COP8ACC528N9AQH_技术文档

National Semiconductor is now part of

Texas Instruments.

Search http://www.ti.com/ for the latest technical

information and details on our current products and services.

May 1999

COP8ACC5

8-Bit CMOS ROM Based Microcontrollers with 4k

Memory and High Resolution A/D

Family features include an 8-bit memory mapped architec-

ture, 4 MHz CKI with 2.5µs instruction cycle, 6 channel A/D

with 12-bit resolution, analog capture timer, analog current

source and V_CC/2 reference, one multi-function 16-bit timer/

counter, MICROWIRE/PLUS serial I/O, two power saving

HALT/IDLE modes, MIWU, high current outputs, software

General Description

The COP8ACC5 ROM based microcontrollers are highly in-

™

tegrated COP8 Feature core devices with 4k memory and

advanced features including a High-Resolution A/D. These

single-chip CMOS devices are suited for applications requir-

ing a full featured, low EMI controller with an A/D (only one

external capacitor required). COP8ACC7 devices are pin

and software compatible (different V_CCrange) 16k OTP

EPROM versions for pre-production. Erasable windowed

versions are available for use with a range of COP8 software

and hardware development tools.

™

selectable I/O options, WATCHDOG timer and Clock Moni-

tor, Low EMI 2.5V to 5.5V operation and 20/28 pin packages.

Devices included in this datasheet are:

Device

Memory (bytes)

4k ROM

RAM (bytes)

128

I/O Pins

15/23

Packages

Temperature

0 to +70˚C

COP8ACC5xxx9

COP8ACC5xxx8

20 SOIC, 28 DIP/SOIC

4k ROM

128

15/23

-40 to +85˚C

Key Features

CPU/Instruction Set Features

n Analog Function Block with 12-bit A/D including

— Analog comparator with seven input mux

— Constant Current Source and V_CC/2Reference

— 16-bit capture timer (upcounter) clocked from CKI

with auto reset on timer startup

n 2.5 µs instruction cycle time

n Eight multi-source vectored interrupt servicing

— External Interrupt

— Idle Timer T0

— Timer T1 associated Interrupts

— MICROWIRE/PLUS

n Quiet design (reduced radiated emissions)

n 4096 bytes on-board ROM

— Multi-Input Wake Up

— Software Trap

— Default VIS

n 128 bytes on-board RAM

— A/D (Capture Timer)

Additional Peripheral Features

n 8-bit Stack Pointer (SP) — stack in RAM

n Two 8-bit Registers Indirect Data Memory Pointers

(B and X)

n Idle Timer

n One 16-bit timer with two 16-bit registers supporting:

— Processor Independent PWM mode

— External Event counter mode

— Input Capture mode

n Multi-Input Wake-Up (MIWU) with optional interrupts

n WATCHDOG and clock monitor logic

Fully Static CMOS

n Two power saving modes: HALT and IDLE

n Single supply operation: 2.5V to 5.5V

n Temperature ranges: 0˚C to +70˚C, −40˚C to +85˚C

™

n MICROWIRE/PLUS serial I/O with programmable shift

clock-polarity

Development System

I/O Features

n Software selectable I/O options (Push-Pull Output, Weak

Pull-Up Input, High Impedance Input)

n High current outputs

n Emulation and OTP devices

n Real time emulation and full program debug offered by

MetaLink development system

Applications

n Battery Chargers

n Appliances

n Schmitt Trigger inputs on ports G and L

n Packages: 28 DIP/SO with 23 I/O pins,

20 SO with 15 I/O pins

n Data Acquisition systems

™

COP8 , MICROWIRE , MICROWIRE/PLUS , and WATCHDOG are trademarks of National Semiconductor Corporation.

TRI-STATE^®is a registered trademark of National Semiconductor Corporation.

iceMASTER^®is a registered trademark of MetaLink Corporation.

DS012865

www.national.com

Block Diagram

DS012865-1

FIGURE 1. Block Diagram

Connection Diagrams

DS012865-3

Top View

Order Number COP8ACC520M9 or COP8ACC520N8

See NS Molded Package Number M20B

DS012865-2

Top View

Order Number COP8ACC528N9 or COP8ACC528N8

See NS Molded Package Number N28A

Order Number COP8ACC528M9 or COP8ACC528M8

See NS Molded Package Number M28B

FIGURE 2. Connection Diagrams

www.national.com

2

Connection Diagrams (Continued)

Pinouts for 28-Pin, 20-Pin Packages

28-Pin

DIP/SO

4

20-Pin

SO

Port

Type

Alt. Fun

L4

L5

I/O

MIWU

INT

Ext. Int.

5

L6

6

L7

7

G0

G1

G2

G3

G4

G5

G6

G7

D0

D1

D2

D3

I0

23

24

25

26

27

28

1

15

16

17

18

19

20

1

WDOUT

I/O

T1B

T1A

SO

SK

I/O

I

SI

I/CKO

HALT Restart

2

O

I

11

12

13

14

15

16

17

18

19

20

21

22

9

7

8

9

Analog CH1

I_SRC

10

11

12

13

14

I1

I

I2

I

Analog CH2

Analog CH3

Analog CH4

Analog CH5

Analog CH6

C_OUT

I3

I

I4

I

I5

I

I6

I

I7

I

V_CC

GND

CKI

RESET

5

4

3

6

8

3

10

Ordering Inforamtion

DS012865-38

FIGURE 3. Part Numbering Scheme

3

www.national.com

Absolute Maximum Ratings (Note 1)

If Military/Aerospace specified devices are required,

please contact the National Semiconductor Sales Office/

Distributors for availability and specifications.

Total Current into V_CCPin (Source)

Total Current out of GND Pin (Sink)

Storage Temperature Range

Note 1: Absolute maximum ratings indicate limits beyond which damage to

the device may occur. DC and AC electrical specifications are not ensured

when operating the device at absolute maximum ratings.

100 mA

110 mA

−65˚C to +140˚C

Supply Voltage (V_CC

)

7V

Voltage at Any Pin

−0.3V to V_CC+0.3V

DC Electrical Characteristics

0˚C ≤ T_A≤ +70˚C unless otherwise specified

Parameter

Conditions

Peak-to-Peak

Min

Typ

Max

5.5

Units

Operating Voltage

Power Supply Ripple (Note 2)

Supply Current (Note 3)

CKI = 4 MHz

2.5

V

0.1 V_CC

V_CC= 5.5V, t_C= 2.5 µs

V_CC= 4V, t_C= 2.5 µs

V_CC= 4V, t_C= 10 µs

5.5

2.5

1.4

8

mA

µA

CKI = 4 MHz

CKI = 1 MHz

<

HALT Current (Note 4)

V_CC= 5.5V, CKI = 0 MHz

V_CC= 4V, CKI = 0 MHz

5

3

4

µA

IDLE Current

CKI = 4 MHz

CKI = 1 MHz

V_CC= 5.5V, t_C= 2.5 µs

V_CC= 4V, t_C= 10 µs

1.5

0.5

mA

Input Levels (V_IH, V_IL

)

RESET

Logic High

0.8 V_CC

0.7 V_CC

V

Logic Low

0.2 V_CC

CKI, All Other Inputs

Logic High

V

Logic Low

0.2 V_CC

1

Hi-Z Input Leakage

Input Pullup Current

V_CC= 5.5V

1

µA

V

V_CC= 5.5V, V_IN= 0V

(Note 6)

−40

−250

G and L Port Input Hysteresis

Output Current Levels

D Outputs

0.35 V_CC

Source

V_CC= 4V, V_OH= 3.3V

V_CC= 2.5V, V_OH= 1.8V

V_CC= 4V, V_OL= 1V

−0.4

−0.2

10

mA

Sink

V_CC= 2.5V, V_OL= 0.4V

2.0

All Others

Source (Weak Pull-Up Mode)

V_CC= 4V, V_OH= 2.7V

V_CC= 2.5V, V_OH= 1.8V

−10

−2.5

−0.4

−0.2

1.6

−110

−33

µA

Source (Push-Pull Mode)

Sink (Push-Pull Mode)

V

_CC= 4V, V_OH= 3.3V

mA

µA

V_CC= 2.5V, V_OH= 1.8V

V_CC= 4V, V_OL= 0.4V

V_CC= 2.5V, V_OL= 0.4V

V_CC= 5.5V

0.7

TRI-STATE^®Leakage

Allowable Sink/Source

Current per Pin

1

D Outputs (Sink)

15

3

mA

All others

±

200

Maximum Input Current

without Latchup (Note 5)

RAM Retention Voltage, V_r

Room Temp

500 ns Rise and Fall Time (min)

4

2

V

www.national.com

DC Electrical Characteristics (Continued)

0˚C ≤ T_A≤ +70˚C unless otherwise specified

Parameter

Input Capacitance

Load Capacitance on D2

Conditions

Min

Typ

Max

7

Units

pF

(Note 6)

1000

pF

AC Electrical Characteristics

0˚C ≤ T_A≤ +70˚C unless otherwise specified

Parameter

Instruction Cycle Time (t_C)

Crystal, Resonator

Conditions

Min

Typ

Max

Units

2.5V ≤ V_CC≤ 4V

4V ≤ V_CC≤ 5.5V

2.5V ≤ V_CC≤ 4V

4V ≤ V_CC≤ 5.5V

2.5

1.0

7.5

3.0

DC

µs

R/C Oscillator

Inputs

t_SETUP

4V ≤ V_CC≤ 5.5V

2.5V ≤ V_CC≤ 4V

4V ≤ V_CC≤ 5.5V

2.5V ≤ V_CC≤ 4V

R_L= 2.2k, C_L= 100 pF

200

500

60

ns

t_HOLD

150

Output Propagation Delay (Note 6)

t

_PD1, t_PD0

SO, SK

4V ≤ V_CC≤ 5.5V

2.5V ≤ V_CC≤ 4V

4V ≤ V_CC≤ 5.5V

2.5V ≤ V_CC≤ 4V

V_CC≥ 4V

0.7

1.75

1

µs

ns

All Others

2.5

™

MICROWIRE Setup Time (t_UWS) (Note

6)

20

56

MICROWIRE Hold Time (t_UWH) (Note 6)

V_CC≥ 4V

ns

MICROWIRE Output Propagation Delay

220

(t_UPD

)

Input Pulse Width (Note 7)

Interrupt Input High Time

Interrupt Input Low Time

Timer 1, 2, 3 Input High Time

Timer 1, 2, 3 Input Low Time

Reset Pulse Width

1

t_C

µs

<

Note 2: Maximum rate of voltage change must be 0.5V/ms.

Note 3: Supply current is measured after running 2000 cycles with a square wave CKI input, CKO open, inputs at rails and outputs open.

Note 4: The HALT mode will stop CKI from oscillating in the RC and the Crystal configurations. Measurement of I HALT is done with device neither sourcing or

DD

sinking current; with L, C, and G0–G5 programmed as low outputs and not driving a load; all outputs programmed low and not driving a load; all inputs tied to V

;

CC

clock monitor and comparator disabled. Parameter refers to HALT mode entered via setting bit 7 of the G Port data register. Part will pull up CKI during HALT in crystal

clock mode.

Note 5: Pins G6 and RESET are designed with a high voltage input network. These pins allow input voltages V and the pins will have sink current to V when

CC CC

biased at voltages V (the pins do not have source current when biased at a voltage below V ). The effective resistance to V is 750Ω (typical). These two pins

CC CC CC

will not latch up. The voltage at the pins must be limited to less than 14V. WARNING: Voltages in excess of 14V will cause damage to the pins. This warning

excludes ESD transients.

Note 6: The output propagation delay is referenced to the end of the instruction cycle where the output change occurs.

Note 7: Parameter characterized but not tested.

Note 8:

t = Instruction Cycle Time.

C

5

www.national.com

Absolute Maximum Ratings (Note 9)

If Military/Aerospace specified devices are required,

please contact the National Semiconductor Sales Office/

Distributors for availability and specifications.

Total Current into V_CCPin (Source)

Total Current out of GND Pin (Sink)

Storage Temperature Range

Note 9: Absolute maximum ratings indicate limits beyond which damage to

the device may occur. DC and AC electrical specifications are not ensured

when operating the device at absolute maximum ratings.

100 mA

110 mA

−65˚C to +140˚C

Supply Voltage (V_CC

)

7V

Voltage at Any Pin

−0.3V to V_CC+0.3V

DC Electrical Characteristics

−40˚C ≤ T_A≤ +85˚C unless otherwise specified

Parameter

Conditions

Min

Typ

Max

5.5

Units

Operating Voltage

2.5

V

Power Supply Ripple (Note 10)

Supply Current (Note 11)

CKI = 4 MHz

Peak-to-Peak

0.1 V_CC

V_CC= 5.5V, t_C= 2.5 µs

V_CC= 4V, t_C= 2.5 µs

V_CC= 4V, t_C= 10 µs

5.5

2.5

1.4

10

6

mA

µA

CKI = 4 MHz

CKI = 1 MHz

<

HALT Current (Note 12)

V_CC= 5.5V, CKI = 0 MHz

V_CC= 4V, CKI = 0 MHz

5

3

µA

IDLE Current

CKI = 4 MHz

CKI = 1 MHz

V_CC= 5.5V, t_C= 2.5 µs

V_CC= 4V, t_C= 10 µs

1.5

0.5

mA

Input Levels (V_IH, V_IL

)

RESET

Logic High

0.8 V_CC

0.7 V_CC

V

Logic Low

0.2 V_CC

CKI, All Other Inputs

Logic High

V

Logic Low

0.2 V_CC

+2

Hi-Z Input Leakage

Input Pullup Current

V_CC= 5.5V

−2

µA

V

V_CC= 5.5V, V_IN= 0V

(Note 14)

−40

−250

G and L Port Input Hysteresis

Output Current Levels

D Outputs

0.35 V_CC

Source

V_CC= 4V, V_OH= 3.3V

V_CC= 2.5V, V_OH= 1.8V

V_CC= 4V, V_OL= 1V

−0.4

−0.2

10

mA

Sink

V_CC= 2.5V, V_OL= 0.4V

2.0

All Others

Source (Weak Pull-Up Mode)

V_CC= 4V, V_OH= 2.7V

V_CC= 2.5V, V_OH= 1.8V

V_CC= 4V, V_OH= 3.3V

V_CC= 2.5V, V_OH= 1.8V

V_CC= 4V, V_OL= 0.4V

V_CC= 2.5V, V_OL= 0.4V

V_CC= 5.5V

−10

−2.5

−0.4

−0.2

1.6

−110

−33

µA

Source (Push-Pull Mode)

Sink (Push-Pull Mode)

mA

µA

0.7

TRI-STATE Leakage

Allowable Sink/Source

Current per Pin

−2

+2

D Outputs (Sink)

15

3

mA

All others

±

200

Maximum Input Current

without Latchup (Note 13)

RAM Retention Voltage, V_r

Room Temp

500 ns Rise and Fall Time (min)

6

2

V

www.national.com

DC Electrical Characteristics (Continued)

−40˚C ≤ T_A≤ +85˚C unless otherwise specified

Parameter

Input Capacitance

Load Capacitance on D2

Conditions

Min

Typ

Max

7

Units

pF

(Note 14)

1000

pF

AC Electrical Characteristics

−40˚C ≤ T_A≤ +85˚C unless otherwise specified

Parameter

Instruction Cycle Time (t_C)

Crystal, Resonator

Conditions

Min

Typ

Max

Units

<

2.5V ≤ V_CC4V

2.5

1.0

7.5

3.0

DC

µs

4V ≤ V_CC≤ 5.5V

<

2.5V ≤ V_CC4V

R/C Oscillator

<

4V ≤ V_CC5.5V

Inputs

t_SETUP

4V ≤ V_CC≤ 5.5V

200

500

60

ns

<

2.5V ≤ V_CC4V

t_HOLD

4V ≤ V_CC≤ 5.5V

<

2.5V ≤ V_CC4V

150

Output Propagation Delay (Note 14)

R_L= 2.2k, C_L= 100 pF

t

_PD1, t_PD0

SO, SK

4V ≤ V_CC≤ 5.5V

0.7

1.75

1

µs

ns

<

2.5V ≤ V_CC4V

All Others

4V ≤ V_CC≤ 5.5V

<

2.5V ≤ V_CC4V

2.5

MICROWIRE Setup Time (t_UWS) (Note 14)

MICROWIRE Hold Time (t_UWH) (Note 14)

MICROWIRE Output Propagation Delay (t_UPD

Input Pulse Width (Note 15)

V_CC≥ 4V

20

56

)

220

Interrupt Input High Time

1

t_C

µs

Interrupt Input Low Time

Timer 1, 2, 3 Input High Time

Timer 1, 2, 3 Input Low Time

Reset Pulse Width

<

Note 10: Maximum rate of voltage change must be 0.5 V/ms.

Note 11: Supply current is measured after running 2000 cycles with a square wave CKI input, CKO open, inputs at rails and outputs open.

Note 12: The HALT mode will stop CKI from oscillating in the RC and the Crystal configurations. Measurement of I HALT is done with device neither sourcing or

DD

sinking current; with L, C, and G0–G5 programmed as low outputs and not driving a load; all outputs programmed low and not driving a load; all inputs tied to V

;

CC

clock monitor and comparator disabled. Parameter refers to HALT mode entered via setting bit 7 of the G Port data register. Part will pull up CKI during HALT in crystal

clock mode.

Note 13: Pins G6 and RESET are designed with a high voltage input network. These pins allow input voltages V and the pins will have sink current to V when

CC

biased at voltages greater than V

CC

(the pins do not have source current when biased at a voltage below V ). The effective resistance to V

is 750Ω (typical).

C

These two pins will not latch up. The voltage at the pins must be limited to less than 14V. WARNING: Voltages in excess of 14V will cause damage to the pins.

This warning excludes ESD transients.

Note 14: The output propagation delay is referenced to the end of the instruction cycle where the output change occurs.

Note 15: Parameter characterized but not tested.

Note 16:

t = Instruction Cycle Time.

C

7

www.national.com

Comparator AC and DC Characteristics

V_CC= 5V, −40˚C ≤ T_A≤ +85˚C

Parameter

Input Offset Voltage

Conditions

Min

Typ

Max

Units

<

0.4V V_INV_CC

10

25

mV

−1.5V

Input Common Mode Voltage Range (Note

17)

0.4

V_CC−1.5

V

Voltage Gain

300k

V/V

V

<

V

_CC/2 Reference

4.0V V_CC5.5V

0.5 V_CC

−0.04

0.5V_CC

+0.04

DC Supply Current

V_CC= 5.5V

250

µA

For Comparator (when enabled)

DC Supply Current

V_CC= 5.5V

50

80

For V_CC/2 reference (when enabled)

DC Supply Current

200

For Constant Current Source (when enabled)

Constant Current Source

<

4.0V V_CC5.5V

7

20

32

2

µA

<

Current Source Variation

4.0V V_CC5.5V

Temp = Constant

Current Source Enable Time

Comparator Response Time

1.5

2

1

µs

10 mV overdrive,

100 pF load

Note 17: The device is capable of operating over a common mode voltage range of 0 to V − 1.5V, however increased offset voltage will be observed between 0V

CC

and 0.4V.

DS012865-4

FIGURE 4. MICROWIRE/PLUS Timing

www.national.com

8

=

Typical Performance Characteristics (−55˚C ≤ T_A+125˚C)

DS012865-40

DS012865-41

DS012865-43

DS012865-44

DS012865-42

DS012865-44

9

www.national.com

=

Typical Performance Characteristics (−55˚C ≤ T_A+125˚C) (Continued)

DS012865-46

DS012865-47

DS012865-48

DS012865-49

DS012865-50

DS012865-51

www.national.com

10

Pin Descriptions

V_CCand GND are the power supply pins. All V_CCand GND

G2–G6 all have Schmitt Triggers on their inputs. Pin G1

serves as the dedicated WDOUT WATCHDOG output, while

pin G7 is either input or output depending on the oscillator

mask option selected. With the crystal oscillator option se-

lected, G7 serves as the dedicated output pin for the CKO

clock output. With the single-pin R/C oscillator mask option

selected, G7 serves as a general purpose input pin but is

also used to bring the device out of HALT mode with a low to

high transition on G7. There are two registers associated

with the G Port, a data register and a configuration register.

Therefore, each of the 5 I/O bits (G0, G2–G5) can be indi-

vidually configured under software control.

pins must be connected.

CKI is the clock input. This can come from an R/C generated

oscillator, or a crystal oscillator (in conjunction with CKO).

See Oscillator Description section.

RESET is the master reset input. See Reset description sec-

tion.

The device contains two bidirectional (one 8-bit, one 4-bit)

I/O ports (G and L), where each individual bit may be inde-

pendently configured as a weak pullup input, TRI-STATE^®

(Hi-Z) input or push pull output under program control. Ports

G- and L- feature Schmitt trigger inputs. Three data memory

address locations are allocated for each of these I/O ports.

Each I/O port has two associated 8-bit memory mapped reg-

isters, the CONFIGURATION register and the output DATA

register. A memory mapped address is also reserved for the

input pins of each I/O port. (See the memory map for the

various addresses associated with the I/O ports.) Figure 5

shows the I/O port configurations. The DATA and CONFIGU-

RATION registers allow for each port bit to be individually

configured under software control as shown below:

Since G6 is an input only pin and G7 is the dedicated CKO

clock output pin (crystal clock option) or general purpose in-

put (R/C clock option), the associated bits in the data and

configuration registers for G6 and G7 are used for special

purpose functions as outlined below. Reading the G6 and G7

data bits will return zeros.

Note that the chip will be placed in the HALT mode by writing

a “1” to bit 7 of the Port G Data Register. Similarly the chip

will be placed in the IDLE mode by writing a “1” to bit 6 of the

Port G Data Register.

PORT L is a 4-bit I/O port. All L-pins have Schmitt triggers on

Writing a “1” to bit 6 of the Port G Configuration Register en-

ables the MICROWIRE/PLUS to operate with the alternate

phase of the SK clock. The G7 configuration bit, if set high,

enables the clock start up delay after HALT when the R/C

clock configuration is used.

the inputs.

The Port L supports Multi-Input Wake Up on all four pins.

The Port L has the following alternate features:

L7 MIWU or external interrupt

L6 MIWU or external interrupt

L5 MIWU or external interrupt

L4 MIWU or external interrupt

Config Reg.

CLKDLY

Data Reg.

HALT

G7

G6

Alternate SK

IDLE

Port G has the following alternate features:

G6 SI (MICROWIRE Serial Data Input)

G5 SK (MICROWIRE Serial Clock)

G4 SO (MICROWIRE Serial Data Output)

G3 T1A (Timer T1 I/O)

G2 T1B (Timer T1 Capture Input)

G0 INTR (External Interrupt Input)

Port G has the following dedicated functions:

G7 CKO Oscillator dedicated output or general purpose

input

G1 WDOUT WATCHDOG and/or Clock Monitor dedicated

output.

Port I is an eight-bit Hi-Z input port.

DS012865-5

Port I0–I7 are used for the analog function block.

The Port I has the following alternate features:

I7 C_OUT(Comparator Output)

FIGURE 5. I/P Port Configurations

Configuration

Data

Port Set-Up

Register

I6 Analog CH6 (Comparator Positive Input 6)

I5 Analog CH5 (Comparator Positive Input 5)

I4 Analog CH4 (Comparator Positive Input 4)

0

1

0

1

Hi-Z Input (TRI-STATE Output)

Input with Weak Pull-Up

Push-Pull Zero Output

0

1

I3 Analog CH3 (Comparator Positive Input 3/Comparator

Output)

1

Push-Pull One Output

Please note:

I2 Analog CH2 (Comparator Positive Input 2)

I1 I_SRC(Comparator Negative Input/Current Source Out)

I0 Analog CH1 (Comparator Positive Input 1)

The lower 4 L-bits read all ones (L0:L3). This is independant

from the states of the associated bits in the L-port Data- and

Configuration register. The lower 4 bits in the L-port Data-

and Configuration register can be used as general purpose

status indicators (flags).

Port D is a 4-bit output port that is preset high when RESET

goes low. The user can tie two or more D port outputs (ex-

cept D2) together in order to get a higher drive.

Port G is an 8-bit port with 5 I/O pins (G0, G2–G5), an input

pin (G6), and a dedicated output pin (G7). Pins G0 and

11

www.national.com

Functional Description

Reset

The architecture of the device is a modified Harvard archi-

tecture. With the Harvard architecture, the control store pro-

gram memory (ROM) is separated from the data store

memory (RAM). Both ROM and RAM have their own sepa-

rate addressing space with separate address buses. The ar-

chitecture, though based on the Harvard architecture, per-

mits transfer of data from ROM to RAM.

The RESET input when pulled low initializes the microcon-

troller. Initialization will occur whenever the RESET input is

pulled low. Upon initialization, the data and configuration

registers for ports L and G are cleared, resulting in these

Ports being initialized to the TRI-STATE mode. Pin G1 of the

G Port is an exception (as noted below) since pin G1 is dedi-

cated as the WATCHDOG and/or Clock Monitor error output

pin. Port

D is set high. The PC, PSW, ICNTRL and

CPU REGISTERS

CNTRL-control registers are cleared. The Comparator Se-

lect Register is cleared. The S register is initialized to zero.

The Multi-Input Wakeup registers WKEN and WKEDG are

cleared. Wakeup register WKPND is unknown. The stack

pointer, SP, is initialized to 6F Hex.

The CPU can do an 8-bit addition, subtraction, logical or shift

operation in one instruction (t_C) cycle time.

There are six CPU registers:

A is the 8-bit Accumulator Register

The device comes out of reset with both the WATCHDOG

logic and the Clock Monitor detector armed, with the

WATCHDOG service window bits set and the Clock Monitor

bit set. The WATCHDOG and Clock Monitor circuits are in-

hibited during reset. The WATCHDOG service window bits

being initialized high default to the maximum WATCHDOG

service window of 64k t_Cclock cycles. The Clock Monitor bit

being initialized high will cause a Clock Monitor error follow-

ing reset if the clock has not reached the minimum specified

frequency at the termination of reset. A Clock Monitor error

will cause an active low error output on pin G1. This error

output will continue until 16 t_C-32 t_Cclock cycles following

the clock frequency reaching the minimum specified value,

at which time the G1 output will enter the TRI-STATE mode.

PC^®is the 15-bit Program Counter Register

PU is the upper 7 bits of the program counter (PC)

PL is the lower 8 bits of the program counter (PC)

B is an 8-bit RAM address pointer, which can be optionally

post auto incremented or decremented.

X is an 8-bit alternate RAM address pointer, which can be

optionally post auto incremented or decremented.

SP is the 8-bit stack pointer, which points to the subroutine/

interrupt stack (in RAM). The SP is initialized to RAM ad-

dress 06F with reset.

All the CPU registers are memory mapped with the excep-

tion of the Accumulator (A) and the Program Counter (PC).

The external RC network shown in Figure 6 should be used

to ensure that the RESET pin is held low until the power sup-

ply to the chip stabilizes.

PROGRAM MEMORY

The program memory consists of 4096 bytes of ROM. These

bytes may hold program instructions or constant data (data

tables for the LAID instruction, jump vectors for the JID in-

struction, and interrupt vectors for the VIS instruction). The

program memory is addressed by the 15-bit program

counter (PC). All interrupts in the device vector to program

memory location 0FF Hex.

WARNING:

When the device is held in reset for a long time it will con-

sume high current (typically about 7 mA). This is not true for

the equivalent ROM device (COP8ACC5).

Oscillator Circuits

DATA MEMORY

The chip can be driven by a clock input on the CKI input pin

which can be between DC and 10 MHz. The CKO output

clock is on pin G7 (crystal configuration). The CKI input fre-

quency is divided down by 10 to produce the instruction

cycle clock (t_C).

The data memory address space includes the on-chip RAM

and data registers, the I/O registers (Configuration, Data and

Pin), the control registers, the MICROWIRE/PLUS SIO shift

register, and the various registers, and counters associated

with the timers (with the exception of the IDLE timer). Data

memory is addressed directly by the instruction or indirectly

by the B, X, and SP pointers.

The data memory consists of 128 bytes of RAM. Sixteen

bytes of RAM are mapped as “registers” at addresses 0F0 to

0FF Hex. These registers can be loaded immediately, and

also decremented and tested with the DRSZ (decrement

register and skip if zero) instruction. The memory pointer

registers X, B and SP are memory mapped into this space at

address locations 0FC to 0FF Hex respectively, with the

other registers being available for general usage.

DS012865-6

>

RC 5 x POWER SUPPLY RISE TIME

The instruction set permits any bit in memory to be set, reset

or tested. All I/O and registers (except A and PC) are

memory mapped; therefore, I/O bits and register bits can be

directly and individually set, reset and tested. The accumula-

tor (A) bits can also be directly and individually tested.

Note: RAM contents are undefined upon power-up.

FIGURE 6. Recommended Reset Circuit

Figure 7 shows the Crystal and R/C Oscillator diagrams.

www.national.com

12

Oscillator Circuits (Continued)

Control Registers

CNTRL Register (Address X'00EE)

T1C3

Bit 7

T1C2

T1C1

T1C0 MSEL

IEDG

SL1

SL0

Bit 0

The Timer1 (T1) and MICROWIRE/PLUS control register

contains the following bits:

T1C3

T1C2

T1C1

T1C0

Timer T1 mode control bit

Timer T1 Start/Stop control in timer

modes 1 and 2, T1 Underflow Interrupt

Pending Flag in timer mode 3

DS012865-7

MSEL

IEDG

Selects G5 and G4 as MICROWIRE/PLUS

signals SK and SO respectively

External interrupt edge polarity select

(0 = Rising edge, 1 = Falling edge)

SL1 & SL0 Select the MICROWIRE/PLUS clock divide

by (00 = 2, 01 = 4, 1x = 8)

PSW Register (Address X'00EF)

DS012865-8

HC

C

T1PNDA T1ENA EXPND BUSY EXEN GIE

Bit 0

FIGURE 7. Crystal and R/C Oscillator Diagrams

Bit 7

CRYSTAL OSCILLATOR

The PSW register contains the following select bits:

CKI and CKO can be connected to make a closed loop crys-

tal (or resonator) controlled oscillator.

HC

C

Half Carry Flag

Carry Flag

Table 1 shows the component values required for various

standard crystal values.

T1PNDA Timer T1 Interrupt Pending Flag (Autoreload

RA in mode 1, T1 Underflow in Mode 2, T1A

capture edge in mode 3)

=

TABLE 1. Crystal Oscillator Configuration, T_A25˚C

T1ENA

Timer T1 Interrupt Enable for Timer Underflow

or T1A Input capture edge

R1

R2

C1

C2

CKI Freq

(MHz)

10

Conditions

(kΩ) (MΩ) (pF)

(pF)

EXPND External interrupt pending

=

0

1

30

30–36

V_CC5V

BUSY

EXEN

GIE

MICROWIRE/PLUS busy shifting flag

=

Enable external interrupt

4

V_CC5V

=

V_CC5V

Global interrupt enable (enables interrupts)

200 100–150

0.455

The Half-Carry flag is also affected by all the instructions that

affect the Carry flag. The SC (Set Carry) and R/C (Reset

Carry) instructions will respectively set or clear both the carry

flags. In addition to the SC and R/C instructions, ADC,

SUBC, RRC and RLC instructions affect the Carry and Half

Carry flags.

R/C OSCILLATOR

By selecting CKI as a single pin oscillator input, a single pin

R/C oscillator circuit can be connected to it. CKO is available

as a general purpose input, and/or HALT restart input.

Note: Use of the R/C oscillator option will result in higher electromagnetic

emissions.

ICNTRL Register (Address X'00E8)

Table 2 shows the variation in the oscillator frequencies as

functions of the component (R and C) values.

Reserved LPEN T0PND T0EN µWPND µWEN T1PNDB T1ENB

Bit 7

Bit 0

=

TABLE 2. RC Oscillator Configuration, T_A25˚C

The ICNTRL register contains the following bits:

Reserved This bit is reserved and should be zero.

R

C

CKI Freq

(MHz)

Instr. Cycle

(µs)

Conditions

LPEN

L Port Interrupt Enable (Multi-Input Wakeup/

(kΩ)

3.3

5.6

6.8

(pF)

82

Interrupt)

=

V_CC5V

2.2 to 2.7

1.1 to 1.3

0.9 to 1.1

3.7 to 4.6

7.4 to 9.0

8.8 to 10.8

T0PND

T0EN

Timer T0 Interrupt pending

=

V_CC5V

100

Timer T0 Interrupt Enable (Bit 12 toggle)

MICROWIRE/PLUS interrupt pending

Enable MICROWIRE/PLUS interrupt

=

V_CC5V

µWPND

µWEN

Note 18: 3k ≤ R ≤ 200k

Note 19: 50 pF ≤ C ≤ 200 pF

T1PNDB Timer T1 Interrupt Pending Flag for T1B cap-

ture edge

T1ENB

Timer T1 Interrupt Enable for T1B Input cap-

ture edge

13

www.national.com

is used to perform a task upon exit from the IDLE mode. For

more information on the IDLE mode, refer to the Power Save

Modes section.

Timers

The device contains a very versatile set of timers (T0 and

T1). All timers and associated autoreload/capture registers

power up containing random data.

The Idle Timer period is selected by bits 0–2 of the ITMR

register Bits 3–7 of the ITMR Register are reserved and

should not be used as software flags.

TIMER T0 (IDLE TIMER)

The device supports applications that require maintaining

real time and low power with the IDLE mode. This IDLE

mode support is furnished by the IDLE timer T0, which is a

16-bit timer. The Timer T0 runs continuously at the fixed rate

of the instruction cycle clock, t_C. The user cannot read or

write to the IDLE Timer T0, which is a count down timer.

ITMR Register (Address X’0xCF)

Reserved

ITSEL2

ITSEL1

ITSEL0

Bit 0

Bit 7

Bit 3

TABLE 3. Idle Timer Window Length

The Timer T0 supports the following functions:

Idle Timer Period

•

Exit out of the Idle Mode (See Idle Mode description)

WATCHDOG logic (See WATCHDOG description)

Start up delay out of the HALT mode

ITSEL2

ITSEL1

ITSEL0

(Instruction Cycles)

4,096

0

1

0

1

X

0

1

0

1

X

8,192

Figure 8 is a functional block diagram showing the structure

of the IDLE Timer and its associated interrupt logic.

16,384

Bits 11 through 15 of the ITMR register can be selected for

triggering the IDLE Timer interrupt. Each time the selected

bit underflows (every 4k, 8k, 16k, 32k or 64k instruction

cycles), the IDLE Timer interrupt pending bit T0PND is set,

thus generating an interrupt (if enabled), and bit 6 of the Port

G data register is reset, thus causing an exit from the IDLE

mode if the device is in that mode.

32,768

65,536

The ITMR register is cleared on Reset and the Idle Timer pe-

riod is reset to 4,096 instruction cycles.

Any time the IDLE Timer period is changed there is the pos-

sibility of generating a spurious IDLE Timer interrupt by set-

ting the T0PND bit. The user is advised to disable IDLE

Timer interrupts prior to changing the value of the ITSEL bits

of the ITMR Register and then clear the T0PND bit before at-

tempting to synchronize operation to the IDLE Timer.

In order for an interrupt to be generated, the IDLE Timer in-

terrupt enable bit T0EN must be set, and the GIE (Global In-

terrupt Enable) bit must also be set. The T0PND flag and

T0EN bit are bits 5 and 4 of the ICNTRL register, respec-

tively. The interrupt can be used for any purpose. Typically, it

DS012865-9

FIGURE 8. Functional Block Diagram for Idle Timer T0

TIMER T1

with minimal software overhead. The timer block has three

operating modes: Processor Independent PWM mode, Ex-

ternal Event Counter mode, and Input Capture mode.

The device has a powerful timer/counter block. The timer

consists of a 16-bit timer, T1, and two supporting 16-bit

autoreload/capture registers, R1A and R1B. The timer block

has two pins associated with it, T1A and T1B. The pin T1A

supports I/O required by the timer block, while the pin T1B is

an input to the timer block. The powerful and flexible timer

block allows the device to easily perform all timer functions

The control bits T1C3, T1C2, and T1C1 allow selection of the

different modes of operation.

Mode 1. Processor Independent PWM Mode

As the name suggests, this mode allows the device to gen-

erate a PWM signal with very minimal user intervention. The

user only has to define the parameters of the PWM signal

www.national.com

14

The timer value gets copied over into the register when a

trigger event occurs on its corresponding pin. Control bits,

T1C3, T1C2 and T1C1, allow the trigger events to be speci-

fied either as a positive or a negative edge. The trigger con-

dition for each input pin can be specified independently.

Timers (Continued)

(ON time and OFF time). Once begun, the timer block will

continuously generate the PWM signal completely indepen-

dent of the microcontroller. The user software services the

timer block only when the PWM parameters require updat-

ing.

In this mode the timer T1 counts down at a fixed rate of t_C.

Upon every underflow the timer is alternately reloaded with

the contents of supporting registers, R1A and R1B. The very

first underflow of the timer causes the timer to reload from

the register R1A. Subsequent underflows cause the timer to

be reloaded from the registers alternately beginning with the

register R1B.

The T1 Timer control bits, T1C3, T1C2 and T1C1 set up the

timer for PWM mode operation.

Figure 9 shows a block diagram of the timer in PWM mode.

The underflows can be programmed to toggle the T1A output

pin. The underflows can also be programmed to generate in-

terrupts.

DS012865-10

Underflows from the timer are alternately latched into two

pending flags, T1PNDA and T1PNDB. The user must reset

these pending flags under software control. Two control en-

able flags, T1ENA and T1ENB, allow the interrupts from the

timer underflow to be enabled or disabled. Setting the timer

enable flag T1ENA will cause an interrupt when a timer un-

derflow causes the R1A register to be reloaded into the

timer. Setting the timer enable flag T1ENB will cause an in-

terrupt when a timer underflow causes the R1B register to be

reloaded into the timer. Resetting the timer enable flags will

disable the associated interrupts.

FIGURE 9. Timer in PWM Mode

The trigger conditions can also be programmed to generate

interrupts. The occurrence of the specified trigger condition

on the T1A and T1B pins will be respectively latched into the

pending flags, T1PNDA and T1PNDB. The control flag

T1ENA allows the interrupt on T1A to be either enabled or

disabled. Setting the T1ENA flag enables interrupts to be

generated when the selected trigger condition occurs on the

T1A pin. Similarly, the flag T1ENB controls the interrupts

from the T1B pin.

Either or both of the timer underflow interrupts may be en-

abled. This gives the user the flexibility of interrupting once

per PWM period on either the rising or falling edge of the

PWM output. Alternatively, the user may choose to interrupt

on both edges of the PWM output.

Underflows from the timer can also be programmed to gen-

erate interrupts. Underflows are latched into the timer T1C0

pending flag (the T1C0 control bit serves as the timer under-

flow interrupt pending flag in the Input Capture mode). Con-

sequently, the T1C0 control bit should be reset when enter-

ing the Input Capture mode. The timer underflow interrupt is

enabled with the T1ENA control flag. When a T1A interrupt

occurs in the Input Capture mode, the user must check both

the T1PNDA and T1C0 pending flags in order to determine

whether a T1A input capture or a timer underflow (or both)

caused the interrupt.

Mode 2. External Event Counter Mode

This mode is quite similar to the processor independent

PWM mode previously described. The main difference is that

the timer, T1, is clocked by the input signal from the T1A pin.

The T1 timer control bits, T1C3, T1C2 and T1C1 allow the

timer to be clocked either on a positive or negative edge from

the T1A pin. Underflows from the timer are latched into the

T1PNDA pending flag. Setting the T1ENA control flag will

cause an interrupt when the timer underflows.

In this mode the input pin T1B can be used as an indepen-

dent positive edge sensitive interrupt input if the T1ENB con-

trol flag is set. The occurrence of a positive edge on the T1B

input pin is latched into the T1PNDB flag.

Figure 10 shows a block diagram of the timer in External

Event Counter mode.

Note: The PWM output is not available in this mode since the T1A pin is be-

ing used as the counter input clock.

Mode 3. Input Capture Mode

The device can precisely measure external frequencies or

time external events by placing the timer block, T1, in the in-

put capture mode.

DS012865-11

FIGURE 10. Timer in External Event Counter Mode

In this mode, the timer T1 is constantly running at the fixed t_C

rate. The two registers, R1A and R1B, act as capture regis-

ters. Each register acts in conjunction with a pin. The register

R1A acts in conjunction with the T1A pin and the register

R1B acts in conjunction with the T1B pin.

15

www.national.com

TIMER CONTROL FLAGS

Timers (Continued)

The control bits and their functions are summarized below.

T1C3

T1C2

T1C1

T1C0

Timer mode control

Timer Start/Stop control in Modes 1 and 2 (Pro-

cessor Independent PWM and External Event

Counter), where 1 = Start, 0 = Stop

Timer Underflow Interrupt Pending Flag in

Mode 3 (Input Capture)

T1PNDA Timer Interrupt Pending Flag

T1ENA

Timer Interrupt Enable Flag

1 = Timer Interrupt Enabled

0 = Timer Interrupt Disabled

T1PNDB Timer Interrupt Pending Flag

DS012865-12

T1ENB

Timer Interrupt Enable Flag

1 = Timer Interrupt Enabled

0 = Timer Interrupt Disabled

FIGURE 11. Timer in Input Capture Mode

Figure 11 shows a block diagram of the timer in Input Cap-

ture mode.

The timer mode control bits (T1C3, T1C2 and T1C1) are detailed below:

Interrupt A

Interrupt B

Source

Timer

Mode

T1C3

T1C2

T1C1

Description

Source

Counts On

1

0

1

0

PWM: T1A Toggle

Autoreload RA

Autoreload RB

t_C

1

PWM: No T1A

Toggle

t_C

0

1

0

1

0

External Event

Counter

Timer

Underflow

Pos. T1B Edge

Pos. T1A

Edge

2

External Event

Counter

Timer

Underflow

Pos. T1A

Edge

Captures:

Pos. T1A Edge

or Timer

t_C

T1A Pos. Edge

T1B Pos. Edge

Captures:

Underflow

1

0

1

0

1

Pos. T1A

Neg. T1B

Edge

T1A Pos. Edge

T1B Neg. Edge

Captures:

Edge or Timer

Underflow

3

Neg. T1A

Neg. T1B

Edge

T1A Neg. Edge

T1B Neg. Edge

Captures:

Edge or Timer

Underflow

Neg. T1A

Neg. T1B

Edge

T1A Neg. Edge

T1B Neg. Edge

Edge or Timer

Underflow

HIGH SPEED CAPTURE TIMER

Setting the Capture Timer Run bit CAPRUN bit in the Cap-

ture Control Register (CAPCNTL) will start the counter. The

counter will count up until a capture event (negative edge) is

received. Upon a capture the counter will be stopped, the

Capture Pending bit (CAPPND) is set, and the CAPRUN bit

is automatically reset. If capture interrupts are enabled

The device provides a 16-bit high-speed capture timer. The

timer consists of a 16-bit up-counter that is clocked with the

device clock input frequency (CKI) and an 8-bit control regis-

ter. The 16-bit counter is mapped as two read/write 8-bit reg-

isters. This timer is specifically designed to be used in con-

junction with the Analog Function Block (comparator, analog

=

(CAPIEN 1), the capture event will generate an interrupt.

Setting the CAPRUN bit again by software will start a new

counting cycle. If the Capture Mode bit is reset (CAP-

multiplexer, constant current source) to implement

low-cost, high-resolution, single-slope A/D.

a

=

MOD 0) the capture timer will be automatically initialized to

The timer is automatically stopped in the event of a capture

to allow the software to read the timer value. Coming out of

reset the counter is disabled (stopped) and reads all “0”.

=

all “0” with each setting of the CAPRUN bit. If CAPMOD

1

the timer will not be cleared when setting the CAPRUN bit,

thus allowing the user’s software to pre-load the timer regis-

www.national.com

16

DOG logic on the device is disabled during the HALT mode.

However, the clock monitor circuitry, if enabled, remains ac-

tive and will cause the WATCHDOG output pin (WDOUT) to

go low. If the HALT mode is used and the user does not want

to activate the WDOUT pin, the Clock Monitor should be dis-

abled after the device comes out of reset (resetting the Clock

Monitor control bit with the first write to the WDSVR register).

In the HALT mode, the power requirements of the device are

minimal and the applied voltage (V_CC) may be decreased to

Timers (Continued)

ters with any desired value. This mode can be used in con-

junction with the timer’s overflow to implement for example a

programmable delay counter.

“CAPTURE MODE” is only active when the CAPRUN bit is

set, i.e. any capture events received while the timer is

=

stopped (CAPRUN 0) will be ignored and will not cause the

CAPPND bit to be set. The capture counter can also be

stopped (frozen) by the user’s software resetting the CA-

PRUN bit.

=

V_r(V_r2.0V) without altering the state of the machine.

The device supports three different ways of exiting the HALT

mode. The first method of exiting the HALT mode is with the

Multi-Input Wakeup feature on the Port L.

If the user program tries to set the CAPRUN bit at the same

time that the hardware gets a capture event and tries to reset

the CAPRUN bit, the hardware will have precedence.

The second method is with a low to high transition on the

CKO (G7) pin. This method precludes the use of the crystal

clock configuration (since CKO becomes a dedicated out-

put), and so may only be used with an RC clock configura-

tion. The third method of exiting the HALT mode is by pulling

the RESET pin low.

Should the counter overflow before a capture condition oc-

curs, the Capture Overflow bit (CAPOVL) bit in the

CAPCNTL register will be set. If Capture interrupts are en-

=

abled (CAPIEN 1) an overflow will generate an interrupt.

The user software should reset this bit before the next over-

flow occurs, otherwise subsequent overflow conditions can-

not be detected.

Since a crystal or ceramic resonator may be selected as the

oscillator, the Wakeup signal is not allowed to start the chip

running immediately since crystal oscillators and ceramic

resonators have a delayed start up time to reach full ampli-

tude and frequency stability. The IDLE timer is used to gen-

erate a fixed delay to ensure that the oscillator has indeed

stabilized before allowing instruction execution. In this case,

upon detecting a valid Wakeup signal, only the oscillator cir-

cuitry is enabled. The IDLE timer is loaded with a value of

256 and is clocked with the t_Cinstruction cycle clock. The t_C

clock is derived by dividing the oscillator clock down by a fac-

tor of 10. The Schmitt trigger following the CKI inverter on

the chip ensures that the IDLE timer is clocked only when the

oscillator has a sufficiently large amplitude to meet the

Schmitt trigger specifications. This Schmitt trigger is not part

of the oscillator closed loop. The startup timeout from the

IDLE timer enables the clock signals to be routed to the rest

of the chip.

Capture Overflow interrupt and Capture Pending interrupt

share the same interrupt vector.

CAPCNTL Register (Address (X’CE)

Reserved CAPMOD CAPRUN CAPOVL CAPPND CAPIEN

Bit 7-5

Bit 4

Bit 0

The CAPCNTL register contains the following bits:

Reserved These bits are reserved and should must be

zero.

CAPMOD Reset Time.

0: reset timer to “0” when CAPRUN bit gets set

1: DO NOT reset timer to “0” when CAPRUN bit

gets set.

CAPRUN Capture Timer Run. Setting this bit to one will

start the capture timer. This bit gets automatically

reset to “0” when a capture events occurs. Writ-

ing a “0” by software will also reset the bit and

stop the timer.

If an RC clock option is being used, the fixed delay is intro-

duced optionally. A control bit, CLKDLY, mapped as configu-

ration bit G7, controls whether the delay is to be introduced

or not. The delay is included if CLKDLY is set, and excluded

if CLKDLY is reset. The CLKDLY bit is cleared on reset.

CAPOVL Capture Timer Overflow. Gets set to “1” upon

timer overflow. Has to be reset by user’s soft-

ware. If CAPIEN 1 an interrupt is generated.

CAPPND Capture pending.

Gets automatically set when a capture event oc-

curs. If CAPIEN

Has to be reset by the user’s software.

CAPIEN Capture Interrupt enable,

The device has two mask options associated with the HALT

mode. The first mask option enables the HALT mode feature,

while the second mask option disables the HALT mode. With

the HALT mode enable mask option, the device will enter

and exit the HALT mode as described above. With the HALT

disable mask option, the device cannot be placed in the

HALT mode (writing a “1” to the HALT flag will have no effect,

the HALT flag will remain “0”).

=

1 an interrupt is generated.

=

enable interrupts, 0 disable interrupts

1

IDLE MODE

In the IDLE mode, program execution stops and power con-

sumption is reduced to a very low level as with the HALT

mode. However, the on-board oscillator, IDLE Timer (Timer

T0), and Clock Monitor continue to operate, allowing real

time to be maintained. The device remains idle for a selected

amount of time up to 65,536 instruction cycles, or 65.536 mil-

liseconds with a 1 MHz instruction clock frequency, and then

automatically exits the IDLE mode and returns to normal pro-

gram execution.

Power Save Modes

The device offers the user two power save modes of opera-

tion: HALT and IDLE. In the HALT mode, all microcontroller

activities are stopped. In the IDLE mode, the on-board oscil-

lator circuitry and timer T0 are active but all other microcon-

troller activities are stopped. In either mode, all on-board

RAM, registers, I/O states, and timers (with the exception of

T0) are unaltered.

The device is placed in the IDLE mode under software con-

trol by setting the IDLE bit (bit 6 of the Port G data register).

HALT MODE

The device can be placed in the HALT mode by writing a “1”

to the HALT flag (G7 data bit). All microcontroller activities,

including the clock and timers, are stopped. The WATCH-

17

www.national.com

by setting the T0PND bit. The user is advised to disable

IDLE Timer interrupts prior to changing the value of the IT-

SEL bits of the ITMR Register and then clear the TOPND bit

before attempting to synchronize operation to the IDLE

Timer.

Power Save Modes (Continued)

The IDLE timer window is selectable from one of five values,

4k, 8k, 16k, 32k or 64k instruction cycles. Selection of this

value is made through the ITMR register.

Note: As with the HALT mode, it is necessary to program two NOP’s to allow

clock resynchronization upon return from the IDLE mode. The NOP’s

are placed either at the beginning of the IDLE timer interrupt routine or

immediately following the “enter IDLE mode” instruction.

The IDLE mode uses the on-chip IDLE Timer (Timer T0) to

keep track of elapsed time in the IDLE state. The IDLE timer

runs continuously at the instruction clock rate, whether or not

the device is in the IDLE mode. Each time the bit of the timer

associated with the selected window toggles, the T0PND bit

is set, an interrupt is generated (if enabled), and the device

exits the IDLE mode if in that mode. If the IDLE timer inter-

rupt is enabled, the interrupt is serviced before execution of

the main program resumes. (However, the instruction which

was started as the part entered the IDLE mode is completed

before the interrupt is serviced. This instruction should be a

NOP which should follow the enter IDLE instruction.) The

user must reset the IDLE timer pending flag (T0PND) before

entering the IDLE mode.

For more information on the IDLE Timer and its associated

interrupt, see the description in the Timers section.

Multi-Input Wakeup

The Multi-Input Wakeup feature is used to return (wakeup)

the device from either the HALT or IDLE modes. Alternately

Multi-Input Wakeup/Interrupt feature may also be used to

generate up to 4 edge selectable external interrupts.

Figure 12 shows the Multi-Input Wakeup logic.

The Multi-Input Wakeup feature utilizes the L Port. The user

selects which particular L port bit (or combination of L Port

bits) will cause the device to exit the HALT or IDLE modes.

The selection is done through the register WKEN. The regis-

ter WKEN is an 8-bit read/write register, which contains a

control bit for every L port bit. Setting a particular WKEN bit

enables a Wakeup from the associated L port pin.

As with the HALT mode, this device can also be returned to

normal operation with a reset, or with a Multi-Input Wakeup

input. Upon reset the ITMR register is cleared and the ITMR

register selects the 4,096 instruction cycle tap of the Idle

Timer.

The IDLE timer cannot be started or stopped under software

control, and it is not memory mapped, so it cannot be read or

written by the software. Its state upon Reset is unknown.

Therefore, if the device is put into the IDLE mode at an arbi-

trary time, it will stay in the IDLE mode for somewhere be-

tween 1 and the selected number of instruction cycles.

The user can select whether the trigger condition on the se-

lected L Port pin is going to be either a positive edge (low to

high transition) or a negative edge (high to low transition).

This selection is made via the register WKEDG, which is an

8-bit control register with a bit assigned to each L Port pin.

Setting the control bit will select the trigger condition to be a

negative edge on that particular L Port pin. Resetting the bit

selects the trigger condition to be a positive edge. Changing

an edge select entails several steps in order to avoid a

Wakeup condition as a result of the edge change. First, the

associated WKEN bit should be reset, followed by the edge

select change in WKEDG. Next, the associated WKPND bit

should be cleared, followed by the associated WKEN bit be-

ing re-enabled.

In order to precisely time the duration of the IDLE state, entry

into the IDLE mode must be synchronized to the state of the

IDLE Timer. The best way to do this is to use the IDLE Timer

interrupt, which occurs on every underflow of the bit of the

IDLE Timer which is associated with the selected window.

Another method is to poll the state of the IDLE Timer pending

bit T0PND, which is set on the same occurrence. The Idle

Timer interrupt is enabled by setting bit T0EN in the ICNTRL

register.

Any time the IDLE Timer window length is changed there is

the possibility of generating a spurious IDLE Timer interrupt

www.national.com

18

Multi-Input Wakeup (Continued)

DS012865-13

FIGURE 12. Multi-Input Wake Up Logic

An example may serve to clarify this procedure. Suppose we

wish to change the edge select from positive (low going high)

to negative (high going low) for L Port bit 5, where bit 5 has

previously been enabled for an input interrupt. The program

would be as follows:

PORT L INTERRUPTS

Port L provides the user with an additional eight fully select-

able, edge sensitive interrupts which are all vectored into the

same service subroutine.

The interrupt from Port L shares logic with the wake up cir-

cuitry. The register WKEN allows interrupts from Port L to be

individually enabled or disabled. The register WKEDG speci-

fies the trigger condition to be either a positive or a negative

edge. Finally, the register WKPND latches in the pending

trigger conditions.

RBIT 5, WKEN

; Disable MIWU

SBIT 5, WKEDG ; Change edge polarity

RBIT 5, WKPND ; Reset pending flag

SBIT 5, WKEN

; Enable MIWU

If the L port bits have been used as outputs and then

changed to inputs with Multi-Input Wakeup/Interrupt, a safety

procedure should also be followed to avoid wakeup condi-

tions. After the selected L port bits have been changed from

output to input but before the associated WKEN bits are en-

abled, the associated edge select bits in WKEDG should be

set or reset for the desired edge selects, followed by the as-

sociated WKPND bits being cleared.

The GIE (Global Interrupt Enable) bit enables the interrupt

function.

A control flag, LPEN, functions as a global interrupt enable

for Port L interrupts. Setting the LPEN flag will enable inter-

rupts and vice versa. A separate global pending flag is not

needed since the register WKPND is adequate.

Since Port L is also used for waking the device out of the

HALT or IDLE modes, the user can elect to exit the HALT or

IDLE modes either with or without the interrupt enabled. If he

elects to disable the interrupt, then the device will restart ex-

ecution from the instruction immediately following the in-

struction that placed the microcontroller in the HALT or IDLE

modes. In the other case, the device will first execute the in-

terrupt service routine and then revert to normal operation.

(See HALT MODE for clock option wakeup information.)

This same procedure should be used following reset, since

the L port inputs are left floating as a result of reset.

The occurrence of the selected trigger condition for

Multi-Input Wakeup is latched into a pending register called

WKPND. The respective bits of the WKPND register will be

set on the occurrence of the selected trigger edge on the cor-

responding Port L pin. The user has the responsibility of

clearing these pending flags. Since WKPND is a pending

register for the occurrence of selected wakeup conditions,

the device will not enter the HALT mode if any Wakeup bit is

both enabled and pending. Consequently, the user must

clear the pending flags before attempting to enter the HALT

mode.

WKEN, WKPND and WKEDG are all read/write registers,

and are cleared at reset.

19

www.national.com

nominal 20 µA constant current at the I1

pin. This current can be used to ensure a

linear charging rate on an external capaci-

tor. This bit has no affect and the current

source is disabled if the comparator is not

Analog Function Block

This device contains an analog function block with the intent

to provide a function which allows for single slope, low cost,

A/D conversion of up to 6 channels.

=

enabled (CMPEN 0).

CMPSL REGISTER (ADDRESS X’00B7)

=

CMPEN

Enable the comparator (“1” enable)

CMPT2B

Bit 7

CMPISEL2

CMPISEL1

CMPISEL0

CMPOE

CSEN

CMPEN

CMPNEG

Bit 0

CMPNEG

Will drive I1 to a low level. This bit can be

used to discharge an external capacitor.

This bit is disabled if the comparator is not

The CMPSL register contains the following bits:

=

enabled (CMPEN 0).

CMPT2B

Selects the “High Speed 16-bit Capture

Timer” input to be driven directly by the

comparator output. If the comparator is dis-

The Comparator Select Register is cleared on RESET (the

comparator is disabled). To save power the program should

also disable the comparator before the µC enters the HALT/

IDLE modes. Disabling the comparator will turn off the con-

stant current source and the V_CC/2 reference, disconnect the

comparator output from the Capture Timer input and pin I3/I7

and remove the low on I1 caused by CMPNEG.

=

abled (CMPEN 0), this function is dis-

abled, i.e. the Capture Timer input is con-

nected to GND.

CMPISEL0/1/2 Will select one of seven possible sources

(I0/I2/I3/I4/I5/I6/internal reference) as

a

positive input to the comparator (see Table

4 for more information)

It is often useful for the user’s program to read the result of

a comparator operation. Since I1 is always selected to be

=

COMPIN — when the comparator is enabled (CMPEN 1),

CMPOE

CSEN

Enables the comparator output to either pin

the comparator output can be read internally by reading bit 1

(CMPRD) of register PORTI (RAM address 0xD7).

=

I3 or pin I7 (“1” enable) depending on the

value of CMPISEL0/1/2.

The following table lists the comparator inputs and outputs

versus the value of the CMPISEL0/1/2 bits. The output will

only be driven if the CMPOE bit is set to 1.

Enables the internal constant current

source. This current source provides

a

DS012865-14

FIGURE 13. Analog Function Block

www.national.com

20

Analog Function Block (Continued)

TABLE 4. Comparator Input Selection

Comparator

Input Source

Control Bit

CMPISEL1

Comparator

Output

Neg.

Pos.

CMPISEL2

CMPISEL0

Input

I1

Input

0

1

0

1

0

1

0

1

0

1

0

1

0

1

I2 CH2

I3 CH3

I0 CH1

I4 CH4

I5 CH5

I6 CH6

I3

I7

I1

V

_CC/2

Ref.

Reset

Interrupts

The state of the Analog Block immediately after RESET is as

follows:

INTRODUCTION

Each device supports eight vectored interrupts. Interrupt

sources include Timer 0, Timer 1, Timer 2, Timer 3, Port L

Wakeup, Software Trap, MICROWIRE/PLUS, and External

Input.

1. The CMPSL Register is set to all zeros

2. The Comparator is disabled

3. The Constant Current Source is disabled

4. CMPNEG is turned off

All interrupts force a branch to location 00FF Hex in program

memory. The VIS instruction may be used to vector to the

appropriate service routine from location 00FF Hex.

5. The Port I inputs are electrically isolated from the com-

parator

6. The Capture Timer input is connected to GND

7. CMPISEL0–CMPISEL2 are set to zero

The Software trap has the highest priority while the default

VIS has the lowest priority.

Each of the 8 maskable inputs has a fixed arbitration ranking

and vector.

8. All Port I inputs are selected to the default digital input

mode

Figure 14 shows the Interrupt Block Diagram.

The comparator outputs have the same specification as

Ports L and G except that the rise and fall times are sym-

metrical.

21

www.national.com

Interrupts (Continued)

DS012865-15

FIGURE 14. Interrupt Block Diagram

MASKABLE INTERRUPTS

abled; if the pending bit is already set, it will immediately trig-

ger an interrupt. A maskable interrupt is active if its associ-

ated enable and pending bits are set.

All interrupts other than the Software Trap are maskable.

Each maskable interrupt has an associated enable bit and

pending flag bit. The pending bit is set to 1 when the interrupt

condition occurs. The state of the interrupt enable bit, com-

bined with the GIE bit determines whether an active pending

flag actually triggers an interrupt. All of the maskable inter-

rupt pending and enable bits are contained in mapped con-

trol registers, and thus can be controlled by the software.

An interrupt is an asychronous event which may occur be-

fore, during, or after an instruction cycle. Any interrupt which

occurs during the execution of an instruction is not acknowl-

edged until the start of the next normally executed instruction

is to be skipped, the skip is performed before the pending in-

terrupt is acknowledged.

A maskable interrupt condition triggers an interrupt under the

following conditions:

At the start of interrupt acknowledgment, the following ac-

tions occur:

1. The enable bit associated with that interrupt is set.

2. The GIE bit is set.

1. The GIE bit is automatically reset to zero, preventing any

subsequent maskable interrupt from interrupting the cur-

rent service routine. This feature prevents one maskable

interrupt from interrupting another one being serviced.

3. The device is not processing a non-maskable interrupt.

(If

a non-maskable interrupt is being serviced, a

2. The address of the instruction about to be executed is

pushed onto the stack.

maskable interrupt must wait until that service routine is

completed.)

3. The program counter (PC) is loaded with 00FF Hex,

causing a jump to that program memory location.

An interrupt is triggered only when all of these conditions are

met at the beginning of an instruction. If different maskable

interrupts meet these conditions simultaneously, the highest

priority interrupt will be serviced first, and the other pending

interrupts must wait.

The device requires seven instruction cycles to perform the

actions listed above.

If the user wishes to allow nested interrupts, the interrupts

service routine may set the GIE bit to 1 by writing to the PSW

register, and thus allow other maskable interrupts to interrupt

the current service routine. If nested interrupts are allowed,

caution must be exercised. The user must write the program

in such a way as to prevent stack overflow, loss of saved

context information, and other unwanted conditions.

Upon Reset, all pending bits, individual enable bits, and the

GIE bit are reset to zero. Thus, a maskable interrupt condi-

tion cannot trigger an interrupt until the program enables it by

setting both the GIE bit and the individual enable bit. When

enabling an interrupt, the user should consider whether or

not a previously activated (set) pending bit should be ac-

knowledged. If, at the time an interrupt is enabled, any pre-

vious occurrences of the interrupt should be ignored, the as-

sociated pending bit must be reset to zero prior to enabling

the interrupt. Otherwise, the interrupt may be simply en-

The interrupt service routine stored at location 00FF Hex

should use the VIS instruction to determine the cause of the

interrupt, and jump to the interrupt handling routine corre-

sponding to the highest priority enabled and active interrupt.

Alternately, the user may choose to poll all interrupt pending

www.national.com

22

Table 5 shows the types of interrupts, the interrupt arbitration

ranking, and the locations of the corresponding vectors in

the vector table.

Interrupts (Continued)

and enable bits to determine the source(s) of the interrupt. If

more than one interrupt is active, the user’s program must

decide which interrupt to service.

The vector table should be filled by the user with the memory

locations of the specific interrupt service routines. For ex-

ample, if the Software Trap routine is located at 0310 Hex,

then the vector location 0yFE and -0yFF should contain the

data 03 and 10 Hex, respectively. When a Software Trap in-

terrupt occurs and the VIS instruction is executed, the pro-

gram jumps to the address specified in the vector table.

Within a specific interrupt service routine, the associated

pending bit should be cleared. This is typically done as early

as possible in the service routine in order to avoid missing

the next occurrence of the same type of interrupt event.

Thus, if the same event occurs a second time, even while the

first occurrence is still being serviced, the second occur-

rence will be serviced immediately upon return from the cur-

rent interrupt routine.

The interrupt sources in the vector table are listed in order of

rank, from highest to lowest priority. If two or more enabled

and pending interrupts are detected at the same time, the

one with the highest priority is serviced first. Upon return

from the interrupt service routine, the next highest-level

pending interrupt is serviced.

An interrupt service routine typically ends with an RETI in-

struction. This instruction sets the GIE bit back to 1, pops the

address stored on the stack, and restores that address to the

program counter. Program execution then proceeds with the

next instruction that would have been executed had there

been no interrupt. If there are any valid interrupts pending,

the highest-priority interrupt is serviced immediately upon re-

turn from the previous interrupt.

If the VIS instruction is executed, but no interrupts are en-

abled and pending, the lowest-priority interrupt vector is

used, and a jump is made to the corresponding address in

the vector table. This is an unusual occurrence, and may be

the result of an error. It can legitimately result from a change

in the enable bits or pending flags prior to the execution of

the VIS instruction, such as executing a single cycle instruc-

tion which clears an enable flag at the same time that the

pending flag is set. It can also result, however, from inadvert-

ent execution of the VIS command outside of the context of

an interrupt.

VIS INSTRUCTION

The general interrupt service routine, which starts at address

00FF Hex, must be capable of handling all types of inter-

rupts. The VIS instruction, together with an interrupt vector

table, directs the device to the specific interrupt handling rou-

tine based on the cause of the interrupt.

The default VIS interrupt vector can be useful for applica-

tions in which time critical interrupts can occur during the

servicing of another interrupt. Rather than restoring the pro-

gram context (A, B, X, etc.) and executing the RETI instruc-

tion, an interrupt service routine can be terminated by return-

ing to the VIS instruction. In this case, interrupts will be

serviced in turn until no further interrupts are pending and

the default VIS routine is started. After testing the GIE bit to

ensure that execution is not erroneous, the routine should

restore the program context and execute the RETI to return

to the interrupted program.

VIS is a single-byte instruction, typically used at the very be-

ginning of the general interrupt service routine at address

00FF Hex, or shortly after that point, just after the code used

for context switching. The VIS instruction determines which

enabled and pending interrupt has the highest priority, and

causes an indirect jump to the address corresponding to that

interrupt source. The jump addresses (vectors) for all pos-

sible interrupts sources are stored in a vector table.

The vector table may be as long as 32 bytes (maximum of 16

vectors) and resides at the top of the 256-byte block contain-

ing the VIS instruction. However, if the VIS instruction is at

the very top of a 256-byte block (such as at 00FF Hex), the

vector table resides at the top of the next 256-byte block.

Thus, if the VIS instruction is located somewhere between

00FF and 01DF Hex (the usual case), the vector table is lo-

cated between addresses 01E0 and 01FF Hex. If the VIS in-

struction is located between 01FF and 02DF Hex, then the

vector table is located between addresses 02E0 and 02FF

Hex, and so on.

This technique can save up to fifty instruction cycles (t_c), or

more, (50µs at 10 MHz oscillator) of latency for pending in-

terrupts with a penalty of fewer than ten instruction cycles if

no further interrupts are pending.

To ensure reliable operation, the user should always use the

VIS instruction to determine the source of an interrupt. Al-

though it is possible to poll the pending bits to detect the

source of an interrupt, this practice is not recommended. The

use of polling allows the standard arbitration ranking to be al-

tered, but the reliability of the interrupt system is compro-

mised. The polling routine must individually test the enable

and pending bits of each maskable interrupt. If a Software

Trap interrupt should occur, it will be serviced last, even

though it should have the highest priority. Under certain con-

ditions, a Software Trap could be triggered but not serviced,

resulting in an inadvertent “locking out” of all maskable inter-

rupts by the Software Trap pending flag. Problems such as

this can be avoided by using VIS instruction.

Each vector is 15 bits long and points to the beginning of a

specific interrupt service routine somewhere in the 32 kbyte

memory space. Each vector occupies two bytes of the vector

table, with the higher-order byte at the lower address. The

vectors are arranged in order of interrupt priority. The vector

of the maskable interrupt with the lowest rank is located to

0yE0 (higher-order byte) and 0yE1 (lower-order byte). The

next priority interrupt is located at 0yE2 and 0yE3, and so

forth in increasing rank. The Software Trap has the highest

rank and its vector is always located at 0yFE and 0yFF. The

number of interrupts which can become active defines the

size of the table.

23

www.national.com

Interrupts (Continued)

TABLE 5. Interrupt Vector Table

*

VECTOR

ARBITRATION

RANKING

SOURCE

DESCRIPTION

ADDRESS

(Hi-Low Byte)

0yFE–0yFF

0yFC–0yFD

0yFA–0yFB

0yF8–0yF9

0yF6–0yF7

0yF4–0yF5

0yF2–0yF3

0yF0–0yF1

0yEE–0yEF

0yEC–0yED

0yEA–0yEB

(1) Highest

(2)

Software

Reserved

External

Timer T0

Timer T1

INTR Instruction

(3)

G0

(4)

Idle Timer

T1A/Underflow

T1B

(5)

(6)

(7)

MICROWIRE/PLUS

Reserved

Busy Low

(8)

(9)

Reserved

(10)

(11)

Reserved

High Speed Capture Timer

Capture Overflow/

Capture Pending

(12)

Reserved

0yE8–0yE9

0yE6–0yE7

0yE4–0yE5

0yE2–0yE3

0yE0–0yE1

(13)

Reserved

(14)

Reserved

(15)

Port L/Wakeup

Default VIS

Port L Edge

Reserved

(16) Lowest

*

Note 20: y is a variable which represents the VIS block. VIS and the vector table must be located in the same 256-byte block except if VIS islocated at the last ad-

dress of a block. In this case, the table must be in the next block.

VIS Execution

vector of the active interrupt with the highest arbitration rank-

ing. This vector is read from program memory and placed

into the PC which is now pointed to the 1st instruction of the

service routine of the active interrupt with the highest arbitra-

tion ranking.

When the VIS instruction is executed it activates the arbitra-

tion logic. The arbitration logic generates an even number

between E0 and FE (E0, E2, E4, E6 etc...) depending on

which active interrupt has the highest arbitration ranking at

the time of the 1st cycle of VIS is executed. For example, if

the software trap interrupt is active, FE is generated. If the

external interrupt is active and the software trap interrupt is

not, then FA is generated and so forth. If the only active inter-

rupt is software trap, than E0 is generated. This number re-

places the lower byte of the PC. The upper byte of the PC re-

mains unchanged. The new PC is therefore pointing to the

Figure 15 illustrates the different steps performed by the VIS

instruction. Figure 16 shows a flowchart for the VIS instruc-

tion.

The non-maskable interrupt pending flag is cleared by the

RPND (Reset Non-Maskable Pending Bit) instruction (under

certain conditions) and upon RESET.

www.national.com

24

Interrupts (Continued)

DS012865-29

FIGURE 15. VIS Operation

DS012865-30

FIGURE 16. VIS Flowchart

25

www.national.com

Interrupts (Continued)

Programming Example: External Interrupt

PSW

CNTRL

RBIT

SBIT

JP

=00EF

=00EE

0,PORTGC

0,PORTGD

IEDG, CNTRL

EXEN, PSW

GIE, PSW

WAIT

; G0 pin configured Hi-Z

; Ext interrupt polarity; falling edge

; Enable the external interrupt

; Set the GIE bit

WAIT:

; Wait for external interrupt

.

.=0FF

VIS

; The interrupt causes a

; branch to address 0FF

; The VIS causes a branch to

;interrupt vector table

.

.=01FA

.ADDRW SERVICE

; Vector table (within 256 byte

; of VIS inst.) containing the ext

; interrupt service routine

.

INT_EXIT:

SERVICE:

RETI

.

RBIT

EXPND, PSW

; Interrupt Service Routine

; Reset ext interrupt pend. bit

.

JP

INT_EXIT

; Return, set the GIE bit

www.national.com

26

flag; upon return to the first Software Trap routine, the

STPND flag will have the wrong state. This will allow

maskable interrupts to be acknowledged during the servicing

of the first Software Trap. To avoid problems such as this, the

user program should contain the Software Trap routine to

perform a recovery procedure rather than a return to normal

execution.

Interrupts (Continued)

NON-MASKABLE INTERRUPT

Pending Flag

There is a pending flag bit associated with the non-maskable

interrupt, called STPND. This pending flag is not memory-

mapped and cannot be accessed directly by the software.

Under normal conditions, the STPND flag is reset by a

RPND instruction in the Software Trap service routine. If a

programming error or hardware condition (brownout, power

supply glitch, etc.) sets the STPND flag without providing a

way for it to be cleared, all other interrupts will be locked out.

To alleviate this condition, the user can use extra RPND in-

structions in the main program and in the WATCHDOG ser-

vice routine (if present). There is no harm in executing extra

RPND instructions in these parts of the program.

The pending flag is reset to zero when a device Reset oc-

curs. When the non-maskable interrupt occurs, the associ-

ated pending bit is set to 1. The interrupt service routine

should contain an RPND instruction to reset the pending flag

to zero. The RPND instruction always resets the STPND

flag.

Software Trap

The Software Trap is a special kind of non-maskable inter-

rupt which occurs when the INTR instruction (used to ac-

knowledge interrupts) is fetched from program memory and

placed in the instruction register. This can happen in a vari-

ety of ways, usually because of an error condition. Some ex-

amples of causes are listed below.

PORT L INTERRUPTS

Port L provides the user with an additional eight fully select-

able, edge sensitive interrupts which are all vectored into the

same service subroutine.

The interrupt from Port L shares logic with the wake up cir-

cuitry. The register WKEN allows interrupts from Port L to be

individually enabled or disabled. The register WKEDG speci-

fies the trigger condition to be either a positive or a negative

edge. Finally, the register WKPND latches in the pending

trigger conditions.

If the program counter incorrectly points to a memory loca-

tion beyond the available program memory space, the non-

existent or unused memory location returns zeroes which is

interpreted as the INTR instruction.

If the stack is popped beyond the allowed limit (address 06F

Hex), a 7FFF will be loaded into the PC, if this last location in

program memory is unprogrammed or unavailable, a Soft-

ware Trap will be triggered.

The GIE (Global Interrupt Enable) bit enables the interrupt

function.

A control flag, LPEN, functions as a global interrupt enable

for Port L interrupts. Setting the LPEN flag will enable inter-

rupts and vice versa. A separate global pending flag is not

needed since the register WKPND is adequate.

A Software Trap can be triggered by a temporary hardware

condition such as a brownout or power supply glitch.

The Software Trap has the highest priority of all interrupts.

When a Software Trap occurs, the STPND bit is set. The GIE

bit is not affected and the pending bit (not accessible by the

user) is used to inhibit other interrupts and to direct the pro-

gram to the ST service routine with the VIS instruction. Noth-

ing can interrupt a Software Trap service routine except for

another Software Trap. The STPND can be reset only by the

RPND instruction or a chip Reset.

Since Port L is also used for waking the device out of the

HALT or IDLE modes, the user can elect to exit the HALT or

IDLE modes either with or without the interrupt enabled. If he

elects to disable the interrupt, then the device will restart ex-

ecution from the instruction immediately following the in-

struction that placed the microcontroller in the HALT or IDLE

modes. In the other case, the device will first execute the in-

terrupt service routine and then revert to normal operation.

(See HALT MODE for clock option wakeup information.)

The Software Trap indicates an unusual or unknown error

condition. Generally, returning to normal execution at the

point where the Software Trap occurred cannot be done re-

liably. Therefore, the Software Trap service routine should

reinitialize the stack pointer and perform a recovery proce-

dure that restarts the software at some known point, similar

to a device Reset, but not necessarily performing all the

same functions as a device Reset. The routine must also ex-

ecute the RPND instruction to reset the STPND flag. Other-

wise, all other interrupts will be locked out. To the extent pos-

sible, the interrupt routine should record or indicate the

context of the device so that the cause of the Software Trap

can be determined.

INTERRUPT SUMMARY

The device uses the following types of interrupts, listed be-

low in order of priority:

1. The Software Trap non-maskable interrupt, triggered by

the INTR (00 opcode) instruction. The Software Trap is

acknowledged immediately. This interrupt service rou-

tine can be interrupted only by another Software Trap.

The Software Trap should end with two RPND instruc-

tions followed by a restart procedure.

2. Maskable interrupts, triggered by an on-chip peripheral

block or an external device connected to the device. Un-

der ordinary conditions, a maskable interrupt will not in-

If the user wishes to return to normal execution from the

point at which the Software Trap was triggered, the user

must first execute RPND, followed by RETSK rather than

RETI or RET. This is because the return address stored on

the stack is the address of the INTR instruction that triggered

the interrupt. The program must skip that instruction in order

to proceed with the next one. Otherwise, an infinite loop of

Software Traps and returns will occur.

terrupt any other interrupt routine in progress.

maskable interrupt routine in progress can be inter-

rupted by the non-maskable interrupt request.

maskable interrupt routine should end with an RETI in-

struction or, prior to restoring context, should return to

execute the VIS instruction. This is particularly useful

when exiting long interrupt service routiness if the time

between interrupts is short. In this case the RETI instruc-

tion would only be executed when the default VIS rou-

tine is reached.

A

Programming a return to normal execution requires careful

consideration. If the Software Trap routine is interrupted by

another Software Trap, the RPND instruction in the service

routine for the second Software Trap will reset the STPND

27

www.national.com

occur after coming out of reset, if the instruction cycle clock

frequency has not reached a minimum specified value, in-

cluding the case where the oscillator fails to start.

WATCHDOG

The devices contain a WATCHDOG and clock monitor. The

WATCHDOG is designed to detect the user program getting

stuck in infinite loops resulting in loss of program control or

“runaway” programs. The Clock Monitor is used to detect the

absence of a clock or a very slow clock below a specified

rate on the CKI pin.

The WDSVR register can be written to only once after reset

and the key data (bits 5 through 1 of the WDSVR Register)

must match to be a valid write. This write to the WDSVR reg-

ister involves two irrevocable choices: (i) the selection of the

WATCHDOG service window (ii) enabling or disabling of the

Clock Monitor. Hence, the first write to WDSVR Register in-

volves selecting or deselecting the Clock Monitor, select the

WATCHDOG service window and match the WATCHDOG

key data. Subsequent writes to the WDSVR register will

compare the value being written by the user to the WATCH-

DOG service window value and the key data (bits 7 through

1) in the WDSVR Register. Table IX shows the sequence of

events that can occur.

The WATCHDOG consists of two independent logic blocks:

WD UPPER and WD LOWER. WD UPPER establishes the

upper limit on the service window and WD LOWER defines

the lower limit of the service window.

Servicing the WATCHDOG consists of writing a specific

value to a WATCHDOG Service Register named WDSVR

which is memory mapped in the RAM. This value is com-

posed of three fields, consisting of a 2-bit Window Select, a

5-bit Key Data field, and the 1-bit Clock Monitor Select field.

Table 6 shows the WDSVR register.

The user must service the WATCHDOG at least once before

the upper limit of the service window expires. The WATCH-

DOG may not be serviced more than once in every lower

limit of the service window. The user may service the

WATCHDOG as many times as wished in the time period be-

tween the lower and upper limits of the service window. The

first write to the WDSVR Register is also counted as a

WATCHDOG service.

TABLE 6. WATCHDOG Service Register (WDSVR)

Window

Select

Key Data

Clock

Monitor

X

6

0

5

1

4

1

3

0

2

0

1

Y

0

The WATCHDOG has an output pin associated with it. This

is the WDOUT pin, on pin 1 of the port G. WDOUT is active

low. The WDOUT pin is in the high impedance state in the in-

active state. Upon triggering the WATCHDOG, the logic will

pull the WDOUT (G1) pin low for an additional 16 t_C–32 t_C

cycles after the signal level on WDOUT pin goes below the

lower Schmitt trigger threshold. After this delay, the device

will stop forcing the WDOUT output low. The WATCHDOG

service window will restart when the WDOUT pin goes high.

It is recommended that the user tie the WDOUT pin back to

V_CCthrough a resistor in order to pull WDOUT high.

7

The lower limit of the service window is fixed at 2048 instruc-

tion cycles. Bits 7 and 6 of the WDSVR register allow the

user to pick an upper limit of the service window.

Table 7 shows the four possible combinations of lower and

upper limits for the WATCHDOG service window. This flex-

ibility in choosing the WATCHDOG service window prevents

any undue burden on the user software.

Bits 5, 4, 3, 2 and 1 of the WDSVR register represent the

5-bit Key Data field. The key data is fixed at 01100. Bit 0 of

the WDSVR Register is the Clock Monitor Select bit.

A WATCHDOG service while the WDOUT signal is active will

be ignored. The state of the WDOUT pin is not guaranteed

on reset, but if it powers up low then the WATCHDOG will

time out and WDOUT will enter high impedance state.

TABLE 7. WATCHDOG Service Window Select

WDSVR WDSVR

Clock

Service Window

(Lower-Upper Limits)

2048–8k t_CCycles

The Clock Monitor forces the G1 pin low upon detecting a

clock frequency error. The Clock Monitor error will continue

until the clock frequency has reached the minimum specified

value, after which the G1 output will enter the high imped-

ance TRI-STATE mode following 16 t_C–32 t_Cclock cycles.

The Clock Monitor generates a continual Clock Monitor error

if the oscillator fails to start, or fails to reach the minimum

specified frequency. The specification for the Clock Monitor

is as follows:

Bit 7

Bit 6

Monitor

0

1

x

0

1

0

1

x

0

1

2048–16k t_CCycles

2048–32k t_CCycles

2048–64k t_CCycles

Clock Monitor Disabled

Clock Monitor Enabled

>

1/t_C10 kHz — No clock rejection.

<

1/t_C10 Hz — Guaranteed clock rejection.

Clock Monitor

WATCHDOG AND CLOCK MONITOR SUMMARY

The Clock Monitor aboard the device can be selected or de-

selected under program control. The Clock Monitor is guar-

anteed not to reject the clock if the instruction cycle clock

(1/t_C) is greater or equal to 10 kHz. This equates to a clock

input rate on CKI of greater or equal to 100 kHz.

The following salient points regarding the WATCHDOG and

CLOCK MONITOR should be noted:

•

Both the WATCHDOG and CLOCK MONITOR detector

circuits are inhibited during RESET.

•

Following RESET, the WATCHDOG and CLOCK MONI-

TOR are both enabled, with the WATCHDOG having the

maximum service window selected.

WATCHDOG Operation

The WATCHDOG and Clock Monitor are disabled during re-

set. The device comes out of reset with the WATCHDOG

armed, the WATCHDOG Window Select bits (bits 6, 7 of the

WDSVR Register) set, and the Clock Monitor bit (bit 0 of the

WDSVR Register) enabled. Thus, a Clock Monitor error will

•

The WATCHDOG service window and CLOCK MONI-

TOR enable/disable option can only be changed once,

during the initial WATCHDOG service following RESET.

www.national.com

28

CLKDLY bit set, the WATCHDOG service window will be

set to its selected value from WDSVR following HALT.

Consequently, the WATCHDOG should not be serviced

for at least 2048 instruction cycles following HALT, but

must be serviced within the selected window to avoid a

WATCHDOG error.

WATCHDOG Operation (Continued)

•

The initial WATCHDOG service must match the key data

value in the WATCHDOG Service register WDSVR in or-

der to avoid a WATCHDOG error.

Subsequent WATCHDOG services must match all three

data fields in WDSVR in order to avoid WATCHDOG er-

rors.

•

The IDLE timer T0 is not initialized with RESET.

The user can sync in to the IDLE counter cycle with an

IDLE counter (T0) interrupt or by monitoring the T0PND

flag. The T0PND flag is set whenever the thirteenth bit of

the IDLE counter toggles (every 4096 instruction cycles).

The user is responsible for resetting the T0PND flag.

The correct key data value cannot be read from the

WATCHDOG Service register WDSVR. Any attempt to

read this key data value of 01100 from WDSVR will read

as key data value of all 0’s.

•

The WATCHDOG detector circuit is inhibited during both

the HALT and IDLE modes.

•

A hardware WATCHDOG service occurs just as the de-

vice exits the IDLE mode. Consequently, the WATCH-

DOG should not be serviced for at least 2048 instruction

cycles following IDLE, but must be serviced within the se-

lected window to avoid a WATCHDOG error.

The CLOCK MONITOR detector circuit is active during

both the HALT and IDLE modes. Consequently, the de-

vice inadvertently entering the HALT mode will be de-

tected as a CLOCK MONITOR error (provided that the

CLOCK MONITOR enable option has been selected by

the program).

Following RESET, the initial WATCHDOG service (where

the service window and the CLOCK MONITOR enable/

disable must be selected) may be programmed any-

where within the maximum service window (65,536 in-

struction cycles) initialized by RESET. Note that this initial

WATCHDOG service may be programmed within the ini-

tial 2048 instruction cycles without causing a WATCH-

DOG error.

•

With the single-pin R/C oscillator mask option selected

and the CLKDLY bit reset, the WATCHDOG service win-

dow will resume following HALT mode from where it left

off before entering the HALT mode.

With the crystal oscillator mask option selected, or with

the single-pin R/C oscillator mask option selected and the

TABLE 8. WATCHDOG Service Actions

Key Data

Match

Window Data

Clock Monitor

Match

Action

Match

Valid Service: Restart Service Window

Error: Generate WATCHDOG Output

Don’t Care

Mismatch

Don’t Care

Mismatch

Don’t Care

Mismatch

ing reset, but might not contain the same program initializa-

tion procedures). The recovery program should reset the

software interrupt pending bit using the RPND instruction.

Detection of Illegal Conditions

The device can detect various illegal conditions resulting

from coding errors, transient noise, power supply voltage

drops, runaway programs, etc.

MICROWIRE/PLUS

Reading of undefined ROM gets zeros. The opcode for soft-

ware interrupt is 00. If the program fetches instructions from

undefined ROM, this will force a software interrupt, thus sig-

naling that an illegal condition has occurred.

MICROWIRE/PLUS is a serial synchronous communications

interface. The MICROWIRE/PLUS capability enables the de-

vice to interface with any of National Semiconductor’s

MICROWIRE peripherals (i.e. A/D converters, display driv-

ers, E2PROMs etc.) and with other microcontrollers which

support the MICROWIRE interface. It consists of an 8-bit se-

rial shift register (SIO) with serial data input (SI), serial data

output (SO) and serial shift clock (SK). Figure 17 shows a

block diagram of the MICROWIRE/PLUS logic.

The subroutine stack grows down for each call (jump to sub-

routine), interrupt, or PUSH, and grows up for each return or

POP. The stack pointer is initialized to RAM location 06F Hex

during reset. Consequently, if there are more returns than

calls, the stack pointer will point to addresses 070 and 071

Hex (which are undefined RAM). Undefined RAM from ad-

dresses 070 to 07F (Segment 0), and all other segments

(i.e., Segments 4... etc.) is read as all 1’s, which in turn will

cause the program to return to address 7FFF Hex. This is an

undefined ROM location and the instruction fetched (all 0’s)

from this location will generate a software interrupt signaling

an illegal condition.

The shift clock can be selected from either an internal source

or an external source. Operating the MICROWIRE/PLUS ar-

rangement with the internal clock source is called the Master

mode of operation. Similarly, operating the MICROWIRE/

PLUS arrangement with an external shift clock is called the

Slave mode of operation.

The CNTRL register is used to configure and control the

MICROWIRE/PLUS mode. To use the MICROWIRE/PLUS,

the MSEL bit in the CNTRL register is set to one. In the mas-

ter mode, the SK clock rate is selected by the two bits, SL0

and SL1, in the CNTRL register. Table 9 details the different

clock rates that may be selected.

Thus, the chip can detect the following illegal conditions:

1. Executing from undefined ROM

2. Over “POP”ing the stack by having more returns than

calls.

When the software interrupt occurs, the user can re-initialize

the stack pointer and do a recovery procedure before restart-

ing (this recovery program is probably similar to that follow-

29

www.national.com

MICROWIRE/PLUS Master Mode Operation

MICROWIRE/PLUS (Continued)

In the MICROWIRE/PLUS Master mode of operation the

shift clock (SK) is generated internally. The MICROWIRE

Master always initiates all data exchanges. The MSEL bit in

the CNTRL register must be set to enable the SO and SK

functions onto the G Port. The SO and SK pins must also be

selected as outputs by setting appropriate bits in the Port G

configuration register. Table 10 summarizes the bit settings

required for Master mode of operation.

TABLE 9. MICROWIRE/PLUS Master Mode Clock Select

SL1

0

SL0

SK period

2 X t_C

0

1

x

0

4 X t_C

1

8 X t_C

Where t_Cis the instruction cycle clock

MICROWIRE/PLUS Slave Mode Operation

MICROWIRE/PLUS OPERATION

In the MICROWIRE/PLUS Slave mode of operation the SK

clock is generated by an external source. Setting the MSEL

bit in the CNTRL register enables the SO and SK functions

onto the G Port. The SK pin must be selected as an input

and the SO pin is selected as an output pin by setting and re-

setting the appropriate bits in the Port G configuration regis-

ter. Table XI summarizes the settings required to enter the

Slave mode of operation.

Setting the BUSY bit in the PSW register causes the

MICROWIRE/PLUS to start shifting the data. It gets reset

when eight data bits have been shifted. The user may reset

the BUSY bit by software to allow less than 8 bits to shift. If

enabled, an interrupt is generated when eight data bits have

been shifted. The device may enter the MICROWIRE/PLUS

mode either as a Master or as a Slave. Figure 18 shows how

two devices, microcontrollers and several peripherals may

The user must set the BUSY flag immediately upon entering

the Slave mode. This will ensure that all data bits sent by the

Master will be shifted properly. After eight clock pulses the

BUSY flag will be cleared and the sequence may be re-

peated.

be

interconnected

using

the

MICROWIRE/PLUS

arrangements.

TABLE 10. MICROWIRE/PLUS Mode Settings

This table assumes that the control flag MSEL is set.

G4 (SO)

Config. Bit

1

G5 (SK)

Config. Bit

1

G4

Fun.

SO

G5

Fun.

Int.

Operation

MICROWIRE/PLUS

Master

SK

0

1

0

1

0

TRI-

STATE

SO

Int.

MICROWIRE/PLUS

Master

SK

Ext.

SK

MICROWIRE/PLUS

Slave

TRI-

Ext.

SK

MICROWIRE/PLUS

Slave

STATE

DS012865-16

FIGURE 17. MICROWIRE/PLUS Block Diagram

WARNING

Alternate SK Phase Operation

The device allows either the normal SK clock or an alternate

phase SK clock to shift data in and out of the SIO register. In

both the modes the SK is normally low. In the normal mode

data is shifted in on the rising edge of the SK clock and the

data is shifted out on the falling edge of the SK clock. The

SIO register is shifted on each falling edge of the SK clock.

In the alternate SK phase operation, data is shifted in on the

falling edge of the SK clock and shifted out on the rising edge

of the SK clock.

The SIO register should only be loaded when the SK clock is

low. Loading the SIO register while the SK clock is high will

result in undefined data in the SIO register. SK clock is nor-

mally low when not shifting.

Setting the BUSY flag when the input SK clock is high in the

MICROWIRE/PLUS slave mode may cause the current SK

clock for the SIO shift register to be narrow. For safety, the

BUSY flag should only be set when the input SK clock is low.

A control flag, SKSEL, allows either the normal SK clock or

the alternate SK clock to be selected. Resetting SKSEL

causes the MICROWIRE/PLUS logic to be clocked from the

normal SK signal. Setting the SKSEL flag selects the alter-

nate SK clock. The SKSEL is mapped into the G6 configura-

tion bit. The SKSEL flag will power up in the reset condition,

selecting the normal SK signal.

www.national.com

30

MICROWIRE/PLUS (Continued)

DS012865-17

FIGURE 18. MICROWIRE/PLUS Application

31

www.national.com

Memory Map

All RAM, ports and registers (except A and PC) are mapped

into data memory address space.

Address

S/ADD REG

xxD9

Contents

Address

Contents

Reserved

Port D

S/ADD REG

xxDA

0000 to 006F

0070 to 007F

xx80 to xxAF

On-Chip RAM bytes (112

bytes)

xxDB

xxDC

Unused RAM Address Space

(Reads As All Ones)

xxDD to DF

xxE0 to xxE5

xxE6

Reserved

Unused RAM Address Space

(Reads Undefined Data)

Timer T1 Autoload Register

T1RB Lower Byte

xxB0

XXB1

xxB2

xxB3

xxB4

xxB5

xxB6

xxB7

Reserved

xxE7

Timer T1 Autoload Register

T1RB Upper Byte

xxE8

xxE9

ICNTRL Register

MICROWIRE/PLUS Shift

Register

xxEA

xxEB

xxEC

Timer T1 Lower Byte

Timer T1 Upper Byte

Comparator Select Register

(CMPSL)

Timer T1 Autoload Register

T1RA Lower Byte

xxB8 to xxBF

xxC0

Reserved

xxED

Timer T1 Autoload Register

T1RA Upper Byte

xxC1

xxEE

xxEF

CNTRL Control Register

PSW Register

xxC2

xxC3

xxF0 to xxFB

On-Chip RAM Mapped as

Registers

xxC4

xxFC

xxFD

X Register

SP Register

B Register

Reserved

xxC5

xxC6

xxFE

xxC7

WATCHDOG Service Register

(Reg:WDSVR)

xxFF

xxC8

xxC9

xxCA

MIWU Edge Select Register

(Reg:WKEDG)

0100-017F

Reading memory locations 0070H-007FH (Segment 0) will

return all ones. Reading unused memory locations

0080H-00AFH (Segment 0) will return undefined data. Read-

ing memory locations from other Segments (i.e., Segment 2,

Segment 3,…etc.) will return undefined data.

MIWU Enable Register

(Reg:WKEN)

MIWU Pending Register

(Reg:WKPND)

xxCB

xxCC

Reserved

Addressing Modes

There are ten addressing modes, six for operand addressing

and four for transfer of control.

CAPTLO (Capture Timer

Low-Byte)

xxCD

xxCE

CAPTHI (Capture Timer

High-Byte)

OPERAND ADDRESSING MODES

Register Indirect

CAPCNTL (Capture Timer

Control Register)

This is the “normal” addressing mode. The operand is the

data memory addressed by the B pointer or X pointer.

xxCF

xxD0

xxD1

xxD2

xxD3

xxD4

xxD5

xxD6

xxD7

xxD8

Idle Timer Control Register

Port L Data Register

Register Indirect (with auto post increment or decre-

ment of pointer)

Port L Configuration Register

Port L Input Pins (Read Only)

Reserved

This addressing mode is used with the LD and X instruc-

tions. The operand is the data memory addressed by the B

pointer or X pointer. This is a register indirect mode that au-

tomatically post increments or decrements the B or X regis-

ter after executing the instruction.

Port G Data Register

Port G Configuration Register

Port G Input Pins (Read Only)

Port I Input Pins (Read Only)

Reserved

Direct

The instruction contains an 8-bit address field that directly

points to the data memory for the operand.

www.national.com

32

Note: The VIS is a special case of the Indirect Transfer of Control addressing

mode, where the double byte vector associated with the interrupt is

transferred from adjacent addresses in the program memory into the

program counter (PC) in order to jump to the associated interrupt ser-

vice routine.

Addressing Modes (Continued)

Immediate

The instruction contains an 8-bit immediate field as the oper-

and.

Instruction Set

Short Immediate

This addressing mode is used with the Load B Immediate in-

struction. The instruction contains a 4-bit immediate field as

the operand.

Register and Symbol Definition

Registers

A

8-Bit Accumulator Register

8-Bit Address Register

Indirect

B

This addressing mode is used with the LAID instruction. The

contents of the accumulator are used as a partial address

(lower 8 bits of PC) for accessing a data operand from the

program memory.

X

8-Bit Address Register

SP

PC

PU

PL

C

8-Bit Stack Pointer Register

15-Bit Program Counter Register

Upper 7 Bits of PC

TRANSFER OF CONTROL ADDRESSING MODES

Relative

Lower 8 Bits of PC

1-Bit of PSW Register for Carry

1-Bit of PSW Register for Half Carry

This mode is used for the JP instruction, with the instruction

field being added to the program counter to get the new pro-

gram location. JP has a range from −31 to +32 to allow a

1-byte relative jump (JP + 1 is implemented by a NOP in-

struction). There are no “pages” when using JP, since all 15

bits of PC are used.

HC

GIE

1-Bit of PSW Register for Global Interrupt

Enable

VU

VL

Interrupt Vector Upper Byte

Interrupt Vector Lower Byte

Symbols

Absolute

[B]

Memory Indirectly Addressed by B Register

Memory Indirectly Addressed by X Register

Direct Addressed Memory

This mode is used with the JMP and JSR instructions, with

the instruction field of 12 bits replacing the lower 12 bits of

the program counter (PC). This allows jumping to any loca-

tion in the current 4k program memory segment.

[X]

MD

Mem

Meml

Direct Addressed Memory or [B]

Direct Addressed Memory or [B] or Immediate

Data

Absolute Long

This mode is used with the JMPL and JSRL instructions, with

the instruction field of 15 bits replacing the entire 15 bits of

the program counter (PC). This allows jumping to any loca-

tion up to 32k in the program memory space.

Imm

Reg

8-Bit Immediate Data

Register Memory: Addresses F0 to FF

(Includes B, X and SP)

Bit

←

↔

Bit Number (0 to 7)

Loaded with

Indirect

This mode is used with the JID instruction. The contents of

the accumulator are used as a partial address (lower 8 bits of

PC) for accessing a location in the program memory. The

contents of this program memory location serve as a partial

address (lower 8 bits of PC) for the jump to the next instruc-

tion.

Exchanged with

INSTRUCTION SET

←

ADD

A,Meml

A,Imm

A,Meml

MD,Imm

A,Meml

#

ADD

A

A + Meml

←

ADC

ADD with Carry

Subtract with Carry

Logical AND

A + Meml + C, C

A − MemI + C, C

A and Meml

Carry, HC

Half Carry

SUBC

AND

=

0

ANDSZ

OR

Logical AND Immed., Skip if Zero

Logical OR

Skip next if (A and Imm)

←

A

A or Meml

XOR

Logical EXclusive OR

IF EQual

A xor Meml

=

Compare MD and Imm, Do next if MD Imm

IFEQ

IFNE

IFGT

IFBNE

DRSZ

=

Compare A and Meml, Do next if A Meml

IF EQual

≠

Compare A and Meml, Do next if A Meml

IF Not Equal

>

Compare A and Meml, Do next if A Meml

IF Greater Than

If B Not Equal

≠

Do next if lower 4 bits of B Imm

←

=

0

Reg

Decrement Reg., Skip if Zero

Reg

Reg − 1, Skip if Reg

33

www.national.com

Instruction Set (Continued)

=

SBIT

RBIT

IFBIT

RPND

X

#,Mem

Set BIT

1 to bit, Mem (bit 0 to 7 immediate)

Reset BIT

0 to bit, Mem

IF BIT

If bit #,A or Mem is true do next instruction

Reset Software Interrupt Pending Flag

Reset PeNDing Flag

EXchange A with Memory

EXchange A with Memory [X]

LoaD A with Memory

LoaD A with Memory [X]

LoaD B with Immed.

LoaD Memory Immed

LoaD Register Memory Immed.

EXchange A with Memory [B]

EXchange A with Memory [X]

LoaD A with Memory [B]

LoaD A with Memory [X]

LoaD Memory [B] Immed.

CLeaR A

↔

←

A,Mem

A,[X]

A

B

Mem

[X]

X

LD

A,Meml

A,[X]

Meml

[X]

LD

B,Imm

Imm

←

LD

Mem,Imm

Reg,Imm

Mem

Reg

Imm

←

LD

Imm

↔

←

±

1)

X

A, [B

A, [X

A, [B

A, [X

]

A

[B], (B

[X], (X

[B], (B

[X], (X

B

↔

±

X

A

X

1)

←

±

LD

A

B

X

←

±

1)

LD

A

←

±

1)

LD

[B ],Imm

[B]

Imm, (B

B

←

0

CLR

INC

DEC

LAID

DCOR

RRC

RLC

SWAP

SC

A

C

←

→

←

INCrement A

A + 1

A − 1

DECrement A

Load A InDirect from ROM

Decimal CORrect A

Rotate A Right thru C

Rotate A Left thru C

SWAP nibbles of A

Set C

ROM (PU,A)

BCD correction of A (follows ADC, SUBC)

A

→

A0 C

A7

...

←

C

A7 ...

A0

A3...A0

↔

1, HC

0, HC

A7...A4

←

C

1

0

RC

Reset C

IFC

IF C

IF C is true, do next instruction

IFNC

POP

PUSH

VIS

IF Not C

If C is not true, do next instruction

←

A

POP the stack into A

PUSH A onto the stack

Vector to Interrupt Service Routine

Jump absolute Long

Jump absolute

SP

SP + 1, A

[SP]

←

SP − 1

←

[SP]

A, SP

←

[VU], PL [VL]

PU

PC

←

=

ii (ii 15 bits, 0 to 32k)

JMPL

JMP

JP

Addr.

Disp.

Addr.

Addr

←

=

PC9...0

i (i 12 bits)

←

PC

Jump relative short

Jump SubRoutine Long

Jump SubRoutine

Jump InDirect

PC + r (r is −31 to +32, except 1)

←

ii

JSRL

JSR

JID

[SP] PL, [SP-1]

PU,SP-2, PC

←

i

[SP] PL, [SP-1]

PU,SP-2, PC9...0

←

PL ROM (PU,A)

← ←

SP + 2, PL [SP], PU [SP-1]

RET

RETSK

RETI

INTR

NOP

RETurn from subroutine

RETurn and SKip

RETurn from Interrupt

Generate an Interrupt

No OPeration

←

SP + 2, PL [SP],PU [SP-1], skip next instruction

←

SP + 2, PL

[SP],PU [SP-1],GIE 1

←

[SP] PL, [SP-1] PU, SP-2, PC 0FF

←

PC PC + 1

www.national.com

34

Instructions Using A and C

Instruction Set (Continued)

CLRA

INCA

DECA

LAID

1/1

Instruction Execution Time

1/1

1/3

1/1

1/3

2/2

Most instructions are single byte (with immediate addressing

mode instructions taking two bytes).

Most single byte instructions take one cycle time to execute.

Skipped instructions require

skipped, where x equals the number of bytes in the skipped

instruction opcode.

x number of cycles to be

DCORA

RRCA

RLCA

SWAPA

SC

See the BYTES and CYCLES per INSTRUCTION table for

details.

Bytes and Cycles per Instruction

RC

The following table shows the number of bytes and cycles for

each instruction in the format of byte/cycle.

IFC

IFNC

PUSHA

POPA

ANDSZ

Arithmetic and Logic Instructions

[B]

1/1

Direct

3/4

Immed

2/2

ADD

ADC

SUBC

AND

OR

3/4

2/2

Transfer of Control Instructions

3/4

2/2

JMPL

JMP

JP

3/4

2/3

1/3

3/5

2/5

1/3

1/5

1/7

1/1

3/4

2/2

3/4

2/2

XOR

IFEQ

IFGT

IFBNE

DRSZ

SBIT

RBIT

IFBIT

3/4

2/2

JSRL

JSR

3/4

2/2

3/4

2/2

JID

VIS

1/3

3/4

RET

RETSK

RETI

INTR

NOP

RPND

1/1

Memory Transfer Instructions

Register

Indirect

Register Indirect

Auto Incr and Decr

Direct Immed.

[B]

[X]

1/3

[B+, B−]

1/2

[X+, X−]

1/3

X A, (Note 21)

LD A, (Note 21)

LD B,Imm

1/1

2/3

2/2

1/1

2/2

1/2

1/3

<

(If B 16)

>

(If B 15)

LD B,Imm

LD Mem,Imm

LD Reg,Imm

IFEQ MD,Imm

2/2

3/3

2/3

3/3

2/2

Note 21: Memory location addressed by B or X or directly.

35

www.national.com

Instruction Set (Continued)

N I B B L E L O W E R

www.national.com

36

COP8 Integrated Software/Hardware Design Develop-

ment Kits

Mask Options

The mask programmable options are shown below. The op-

tions are programmed at the same time as the ROM pattern

submission.

•

COP8-EPU: Very Low cost Evaluation & Programming

Unit. Windows based development and hardware-

simulation tool for COPSx/xG families, with COP8 device

programmer and samples. Includes COP8-NSDEV,

Driveway COP8 Demo, MetaLink Debugger, cables and

power supply.

OPTION 1: CLOCK CONFIGURATION

= 1

Crystal Oscillator (CKI/10)

G7 (CKO) is clock generator output

to crystal/resonator CKI is the

clock input

•

COP8-DM: Moderate cost Debug Module from MetaLink.

A Windows based, real-time in-circuit emulation tool with

COP8 device programmer. Includes COP8-NSDEV,

DriveWay COP8 Demo, MetaLink Debugger, power sup-

ply, emulation cables and adapters.

= 2

Single-pin RC controlled oscillator

(CKI/10)

G7 is available as a HALT restart

and/or general purpose input

OPTION 2: HALT

COP8 Development Languages and Environments

= 1

= 2

Enable HALT mode

Disable HALT mode

•

COP8-NSASM: Free COP8 Assembler v5 for Win32.

Macro assembler, linker, and librarian for COP8 software

development. Supports all COP8 devices. (DOS/Win16

v4.10.2 available with limited support). (Compatible with

WCOP8 IDE, COP8C, and DriveWay COP8).

OPTION 3: BONDING OPTIONS

= 1

= 2

= 3

= 4

28-Pin DIP

28-Pin SO

N/A

•

COP8-NSDEV: Very low cost Software Development

Package for Windows. An integrated development envi-

ronment for COP8, including WCOP8 IDE, COP8-

NSASM, COP8-MLSIM.

20-Pin SO

Development Tools Support

COP8C: Moderately priced C Cross-Compiler and Code

Development System from Byte Craft (no code limit). In-

cludes BCLIDE (Byte Craft Limited Integrated Develop-

ment Environment) for Win32, editor, optimizing C Cross-

Compiler, macro cross assembler, BC-Linker, and

MetaLink tools support. (DOS/SUN versions available;

Compiler is installable under WCOP8 IDE; Compatible

with DriveWay COP8).

OVERVIEW

National is engaged with an international community of inde-

pendent 3rd party vendors who provide hardware and soft-

ware development tool support. Through National’s interac-

tion and guidance, these tools cooperate to form a choice of

solutions that fits each developer’s needs.

This section provides a summary of the tool and develop-

ment kits currently available. Up-to-date information, selec-

tion guides, free tools, demos, updates, and purchase infor-

mation can be obtained at our web site at:

www.national.com/cop8.

•

EWCOP8-KS: Very Low cost ANSI C-Compiler and Em-

bedded Workbench from IAR (Kickstart version:

COP8Sx/Fx only with 2k code limit; No FP). A fully inte-

grated Win32 IDE, ANSI C-Compiler, macro assembler,

editor, linker, Liberian, C-Spy simulator/debugger, PLUS

MetaLink EPU/DM emulator support.

SUMMARY OF TOOLS

COP8 Evaluation Tools

EWCOP8-AS: Moderately priced COP8 Assembler and

Embedded Workbench from IAR (no code limit). A fully in-

tegrated Win32 IDE, macro assembler, editor, linker, li-

brarian, and C-Spy high-level simulator/debugger with

I/O and interrupts support. (Upgradeable with optional

C-Compiler and/or MetaLink Debugger/Emulator sup-

port).

•

COP8–NSEVAL: Free Software Evaluation package for

Windows. A fully integrated evaluation environment for

COP8, including versions of WCOP8 IDE (Integrated De-

velopment Environment), COP8-NSASM, COP8-MLSIM,

COP8C, DriveWay COP8, Manuals, and other COP8

information.

™

•

EWCOP8-BL: Moderately priced ANSI C-Compiler and

Embedded Workbench from IAR (Baseline version: All

COP8 devices; 4k code limit; no FP). A fully integrated

Win32 IDE, ANSI C-Compiler, macro assembler, editor,

linker, librarian, and C-Spy high-level simulator/debugger.

(Upgradeable; CWCOP8-M MetaLink tools interface sup-

port optional).

•

COP8–MLSIM: Free Instruction Level Simulator tool for

Windows. For testing and debugging software instruc-

tions only (No I/O or interrupt support).

COP8–EPU: Very Low cost COP8 Evaluation & Pro-

gramming Unit. Windows based evaluation and

hardware-simulation tool, with COP8 device programmer

and erasable samples. Includes COP8-NSDEV, Drive-

way COP8 Demo, MetaLink Debugger, I/O cables and

power supply.

•

EWCOP8: Full featured ANSI C-Compiler and Embed-

ded Workbench for Windows from IAR (no code limit). A

fully integrated Win32 IDE, ANSI C-Compiler, macro as-

sembler, editor, linker, librarian, and C-Spy high-level

simulator/debugger. (CWCOP8-M MetaLink tools inter-

face support optional).

•

COP8–EVAL-ICUxx: Very Low cost evaluation and de-

sign test board for COP8ACC and COP8SGx Families,

from ICU. Real-time environment with add-on A/D, D/A,

and EEPROM. Includes software routines and reference

designs.

EWCOP8-M: Full featured ANSI C-Compiler and Embed-

ded Workbench for Windows from IAR (no code limit). A

fully integrated Win32 IDE, ANSI C-Compiler, macro as-

sembler, editor, linker, librarian, C-Spy high-level

simulator/debugger, PLUS MetaLink debugger/hardware

interface (CWCOP8-M).

Manuals, Applications Notes, Literature: Available free

from our web site at: www.national.com/cop8.

37

www.national.com

COP8 Real-Time Emulation Tools

Development Tools Support

•

COP8-DM: MetaLink Debug Module. A moderately

(Continued)

priced real-time in-circuit emulation tool, with COP8 de-

vice programmer. Includes COP8-NSDEV, DriveWay

COP8 Demo, MetaLink Debugger, power supply, emula-

tion cables and adapters.

IM-COP8: MetaLink iceMASTER^®. A full featured, real-

time in-circuit emulator for COP8 devices. Includes Met-

aLink Windows Debugger, and power supply. Package-

specific probes and surface mount adaptors are ordered

separately.

COP8 Productivity Enhancement Tools

•

WCOP8 IDE: Very Low cost IDE (Integrated Develop-

ment Environment) from KKD. Supports COP8C, COP8-

NSASM, COP8-MLSIM, DriveWay COP8, and MetaLink

debugger under a common Windows Project Manage-

ment environment. Code development, debug, and emu-

lation tools can be launched from the project window

framework.

•

DriveWay-COP8: Low cost COP8 Peripherals Code

Generation tool from Aisys Corporation. Automatically

generates tested and documented C or Assembly source

code modules containing I/O drivers and interrupt han-

dlers for each on-chip peripheral. Application specific

code can be inserted for customization using the inte-

grated editor. (Compatible with COP8-NSASM, COP8C,

and WCOP8 IDE.)

COP8 Device Programmer Support

•

MetaLink’s EPU and Debug Module include development

device programming capability for COP8 devices.

•

Third-party programmers and automatic handling equip-

ment cover needs from engineering prototype and pilot

production, to full production environments.

•

Factory programming available for high-volume require-

ments.

•

COP8-UTILS: Free set of COP8 assembly code ex-

amples, device drivers, and utilities to speed up code de-

velopment.

COP8-MLSIM: Free Instruction Level Simulator tool for

Windows. For testing and debugging software instruc-

tions only (No I/O or interrupt support).

TOOLS ORDERING NUMBERS FOR THE COP8ACC5 FAMILY DEVICES

Vendor

Tools

Order Number

COP8-NSEVAL

Cost

Notes

National COP8-NSEVAL

COP8-NSASM

COP8-MLSIM

COP8-NSDEV

COP8-EPU

Free Web site download

COP8-NSASM

Free Included in EPU and DM. Web site download

COP8-MLSIM

COP8-NSDEV

VL

Included in EPU and DM. Order CD from website

Not available for this device

Contact MetaLink

COP8ACC7

COP8-DM

Development

Devices

VL

L

16k OTP devices; 20/28 pin.

OTP

PN# EDI 28D

(SO)/40D-Z-COP8LXC

For programming 20/28 SOIC and DIP on any

programmer.

Programming

Adapters

IM-COP8

Contact MetaLink

COP8-EPU

COP8-DM

Not available for this device

DM4-COP8-ACx (10

MHz), plus PS-10, plus

DM-COP8/xxx (ie. 28D)

M

Included p/s (PS-10), target cable of choice (DIP or

PLCC; i.e. DM-COP8/28D), EDI programming sockets.

Add target adapter (if needed)

DM Target

Adapters

MHW-CNV38 or 39

L

DM target converters for 20SO or 28SO; (i.e.

MHW-CNV38 for 20 pin DIP to SO package converter)

OTP

Programming

Adapters

PN# EDI 28D

(SO)/40D-Z-COP8LXC

For programming 20/28 SOIC and DIP on any

programmer.

IM-COP8

IM-COP8-AD-464 (-220)

(10 MHz maximum)

H

Base unit 10 MHz; -220 = 220V; add probe card

(required) and target adapter (if needed); included

software and manuals

PC-8AC28DW-AD-10

MHW-SOIC28

M

L

10 MHz 20/28 DIP probe card; 2.5V to 5.5V

28 pin SOIC adapter for probe card

IM Probe Target

Adapter

ICU

KKD

IAR

COP8-EVAL

WCOP8-IDE

EWCOP8-xx

COP8-EVAL_ICUAC

WCOP8-IDE

L

No poweer supply

VL

Included in EPU and DM

See summary above

L - H Included all software and manuals

www.national.com

38

Development Tools Support (Continued)

Byte

Craft

COP8C

M

L

Included all software and manuals

Aisys

DriveWay COP8

Contact vendors

OTP Programmers

L - H For approved programmer listings and vendor

information, go to our OTP support page at:

www.national.com/cop8

<

Cost: Free; VL = $100; L = $100 - $300; M = $300 - $1k; H = $1k - $3k; VH = $3k - $5k

WHERE TO GET TOOLS

Tools are ordered directly from the following vendors. Please go to the vendor’s web site for current listings of distributors.

Vendor

Home Office

U.S.A.: Santa Clara, CA

1-408-327-8820

Electronic Sites

Other Main Offices

Distributors

Aisys

www.aisysinc.com

@

info aisysinc.com

fax: 1-408-327-8830

U.S.A.

Byte Craft

IAR

www.bytecraft.com

Distributors

@

1-519-888-6911

info bytecraft.com

fax: 1-519-746-6751

Sweden: Uppsala

+46 18 16 78 00

fax: +46 18 16 78 38

www.iar.se

U.S.A.: San Francisco

1-415-765-5500

@

info iar.se

@

info iar.com

fax: 1-415-765-5503

U.K.: London

@

info iarsys.co.uk

@

info iar.de

+44 171 924 33 34

fax: +44 171 924 53 41

Germany: Munich

+49 89 470 6022

fax: +49 89 470 956

Switzeland: Hoehe

+41 34 497 28 20

fax: +41 34 497 28 21

ICU

Sweden: Polygonvaegen

+46 8 630 11 20

www.icu.se

@

support icu.se

@

fax: +46 8 630 11 70

Denmark:

support icu.ch

KKD

www.kkd.dk

MetaLink

U.S.A.: Chandler, AZ

1-800-638-2423

www.metaice.com

Germany: Kirchseeon

80-91-5696-0

@

sales metaice.com

@

fax: 1-602-926-1198

support metaice.com

fax: 80-91-2386

@

bbs: 1-602-962-0013

www.metalink.de

islanger metalink.de

Distributors Worldwide

National

U.S.A.: Santa Clara, CA

1-800-272-9959

www.national.com/cop8

Europe: +49 (0) 180 530 8585

fax: +49 (0) 180 530 8586

Distributors Worldwide

@

support nsc.com

@

fax: 1-800-737-7018

europe.support nsc.com

The following companies have approved COP8 program-

mers in a variety of configurations. Contact your local office

or distributor. You can link to their web sites and get the lat-

est listing of approved programmers from National’s COP8

OTP Support page at: www.national.com/cop8.

Customer Support

Complete product information and technical support is avail-

able from National’s customer response centers, and from

our on-line COP8 customer support sites.

Advantech; Advin; BP Microsystems; Data I/O; Hi-Lo Sys-

tems; ICE Technology; Lloyd Research; Logical Devices;

MQP; Needhams; Phyton; SMS; Stag Programmers; Sys-

tem General; Tribal Microsystems; Xeltek.

39

www.national.com

Physical Dimensions inches (millimeters) unless otherwise noted

Order Number COP8ACC528N9 or COP8ACC528N8

NS Molded Package Number N28B

Order Number COP8ACC528M9 or COP8ACC528M8

NS Molded Package Number M28B

www.national.com

40

Physical Dimensions inches (millimeters) unless otherwise noted (Continued)

Order Number COP8ACC520M9 or COP8ACC520M8

NS Molded Package Number M20B

LIFE SUPPORT POLICY

NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT

DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL

COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein:

1. Life support devices or systems are devices or

systems which, (a) are intended for surgical implant

into the body, or (b) support or sustain life, and

whose failure to perform when properly used in

accordance with instructions for use provided in the

labeling, can be reasonably expected to result in a

significant injury to the user.

2. A critical component is any component of a life

support device or system whose failure to perform

can be reasonably expected to cause the failure of

the life support device or system, or to affect its

safety or effectiveness.

National Semiconductor

Corporation

Americas

Tel: 1-800-272-9959

Fax: 1-800-737-7018

Email: support@nsc.com

National Semiconductor

Europe

National Semiconductor

Asia Pacific Customer

Response Group

Tel: 65-2544466

Fax: 65-2504466

National Semiconductor

Japan Ltd.

Tel: 81-3-5639-7560

Fax: 81-3-5639-7507

Fax: +49 (0) 1 80-530 85 86

Email: europe.support@nsc.com

Deutsch Tel: +49 (0) 1 80-530 85 85

English Tel: +49 (0) 1 80-532 78 32

Français Tel: +49 (0) 1 80-532 93 58

Italiano Tel: +49 (0) 1 80-534 16 80

Email: sea.support@nsc.com

www.national.com

National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications.


型号：	COP8ACC528N9AQH
厂家：	TEXAS INSTRUMENTS
描述：	8-BIT, MROM, MICROCONTROLLER, PDIP28, PLASTIC, DIP-28 光电二极管
文件：	总42页 (文件大小：507K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

COP8ACC528N9AQH [TI]

相关型号：

COP8ACC528N9FGZ

COP8ACC528N9XXX

COP8ACC5DWF9CAR

COP8ACC5DWF9XXX

COP8ACC5XXX8

COP8ACC5XXX9

COP8ACC7

COP8ACC720M6

COP8ACC720M8

COP8ACC720M8-RE

COP8ACC720M8-XE

COP8ACC720M9