
Transition from SEC_RUN Mode to  
PRI_RUN Mode (HSPLL) .................................. 43  
Transition to RC_RUN Mode ..................................... 44  
Type-A in 1/2 MUX, 1/2 Bias Drive .......................... 266  
Type-A in 1/2 MUX, 1/3 Bias Drive .......................... 268  
Type-A in 1/3 MUX, 1/2 Bias Drive .......................... 270  
Type-A in 1/3 MUX, 1/3 Bias Drive .......................... 272  
Type-A in 1/4 MUX, 1/3 Bias Drive .......................... 274  
Type-A/Type-B in Static Drive ................................. 265  
Type-B in 1/2 MUX, 1/2 Bias Drive .......................... 267  
Type-B in 1/2 MUX, 1/3 Bias Drive .......................... 269  
Type-B in 1/3 MUX, 1/2 Bias Drive .......................... 271  
Type-B in 1/3 MUX, 1/3 Bias Drive .......................... 273  
Type-B in 1/4 MUX, 1/3 Bias Drive .......................... 275  
USART Synchronous Receive (Master/Slave) ........ 383  
USART Synchronous Transmission  
2
I C Bus Data ............................................................ 379  
2
I C Bus Start/Stop Bits ............................................. 379  
2
I C Master Mode (7 or 10-Bit Transmission) ........... 188  
2
I C Master Mode (7-Bit Reception) .......................... 189  
2
I C Master Mode First Start Bit ................................ 185  
(Master/Slave) ................................................. 383  
Timing Diagrams and Specifications  
2
I C Slave Mode (10-Bit Reception, SEN = 0) .......... 174  
2
I C Slave Mode (10-Bit Reception, SEN = 1) .......... 179  
A/D Conversion Requirements ................................ 385  
AC Characteristics - Internal RC Accuracy .............. 370  
Capture/Compare/PWM Requirements  
(All CCP Modules) ........................................... 374  
CLKO and I/O Requirements ................................... 371  
Example SPI Mode Requirements  
2
I C Slave Mode (10-Bit Transmission) ..................... 175  
2
I C Slave Mode (7-Bit Reception, SEN = 0) ............ 172  
2
I C Slave Mode (7-Bit Reception, SEN = 1) ............ 178  
2
I C Slave Mode (7-Bit Transmission) ....................... 173  
2
I C Slave Mode General Call Address  
Sequence (7 or 10-Bit Addressing Mode) ........ 180  
I C Stop Condition Receive or Transmit Mode ........ 190  
(Master Mode, CKE = 0) .................................. 375  
Example SPI Mode Requirements  
2
LCD Interrupt Timing in Quarter-Duty Cycle Drive ... 276  
LCD Sleep Entry/Exit When SLPEN = 1 or  
(Master Mode, CKE = 1) .................................. 376  
Example SPI Mode Requirements  
CS1:CS0 = 00 .................................................. 277  
Low-Voltage Detect Operation (VDIRMAG = 0) ...... 253  
(Slave Mode, CKE = 0) .................................... 377  
Example SPI Slave Mode Requirements  
2
Master SSP I C Bus Data ........................................ 381  
(CKE = 1) ......................................................... 378  
External Clock Requirements .................................. 369  
2
Master SSP I C Bus Start/Stop Bits ........................ 381  
2
PWM Output ............................................................ 153  
Repeat Start Condition ............................................. 186  
Reset, Watchdog Timer (WDT), Oscillator Start-up  
Timer (OST) and Power-up Timer (PWRT) ..... 372  
Send Break Character Sequence ............................ 211  
Slave Synchronization ............................................. 163  
Slow Rise Time (MCLR Tied to VDD,  
VDD Rise > TPWRT) ............................................ 57  
SPI Mode (Master Mode) ......................................... 162  
SPI Mode (Slave Mode, CKE = 0) ........................... 164  
SPI Mode (Slave Mode, CKE = 1) ........................... 164  
Synchronous Reception  
I C Bus Data Requirements (Slave Mode) .............. 380  
2
I C Bus Start/Stop Bits Requirements  
(Slave Mode) ................................................... 379  
2
Master SSP I C Bus Data Requirements ................ 382  
2
Master SSP I C Bus Start/Stop Bits  
Requirements .................................................. 381  
PLL Clock ................................................................ 370  
Reset, Watchdog Timer, Oscillator Start-up  
Timer, Power-up Timer and Brown-out  
Reset Requirements ........................................ 372  
Timer0 and Timer1 External  
Clock Requirements ........................................ 373  
USART Synchronous Receive  
Requirements .................................................. 383  
USART Synchronous Transmission  
(Master Mode, SREN) ............................. 214, 228  
Synchronous Transmission .............................. 212, 226  
Synchronous Transmission  
(Through TXEN) ...................................... 213, 227  
Requirements .................................................. 383  
© 2007 Microchip Technology Inc.  
DS39629C-page 407  
PIC18F6390/6490/8390/8490  
Top-of-Stack Access ..........................................................66  
TSTFSZ ............................................................................335  
W
Watchdog Timer (WDT) ........................................... 281, 287  
Two-Speed Start-up ................................................. 281, 289  
Two-Word Instructions  
Example Cases ..........................................................70  
TXSTA1 Register  
BRGH Bit .................................................................201  
TXSTA2 Register  
Associated Registers ............................................... 288  
Control Register ....................................................... 287  
During Oscillator Failure .......................................... 290  
Programming Considerations .................................. 287  
WCOL ...................................................... 185, 186, 187, 190  
WCOL Status Flag ................................... 185, 186, 187, 190  
WWW Address ................................................................ 409  
WWW, On-Line Support ...................................................... 5  
BRGH Bit .................................................................220  
V
Voltage Reference Specifications ....................................365  
X
XORLW ............................................................................ 335  
XORWF ........................................................................... 336  
DS39629C-page 408  
© 2007 Microchip Technology Inc.  
PIC18FXX90  
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© 2007 Microchip Technology Inc.  
DS39629C-page 409  
PIC18FXX90  
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PIC18F6390/6490/8390/8490  
DS39629C  
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© 2007 Microchip Technology Inc.  
PIC18F6390/6490/8390/8490  
PIC18F6390/6490/8390/8490 PRODUCT IDENTIFICATION SYSTEM  
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Device(1), (2)  
PIC18F6390/6490/8390/8490,  
PIC18F6390/6490/8390/8490T;  
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PIC18F8490-E/PT = Extended temp., TQFP  
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PIC18LF6390/6490/8390/8490,  
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VDD range 2.0V to 5.5V  
Temperature Range  
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=
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=
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Note 1:  
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© 2007 Microchip Technology Inc.  
DS39629C-page 411  
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DS39629C-page 412  
© 2007 Microchip Technology Inc.  

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