COP8SG Family
8-Bit CMOS ROM Based and OTP Microcontrollers with
8k to 32k Memory, Two Comparators and USART
General Description
The COP8SG Family ROM and OTP based microcontrollers
are highly integrated COP8™Feature core devices with 8k
to 32k memory and advanced features including Analog
comparators, and zero external components. These single-
chip CMOS devices are suited for more complex applica-
tions requiring a full featured controller with larger memory,
low EMI, two comparators, and a full-duplex USART.
COP8SGx7 devices are 100% form-fit-function compatible
OTP (One Time Programmable) versions for use in produc-
tion or development of the COP8SGx5 ROM.
Erasable windowed versions (Q3) are available for use with
a range of COP8 software and hardware development tools.
Family features include an 8-bit memory mapped architec-
ture, 15 MHz CKI with 0.67 µs instruction cycle, 14 inter-
rupts, three multi-function 16-bit timer/counters with PWM,
full duplex USART, MICROWIRE/PLUS™, two analog com-
parators, two power saving HALT/IDLE modes, MIWU, idle
timer, on-chip R/C oscillator, high current outputs, user se-
lectable options (WATCHDOG™, 4 clock/oscillator modes,
power-on-reset), 2.7V to 5.5V operation, program code se-
curity, and 28/40/44 pin packages.
Devices included in this datasheet are:
Device Memory (bytes) RAM
(bytes) I/O Pins Packages Temperature
COP8SGE5 8k ROM 256 24/36/40 28 DIP/SOIC, 40 DIP,
44 PLCC/QFP/CSP -40 to +85˚C,
-40 to +125˚C
COP8SGG5 16k ROM 512 24/36/40 28 DIP/SOIC, 40 DIP,
44 PLCC/QFP/CSP -40 to +85˚C,
-40 to +125˚C
COP8SGH5 20k ROM 512 24/36/40 28 DIP/SOIC, 40 DIP,
44 PLCC/QFP/CSP -40 to +85˚C,
-40 to +125˚C
COP8SGK5 24k ROM 512 24/36/40 28 DIP/SOIC, 40 DIP,
44 PLCC/QFP/CSP -40 to +85˚C,
-40 to +125˚C
COP8SGR5 32k ROM 512 24/36/40 28 DIP/SOIC, 40 DIP,
44 PLCC/QFP/CSP -40 to +85˚C,
-40 to +125˚C
COP8SGE7 8k OTP EPROM 256 24/36/40 28 DIP/SOIC, 40 DIP,
44 PLCC/QFP/CSP -40 to +85˚C,
-40 to +125˚C
COP8SGR7 32k OTP EPROM 512 24/36/40 28 DIP/SOIC, 40 DIP,
44 PLCC/QFP/CSP -40 to +85˚C,
-40 to +125˚C
COP8SGR7-Q3 32k EPROM 512 24/36/40 28 DIP, 40 DIP, 44 PLCC Room Temp.
Key Features
nLow cost 8-bit microcontroller
nQuiet Design (low radiated emissions)
nMulti-Input Wakeup pins with optional interrupts (8 pins)
nMask selectable clock options
— Crystal oscillator
— Crystal oscillator option with on-chip bias resistor
— External oscillator
— Internal R/C oscillator
nInternal Power-On-Reset—user selectable
nWATCHDOG and Clock Monitor Logic—user selectable
nEight high current outputs
n256 or 512 bytes on-board RAM
n8k to 32k ROM or OTP EPROM with security feature
CPU Features
nVersatile easy to use instruction set
n0.67 µs instruction cycle time
nFourteen multi-source vectored interrupts servicing
— External interrupt / Timers T0 — T3
— MICROWIRE/PLUS Serial Interface
— Multi-Input Wake Up
— Software Trap
— USART (2; 1 receive and 1 transmit)
— Default VIS (default interrupt)
n8-bit Stack Pointer SP (stack in RAM)
nTwo 8-bit Register Indirect Data Memory Pointers
nTrue bit manipulation
nBCD arithmetic instructions
Peripheral Features
nMulti-Input Wakeup Logic
nThree 16-bit timers (T1 — T3), each with two 16-bit
registers supporting:
— Processor Independent PWM mode
— External Event Counter mode
— Input Capture mode
COP8™is a trademark of National Semiconductor Corporation.
October 2001
COP8SG Family, 8-Bit CMOS ROM Based and OTP Microcontrollers with 8k to 32k Memory, Two
Comparators and USART
© 2001 National Semiconductor Corporation DS101317 www.national.com
Peripheral Features (Continued)
nIdle Timer (T0)
nMICROWIRE/PLUS Serial Interface (SPI Compatible)
nFull Duplex USART
nTwo Analog Comparators
I/O Features
nSoftware selectable I/O options (TRI-STATE®
Output,Push-Pull Output, Weak Pull-Up Input, and High
Impedance Input)
nSchmitt trigger inputs on ports G and L
nEight high current outputs
nPackages: 28 SO with 24 I/O pins, 40 DIP with 36 I/O
pins, 44 PLCC, PQFP and CSP with 40 I/O pins
Fully Static CMOS Design
nLow current drain (typically <4 µA)
nTwo power saving modes: HALT and IDLE
Temperature Range
n−40˚C to +85˚C, −40˚C to +125˚C
Development Support
nWindowed packages for DIP and PLCC
nReal time emulation and debug tools available
Block Diagram
10131744
FIGURE 1. COP8SGx Block Diagram
COP8SG Family
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1.0 Device Description
1.1 ARCHITECTURE
The COP8 family is based on a modified Harvard architec-
ture, which allows data tables to be accessed directly from
program memory. This is very important with modern
microcontroller-based applications, since program memory
is usually ROM or EPROM, while data memory is usually
RAM. Consequently data tables need to be contained in
non-volatile memory, so they are not lost when the micro-
controller is powered down. In a modified Harvard architec-
ture, instruction fetch and memory data transfers can be
overlapped with a two stage pipeline, which allows the next
instruction to be fetched from program memory while the
current instruction is being executed using data memory.
This is not possible with a Von Neumann single-address bus
architecture.
The COP8 family supports a software stack scheme that
allows the user to incorporate many subroutine calls. This
capability is important when using High Level Languages.
With a hardware stack, the user is limited to a small fixed
number of stack levels.
1.2 INSTRUCTION SET
In today’s 8-bit microcontroller application arena cost/
performance, flexibility and time to market are several of the
key issues that system designers face in attempting to build
well-engineered products that compete in the marketplace.
Many of these issues can be addressed through the manner
in which a microcontroller’s instruction set handles process-
ing tasks. And that’s why COP8 family offers a unique and
code-efficient instruction set—one that provides the flexibil-
ity, functionality, reduced costs and faster time to market that
today’s microcontroller based products require.
Code efficiency is important because it enables designers to
pack more on-chip functionality into less program memory
space. Selecting a microcontroller with less program
memory size translates into lower system costs, and the
added security of knowing that more code can be packed
into the available program memory space.
1.2.1 Key Instruction Set Features
The COP8 family incorporates a unique combination of in-
struction set features, which provide designers with optimum
code efficiency and program memory utilization.
Single Byte/Single Cycle Code Execution
The efficiency is due to the fact that the majority of instruc-
tions are of the single byte variety, resulting in minimum
program space. Because compact code does not occupy a
substantial amount of program memory space, designers
can integrate additional features and functionality into the
microcontroller program memory space. Also, the majority
instructions executed by the device are single cycle, result-
ing in minimum program execution time. In fact, 77% of the
instructions are single byte single cycle, providing greater
code and I/O efficiency, and faster code execution.
1.2.2 Many Single-Byte, Multifunction Instructions
The COP8 instruction set utilizes many single-byte, multi-
function instructions. This enables a single instruction to
accomplish multiple functions, such as DRSZ, DCOR, JID,
LD (Load) and X (Exchange) instructions with post-
incrementing and post-decrementing, to name just a few
examples. In many cases, the instruction set can simulta-
neously execute as many as three functions with the same
single-byte instruction.
JID: (Jump Indirect); Single byte instruction; decodes exter-
nal events and jumps to corresponding service routines
(analogous to “DO CASE” statements in higher level lan-
guages).
LAID: (LoadAccumulator-Indirect); Single byte look up table
instruction provides efficient data path from the program
memory to the CPU. This instruction can be used for table
lookup and to read the entire program memory for checksum
calculations.
RETSK: (Return Skip); Single byte instruction allows return
from subroutine and skips next instruction. Decision to
branch can be made in the subroutine itself, saving code.
AUTOINC/DEC: (Auto-Increment/Auto-Decrement); These
instructions use the two memory pointers B and X to effi-
ciently process a block of data (analogous to “FOR NEXT” in
higher level languages).
1.2.3 Bit-Level Control
Bit-level control over many of the microcontroller’s I/O ports
provides a flexible means to ease layout concerns and save
board space. All members of the COP8 family provide the
ability to set, reset and test any individual bit in the data
memory address space, including memory-mapped I/O ports
and associated registers.
1.2.4 Register Set
Three memory-mapped pointers handle register indirect ad-
dressing and software stack pointer functions. The memory
data pointers allow the option of post-incrementing or post-
decrementing with the data movement instructions (LOAD/
EXCHANGE). And 15 memory-maped registers allow de-
signers to optimize the precise implementation of certain
specific instructions.
1.3 EMI REDUCTION
The COP8SGx5 family of devices incorporates circuitry that
guards against electromagnetic interference—an increasing
problem in today’s microcontroller board designs. National’s
patented EMI reduction technology offers low EMI clock
circuitry, gradual turn-on output drivers (GTOs) and internal
I
CC
smoothing filters, to help circumvent many of the EMI
issues influencing embedded control designs. National has
achieved 15 dB–20 dB reduction in EMI transmissions when
designs have incorporated its patented EMI reducing cir-
cuitry.
1.4 PACKAGING/PIN EFFICIENCY
Real estate and board configuration considerations demand
maximum space and pin efficiency, particularly given today’s
high integration and small product form factors. Microcon-
troller users try to avoid using large packages to get the I/O
needed. Large packages take valuable board space and
increases device cost, two trade-offs that microcontroller
designs can ill afford.
The COP8 family offers a wide range of packages and do not
waste pins: up to 90.9% (or 40 pins in the 44-pin package)
are devoted to useful I/O.
COP8SG Family
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Connection Diagrams
10131704
Top View
Order Number COP8SGXY28M8
See NS Package Number M28B
Order Number COP8SGXY28N8
See NS Package Number N28B
Order Number COP8SGR728Q3
See NS Package Number D28JQ
10131753
Top View
Order Number COP8SGR7HLQ8
See NS Package Number LQA44A
10131705
Top View
Order Number COP8SGXY40N8
See NS Package Number N40A
Order Number COP8SGR5740Q3
See NS Package Number D40KQ
10131706
Top View
Order Number COP8SGXY44V8
See NS Package Number V44A
Order Number COP8SGR744J3
See NS Package Number EL44C
10131743
Top View
Order Number COP8SGXYVEJ8
See NS Package Number VEJ44A
Note 1: X = E for 8k, G for 16k,
H for 20k, K for 24k, R for 32k
Y = 5 for ROM, 7 for OTP
COP8SG Family
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Pinouts for 28 -, 40- and 44-Pin Packages
Port Type Alt. Fun 28-Pin
SO 40-Pin DIP 44-Pin
PLCC 44-Pin PQFP 44-Pin CSP
L0 I/O MIWU 11 17 17 11 12
L1 I/O MIWU or CKX 12 18 18 12 13
L2 I/O MIWU or TDX 13 19 19 13 14
L3 I/O MIWU or RDX 14 20 20 14 15
L4 I/O MIWU or T2A 15 21 25 19 20
L5 I/O MIWU or T2B 16 22 26 20 21
L6 I/O MIWU or T3A 17 23 27 21 22
L7 I/O MIWU or T3B 18 24 28 22 23
G0 I/O INT 25 35 39 33 34
G1 I/O WDOUT* 26 36 40 34 35
G2 I/O T1B 27 37 41 35 36
G3 I/O T1A 28 38 42 36 37
G4 I/O SO 1 3 3 41 42
G5 I/O SK 2 4 4 42 43
G6 I SI 3 5 5 43 44
G7 I CKO 4 6 6 44 1
D0 O 19 25 29 23 24
D1 O 20 26 30 24 25
D2 O 21 27 31 25 26
D3 O 22 28 32 26 27
D4 O 29 33 27 28
D5 O 30 34 28 29
D6 O 31 35 29 30
D7 O 32 36 30 31
F0 I/O 7 9 9 3 4
F1 I/O COMP1IN− 8 10 10 4 5
F2 I/O COMP1IN+ 9 11 11 5 6
F3 I/O COMP1OUT 10 12 12 6 7
F4 I/O COMP2IN− 13 13 7 8
F5 I/O COMP2IN+ 14 14 8 9
F6 I/O COMP2OUT 15 15 9 10
F7 I/O 16 16 10 11
C0 I/O 39 43 37 38
C1 I/O 40 44 38 39
C2 I/O 1 1 39 40
C3 I/O 2 2 40 41
C4 I/O 21 15 16
C5 I/O 22 16 17
C6 I/O 23 17 18
C7 I/O 24 18 19
V
CC
68 8 2 3
GND 23 33 37 31 32
CKI I 5 7 7 1 2
RESET I2434383233
* G1 operation as WDOUT is controlled by ECON bit 2.
COP8SG Family
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2.1 Ordering Information
10131708
FIGURE 2. Part Numbering Scheme
COP8SG Family
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3.0 Electrical Characteristics
Absolute Maximum Ratings (Note 2)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Supply Voltage (V
CC
)7V
Voltage at Any Pin −0.3V to V
CC
+0.3V
Total Current into V
CC
Pin (Source) 100 mA
Total Current out of
GND Pin (Sink) 110 mA
Storage Temperature
Range −65˚C to +140˚C
ESD Protection Level 2kV (Human Body
Model)
Note 2:
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.
DC Electrical Characteristics
−40˚C ≤T
A
≤+85˚C unless otherwise specified.
Parameter Conditions Min Typ Max Units
Operating Voltage 2.7 5.5 V
Power Supply Rise Time 10 50 x 10
6
ns
V
CC
Start Voltage to Guarantee POR 0 0.25 V
Power Supply Ripple (Note 4) Peak-to-Peak 0.1 V
cc
V
Supply Current (Note 5)
CKI = 15 MHz V
CC
= 5.5V, t
C
= 0.67 µs 9.0 mA
CKI = 10 MHz V
CC
= 5.5V, t
C
= 1 µs 6.0 mA
CKI = 4 MHz V
CC
= 4.5V, t
C
= 2.5 µs 2.1 mA
HALT Current (Note 6) V
CC
= 5.5V, CKI=0MHz <
410 µA
IDLE Current (Note 5)
CKI = 15 MHz V
CC
= 5.5V, t
C
= 0.67 µs 2.25 mA
CKI = 10 MHz V
CC
= 5.5V, t
C
= 1 µs 1.5 mA
CKI = 4 MHz V
CC
= 4.5V, t
C
= 2.5 µs 0.8 mA
Input Levels (V
IH
,V
IL
)
RESET
Logic High 0.8 V
cc
V
Logic Low 0.2 V
cc
V
CKI, All Other Inputs
Logic High 0.7 V
cc
V
Logic Low 0.2 V
cc
V
Internal Bias Resistor for the
Crystal/Resonator Oscillator 0.5 1 2 MΩ
CKI Resistance to V
CC
or GND when R/C
Oscillator is selected V
CC
= 5.5V 5 8 11 kΩ
Hi-Z Input Leakage V
CC
= 5.5V −2 +2 µA
Input Pullup Current V
CC
= 5.5V, V
IN
= 0V −40 −250 µA
G and L Port Input Hysteresis V
CC
= 5.5V 0.25 V
cc
V
COP8SG Family
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DC Electrical Characteristics (Continued)
−40˚C ≤T
A
≤+85˚C unless otherwise specified.
Parameter Conditions Min Typ Max Units
Output Current Levels
D Outputs
Source V
CC
= 4.5V, V
OH
= 3.3V −0.4 mA
V
CC
= 2.7V, V
OH
= 1.8V -0.2 mA
Sink V
CC
= 4.5V, V
OL
= 1.0V 10 mA
V
CC
= 2.7V, V
OL
= 0.4V 2 mA
All Others
Source (Weak Pull-Up Mode) V
CC
= 4.5V, V
OH
= 2.7V −10.0 −110 µA
V
CC
= 2.7V, V
OH
= 1.8V -2.5 -33 µA
Source (Push-Pull Mode) V
CC
= 4.5V, V
OH
= 3.3V −0.4 mA
V
CC
= 2.7V, V
OH
= 1.8V -0.2 mA
Sink (Push-Pull Mode) V
CC
= 4.5V, V
OL
= 0.4V
V
CC
= 2.7V, V
OL
= 0.4V 1.6
0.7 mA
mA
TRI-STATE Leakage V
CC
= 5.5V −2 +2 µA
Allowable Sink Current per Pin (Note 9)
D Outputs and L0 to L3 15 mA
All Others 3mA
Maximum Input Current without Latchup
(Note 7) Room Temp. ±200 mA
RAM Retention Voltage, Vr 2.0 V
V
CC
Rise Time from a V
CC
≥2.0V (Note 10) 12 µs
EPROM Data Retenton (Note 8), (Note 9) T
A
= 55˚C >29 years
Input Capacitance (Note 9) 7 pF
Load Capacitance on D2 (Note 9) 1000 pF
AC Electrical Characteristics
−40˚C ≤T
A
≤+85˚C unless otherwise specified.
Parameter Conditions Min Typ Max Units
Instruction Cycle Time (t
C
)
Crystal/Resonator, External 4.5V ≤V
CC
≤5.5V 0.67 µs
2.7V ≤V
CC
≤4.5V 2 µs
R/C Oscillator (Internal) 4.5V ≤V
CC
≤5.5V 2 µs
Frequency Variation (Note 9) 4.5V ≤V
CC
≤5.5V ±35 %
External CKI Clock Duty Cycle (Note 9) fr = Max 45 55 %
Rise Time (Note 9) fr = 10 MHz Ext Clock 8 ns
Fall Time (Note 9) fr = 10 MHz Ext Clock 5 ns
MICROWIRE Setup Time (t
UWS
) (Note
11) 20 ns
MICROWIRE Hold Time (t
UWH
) (Note
11) 56 ns
MICROWIRE Output Propagation Delay
(t
UPD
) (Note 11) 220 ns
Input Pulse Width (Note 9)
Interrupt Input High Time 1 t
C
Interrupt Input Low Time 1 t
C
Timer 1, 2, 3, Input High Time 1 t
C
Timer 1 2, 3, Input Low Time 1 t
C
Reset Pulse Width 1 µs
Note 3: tC= Instruction cycle time.
COP8SG Family
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AC Electrical Characteristics (Continued)
Note 4: Maximum rate of voltage change must be <0.5 V/ms.
Note 5: Supply and IDLE currents are measured with CKI driven with a square wave Oscillator, External Oscillator, inputs connected to VCC and outputs driven low
but not connected to a load.
Note 6: The HALT mode will stop CKI from oscillating in the R/C and the Crystal configurations. In the R/C configuration, CKI is forced high internally. In the crystal
or external configuration, CKI is TRI-STATE. Measurement of IDD HALT is done with device neither sourcing nor sinking current; with L. F, C, G0, and G2–G5
programmed as low outputs and not driving a load; all outputs programmed low and not driving a load; all inputs tied to VCC; clock monitor disabled. Parameter refers
to HALT mode entered via setting bit 7 of the G Port data register.
Note 7: Pins G6 and RESET are designed with a high voltage input network.These pins allow input voltages >VCC and the pins will have sink current to VCC when
biased at voltages >VCC (the pins do not have source current when biased at a voltage below VCC). The effective resistance to VCC is 750Ω(typical). These two
pins will not latch up. The voltage at the pins must be limited to <14V. WARNING: Voltages in excess of 14V will cause damage to the pins. This warning excludes
ESD transients.
Note 8: National Semiconductor uses the High Temperature Storage Life (HTSL) test to evaluate the data retention capabilities of the EPROM memory cells used
in our OTP microcontrollers. Qualification devices have been stressed at 150˚C for 1000 hours. Under these conditions, our EPROM cells exhibit data retention
capabilities in excess of 29 years. This is based on an activation energy of 0.7eV derated to 55˚C.
Note 9: Parameter characterized but not tested.
Note 10: Rise times faster than the minimum specification may trigger an internal power-on-reset.
Note 11: MICROWIRE Setup and Hold Times and Propagation Delays are referenced to the appropriate edge of the MICROWIRE clock. See and the MICROWIRE
operation description.
Comparators AC and DC Characteristics
V
CC
= 5V, −40˚C ≤T
A
≤+85˚C.
Parameter Conditions Min Typ Max Units
Input Offset Voltage (Note 12) 0.4V ≤V
IN
≤V
CC
− 1.5V ±5±15 mV
Input Common Mode Voltage Range 0.4 V
CC
− 1.5 V
Voltage Gain 100 dB
Low Level Output Current V
OL
= 0.4V −1.6 mA
High Level Output Current V
OH
=V
CC
− 0.4V 1.6 mA
DC Supply Current per Comparator
(When Enabled) 150 µA
Response Time (Note 13) 200 mV step input
100 mV Overdrive,
100 pF Load 600 ns
Comparator Enable Time(Note 14) 600 ns
Note 12: The comparator inputs are high impedance port inputs and, as such, input current is limited to port input leakage current.
Note 13: Response time is measured from a step input to a valid logic level at the comparator output. software response time is dependent of instruction execution.
Note 14: Comparator enable time is that delay time required between the end of the instruction cycle that enables the comparator and using the output of the
comparator, either by hardware or by software.
10131709
FIGURE 3. MICROWIRE/PLUS Timing
COP8SG Family
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Absolute Maximum Ratings (Note 2)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Supply Voltage (V
CC
)7V
Voltage at Any Pin −0.3V to V
CC
+0.3V
Total Current into V
CC
Pin (Source) 100 mA
Total Current out of
GND Pin (Sink) 110 mA
Storage Temperature
Range −65˚C to +140˚C
ESD Protection Level 2kV (Human Body
Model)
Note 15:
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.
DC Electrical Characteristics
−40˚C ≤T
A
≤+125˚C unless otherwise specified.
Parameter Conditions Min Typ Max Units
Operating Voltage 4.5 5.5 V
Power Supply Rise Time 10 50 x 10
6
ns
V
CC
Start Voltage to Guarantee POR 0 0.25 V
Power Supply Ripple (Note 4) Peak-to-Peak 0.1 V
cc
V
Supply Current (Note 5)
CKI = 10 MHz V
CC
= 5.5V, t
C
= 1 µs 6.0 mA
CKI = 4 MHz V
CC
= 4.5V, t
C
= 2.5 µs 2.1 mA
HALT Current (Note 6) V
CC
= 5.5V, CKI=0MHz <
410 µA
IDLE Current (Note 5)
CKI = 10 MHz V
CC
= 5.5V, t
C
= 1 µs 1.5 mA
CKI = 4 MHz V
CC
= 4.5V, t
C
= 2.5 µs 0.8 mA
Input Levels (V
IH
,V
IL
)
RESET
Logic High 0.8 V
cc
V
Logic Low 0.2 V
cc
V
CKI, All Other Inputs
Logic High 0.7 V
cc
V
Logic Low 0.2 V
cc
V
Internal Bias Resistor for the
Crystal/Resonator Oscillator 0.5 1 2 MΩ
CKI Resistance to V
CC
or GND when R/C
Oscillator is selected V
CC
= 5.5V 5 8 11 kΩ
Hi-Z Input Leakage V
CC
= 5.5V −5 +5 µA
Input Pullup Current V
CC
= 5.5V, V
IN
= 0V −35 −400 µA
G and L Port Input Hysteresis V
CC
= 5.5V 0.25 V
cc
V
Output Current Levels
D Outputs
Source V
CC
= 4.5V, V
OH
= 3.3V −0.4 mA
Sink V
CC
= 4.5V, V
OL
= 1.0V 9 mA
All Others
Source (Weak Pull-Up Mode) V
CC
= 4.5V, V
OH
= 2.7V −9 −140 µA
Source (Push-Pull Mode) V
CC
= 4.5V, V
OH
= 3.3V −0.4 mA
Sink (Push-Pull Mode) V
CC
= 4.5V, V
OL
= 0.4V 1.4 mA
TRI-STATE Leakage V
CC
= 5.5V −5 +5 µA
Allowable Sink Current per Pin (Note 9)
D Outputs and L0 to L3 15 15 mA
All Others 33mA
COP8SG Family
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DC Electrical Characteristics (Continued)
−40˚C ≤T
A
≤+125˚C unless otherwise specified.
Parameter Conditions Min Typ Max Units
Maximum Input Current without Latchup
(Note 7) Room Temp. ±200 mA
RAM Retention Voltage, Vr 2.0 V
V
CC
Rise Time from a V
CC
≥2.0V (Note 10) 12 µs
EPROM Data Retenton (Note 8),(Note 9) T
A
= 55˚C >29 years
Input Capacitance (Note 9) 7 pF
Load Capacitance on D2 (Note 9) 1000 pF
COP8SG Family
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AC Electrical Characteristics
−40˚C ≤T
A
≤+125˚C unless otherwise specified.
Parameter Conditions Min Typ Max Units
Instruction Cycle Time (t
C
)
Crystal/Resonator, External 4.5V ≤V
CC
≤5.5V 1 µs
R/C Oscillator (Internal) 4.5V ≤V
CC
≤5.5V 2 µs
Frequency Variation (Note 9) 4.5V ≤V
CC
≤5.5V ±35 %
External CKI Clock Duty Cycle (Note 9) fr = Max 45 55 %
Rise Time (Note 9) fr = 10 MHz Ext Clock 12 ns
Fall Time (Note 9) fr = 10 MHz Ext Clock 8 ns
MICROWIRE Setup Time (t
UWS
) (Note
11) 20 ns
MICROWIRE Hold Time (t
UWH
) (Note
11) 56 ns
MICROWIRE Output Propagation Delay
(t
UPD
) (Note 11) 220 ns
Input Pulse Width (Note 9)
Interrupt Input High Time 1 t
C
Interrupt Input Low Time 1 t
C
Timer 1, 2, 3, Input High Time 1 t
C
Timer 1 2, 3, Input Low Time 1 t
C
Reset Pulse Width 1 µs
Comparators AC and DC Characteristics
V
CC
= 5V, −40˚C ≤T
A
≤+125˚C.
Parameter Conditions Min Typ Max Units
Input Offset Voltage (Note 12) 0.4V ≤V
IN
≤V
CC
− 1.5V ±5±25 mV
Input Common Mode Voltage Range 0.4 V
CC
− 1.5 V
Voltage Gain 100 dB
Low Level Output Current V
OL
= 0.4V −1.6 mA
High Level Output Current V
OH
=V
CC
− 0.4V 1.6 mA
DC Supply Current per Comparator
(When Enabled) 150 µA
Response Time (Note 13) 200 mV step input
100 mV Overdrive, 600 ns
Comparator Enable Time 600 ns
COP8SG Family
www.national.com 12
Typical Performance Characteristics T
A
= 25˚C (unless otherwise specified)
10131749 10131750
10131751 10131752
COP8SG Family
www.national.com13
4.0 Pin Descriptions
The COP8SGx I/O structure enables designers to reconfig-
ure the microcontroller’s I/O functions with a single instruc-
tion. Each individual I/O pin can be independently configured
as output pin low, output high, input with high impedance or
input with weak pull-up device. A typical example is the use
of I/O pins as the keyboard matrix input lines. The input lines
can be programmed with internal weak pull-ups so that the
input lines read logic high when the keys are all open. With
a key closure, the corresponding input line will read a logic
zero since the weak pull-up can easily be overdriven. When
the key is released, the internal weak pull-up will pull the
input line back to logic high. This eliminates the need for
external pull-up resistors. The high current options are avail-
able for driving LEDs, motors and speakers. This flexibility
helps to ensure a cleaner design, with less external compo-
nents and lower costs. Below is the general description of all
available pins.
V
CC
and GND are the power supply pins. All V
CC
and GND
pins must be connected.
CKI is the clock input. This can come from the Internal R/C
oscillator, external, or a crystal oscillator (in conjunction with
CKO). See Oscillator Description section.
RESET is the master reset input. See Reset description
section.
Each device contains four bidirectional 8-bit I/O ports (C, G,
L and F), where each individual bit may be independently
configured as an input (Schmitt trigger inputs on ports L and
G), output or TRI-STATE under program control. 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 registers, 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 4
shows the I/O port configurations. The DATA and
CONFIGURATION registers allow for each port bit to be
individually configured under software control as shown be-
low:
CONFIGURATION
Register DATA
Register Port Set-Up
0 0 Hi-Z Input
(TRI-STATE Output)
0 1 Input with Weak Pull-Up
1 0 Push-Pull Zero Output
1 1 Push-Pull One Output
Port L is an 8-bit I/O port. All L-pins have Schmitt triggers on
the inputs.
Port L supports the Multi-Input Wake Up feature on all eight
pins. Port L has the following alternate pin functions:
L7 Multi-input Wakeup or T3B (Timer T3B Input)
L6 Multi-input Wakeup or T3A (Timer T3A Input)
L5 Multi-input Wakeup or T2B (Timer T2B Input)
L4 Multi-input Wakeup or T2A (Timer T2A Input)
L3 Multi-input Wakeup and/or RDX (USART Receive)
L2 Multi-input Wakeup or TDX (USART Transmit)
L1 Multi-input Wakeup and/or CKX (USART Clock)
L0 Multi-input Wakeup
Port G is an 8-bit port. Pin G0, G2–G5 are bi-directional I/O
ports. Pin G6 is always a general purpose Hi-Z input.All pins
have Schmitt Triggers on their inputs.Pin G1 serves as the
dedicated WATCHDOG output with weak pullup if
WATCHDOG feature is selected by the Mask Option reg-
ister. The pin is a general purpose I/O if WATCHDOG
feature is not selected. If WATCHDOG feature is selected,
bit 1 of the Port G configuration and data register does not
have any effect on Pin G1 setup. Pin G7 is either input or
output depending on the oscillator option selected. With the
crystal oscillator option selected, G7 serves as the dedicated
output pin for the CKO clock output. With the internal R/C or
the external oscillator option selected, G7 serves as a gen-
eral purpose Hi-Z input pin and is also used to bring the
device out of HALT mode with a low to high transition on G7.
Since G6 is an input only pin and G7 is the dedicated CKO
clock output pin (crystal clock option) or general purpose
input (R/C or external 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 zeroes.
Each device will be placed in the HALT mode by writing a “1”
to bit 7 of the Port G Data Register. Similarly the device will
be placed in the IDLE mode by writing a “1” to bit 6 of the
Port G Data Register.
Writing a “1” to bit 6 of the Port G Configuration Register
enables the MICROWIRE/PLUS to operate with the alter-
nate 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.
Config. Reg. Data Reg.
G7 CLKDLY HALT
G6 Alternate SK IDLE
Port G has the following alternate features:
G7 CKO Oscillator dedicated output or general purpose
input
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)
G1 WDOUT WATCHDOG and/or CLock Monitor if WATCH-
DOG enabled, otherwise it is a general purpose I/O
G0 INTR (External Interrupt Input)
Port C is an 8-bit I/O port. The 40-pin device does not have
a full complement of Port C pins. The unavailable pins are
not terminated. Aread operation on these unterminated pins
will return unpredictable values. The 28 pin device do not
offer Port C. On this device, the associated Port C Data and
Configuration registers should not be used.
Port F is an 8-bit I/O port. The 28--pin device does not have
a full complement of Port F pins. The unavailable pins are
not terminated. Aread operation on these unterminated pins
will return unpredictable values.
Port F1–F3 are used for Comparator 1. Port F4–F6 are used
for Comparator 2.
The Port F has the following alternate features:
F6 COMP2OUT (Comparator 2 Output)
F5 COMP2+IN (Comparator 2 Positive Input)
F4 COMP2-IN (Comparator 2 Negative Input)
F3 COMP1OUT (Comparator 1 Output)
F2 COMP1+IN (Comparator 1 Positive Input)
F1 COMP1-IN (Comparator 1 Negative Input)
COP8SG Family
www.national.com 14
4.0 Pin Descriptions (Continued)
Note: For compatibility with existing software written for COP888xG devices
and with existing Mask ROM devices, a read of the Port I input pins
(address xxD7) will return the same data as reading the Port F input
pins (address xx96). It is recommended new applications which will go
to production with the COP8SGx use the Port F addresses. Note that
compatible ROM devices contains the input only Port I instead of the
bi-directional Port F.
Port D is an 8-bit output port that is preset high when RESET
goes low. The user can tie two or more D port outputs
(except D2) together in order to get a higher drive.
Note: Care must be exercised with the D2 pin operation. At RESET, the
external loads on this pin must ensure that the output voltages stay
above 0.7 VCC to prevent the chip from entering special modes. Also
keep the external loading on D2 to less than 1000 pF.
10131710
FIGURE 4. I/O Port Configurations
10131712
FIGURE 5. I/O Port Configurations—Output Mode
10131711
FIGURE 6. I/O Port Configurations—Input Mode
COP8SG Family
www.national.com15
5.0 Functional Description
The architecture of the devices are a modified Harvard ar-
chitecture. With the Harvard architecture, the program
memory ROM is separated from the data store memory
(RAM). Both ROM and RAM have their own separate ad-
dressing space with separate address buses. The architec-
ture, though based on the Harvard architecture, permits
transfer of data from ROM to RAM.
5.1 CPU REGISTERS
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
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.
S is the 8-bit Segment Address Register used to extend the
lower half of the address range (00 to 7F) into 256 data
segments of 128 bytes each.
SP is the 8-bit stack pointer, which points to the subroutine/
interrupt stack (in RAM). With reset the SP is initialized to
RAM address 02F Hex (devices with 64 bytes of RAM), or
initialized to RAM address 06F Hex (devices with 128 bytes
of RAM).
All the CPU registers are memory mapped with the excep-
tion of the Accumulator (A) and the Program Counter (PC).
5.2 PROGRAM MEMORY
The program memory consists of varies sizes of ROM.
These bytes may hold program instructions or constant data
(data tables for the LAID instruction, jump vectors for the JID
instruction, 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. The contents of the program
memory read 00 Hex in the erased state. Program execution
starts at location 0 after RESET.
5.3 DATA MEMORY
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 256 or 512 bytes of RAM.
Sixteen bytes of RAM are mapped as “registers” at ad-
dresses 0F0 to 0FE 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, SP and B are memory mapped
into this space at address locations 0FC to 0FE Hex respec-
tively, with the other registers (except 0FF) being available
for general usage.
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 accumu-
lator (A) bits can also be directly and individually tested.
Note: RAM contents are undefined upon power-up.
5.4 DATA MEMORY SEGMENT RAM EXTENSION
Data memory address 0FF is used as a memory mapped
location for the Data Segment Address Register (S).
The data store memory is either addressed directly by a
single byte address within the instruction, or indirectly rela-
tive to the reference of the B, X, or SP pointers (each
contains a single-byte address). This single-byte address
allows an addressing range of 256 locations from 00 to FF
hex. The upper bit of this single-byte address divides the
data store memory into two separate sections as outlined
previously. With the exception of the RAM register memory
from address locations 00F0 to 00FF, all RAM memory is
memory mapped with the upper bit of the single-byte ad-
dress being equal to zero. This allows the upper bit of the
single-byte address to determine whether or not the base
address range (from 0000 to 00FF) is extended. If this upper
bit equals one (representing address range 0080 to 00FF),
then address extension does not take place. Alternatively, if
this upper bit equals zero, then the data segment extension
register S is used to extend the base address range (from
0000 to 007F) from XX00 to XX7F, where XX represents the
8 bits from the S register. Thus the 128-byte data segment
extensions are located from addresses 0100 to 017F for
data segment 1, 0200 to 027F for data segment 2, etc., up to
FF00 to FF7F for data segment 255. The base address
range from 0000 to 007F represents data segment 0.
Figure 7
illustrates how the S register data memory exten-
sion is used in extending the lower half of the base address
range (00 to 7F hex) into 256 data segments of 128 bytes
each, with a total addressing range of 32 kbytes from XX00
to XX7F. This organization allows a total of 256 data seg-
ments of 128 bytes each with an additional upper base
segment of 128 bytes. Furthermore, all addressing modes
are available for all data segments. The S register must be
changed under program control to move from one data
segment (128 bytes) to another. However, the upper base
segment (containing the 16 memory registers, I/O registers,
control registers, etc.) is always available regardless of the
contents of the S register, since the upper base segment
(address range 0080 to 00FF) is independent of data seg-
ment extension.
COP8SG Family
www.national.com 16
5.0 Functional Description (Continued)
The instructions that utilize the stack pointer (SP) always
reference the stack as part of the base segment (Segment
0), regardless of the contents of the S register. The S register
is not changed by these instructions. Consequently, the
stack (used with subroutine linkage and interrupts) is always
located in the base segment. The stack pointer will be initial-
ized to point at data memory location 006F as a result of
reset.
The 128 bytes of RAM contained in the base segment are
split between the lower and upper base segments. The first
112 bytes of RAM are resident from address 0000 to 006F in
the lower base segment, while the remaining 16 bytes of
RAM represent the 16 data memory registers located at
addresses 00F0 to 00FF of the upper base segment. No
RAM is located at the upper sixteen addresses (0070 to
007F) of the lower base segment.
Additional RAM beyond these initial 128 bytes, however, will
always be memory mapped in groups of 128 bytes (or less)
at the data segment address extensions (XX00 to XX7F) of
the lower base segment. The additional 384 bytes of RAM in
this device are memory mapped at address locations 0100
to 017F, 0200 to 027F and 0300 to 037F hex.
Memory address ranges 0200 to 027F and 0300 to 037F are
unavailable on the COP8SGx5 and, if read, will return un-
derfined data.
5.5 ECON (CONFIGURATION) REGISTER
For compatibility with COP8SGx7 devices, mask options are
defined by an ECON Configuration Register which is pro-
grammed at the same time as the program code. Therefore,
the register is programmed at the same time as the program
memory.
The format of the ECON register is as follows:
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
X POR SECURITY CKI 2 CKI 1 WATCH F-Port HALT
DOG
Bit 7 = x This is for factory test. The polarity is “Don’t
Care.”
Bit 6 = 1 Power-on reset enabled.
= 0 Power-on reset disabled.
Bit 5 = 1 Security enabled.
Bits 4,3=0,0 External CKI option selected. G7 is avail-
able as a HALT restart and/or general pur-
pose input. CKI is clock input.
= 0, 1 R/C oscillator option selected. G7 is avail-
able as a HALT restart and/or general pur-
pose input. CKI clock input. Internal R/C
components are supplied for maximum R/C
frequency.
= 1, 0 Crystal oscillator with on-chip crystal bias
resistor disabled. G7 (CKO) is the clock
generator output to crystal/resonator.
= 1, 1 Crystal oscillator with on-chip crystal bias
resistor enabled. G7 (CKO) is the clock gen-
erator output to crystal/resonator.
Bit 2 = 1 WATCHDOG feature disabled. G1 is a gen-
eral purpose I/O.
= 0 WATCHDOG feature enabled. G1 pin is
WATCHDOG output with weak pullup.
Bit 1 = 1 Force port I compatibility. Disable port F
outputs and pull-ups. This is intended for
compatibility with existing code and Mask
ROMMed devices only. This bit should be
10131745
FIGURE 7. RAM Organization
COP8SG Family
www.national.com17
5.0 Functional Description (Continued)
programmed to 0 for all other applications.
= 0 Enable full port F capability.
Bit 0 = 1 HALT mode disabled.
= 0 HALT mode enabled.
5.6 USER STORAGE SPACE IN EPROM
The ECON register is outside of the normal address range of
the ROM and can not be accessed by the executing soft-
ware.
The COP8 assembler defines a special ROM section type,
CONF, into which the ECON may be coded. Both ECON and
User Data are programmed automatically by programmers
that are certified by National.
The following examples illustrate the declaration of ECON
and the User information.
Syntax:
[label:] .sect econ, conf
.db value ;1 byte,
;configures options
.db <user information>
.endsect ; up to 8 bytes
Example: The following sets a value in the ECON register
and User Identification for a COP8SGR728M7. The ECON
bit values shown select options: Power-on enabled, Security
disabled, Crystal oscillator with on-chip bias disabled,
WATCHDOG enabled and HALT mode enabled.
.sect econ, conf
.db 0x55 ;por, xtal, wd, halt
.db 'my v1.00' ;user data declaration
.endsect
5.7 OTP SECURITY
The device has a security feature that, when enabled, pre-
vents external reading of the OTP program memory. The
security bit in the ECON register determines, whether secu-
rity is enabled or disabled. If the security feature is disabled,
the contents of the internal EPROM may be read.
If the security feature is enabled, then any attempt to
externally read the contents of the EPROM will result in
the value FF Hex being read from all program locations
Under no circumstances can a secured part be read. In
addition, with the security feature enabled, the write opera-
tion to the EPROM program memory and ECON register is
inhibited. The ECON register is readable regardless of the
state of the security bit. The security bit, when set, cannot
be erased, even in windowed packages. If the security bit
is set in a device in a windowed package, that device may be
erased but will not be further programmable.
If security is being used, it is recommended that all other bits
in the ECON register be programmed first. Then the security
bit can be programmed.
5.8 ERASURE CHARACTERISTICS
The erasure characteristics of the device are such that era-
sure begins to occur when exposed to light with wavelengths
shorter than approximately 4000Angstroms (Å). It should be
noted that sunlight and certain types of fluorescent lamps
have wavelengths in the 3000Å - 4000Å range.
After programming, opaque labels should be placed over the
window of windowed devices to prevent unintentional era-
sure. Covering the window will also prevent temporary func-
tional failure due to the generation of photo currents.
The recommended erasure procedure for windowed devices
is exposure to short wave ultraviolet light which has a wave-
length of 2537 Angstroms (Å). The integrated dose (i.e. UV
intensity X exposure time) for erasure should be a minimum
of 15W-sec/cm
2
.
5.9 RESET
The devices are initialized when the RESET pin is pulled low
or the On-chip Power-On Reset is enabled.
The following occurs upon initialization:
Port L: TRI-STATE (High Impedance Input)
Port C: TRI-STATE (High Impedance Input)
Port G: TRI-STATE (High Impedance Input)
Port F: TRI-STATE (High Impedance Input)
Port D: HIGH
PC: CLEARED to 0000
PSW, CNTRL and ICNTRL registers: CLEARED
SIOR:
UNAFFECTED after RESET with power already applied
RANDOM after RESET at power-on
T2CNTRL: CLEARED
T3CNTRL: CLEARED
Accumulator, Timer 1, Timer 2 and Timer 3:
RANDOM after RESET with crystal clock option
(power already applied)
UNAFFECTED after RESET with R/C clock option
(power already applied)
RANDOM after RESET at power-on
WKEN, WKEDG: CLEARED
WKPND: RANDOM
SP (Stack Pointer):
Initialized to RAM address 06F Hex
B and X Pointers:
UNAFFECTED after RESET with power already applied
RANDOM after RESET at power-on
S Register: CLEARED
RAM:
UNAFFECTED after RESET with power already applied
RANDOM after RESET at power-on
USART:
PSR, ENU, ENUR, ENUI: Cleared except the TBMT bit
which is set to one.
COMPARATORS:
CMPSL; CLEARED
WATCHDOG (if enabled):
10131713
FIGURE 8. Reset Logic
COP8SG Family
www.national.com 18
5.0 Functional Description (Continued)
The device comes out of reset with both the WATCH-
DOG 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
inhibited during reset. The WATCHDOG service window bits
being initialized high default to the maximum WATCHDOG
service window of 64k t
C
clock 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
C
clock cycles following
the clock frequency reaching the minimum specified value,
at which time the G1 output will go high.
5.9.1 External Reset
The RESET input when pulled low initializes the device. The
RESET pin must be held low for a minimum of one instruc-
tion cycle to guarantee a valid reset. During Power-Up ini-
tialization, the user must ensure that the RESET pin is held
low until the device is within the specified V
CC
voltage. An
R/C circuit on the RESET pin with a delay 5 times (5x)
greater than the power supply rise time or 15 µs whichever is
greater, is recommended. Reset should also be wide enough
to ensure crystal start-up upon Power-Up.
RESET may also be used to cause an exit from the HALT
mode.
A recommended reset circuit for this device is shown in
Figure 9
.
5.9.2 On-Chip Power-On Reset
The on-chip reset circuit is selected by a bit in the ECON
register. When enabled, the device generates an internal
reset as V
CC
rises to a voltage level above 2.0V. The on-chip
reset circuitry is able to detect both fast and slow rise times
on V
CC
(V
CC
rise time between 10 ns and 50 ms).To guar-
antee an on-chip power-on-reset, V
CC
must start at a voltage
less than the start voltage specified in the DC characteris-
tics. Also, if V
CC
be lowered to the start voltage before
powering back up to the operating range. If this is not pos-
sible, it is recommended that external reset be used.
Under no circumstances should the RESET pin be allowed
to float. If the on-chip Power-On Reset feature is being used,
RESET pin should be connected directly, or through a
pull-up resistor, to V
CC
. The output of the power-on reset
detector will always preset the Idle timer to 0FFF(4096 t
C
).
At this time, the internal reset will be generated.
If the Power-On Reset feature is enabled, the internal reset
will not be turned off until the Idle timer underflows. The
internal reset will perform the same functions as external
reset. The user is responsible for ensuring that V
CC
is at the
minimum level for the operating frequency within the 4096
t
C
. After the underflow, the logic is designed such that no
additional internal resets occur as long as V
CC
remains
above 2.0V.
The contents of data registers and RAM are unknown fol-
lowing the on-chip reset.
10131714
RC >5x power supply rise time or 15 µs, whichever is greater.
FIGURE 9. Reset Circuit Using External Reset
10131715
FIGURE 10. Reset Timing (Power-On Reset Enabled)
with V
CC
Tied to RESET
10131716
FIGURE 11. Reset Circuit Using Power-On Reset
COP8SG Family
www.national.com19
5.0 Functional Description (Continued)
5.10 OSCILLATOR CIRCUITS
There are four clock oscillator options available: Crystal
Oscillator with or without on-chip bias resistor, R/C Oscillator
with on-chip resistor and capacitor, and External Oscillator.
The oscillator feature is selected by programming the ECON
register, which is summarized in
Table 1
.
TABLE 1. Oscillator Option
ECON4 ECON3 Oscillator Option
0 0 External Oscillator
1 0 Crystal Oscillator without Bias Resistor
0 1 R/C Oscillator
1 1 Crystal Oscillator with Bias Resistor
5.10.1 Crystal Oscillator
The crystal Oscillator mode can be selected by programming
ECON Bit 4 to 1. CKI is the clock input while G7/CKO is the
clock generator output to the crystal.An on-chip bias resistor
connected between CKI and CKO can be enabled by pro-
gramming ECON Bit 3 to 1 with the crystal oscillator option
selection. The value of the resistor is in the range of 0.5M to
2M (typically 1.0M).
Table 2
shows the component values
required for various standard crystal values. Resistor R2 is
only used when the on-chip bias resistor is disabled.
Figure
12
shows the crystal oscillator connection diagram.
TABLE 2. Crystal Oscillator Configuration,
T
A
= 25˚C, V
CC
=5V
R1 (kΩ)R2(MΩ) C1 (pF) C2 (pF) CKI Freq.
(MHz)
0 1 18 18 15
0 1 20 20 10
0 1 25 25 4
5.6 1 100 100–156 0.455
5.10.2 External Oscillator
The External Oscillator mode can be selected by program-
ming ECON Bit 3 to 0 and ECON Bit 4 to 0. CKI can be
driven by an external clock signal provided it meets the
specified duty cycle, rise and fall times, and input levels.
G7/CKO is available as a general purpose input G7 and/or
Halt control.
Figure 13
shows the external oscillator connec-
tion diagram.
5.10.3 R/C Oscillator
The R/C Oscillator mode can be selected by programming
ECON Bit 3 to 1 and ECON Bit 4 to 0. In R/C oscillation
mode, CKI is left floating, while G7/CKO is available as a
general purpose input G7 and/or HALT control. The R/C
controlled oscillator has on-chip resistor and capacitor for
maximum R/C oscillator frequency operation. The maximum
frequency is 5 MHz ±35% for V
CC
between 4.5V to 5.5V
and temperature range of −40˚C to +85˚C. For max fre-
quency operation, the CKI pin should be left floating. For
lower frequencies, an external capacitor should be con-
nected between CKI and either V
CC
or GND. Immunity of the
R/C oscillator to external noise can be improved by connect-
ing one half the external capacitance to V
CC
and one half to
GND. PC board trace length on the CKI pin should be kept
as short as possible.
Table 3
shows the oscillator frequency
as a function of external capacitance on the CKI pin.
Figure
14
shows the R/C oscillator configuration.
TABLE 3. R/C Oscillator Configuration,
−40˚C to +85˚C, V
CC
= 4.5V to 5.5V,
OSC Freq. Variation of ±35%
External
Capacitor (pF)* R/C OSC Freq
(MHz) Instr. Cycle (µs)
0 5 2.0
9 4 2.5
52 2 5.0
125 1 10
6100 32 kHz 312.5
* Assumes 3-5 pF board capacitance.
With On-Chip Bias Resistor Without On-Chip Bias Resistor
10131717 10131718
FIGURE 12. Crystal Oscillator
COP8SG Family
www.national.com 20
5.0 Functional Description (Continued)
5.11 CONTROL REGISTERS
CNTRL Register (Address X'00EE)
T1C3 T1C2 T1C1 T1C0 MSEL IEDG SL1 SL0
Bit 7 Bit 0
The Timer1 (T1) and MICROWIRE/PLUS control register
contains the following bits:
T1C3 Timer T1 mode control bit
T1C2 Timer T1 mode control bit
T1C1 Timer T1 mode control bit
T1C0 Timer T1 Start/Stop control in timer
modes 1 and 2, T1 Underflow Interrupt
Pending Flag in timer mode 3
MSEL Selects G5 and G4 as MICROWIRE/PLUS
signals SK and SO respectively
IEDG 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)
HC C T1PNDA T1ENA EXPND BUSY EXEN GIE
Bit 7 Bit 0
The PSW register contains the following select bits:
HC Half Carry Flag
C Carry Flag
T1PNDA Timer T1 Interrupt Pending Flag (Autoreload RA
in mode 1, T1 Underflow in Mode 2,T1Acapture
edge in mode 3)
T1ENA Timer T1 Interrupt Enable for Timer Underflow
or T1A Input capture edge
EXPND External interrupt pending
BUSY MICROWIRE/PLUS busy shifting flag
EXEN Enable external interrupt
GIE Global interrupt enable (enables interrupts)
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.
ICNTRL Register (Address X'00E8)
Reserved LPEN T0PND T0EN µWPND µWEN T1PNDB T1ENB
Bit 7 Bit 0
The ICNTRL register contains the following bits:
Reserved This bit is reserved and must be zero
LPEN L Port Interrupt Enable (Multi-Input
Wakeup/Interrupt)
T0PND Timer T0 Interrupt pending
T0EN Timer T0 Interrupt Enable (Bit 12 toggle)
µWPND MICROWIRE/PLUS interrupt pending
µWEN Enable MICROWIRE/PLUS interrupt
T1PNDB Timer T1 Interrupt Pending Flag for T1B cap-
ture edge
T1ENB TimerT1 Interrupt Enable for T1B Input capture
edge
T2CNTRL Register (Address X'00C6)
T2C3 T2C2 T2C1 T2C0 T2PNDA T2ENA T2PNDB T2ENB
Bit 7 Bit 0
The T2CNTRL control register contains the following bits:
T2C3 Timer T2 mode control bit
T2C2 Timer T2 mode control bit
T2C1 Timer T2 mode control bit
T2C0 Timer T2 Start/Stop control in timer
modes 1 and 2, T2 Underflow Interrupt Pend-
ing Flag in timer mode 3
T2PNDA Timer T2 Interrupt Pending Flag (Autoreload
RA in mode 1, T2 Underflow in mode 2, T2A
capture edge in mode 3)
T2ENA Timer T2 Interrupt Enable for Timer Underflow
or T2A Input capture edge
T2PNDB Timer T2 Interrupt Pending Flag for T2B cap-
ture edge
T2ENB Timer T2 Interrupt Enable for Timer Underflow
or T2B Input capture edge
10131719
FIGURE 13. External Oscillator
10131720
For operation at lower than maximum R/C oscillator frequency.
10131721
For operation at maximum R/C oscillator frequency.
FIGURE 14. R/C Oscillator
COP8SG Family
www.national.com21
5.0 Functional Description (Continued)
T3CNTRL Register (Address X'00B6)
T3C3 T3C2 T3C1 T3C0 T3PNDA T3ENA T3PNDB T3ENB
Bit 7 Bit 0
The T3CNTRL control register contains the following bits:
T3C3 Timer T3 mode control bit
T3C2 Timer T3 mode control bit
T3C1 Timer T3 mode control bit
T3C0 Timer T3 Start/Stop control in timer
modes 1 and 2, T3 Underflow Interrupt Pend-
ing Flag in timer mode 3
T3PNDA Timer T3 Interrupt Pending Flag (Autoreload
RA in mode 1, T3 Underflow in mode 2, T3A
capture edge in mode 3)
T3ENA Timer T3 Interrupt Enable for Timer Underflow
or T3A Input capture edge
T3PNDB Timer T3 Interrupt Pending Flag for T3B cap-
ture edge
T3ENB Timer T3 Interrupt Enable for Timer Underflow
or T3B Input capture edge
6.0 Timers
Each device contains a very versatile set of timers (T0, T1,
T2 and T3). Timer T1, T2 and T3 and associated autoreload/
capture registers power up containing random data.
6.1 TIMER T0 (IDLE TIMER)
Each 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. The Timer
T0 runs continuously at the fixed rate of the instruction cycle
clock, t
C
. The user cannot read or write to the IDLETimerT0,
which is a count down timer.
The Timer T0 supports the following functions:
•Exit out of the Idle Mode (See Idle Mode description)
•WATCHDOG logic (See WATCHDOG description)
•Start up delay out of the HALT mode
•Timing the width of the internal power-on-reset
The IDLE Timer T0 can generate an interrupt when the
twelfth bit toggles. This toggle is latched into the T0PND
pending flag, and will occur every 2.731 ms at the maximum
clock frequency (t
C
= 0.67 µs).Acontrol flag T0EN allows the
interrupt from the twelfth bit of Timer T0 to be enabled or
disabled. Setting T0EN will enable the interrupt, while reset-
ting it will disable the interrupt.
6.2 TIMER T1, TIMER T2 and TIMER T3
Each device have a set of three powerful timer/counter
blocks, T1, T2 and T3. Since T1, T2, and T3 are identical, all
comments are equally applicable to any of the three timer
blocks which will be referred to as Tx.
Each timer block consists of a 16-bit timer, Tx, and two
supporting 16-bit autoreload/capture registers, RxA and
RxB. Each timer block has two pins associated with it, TxA
and TxB. The pin TxA supports I/O required by the timer
block, while the pin TxB is an input to the timer block. The
timer block has three operating modes: Processor Indepen-
dent PWM mode, External Event Counter mode, and Input
Capture mode.
The control bits TxC3, TxC2, and TxC1 allow selection of the
different modes of operation.
6.2.1 Mode 1. Processor Independent PWM Mode
One of the timer’s operating modes is the Processor Inde-
pendent PWM mode. In this mode, the timer generates a
“Processor Independent” PWM signal because once the
timer is setup, no more action is required from the CPU
which translates to less software overhead and greater
throughput. The user software services the timer block only
when the PWM parameters require updating. This capability
is provided by the fact that the timer has two separate 16-bit
reload registers. One of the reload registers contains the
“ON” timer while the other holds the “OFF” time. By contrast,
a microcontroller that has only a single reload register re-
quires an additional software to update the reload value
(alternate between the on-time/off-time).
The timer can generate the PWM output with the width and
duty cycle controlled by the values stored in the reload
registers. The reload registers control the countdown values
and the reload values are automatically written into the timer
when it counts down through 0, generating interrupt on each
reload. Under software control and with minimal overhead,
the PMW outputs are useful in controlling motors, triacs, the
intensity of displays, and in providing inputs for data acqui-
sition and sine wave generators.
In this mode, the timer Tx counts down at a fixed rate of t
C
.
Upon every underflow the timer is alternately reloaded with
the contents of supporting registers, RxA and RxB. The very
first underflow of the timer causes the timer to reload from
the register RxA. Subsequent underflows cause the timer to
be reloaded from the registers alternately beginning with the
register RxB.
Figure 15
shows a block diagram of the timer in PWM mode.
The underflows can be programmed to toggle the TxAoutput
pin. The underflows can also be programmed to generate
interrupts.
Underflows from the timer are alternately latched into two
pending flags, TxPNDA and TxPNDB. The user must reset
these pending flags under software control. Two control
enable flags, TxENA and TxENB, allow the interrupts from
the timer underflow to be enabled or disabled. Setting the
timer enable flag TxENAwill cause an interrupt when a timer
underflow causes the RxA register to be reloaded into the
timer. Setting the timer enable flag TxENB will cause an
interrupt when a timer underflow causes the RxB register to
be reloaded into the timer. Resetting the timer enable flags
will disable the associated interrupts.
Either or both of the timer underflow interrupts may be
enabled. 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 inter-
rupt on both edges of the PWM output.
6.2.2 Mode 2. External Event Counter Mode
This mode is quite similar to the processor independent
PWM mode described above. The main difference is that the
timer, Tx, is clocked by the input signal from the TxApin. The
Tx timer control bits, TxC3,TxC2 and TxC1 allow the timer to
be clocked either on a positive or negative edge from the
TxA pin. Underflows from the timer are latched into the
TxPNDA pending flag. Setting the TxENA control flag will
cause an interrupt when the timer underflows.
COP8SG Family
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6.0 Timers (Continued)
In this mode the input pin TxB can be used as an indepen-
dent positive edge sensitive interrupt input if the TxENB
control flag is set. The occurrence of a positive edge on the
TxB input pin is latched into the TxPNDB flag.
Figure 16
shows a block diagram of the timer in External
Event Counter mode.
Note: The PWM output is not available in this mode since the TxApin is being
used as the counter input clock.
6.2.3 Mode 3. Input Capture Mode
Each device can precisely measure external frequencies or
time external events by placing the timer block, Tx, in the
input capture mode. In this mode, the reload registers serve
as independent capture registers, capturing the contents of
the timer when an external event occurs (transition on the
timer input pin). The capture registers can be read while
maintaining count, a feature that lets the user measure
elapsed time and time between events. By saving the timer
value when the external event occurs, the time of the exter-
nal event is recorded. Most microcontrollers have a latency
time because they cannot determine the timer value when
the external event occurs. The capture register eliminates
the latency time, thereby allowing the applications program
to retrieve the timer value stored in the capture register.
In this mode, the timer Tx is constantly running at the fixed t
C
rate. The two registers, RxA and RxB, act as capture regis-
ters. Each register acts in conjunction with a pin. The register
RxAacts in conjunction with the TxApin and the register RxB
acts in conjunction with the TxB pin.
The timer value gets copied over into the register when a
trigger event occurs on its corresponding pin. Control bits,
TxC3, TxC2 and TxC1, allow the trigger events to be speci-
fied either as a positive or a negative edge. The trigger
condition for each input pin can be specified independently.
The trigger conditions can also be programmed to generate
interrupts. The occurrence of the specified trigger condition
on the TxAand TxB pins will be respectively latched into the
pending flags, TxPNDA and TxPNDB. The control flag Tx-
ENA allows the interrupt on TxA to be either enabled or
disabled. Setting the TxENA flag enables interrupts to be
generated when the selected trigger condition occurs on the
TxA pin. Similarly, the flag TxENB controls the interrupts
from the TxB pin.
Underflows from the timer can also be programmed to gen-
erate interrupts. Underflows are latched into the timer TxC0
pending flag (the TxC0 control bit serves as the timer under-
flow interrupt pending flag in the Input Capture mode). Con-
sequently, the TxC0 control bit should be reset when enter-
ing the Input Capture mode. The timer underflow interrupt is
enabled with the TxENA control flag. When a TxA interrupt
occurs in the Input Capture mode, the user must check both
the TxPNDA and TxC0 pending flags in order to determine
whether a TxA input capture or a timer underflow (or both)
caused the interrupt.
Figure 17
shows a block diagram of the timer T1 in Input
Capture mode. Timer T2 and T3 are identical to T1.
10131746
FIGURE 15. Timer in PWM Mode
10131747
FIGURE 16. Timer in External Event Counter Mode
10131748
FIGURE 17. Timer in Input Capture Mode
COP8SG Family
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6.0 Timers (Continued)
6.3 TIMER CONTROL FLAGS
The control bits and their functions are summarized below.
TxC3 Timer mode control
TxC2 Timer mode control
TxC1 Timer mode control
TxC0 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)
TxPNDA Timer Interrupt Pending Flag
TxENA Timer Interrupt Enable Flag
1 = Timer Interrupt Enabled
0 = Timer Interrupt Disabled
TxPNDB Timer Interrupt Pending Flag
TxENB Timer Interrupt Enable Flag
1 = Timer Interrupt Enabled
0 = Timer Interrupt Disabled
The timer mode control bits (TxC3, TxC2 and TxC1) are
detailed below:
Mode TxC3 TxC2 TxC1 Description Interrupt A
Source Interrupt B
Source Timer
Counts On
11 0 1 PWM: TxA Toggle Autoreload RA Autoreload RB t
C
1 0 0 PWM: No TxA
Toggle Autoreload RA Autoreload RB t
C
2
0 0 0 External Event
Counter Timer Underflow Pos. TxB Edge Pos. TxA
Edge
0 0 1 External Event
Counter Timer Underflow Pos. TxB Edge Pos. TxA
Edge
3
0 1 0 Captures: Pos. TxA Edge Pos. TxB Edge t
C
TxA Pos. Edge or Timer
TxB Pos. Edge Underflow
1 1 0 Captures: Pos. TxA Neg. TxB t
C
TxA Pos. Edge Edge or Timer Edge
TxB Neg. Edge Underflow
0 1 1 Captures: Neg. TxA Neg. TxB t
C
TxA Neg. Edge Edge or Timer Edge
TxB Neg. Edge Underflow
1 1 1 Captures: Neg. TxA Neg. TxB t
C
TxA Neg. Edge Edge or Timer Edge
TxB Neg. Edge Underflow
COP8SG Family
www.national.com 24
7.0 Power Saving Features
Today, the proliferation of battery-operated based applica-
tions has placed new demands on designers to drive power
consumption down. Battery-operated systems are not the
only type of applications demanding low power. The power
budget constraints are also imposed on those consumer/
industrial applications where well regulated and expensive
power supply costs cannot be tolerated. Such applications
rely on low cost and low power supply voltage derived di-
rectly from the “mains” by using voltage rectifier and passive
components. Low power is demanded even in automotive
applications, due to increased vehicle electronics content.
This is required to ease the burden from the car battery. Low
power 8-bit microcontrollers supply the smarts to control
battery-operated, consumer/industrial, and automotive appli-
cations.
Each device offers system designers a variety of low-power
consumption features that enable them to meet the demand-
ing requirements of today’s increasing range of low-power
applications. These features include low voltage operation,
low current drain, and power saving features such as HALT,
IDLE, and Multi-Input wakeup (MIWU).
Each device offers the user two power save modes of op-
eration: HALT and IDLE. In the HALT mode, all microcontrol-
ler activities are stopped. In the IDLE mode, the on-board
oscillator circuitry and timer T0 are active but all other micro-
controller activities are stopped. In either mode, all on-board
RAM, registers, I/O states, and timers (with the exception of
T0) are unaltered.
Clock Monitor, if enabled, can be active in both modes.
7.1 HALT MODE
Each 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-
DOG logic on the devices are disabled during the HALT
mode. However, the clock monitor circuitry, if enabled, re-
mains active 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 disabled after the devices come out of reset
(resetting the Clock Monitor control bit with the first write to
the WDSVR register). In the HALT mode, the power require-
ments of the devices are minimal and the applied voltage
(V
CC
) may be decreased to V
r
(V
r
= 2.0V) without altering the
state of the machine.
Each 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 Port L. The second
method is with a low to high transition on the CKO (G7) pin.
This method precludes the use of the crystal clock configu-
ration (since CKO becomes a dedicated output), and so may
only be used with an R/C clock configuration. The third
method of exiting the HALT mode is by pulling the RESET
pin low.
On wakeup from G7 or Port L, the devices resume execution
from the HALT point. On wakeup from RESET execution will
resume from location PC=0 and all RESET conditions apply.
If 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
generate 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 circuitry is enabled. The IDLE timer is loaded with
a value of 256 and is clocked with the t
C
instruction cycle
clock. The t
C
clock is derived by dividing the oscillator clock
down by a factor of 9. 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 start-up time-out
from the IDLE timer enables the clock signals to be routed to
the rest of the chip.
If an R/C clock option is being used, the fixed delay is
introduced optionally. A control bit, CLKDLY, mapped as
configuration 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.
Each device has two options associated with the HALT
mode. The first option enables the HALT mode feature, while
the second option disables the HALT mode selected through
bit 0 of the ECON register. With the HALT mode enable
option, the device will enter and exit the HALT mode as
described above. With the HALT disable 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”).
The WATCHDOG detector circuit is inhibited during the
HALT mode. However, the clock monitor circuit if enabled
remains active during HALT mode in order to ensure a clock
monitor error if the device inadvertently enters the HALT
mode as a result of a runaway program or power glitch.
If the device is placed in the HALT mode, with the R/C
oscillator selected, the clock input pin (CKI) is forced to a
logic high internally. With the crystal or external oscillator the
CKI pin is TRI-STATE.
It is recommended that the user not halt the device by merely
stopping the clock in external oscillator mode. If this method
is used, there is a possibility of greater than specified HALT
current.
If the user wishes to stop an external clock, it is recom-
mended that the CPU be halted by setting the Halt flag first
and the clock be stopped only after the CPU has halted.
COP8SG Family
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7.0 Power Saving Features (Continued)
7.2 IDLE MODE
The device is placed in the IDLE mode by writing a “1” to the
IDLE flag (G6 data bit). In this mode, all activities, except the
associated on-board oscillator circuitry and the IDLE Timer
T0, are stopped.
As with the HALT mode, the device can be returned to
normal operation with a reset, or with a Multi-Input Wakeup
from the L Port. Alternately, the microcontroller resumes
normal operation from the IDLE mode when the twelfth bit
(representing 4.096 ms at internal clock frequency of
10 MHz, t
C
= 1 µs) of the IDLE Timer toggles.
This toggle condition of the twelfth bit of the IDLE Timer T0 is
latched into the T0PND pending flag.
The user has the option of being interrupted with a transition
on the twelfth bit of the IDLE Timer T0. The interrupt can be
enabled or disabled via the T0EN control bit. Setting the
T0EN flag enables the interrupt and vice versa.
The user can enter the IDLE mode with the Timer T0 inter-
rupt enabled. In this case, when the T0PND bit gets set, the
device will first execute the Timer T0 interrupt service routine
and then return to the instruction following the “Enter Idle
Mode” instruction.
Alternatively, the user can enter the IDLE mode with the
IDLE Timer T0 interrupt disabled. In this case, the device will
resume normal operation with the instruction immediately
following the “Enter IDLE Mode” instruction.
Note: It is necessary to program two NOP instructions following both the set
HALT mode and set IDLE mode instructions. These NOP instructions
are necessary to allow clock resynchronization following the HALT or
IDLE modes.
10131725
FIGURE 18. Wakeup from HALT
10131726
FIGURE 19. Wakeup from IDLE
COP8SG Family
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7.0 Power Saving Features (Continued)
7.3 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 8 edge selectable external interrupts.
Figure 20
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 reg-
ister 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.
The user can select whether the trigger condition on the
selected 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
being re-enabled.
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:
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
enabled, the associated edge select bits in WKEDG should
be set or reset for the desired edge selects, followed by the
associated WKPND bits being cleared.
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 WK-
PND. The respective bits of the WKPND register will be set
on the occurrence of the selected trigger edge on the corre-
sponding Port L pin. The user has the responsibility of clear-
ing 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 and WKEDG are all read/write registers, and are
cleared at reset. WKPND register contains random value
after reset.
10131727
FIGURE 20. Multi-Input Wake Up Logic
COP8SG Family
www.national.com27
8.0 USART
Each device contains a full-duplex software programmable
USART. The USART (
Figure 21
) consists of a transmit shift
register, a receive shift register and seven addressable reg-
isters, as follows: a transmit buffer register (TBUF), a re-
ceiver buffer register (RBUF), a USART control and status
register (ENU), a USART receive control and status register
(ENUR), a USART interrupt and clock source register
(ENUI), a prescaler select register (PSR) and baud (BAUD)
register. The ENU register contains flags for transmit and
receive functions; this register also determines the length of
the data frame (7, 8 or 9 bits), the value of the ninth bit in
transmission, and parity selection bits. The ENUR register
flags framing, data overrun and parity errors while the US-
ART is receiving.
Other functions of the ENUR register include saving the
ninth bit received in the data frame, enabling or disabling the
USART’s attention mode of operation and providing addi-
tional receiver/transmitter status information via RCVG and
XMTG bits. The determination of an internal or external clock
source is done by the ENUI register, as well as selecting the
number of stop bits and enabling or disabling transmit and
receive interrupts. A control flag in this register can also
select the USART mode of operation: asynchronous or
synchronous.
8.1 USART CONTROL AND STATUS REGISTERS
The operation of the USART is programmed through three
registers: ENU, ENUR and ENUI.
8.2 DESCRIPTION OF USART REGISTER BITS
ENU-USART Control and Status Register (Address at 0BA)
PEN PSEL1 XBIT9/ CHL1 CHL0 ERR RBFL TBMT
PSEL0
Bit 7 Bit 0
10131739
FIGURE 21. USART Block Diagram
COP8SG Family
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8.0 USART (Continued)
PEN: This bit enables/disables Parity (7- and 8-bit modes
only). Read/Write, cleared on reset.
PEN = 0 Parity disabled.
PEN = 1 Parity enabled.
PSEL1, PSEL0: Parity select bits. Read/Write, cleared on
reset.
PSEL1 = 0, PSEL0 = 0 Odd Parity (if Parity enabled)
PSEL1 = 0, PSEL0 = 1 Even Parity (if Parity enabled)
PSEL1 = 1, PSEL0 = 0 Mark(1) (if Parity enabled)
PSEL1 = 1, PSEL0 = 1 Space(0) (if Parity enabled)
XBIT9/PSEL0: Programs the ninth bit for transmission when
the USART is operating with nine data bits per frame. For
seven or eight data bits per frame, this bit in conjunction with
PSEL1 selects parity. Read/Write, cleared on reset.
CHL1, CHL0: These bits select the character frame format.
Parity is not included and is generated/verified by hardware.
Read/Write, cleared on reset.
CHL1 = 0, CHL0 = 0 The frame contains eight data bits.
CHL1 = 0, CHL0 = 1 The frame contains seven data bits.
CHL1 = 1, CHL0 = 0 The frame contains nine data bits.
CHL1 = 1, CHL0 = 1 Loopback Mode selected. Trans-
mitter output internally looped back
to receiver input. Nine bit framing
format is used.
ERR: This bit is a global USART error flag which gets set if
any or a combination of the errors (DOE, FE, PE) occur.
Read only; it cannot be written by software, cleared on reset.
RBFL: This bit is set when the USART has received a
complete character and has copied it into the RBUF register.
It is automatically reset when software reads the character
from RBUF. Read only; it cannot be written by software,
cleared on reset.
TBMT: This bit is set when the USART transfers a byte of
data from the TBUF register into the TSFT register for trans-
mission. It is automatically reset when software writes into
the TBUF register. Read only, bit is set to “one” on reset; it
cannot be written by software.
ENUR-USART Receive Control and Status Register
(Address at 0BB)
DOE FE PE Reserved RBIT9 ATTN XMTG RCVG
(Note 16)
Bit 7 Bit 0
Note 16: Bit is reserved for future use. User must set to zero.
DOE: Flags a Data Overrun Error. Read only, cleared on
read, cleared on reset.
DOE = 0 Indicates no Data Overrun Error has been de-
tected since the last time the ENUR register
was read.
DOE = 1 Indicates the occurrence of a Data Overrun
Error.
FE: Flags a Framing Error. Read only, cleared on read,
cleared on reset.
FE = 0 Indicates no Framing Error has been detected
since the last time the ENUR register was read.
FE = 1 Indicates the occurrence of a Framing Error.
PE: Flags a Parity Error. Read only, cleared on read, cleared
on reset.
PE = 0 Indicates no Parity Error has been detected since
the last time the ENUR register was read.
PE = 1 Indicates the occurrence of a Parity Error.
SPARE: Reserved for future use. Read/Write, cleared on
reset.
RBIT9: Contains the ninth data bit received when the US-
ART is operating with nine data bits per frame. Read only,
cleared on reset.
ATTN: ATTENTION Mode is enabled while this bit is set.
This bit is cleared automatically on receiving a character with
data bit nine set. Read/Write, cleared on reset.
XMTG: This bit is set to indicate that the USART is transmit-
ting. It gets reset at the end of the last frame (end of last Stop
bit). Read only, cleared on reset.
RCVG: This bit is set high whenever a framing error occurs
and goes low when RDX goes high. Read only, cleared on
reset.
ENUI-USART Interrupt and Clock Source Register
(Address at 0BC)
STP2 STP78 ETDX SSEL XRCLK XTCLK ERI ETI
Bit 7 Bit 0
STP2: This bit programs the number of Stop bits to be
transmitted. Read/Write, cleared on reset.
STP2 = 0 One Stop bit transmitted.
STP2 = 1 Two Stop bits transmitted.
STP78: This bit is set to program the last Stop bit to be 7/8th
of a bit in length. Read/Write, cleared on reset.
ETDX: TDX (USART Transmit Pin) is the alternate function
assigned to Port L pin L2; it is selected by setting ETDX bit.
To simulate line break generation, software should reset
ETDX bit and output logic zero to TDX pin through Port L
data and configuration registers. Read/Write, cleared on
reset.
SSEL: USART mode select. Read/Write, cleared on reset.
SSEL = 0 Asynchronous Mode.
SSEL = 1 Synchronous Mode.
XRCLK: This bit selects the clock source for the receiver
section. Read/Write, cleared on reset.
XRCLK = 0 The clock source is selected through the
PSR and BAUD registers.
XRCLK = 1 Signal on CKX (L1) pin is used as the clock.
XTCLK: This bit selects the clock source for the transmitter
section. Read/Write, cleared on reset.
XTCLK = 0 The clock source is selected through the PSR
and BAUD registers.
XTCLK = 1 Signal on CKX (L1) pin is used as the clock.
ERI: This bit enables/disables interrupt from the receiver
section. Read/Write, cleared on reset.
ERI = 0 Interrupt from the receiver is disabled.
ERI = 1 Interrupt from the receiver is enabled.
ETI: This bit enables/disables interrupt from the transmitter
section. Read/Write, cleared on reset.
ETI = 0 Interrupt from the transmitter is disabled.
ETI = 1 Interrupt from the transmitter is enabled.
COP8SG Family
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8.0 USART (Continued)
8.3 Associated I/O Pins
Data is transmitted on the TDX pin and received on the RDX
pin. TDX is the alternate function assigned to Port L pin L2;
it is selected by setting ETDX (in the ENUI register) to one.
RDX is an inherent function of Port L pin L3, requiring no
setup.
The baud rate clock for the USART can be generated on-
chip, or can be taken from an external source. Port L pin L1
(CKX) is the external clock I/O pin. The CKX pin can be
either an input or an output, as determined by Port L Con-
figuration and Data registers (Bit 1). As an input, it accepts a
clock signal which may be selected to drive the transmitter
and/or receiver. As an output, it presents the internal Baud
Rate Generator output.
8.4 USART Operation
The USART has two modes of operation: asynchronous
mode and synchronous mode.
8.4.1 ASYNCHRONOUS MODE
This mode is selected by resetting the SSEL (in the ENUI
register) bit to zero. The input frequency to the USART is 16
times the baud rate.
The TSFT and TBUF registers double-buffer data for trans-
mission. While TSFT is shifting out the current character on
the TDX pin, the TBUF register may be loaded by software
with the next byte to be transmitted. When TSFT finishes
transmitting the current character the contents of TBUF are
transferred to the TSFT register and the Transmit Buffer
Empty Flag (TBMT in the ENU register) is set. The TBMT
flag is automatically reset by the USART when software
loads a new character into the TBUF register. There is also
the XMTG bit which is set to indicate that the USART is
transmitting. This bit gets reset at the end of the last frame
(end of last Stop bit). TBUF is a read/write register.
The RSFT and RBUF registers double-buffer data being
received. The USART receiver continually monitors the sig-
nal on the RDX pin for a low level to detect the beginning of
a Start bit. Upon sensing this low level, it waits for half a bit
time and samples again. If the RDX pin is still low, the
receiver considers this to be a valid Start bit, and the remain-
ing bits in the character frame are each sampled a single
time, at the mid-bit position. Serial data input on the RDX pin
is shifted into the RSFT register. Upon receiving the com-
plete character, the contents of the RSFT register are copied
into the RBUF register and the Received Buffer Full Flag
(RBFL) is set. RBFL is automatically reset when software
reads the character from the RBUF register. RBUF is a read
only register. There is also the RCVG bit which is set high
when a framing error occurs and goes low once RDX goes
high. TBMT, XMTG, RBFL and RCVG are read only bits.
8.4.2 SYNCHRONOUS MODE
In this mode data is transferred synchronously with the
clock. Data is transmitted on the rising edge and received on
the falling edge of the synchronous clock.
This mode is selected by setting SSEL bit in the ENUI
register. The input frequency to the USART is the same as
the baud rate.
When an external clock input is selected at the CKX pin, data
transmit and receive are performed synchronously with this
clock through TDX/RDX pins.
If data transmit and receive are selected with the CKX pin as
clock output, the device generates the synchronous clock
output at the CKX pin. The internal baud rate generator is
used to produce the synchronous clock. Data transmit and
receive are performed synchronously with this clock.
8.5 FRAMING FORMATS
The USART supports several serial framing formats (
Figure
22
). The format is selected using control bits in the ENU,
ENUR and ENUI registers.
The first format (1, 1a, 1b, 1c) for data transmission (CHL0 =
1, CHL1 = 0) consists of Start bit, seven Data bits (excluding
parity) and 7/8, one or two Stop bits. In applications using
parity, the parity bit is generated and verified by hardware.
The second format (CHL0 = 0, CHL1 = 0) consists of one
Start bit, eight Data bits (excluding parity) and 7/8, one or
two Stop bits. Parity bit is generated and verified by hard-
ware.
The third format for transmission (CHL0 = 0, CHL1 = 1)
consists of one Start bit, nine Data bits and 7/8, one or two
Stop bits. This format also supports the USART “ATTEN-
TION” feature. When operating in this format, all eight bits of
TBUF and RBUF are used for data. The ninth data bit is
transmitted and received using two bits in the ENU and
ENUR registers, called XBIT9 and RBIT9. RBIT9 is a read
only bit. Parity is not generated or verified in this mode.
For any of the above framing formats, the last Stop bit can
be programmed to be 7/8th of a bit in length. If two Stop bits
are selected and the 7/8th bit is set (selected), the second
Stop bit will be 7/8th of a bit in length.
The parity is enabled/disabled by PEN bit located in the ENU
register. Parity is selected for 7- and 8-bit modes only. If
parity is enabled (PEN = 1), the parity selection is then
performed by PSEL0 and PSEL1 bits located in the ENU
register.
Note that the XBIT9/PSEL0 bit located in the ENU register
serves two mutually exclusive functions. This bit programs
the ninth bit for transmission when the USART is operating
with nine data bits per frame. There is no parity selection in
this framing format. For other framing formats XBIT9 is not
needed and the bit is PSEL0 used in conjunction with PSEL1
to select parity.
The frame formats for the receiver differ from the transmitter
in the number of Stop bits required. The receiver only re-
quires one Stop bit in a frame, regardless of the setting of the
Stop bit selection bits in the control register. Note that an
implicit assumption is made for full duplex USART operation
that the framing formats are the same for the transmitter and
receiver.
COP8SG Family
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8.0 USART (Continued)
8.6 USART INTERRUPTS
The USART is capable of generating interrupts. Interrupts
are generated on Receive Buffer Full and Transmit Buffer
Empty. Both interrupts have individual interrupt vectors. Two
bytes of program memory space are reserved for each in-
terrupt vector. The two vectors are located at addresses
0xEC to 0xEF Hex in the program memory space. The
interrupts can be individually enabled or disabled using En-
able Transmit Interrupt (ETI) and Enable Receive Interrupt
(ERI) bits in the ENUI register.
The interrupt from the Transmitter is set pending, and re-
mains pending, as long as both the TBMT and ETI bits are
set. To remove this interrupt, software must either clear the
ETI bit or write to the TBUF register (thus clearing the TBMT
bit).
The interrupt from the receiver is set pending, and remains
pending, as long as both the RBFL and ERI bits are set. To
remove this interrupt, software must either clear the ERI bit
or read from the RBUF register (thus clearing the RBFL bit).
8.7 Baud Clock Generation
The clock inputs to the transmitter and receiver sections of
the USART can be individually selected to come either from
an external source at the CKX pin (port L, pin L1) or from a
source selected in the PSR and BAUD registers. Internally,
the basic baud clock is created from the oscillator frequency
through a two-stage divider chain consisting of a 1–16 (in-
crements of 0.5) prescaler and an 11-bit binary counter.
(
Figure 23
). The divide factors are specified through two
read/write registers shown in
Figure 24
. Note that the 11-bit
Baud Rate Divisor spills over into the Prescaler Select Reg-
ister (PSR). PSR is cleared upon reset.
As shown in
Table 5
, a Prescaler Factor of 0 corresponds to
NO CLOCK. This condition is the USART power down mode
where the USART clock is turned off for power saving pur-
pose. The user must also turn the USART clock off when a
different baud rate is chosen.
The correspondences between the 5-bit Prescaler Select
and Prescaler factors are shown in
Table 5
. There are many
ways to calculate the two divisor factors, but one particularly
effective method would be to achieve a 1.8432 MHz fre-
quency coming out of the first stage. The 1.8432 MHz pres-
caler output is then used to drive the software programmable
baud rate counter to create a 16x clock for the following baud
rates: 110, 134.5, 150, 300, 600, 1200, 1800, 2400, 3600,
4800, 7200, 9600, 19200 and 38400 (
Table 4
). Other baud
10131740
FIGURE 22. Framing Formats
COP8SG Family
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8.0 USART (Continued)
rates may be created by using appropriate divisors. The 16x
clock is then divided by 16 to provide the rate for the serial
shift registers of the transmitter and receiver.
TABLE 4. Baud Rate Divisors
(1.8432 MHz Prescaler Output)
Baud Baud Rate
Rate Divisor − 1
(N-1)
110 (110.03) 1046
134.5
(134.58) 855
150 767
300 383
600 191
1200 95
1800 63
2400 47
3600 31
4800 23
7200 15
9600 11
19200 5
38400 2
Note: The entries in
Table 4
assume a prescaler output of 1.8432 MHz. In the
asynchronous mode the baud rate could be as high as 987.5k.
TABLE 5. Prescaler Factors
Prescaler Prescaler
Select Factor
00000 NO CLOCK
00001 1
00010 1.5
00011 2
Prescaler Prescaler
Select Factor
00100 2.5
00101 3
00110 3.5
00111 4
01000 4.5
01001 5
01010 5.5
01011 6
01100 6.5
01101 7
01110 7.5
01111 8
10000 8.5
10001 9
10010 9.5
10011 10
10100 10.5
10101 11
10110 11.5
10111 12
11000 12.5
11001 13
11010 13.5
11011 14
11100 14.5
11101 15
11110 15.5
11111 16
10131741
FIGURE 23. USART BAUD Clock Generation
10131742
FIGURE 24. USART BAUD Clock Divisor Registers
COP8SG Family
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8.0 USART (Continued)
As an example, considering Asynchronous Mode and a CKI
clock of 4.608 MHz, the prescaler factor selected is:
4.608/1.8432 = 2.5
The 2.5 entry is available in
Table 5
. The 1.8432 MHz
prescaler output is then used with proper Baud Rate Divisor
(
Table 4
) to obtain different baud rates. For a baud rate of
19200 e.g., the entry in
Table 4
is 5.
N−1=5(N−1isthevalue from
Table 4
)
N=6(NistheBaud Rate Divisor)
Baud Rate = 1.8432 MHz/(16 x 6) = 19200
The divide by 16 is performed because in the asynchronous
mode, the input frequency to the USART is 16 times the
baud rate. The equation to calculate baud rates is given
below.
The actual Baud Rate may be found from:
BR = Fc/(16xNxP)
Where:
BR is the Baud Rate
Fc is the CKI frequency
N is the Baud Rate Divisor (
Table 4
).
P is the Prescaler Divide Factor selected by the value in the
Prescaler Select Register (
Table 5
)
Note: In the Synchronous Mode, the divisor 16 is replaced by two.
Example:
Asynchronous Mode:
Crystal Frequency=5MHz
Desired baud rate = 9600
Using the above equationNxPcanbecalculated first.
NxP=(5x10
6
)/(16 x 9600) = 32.552
Now 32.552 is divided by each Prescaler Factor (
Table 5
)to
obtain a value closest to an integer. This factor happens to
be 6.5 (P = 6.5).
N = 32.552/6.5 = 5.008 (N = 5)
The programmed value (from
Table 4
) should be 4 (N − 1).
Using the above values calculated for N and P:
BR=(5x10
6
)/(16x5x6.5) = 9615.384
% error = (9615.385 − 9600)/9600 x 100 = 0.16%
8.8 Effect of HALT/IDLE
The USART logic is reinitialized when either the HALT or
IDLE modes are entered. This reinitialization sets the TBMT
flag and resets all read only bits in the USART control and
status registers. Read/Write bits remain unchanged. The
Transmit Buffer (TBUF) is not affected, but the Transmit Shift
register (TSFT) bits are set to one. The receiver registers
RBUF and RSFT are not affected.
The device will exit from the HALT/IDLE modes when the
Start bit of a character is detected at the RDX (L3) pin. This
feature is obtained by using the Multi-Input Wakeup scheme
provided on the device.
Before entering the HALT or IDLE modes the user program
must select the Wakeup source to be on the RDX pin. This
selection is done by setting bit 3 of WKEN (Wakeup Enable)
register. The Wakeup trigger condition is then selected to be
high to low transition. This is done via the WKEDG register
(Bit 3 is one.)
If the device is halted and crystal oscillator is used, the
Wakeup signal will not start the chip running immediately
because of the finite start up time requirement of the crystal
oscillator. The idle timer (T0) generates a fixed (256 t
c
) delay
to ensure that the oscillator has indeed stabilized before
allowing the device to execute code. The user has to con-
sider this delay when data transfer is expected immediately
after exiting the HALT mode.
8.9 Diagnostic
Bits CHARL0 and CHARL1 in the ENU register provide a
loopback feature for diagnostic testing of the USART. When
these bits are set to one, the following occur: The receiver
input pin (RDX) is internally connected to the transmitter
output pin (TDX); the output of the Transmitter Shift Register
is “looped back” into the Receive Shift Register input. In this
mode, data that is transmitted is immediately received. This
feature allows the processor to verify the transmit and re-
ceive data paths of the USART.
Note that the framing format for this mode is the nine bit
format; one Start bit, nine data bits, and 7/8, one or two Stop
bits. Parity is not generated or verified in this mode.
8.10 Attention Mode
The USART Receiver section supports an alternate mode of
operation, referred to as ATTENTION Mode. This mode of
operation is selected by the ATTN bit in the ENUR register.
The data format for transmission must also be selected as
having nine Data bits and either 7/8, one or two Stop bits.
The ATTENTION mode of operation is intended for use in
networking the device with other processors. Typically in
such environments the messages consists of device ad-
dresses, indicating which of several destinations should re-
ceive them, and the actual data. This Mode supports a
scheme in which addresses are flagged by having the ninth
bit of the data field set to a 1. If the ninth bit is reset to a zero
the byte is a Data byte.
While in ATTENTION mode, the USART monitors the com-
munication flow, but ignores all characters until an address
character is received. Upon receiving an address character,
the USART signals that the character is ready by setting the
RBFL flag, which in turn interrupts the processor if USART
Receiver interrupts are enabled. TheATTN bit is also cleared
automatically at this point, so that data characters as well as
address characters are recognized. Software examines the
contents of the RBUF and responds by deciding either to
accept the subsequent data stream (by leaving the ATTN bit
reset) or to wait until the next address character is seen (by
setting the ATTN bit again).
Operation of the USART Transmitter is not affected by se-
lection of this Mode. The value of the ninth bit to be trans-
mitted is programmed by setting XBIT9 appropriately. The
value of the ninth bit received is obtained by reading RBIT9.
Since this bit is located in ENUR register where the error
flags reside, a bit operation on it will reset the error flags.
9.0 Comparators
The device contains two differential comparators, each with
a pair of inputs (positive and negative) and an output. Ports
F1–F3 and F4–F6 are used for the comparators. The follow-
ing is the Port F assignment:
F6 Comparator2 output
F5 Comparator2 positive input
F4 Comparator2 negative input
F3 Comparator1 output
F2 Comparator1 positive input
COP8SG Family
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9.0 Comparators (Continued)
F1 Comparator1 negative input
A Comparator Select Register (CMPSL) is used to enable
the comparators, read the outputs of the comparators inter-
nally, and enable the outputs of the comparators to the pins.
Two control bits (enable and output enable) and one result
bit are associated with each comparator. The comparator
result bits (CMP1RD and CMP2RD) are read only bits which
will read as zero if the associated comparator is not enabled.
The Comparator Select Register is cleared with reset, result-
ing in the comparators being disabled. The comparators
should also be disabled before entering either the HALT or
IDLE modes in order to save power. The configuration of the
CMPSL register is as follows:
CMPSL REGISTER (ADDRESS X’00B7)
Reserved CMP20E CMP2RD CMP2EN CMP10E CMP1RD CMP1EN Reserved
Bit 7 Bit 0
The CMPSL register contains the following bits:
Reserved These bits are reserved and must be zero
CMP20E Selects pin I6 as comparator 2 output provided
that CMP2EN is set to enable the comparator
CMP2RD Comparator 2 result (this is a read only bit, which
will read as 0 if the comparator is not enabled)
CMP2EN Enable comparator 2
CMP10E Selects pin I3 as comparator 1 output provided
that CMPIEN is set to enable the comparator
CMP1RD Comparator 1 result (this is a read only bit, which
will read as 0 if the comparator is not enabled)
CMP1EN Enable comparator 1
Note that the two unused bits of CMPSL may be used as
software flags.
Note: If the user attempts to use the comparator output
immediately after enabling the comparator, an incorrect
value may be read.At least one instruction cycle should pass
between these operations. The use of a direct addressing
mode instruction for either of these two operations will guar-
antee this delay in the software.
Note: For compatibility with existing code and with existing Mask ROMMed
devices the bits of the CMPSL register will take precedence over the
associated Port F configuration and data output bits.
10.0 Interrupts
10.1 INTRODUCTION
Each device supports thirteen vectored interrupts. Interrupt
sources include Timer 0, Timer 1, Timer 2, Timer 3, Port L
Wakeup, Software Trap, MICROWIRE/PLUS, and External
Input.
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.
The Software trap has the highest priority while the default
VIS has the lowest priority.
Each of the 13 maskable inputs has a fixed arbitration rank-
ing and vector.
Figure 25
shows the Interrupt Block Diagram.
10131728
FIGURE 25. Interrupt Block Diagram
COP8SG Family
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10.0 Interrupts (Continued)
10.2 MASKABLE INTERRUPTS
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.
Amaskable interrupt condition triggers an interrupt under the
following conditions:
1. The enable bit associated with that interrupt is set.
2. The GIE bit is set.
3. The device is not processing a non-maskable interrupt.
(If a non-maskable interrupt is being serviced, a
maskable interrupt must wait until that service routine is
completed.)
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.
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
previous occurrences of the interrupt should be ignored, the
associated pending bit must be reset to zero prior to en-
abling the interrupt. Otherwise, the interrupt may be simply
enabled; if the pending bit is already set, it will immediately
trigger an interrupt. A maskable interrupt is active if its asso-
ciated enable and pending bits are set.
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
interrupt is acknowledged.
At the start of interrupt acknowledgment, the following ac-
tions occur:
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.
2. The address of the instruction about to be executed is
pushed onto the stack.
3. The program counter (PC) is loaded with 00FF Hex,
causing a jump to that program memory location.
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.
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
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.
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
current interrupt routine.
An interrupt service routine typically ends with an RETI
instruction. 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 immedi-
ately upon return from the previous interrupt.
10.3 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
routine based on the cause of the interrupt.
VIS is a single-byte instruction, typically used at the very
beginning 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 con-
taining 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
located between addresses 01E0 and 01FF Hex. If the VIS
instruction is located between 01FF and 02DF Hex, then the
vector table is located between addresses 02E0 and 02FF
Hex, and so on.
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.
Table 6
shows the types of interrupts, the interrupt arbitration
ranking, and the locations of the corresponding vectors in
the vector table.
The vector table should be filled by the user with the memory
locations of the specific interrupt service routines. For ex-
COP8SG Family
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10.0 Interrupts (Continued)
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
interrupt occurs and the VIS instruction is executed, the
program jumps to the address specified in the vector table.
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.
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 inad-
vertent execution of the VIS command outside of the context
of an 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.
This technique can save up to fifty instruction cycles (t
c
), or
more, (50µs at 10 MHz oscillator) of latency for pending
interrupts 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
altered, 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
conditions, a Software Trap could be triggered but not ser-
viced, resulting in an inadvertent “locking out” of all
maskable interrupts by the Software Trap pending flag.
Problems such as this can be avoided by using VIS
instruction.
TABLE 6. Interrupt Vector Table
Arbitration Ranking Source Description Vector Address (Note 17)
(Hi-Low Byte)
(1) Highest Software INTR Instruction 0yFE–0yFF
(2) Reserved 0yFC–0yFD
(3) External G0 0yFA–0yFB
(4) Timer T0 Underflow 0yF8–0yF9
(5) Timer T1 T1A/Underflow 0yF6–0yF7
(6) Timer T1 T1B 0yF4–0yF5
(7) MICROWIRE/PLUS BUSY Low 0yF2–0yF3
(8) Reserved 0yF0–0yF1
(9) USART Receive 0yEE–0yEF
(10) USART Transmit 0yEC–0yED
(11) Timer T2 T2A/Underflow 0yEA–0yEB
(12) Timer T2 T2B 0yE8–0yE9
(13) Timer T3 T2A/Underflow 0yE6–0yE7
(14) Timer T3 T3B 0yE4–0yE5
(15) Port L/Wakeup Port L Edge 0yE2–0yE3
(16) Lowest Default VIS Reserved 0yE0–0yE1
Note 17: 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 is located at the last
address of a block. In this case, the table must be in the next block.
COP8SG Family
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10.0 Interrupts (Continued)
10.3.1 VIS Execution
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
interrupt is software trap, than E0 is generated. This number
replaces the lower byte of the PC. The upper byte of the PC
remains unchanged. The new PC is therefore pointing to the
vector of the active interrupt with the highest arbitration
ranking. 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
arbitration ranking.
Figure 26
illustrates the different steps performed by the VIS
instruction.
Figure 27
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.
10131729
FIGURE 26. VIS Operation
COP8SG Family
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10.0 Interrupts (Continued)
10131730
FIGURE 27. VIS Flowchart
COP8SG Family
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10.0 Interrupts (Continued)
Programming Example: External Interrupt
PSW =00EF
CNTRL =00EE
RBIT 0,PORTGC
RBIT 0,PORTGD ; G0 pin configured Hi-Z
SBIT IEDG, CNTRL ; Ext interrupt polarity; falling edge
SBIT EXEN, PSW ; Enable the external interrupt
SBIT GIE, PSW ; Set the GIE bit
WAIT: JP WAIT ; Wait for external interrupt
.
.
.
.=0FF ; The interrupt causes a
VIS ; branch to address 0FF
; The VIS causes a branch to
;interrupt vector table
.
.
.
.=01FA ; Vector table (within 256 byte
.ADDRW SERVICE ; of VIS inst.) containing the ext
; interrupt service routine
.
.
INT_EXIT: RETI
.
.
SERVICE: RBIT EXPND, PSW ; Interrupt Service Routine
; Reset ext interrupt pend. bit
.
.
.
JP INT_EXIT ; Return, set the GIE bit
COP8SG Family
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10.0 Interrupts (Continued)
10.4 NON-MASKABLE INTERRUPT
10.4.1 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.
The pending flag is reset to zero when a device Reset
occurs. When the non-maskable interrupt occurs, the asso-
ciated 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.
10.4.2 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
variety of ways, usually because of an error condition. Some
examples of causes are listed below.
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.
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
program to the ST service routine with the VIS instruction.
Nothing 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.
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
reliably. 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
execute the RPND instruction to reset the STPND flag.
Otherwise, all other interrupts will be locked out. To the
extent possible, the interrupt routine should record or indi-
cate the context of the device so that the cause of the
Software Trap can be determined.
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.
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
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.
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
instructions in the main program and in the WATCHDOG
service routine (if present). There is no harm in executing
extra RPND instructions in these parts of the program.
10.5 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
circuitry. The register WKEN allows interrupts from Port L to
be individually enabled or disabled. The register WKEDG
specifies the trigger condition to be either a positive or a
negative edge. Finally, the register WKPND latches in the
pending trigger conditions.
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
execution 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
interrupt service routine and then revert to normal operation.
(See HALT MODE for clock option wakeup information.)
10.6 INTERRUPT SUMMARY
The device uses the following types of interrupts, listed
below 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.
Under ordinary conditions, a maskable interrupt will not
interrupt any other interrupt routine in progress. A
maskable interrupt routine in progress can be inter-
rupted by the non-maskable interrupt request. A
maskable interrupt routine should end with an RETI
instruction 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.
COP8SG Family
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11.0 WATCHDOG/Clock Monitor
Each device contains a user selectable WATCHDOG and
clock monitor. The following section is applicable only if
WATCHDOG feature has been selected in the ECON regis-
ter. The WATCHDOG is designed to detect the user program
getting stuck in infinite loops resulting in loss of program
control or “runaway” programs.
The WATCHDOG logic contains two separate service win-
dows. While the user programmable upper window selects
the WATCHDOG service time, the lower window provides
protection against an infinite program loop that contains the
WATCHDOG service instruction.
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 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 7
shows the WDSVR register.
TABLE 7. WATCHDOG Service Register (WDSVR)
Window
Select Key Data Clock
Monitor
XX01100 Y
7654321 0
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 8
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.
TABLE 8. WATCHDOG Service Window Select
WDSVR WDSVR Clock Service Window
Bit 7 Bit 6 Monitor (Lower-Upper Limits)
0 0 x 2048–8k t
C
Cycles
0 1 x 2048–16k t
C
Cycles
1 0 x 2048–32k t
C
Cycles
1 1 x 2048–64k t
C
Cycles
x x 0 Clock Monitor Disabled
x x 1 Clock Monitor Enabled
11.1 CLOCK MONITOR
The Clock Monitor aboard the device can be selected or
deselected under program control. The Clock Monitor is
guaranteed 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.
11.2 WATCHDOG/CLOCK MONITOR OPERATION
The WATCHDOG is enabled by bit 2 of the ECON register.
When this ECON bit is 0, the WATCHDOG is enabled and
pin G1 becomes the WATCHDOG output with a weak pullup.
The WATCHDOG and Clock Monitor are disabled during
reset. 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
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.
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
register 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
involves selecting or deselecting the Clock Monitor, select
the WATCHDOG service window and match the WATCH-
DOG key data. Subsequent writes to the WDSVR register
will compare the value being written by the user to the
WATCHDOG service window value and the key data (bits 7
through 1) in the WDSVR Register.
Table 9
shows the se-
quence of events that can occur.
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 WATCHDOG has an output pin associated with it. This
is the WDOUT pin, on pin 1 of the port G. WDOUT is active
low and must be externally connected to the RESET pin or to
some other external logic which handles WATCHDOG event.
The WDOUT pin has a weak pullup in the inactive state. This
pull-up is sufficient to serve as the connection to V
CC
for
systems which use the internal Power On Reset. 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.
AWATCHDOG 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 go high.
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 go high following 16
t
C
–32 t
C
clock cycles. The Clock Monitor generates a con-
tinual 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:
1/t
C
>10 kHz—No clock rejection.
1/t
C
<10 Hz—Guaranteed clock rejection.
COP8SG Family
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11.0 WATCHDOG/Clock Monitor (Continued)
TABLE 9. WATCHDOG Service Actions
Key Window Clock Action
Data Data Monitor
Match Match Match Valid Service: Restart Service Window
Don’t Care Mismatch Don’t Care Error: Generate WATCHDOG Output
Mismatch Don’t Care Don’t Care Error: Generate WATCHDOG Output
Don’t Care Don’t Care Mismatch Error: Generate WATCHDOG Output
11.3 WATCHDOG AND CLOCK MONITOR SUMMARY
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.
•The WATCHDOG service window and CLOCK MONI-
TOR enable/disable option can only be changed once,
during the initial WATCHDOG service following RESET.
•The initial WATCHDOG service must match the key data
value in the WATCHDOG Service register WDSVR in
order to avoid a WATCHDOG error.
•Subsequent WATCHDOG services must match all three
data fields in WDSVR in order to avoid WATCHDOG
errors.
•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.
•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).
•With the single-pin R/C oscillator option selected and the
CLKDLY bit reset, the WATCHDOG service window will
resume following HALT mode from where it left off before
entering the HALT mode.
•With the crystal oscillator option selected, or with the
single-pin R/C oscillator option selected and the CLKDLY
bit set, the WATCHDOG service window will be set to its
selected value from WDSVR following HALT. Conse-
quently, 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 WATCH-
DOG error.
•The IDLE timer T0 is not initialized with external RESET.
•The user can sync in to the IDLE counter cycle with an
IDLE counter (T0) interrupt or by monitoring the T0PND
flag. TheT0PND flag is set whenever the twelfth bit of the
IDLE counter toggles (every 4096 instruction cycles). The
user is responsible for resetting the T0PND flag.
•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
selected window to avoid a WATCHDOG error.
•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.
11.4 DETECTION OF ILLEGAL CONDITIONS
The device can detect various illegal conditions resulting
from coding errors, transient noise, power supply voltage
drops, runaway programs, etc.
Reading of undefined ROM gets zeroes. The opcode for
software interrupt is 00. If the program fetches instructions
from undefined ROM, this will force a software interrupt, thus
signaling that an illegal condition has occurred.
The subroutine stack grows down for each call (jump to
subroutine), 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 re-
turns than calls, the stack pointer will point to addresses 070
and 071 Hex (which are undefined RAM). Undefined RAM
from addresses 070 to 07F (Segment 0), and all other seg-
ments (i.e., Segments 4 … etc.) is read as all 1’s, which in
turn will cause the program to return to address 7FFF Hex. It
is recommended that the user either leave this location
unprogrammed or place an INTR instruction (all 0’s) in this
location to generate a software interrupt signaling an illegal
condition.
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-
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.
12.0 MICROWIRE/PLUS
MICROWIRE/PLUS is a serial SPI compatible synchronous
communications interface. The MICROWIRE/PLUS capabil-
ity enables the device to interface with MICROWIRE/PLUS
or SPI peripherals (i.e. A/D converters, display drivers, EE-
PROMs etc.) and with other microcontrollers which support
the MICROWIRE/PLUS or SPI interface. It consists of an
8-bit serial shift register (SIO) with serial data input (SI),
serial data output (SO) and serial shift clock (SK).
Figure 28
shows a block diagram of the MICROWIRE/PLUS logic.
The shift clock can be selected from either an internal source
or an external source. Operating the MICROWIRE/PLUS
COP8SG Family
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12.0 MICROWIRE/PLUS (Continued)
arrangement 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
master mode, the SK clock rate is selected by the two bits,
SL0 and SL1, in the CNTRL register.
Table 10
details the
different clock rates that may be selected.
TABLE 10. MICROWIRE/PLUS
Master Mode Clock Select
SL1 SL0 SK Period
0 0 2xt
C
0 1 4xt
C
1 x 8xt
C
Where tCis the instruction cycle clock
12.1 MICROWIRE/PLUS 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 28
shows how
two microcontroller devices and several peripherals may be
interconnected using the MICROWIRE/PLUS arrangements.
WARNING
The SIO register should only be loaded when the SK clock is
in the idle phase. Loading the SIO register while the SK clock
is in the active phase, will result in undefined data in the SIO
register.
Setting the BUSY flag when the input SK clock is in the
active phase while in the MICROWIRE/PLUS is in the 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 in the idle phase.
12.1.1 MICROWIRE/PLUS Master Mode Operation
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. In the slave mode, the shift clock
stops after 8 clock pulses.
Table 11
summarizes the bit
settings required for Master mode of operation.
10131732
FIGURE 28. MICROWIRE/PLUS Application
COP8SG Family
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12.0 MICROWIRE/PLUS (Continued)
12.1.2 MICROWIRE/PLUS Slave Mode 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
resetting the appropriate bits in the Port G configuration
register.
Table 11
summarizes the settings required to enter
the Slave mode of operation.
TABLE 11. MICROWIRE/PLUS Mode Settings
This table assumes that the control flag MSEL is set.
G4 (SO) G5 (SK) G4 G5 Operation
Config. Bit Config. Bit Fun. Fun.
1 1 SO Int. MICROWIRE/PLUS
SK Master
0 1 TRI- Int. MICROWIRE/PLUS
STATE SK Master
1 0 SO Ext. MICROWIRE/PLUS
SK Slave
0 0 TRI- Ext. MICROWIRE/PLUS
STATE SK Slave
The user must set the BUSY flag immediately upon entering
the Slave mode. This ensures that all data bits sent by the
Master is shifted properly. After eight clock pulses the BUSY
flag is clear, the shift clock is stopped, and the sequence
may be repeated.
12.1.3 Alternate SK Phase Operation and SK Idle P
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 idle polarity can be either high or low.
The polarity is selected by bit 5 of Port G data register. 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. 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. Bit 6 of Port G configuration
register selects the SK edge.
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 configu-
ration bit. The SKSEL flag will power up in the reset condi-
tion, selecting the normal SK signal.
TABLE 12. MICROWIRE/PLUS Shift Clock Polarity and Sample/Shift Phase
Port G
SK Phase G6 (SKSEL)
Config. Bit G5 Data
Bit SO Clocked Out On: SI Sampled On: SK Idle
Phase
Normal 0 0 SK Falling Edge SK Rising Edge Low
Alternate 1 0 SK Rising Edge SK Falling Edge Low
Alternate 0 1 SK Rising Edge SK Falling Edge High
Normal 1 1 SK Falling Edge SK Rising Edge High
10131733
FIGURE 29. MICROWIRE/PLUS SPI Mode Interface Timing, Normal SK Mode, SK Idle Phase being Low
COP8SG Family
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12.0 MICROWIRE/PLUS (Continued)
10131734
FIGURE 30. MICROWIRE/PLUS SPI Mode Interface Timing, Alternate SK Mode, SK Idle Phase being Low
10131735
FIGURE 31. MICROWIRE/PLUS SPI Mode Interface Timing, Normal SK Mode, SK Idle Phase being High
10131731
FIGURE 32. MICROWIRE/PLUS SPI Mode Interface Timing, Alternate SK Mode, SK Idle Phase being High
COP8SG Family
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13.0 Memory Map
All RAM, ports and registers (except A and PC) are mapped
into data memory address space.
Address Contents
S/ADD REG
0000 to 006F On-Chip RAM bytes (112 bytes)
0070 to 007F Unused RAM Address Space (Reads As
All Ones)
xx80 to xx93 Unused RAM Address Space (Reads
Undefined Data)
xx94 Port F data register, PORTFD
xx95 Port F configuration register, PORTFC
xx96 Port F input pins (read only), PORTFP
xx97 to xxAF Unused address space (Reads Undefined
Data)
xxB0 Timer T3 Lower Byte
xxB1 Timer T3 Upper Byte
xxB2 Timer T3 Autoload Register T3RA Lower
Byte
xxB3 Timer T3 Autoload Register T3RA Upper
Byte
xxB4 Timer T3 Autoload Register T3RB Lower
Byte
xxB5 Timer T3 Autoload Register T3RB Upper
Byte
xxB6 Timer T3 Control Register
xxB7 Comparator Select Register (Reg:CMPSL)
xxB8 UART Transmit Buffer (Reg:TBUF)
xxB9 UART Receive Buffer (Reg:RBUF)
xxBA UART Control and Status Register
(Reg:ENU)
xxBB UART Receive Control and Status
Register (Reg:ENUR)
xxBC UART Interrupt and Clock Source Register
(Reg:ENUI)
xxBD UART Baud Register (Reg:BAUD)
xxBE UART Prescale Select Register (Reg:PSR)
xxBF Reserved for UART
xxC0 Timer T2 Lower Byte
xxC1 Timer T2 Upper Byte
xxC2 Timer T2 Autoload Register T2RA Lower
Byte
xxC3 Timer T2 Autoload Register T2RA Upper
Byte
xxC4 Timer T2 Autoload Register T2RB Lower
Byte
xxC5 Timer T2 Autoload Register T2RB Upper
Byte
xxC6 Timer T2 Control Register
xxC7 WATCHDOG Service Register
(Reg:WDSVR)
xxC8 MIWU Edge Select Register
(Reg:WKEDG)
Address Contents
S/ADD REG
xxC9 MIWU Enable Register (Reg:WKEN)
xxCA MIWU Pending Register (Reg:WKPND)
xxCB to xxCF Reserved
xxD0 Port L Data Register
xxD1 Port L Configuration Register
xxD2 Port L Input Pins (Read Only)
xxD3 Reserved for Port L
xxD4 Port G Data Register
xxD5 Port G Configuration Register
xxD6 Port G Input Pins (Read Only)
xxD7 Port I Input Pins (Read Only) (Actually
reads Port F input pins)
xxD8 Port C Data Register
xxD9 Port C Configuration Register
xxDA Port C Input Pins (Read Only)
xxDB Reserved for Port C
xxDC Port D
xxDD to xxDF Reserved for Port D
xxE0 to xxE5 Reserved for EE Control Registers
xxE6 Timer T1 Autoload Register T1RB Lower
Byte
xxE7 Timer T1 Autoload Register T1RB Upper
Byte
xxE8 ICNTRL Register
xxE9 MICROWIRE/PLUS Shift Register
xxEA Timer T1 Lower Byte
xxEB Timer T1 Upper Byte
xxEC Timer T1 Autoload Register T1RA Lower
Byte
xxED Timer T1 Autoload Register T1RA Upper
Byte
xxEE CNTRL Control Register
xxEF PSW Register
xxF0 to FB On-Chip RAM Mapped as Registers
xxFC X Register
xxFD SP Register
xxFE B Register
xxFF S Register
0100–017F On-Chip 128 RAM Bytes
0200–027F On-Chip 128 RAM Bytes (Reads as
undefined data on COP8SGE)
0300–037F On-Chip 128 RAM Bytes (Reads as
undefined data on COP8SGE)
Note: Reading memory locations 0070H–007FH (Segment 0) will return all
ones. Reading unused memory locations 0080H–0093H (Segment 0)
will return undefined data. Reading memory locations from other Seg-
ments (i.e., Segment 4, Segment 5, … etc.) will return undefined data.
COP8SG Family
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14.0 Instruction Set
14.1 INTRODUCTION
This section defines the instruction set of the COP8 Family
members. It contains information about the instruction set
features, addressing modes and types.
14.2 INSTRUCTION FEATURES
The strength of the instruction set is based on the following
features:
•Mostly single-byte opcode instructions minimize program
size.
•One instruction cycle for the majority of single-byte in-
structions to minimize program execution time.
•Many single-byte, multiple function instructions such as
DRSZ.
•Three memory mapped pointers: two for register indirect
addressing, and one for the software stack.
•Sixteen memory mapped registers that allow an opti-
mized implementation of certain instructions.
•Ability to set, reset, and test any individual bit in data
memory address space, including the memory-mapped
I/O ports and registers.
•Register-Indirect LOAD and EXCHANGE instructions
with optional automatic post-incrementing or decrement-
ing of the register pointer. This allows for greater effi-
ciency (both in cycle time and program code) in loading,
walking across and processing fields in data memory.
•Unique instructions to optimize program size and
throughput efficiency. Some of these instructions are
DRSZ, IFBNE, DCOR, RETSK, VIS and RRC.
14.3 ADDRESSING MODES
The instruction set offers a variety of methods for specifying
memory addresses. Each method is called an addressing
mode. These modes are classified into two categories: op-
erand addressing modes and transfer-of-control addressing
modes. Operand addressing modes are the various meth-
ods of specifying an address for accessing (reading or writ-
ing) data. Transfer-of-control addressing modes are used in
conjunction with jump instructions to control the execution
sequence of the software program.
14.3.1 Operand Addressing Modes
The operand of an instruction specifies what memory loca-
tion is to be affected by that instruction. Several different
operand addressing modes are available, allowing memory
locations to be specified in a variety of ways. An instruction
can specify an address directly by supplying the specific
address, or indirectly by specifying a register pointer. The
contents of the register (or in some cases, two registers)
point to the desired memory location. In the immediate
mode, the data byte to be used is contained in the instruction
itself.
Each addressing mode has its own advantages and disad-
vantages with respect to flexibility, execution speed, and
program compactness. Not all modes are available with all
instructions. The Load (LD) instruction offers the largest
number of addressing modes.
The available addressing modes are:
•Direct
•Register B or X Indirect
•Register B or X Indirect with Post-Incrementing/
Decrementing
•Immediate
•Immediate Short
•Indirect from Program Memory
The addressing modes are described below. Each descrip-
tion includes an example of an assembly language instruc-
tion using the described addressing mode.
Direct. The memory address is specified directly as a byte in
the instruction. In assembly language, the direct address is
written as a numerical value (or a label that has been defined
elsewhere in the program as a numerical value).
Example: Load Accumulator Memory Direct
LD A,05
Reg/Data Contents Contents
Memory Before After
Accumulator XX Hex A6 Hex
Memory Location A6 Hex A6 Hex
0005 Hex
Register B or X Indirect. The memory address is specified
by the contents of the B Register or X register (pointer
register). In assembly language, the notation [B] or [X] speci-
fies which register serves as the pointer.
Example: Exchange Memory with Accumulator, B Indirect
X A,[B]
Reg/Data Contents Contents
Memory Before After
Accumulator 01 Hex 87 Hex
Memory Location 87 Hex 01 Hex
0005 Hex
B Pointer 05 Hex 05 Hex
Register B or X Indirect with Post-Incrementing/
Decrementing. The relevant memory address is specified
by the contents of the B Register or X register (pointer
register). The pointer register is automatically incremented
or decremented after execution, allowing easy manipulation
of memory blocks with software loops. In assembly lan-
guage, the notation [B+], [B−], [X+], or [X−] specifies which
register serves as the pointer, and whether the pointer is to
be incremented or decremented.
Example: Exchange Memory with Accumulator, B Indirect
with Post-Increment
X A,[B+]
Reg/Data Contents Contents
Memory Before After
Accumulator 03 Hex 62 Hex
Memory Location 62 Hex 03 Hex
0005 Hex
B Pointer 05 Hex 06 Hex
Intermediate. The data for the operation follows the instruc-
tion opcode in program memory. In assembly language, the
number sign character (#) indicates an immediate operand.
COP8SG Family
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14.0 Instruction Set (Continued)
Example: Load Accumulator Immediate
LD A,#05
Reg/Data Contents Contents
Memory Before After
Accumulator XX Hex 05 Hex
Immediate Short. This is a special case of an immediate
instruction. In the “Load B immediate” instruction, the 4-bit
immediate value in the instruction is loaded into the lower
nibble of the B register. The upper nibble of the B register is
reset to 0000 binary.
Example: Load B Register Immediate Short
LD B,#7
Reg/Data Contents Contents
Memory Before After
B Pointer 12 Hex 07 Hex
Indirect from Program Memory. This is a special case of
an indirect instruction that allows access to data tables
stored in program memory. In the “Load Accumulator Indi-
rect” (LAID) instruction, the upper and lower bytes of the
Program Counter (PCU and PCL) are used temporarily as a
pointer to program memory. For purposes of accessing pro-
gram memory, the contents of the Accumulator and PCL are
exchanged. The data pointed to by the Program Counter is
loaded into theAccumulator, and simultaneously, the original
contents of PCL are restored so that the program can re-
sume normal execution.
Example: Load Accumulator Indirect
LAID
Reg/Data Contents Contents
Memory Before After
PCU 04 Hex 04 Hex
PCL 35 Hex 36 Hex
Accumulator 1F Hex 25 Hex
Memory Location 25 Hex 25 Hex
041F Hex
14.3.2 Tranfer-of-Control Addressing Modes
Program instructions are usually executed in sequential or-
der. However, Jump instructions can be used to change the
normal execution sequence. Several transfer-of-control ad-
dressing modes are available to specify jump addresses.
A change in program flow requires a non-incremental
change in the Program Counter contents. The Program
Counter consists of two bytes, designated the upper byte
(PCU) and lower byte (PCL). The most significant bit of PCU
is not used, leaving 15 bits to address the program memory.
Different addressing modes are used to specify the new
address for the Program Counter. The choice of addressing
mode depends primarily on the distance of the jump. Farther
jumps sometimes require more instruction bytes in order to
completely specify the new Program Counter contents.
The available transfer-of-control addressing modes are:
•Jump Relative
•Jump Absolute
•Jump Absolute Long
•Jump Indirect
The transfer-of-control addressing modes are described be-
low. Each description includes an example of a Jump in-
struction using a particular addressing mode, and the effect
on the Program Counter bytes of executing that instruction.
Jump Relative. In this 1-byte instruction, six bits of the
instruction opcode specify the distance of the jump from the
current program memory location. The distance of the jump
can range from −31 to +32.AJP+1 instruction is not allowed.
The programmer should use a NOP instead.
Example: Jump Relative
JP 0A
Reg Contents Contents
Before After
PCU 02 Hex 02 Hex
PCL 05 Hex 0F Hex
Jump Absolute. In this 2-byte instruction, 12 bits of the
instruction opcode specify the new contents of the Program
Counter. The upper three bits of the Program Counter re-
main unchanged, restricting the new Program Counter ad-
dress to the same 4 kbyte address space as the current
instruction.
(This restriction is relevant only in devices using more than
one 4 kbyte program memory space.)
Example: Jump Absolute
JMP 0125
Reg Contents Contents
Before After
PCU 0C Hex 01 Hex
PCL 77 Hex 25 Hex
Jump Absolute Long. In this 3-byte instruction, 15 bits of
the instruction opcode specify the new contents of the Pro-
gram Counter.
Example: Jump Absolute Long
JMP 03625
Reg/ Contents Contents
Memory Before After
PCU 42 Hex 36 Hex
PCL 36 Hex 25 Hex
Jump Indirect. In this 1-byte instruction, the lower byte of
the jump address is obtained from a table stored in program
memory, with the Accumulator serving as the low order byte
of a pointer into program memory. For purposes of access-
ing program memory, the contents of the Accumulator are
written to PCL (temporarily). The data pointed to by the
Program Counter (PCH/PCL) is loaded into PCL, while PCH
remains unchanged.
Example: Jump Indirect
JID
Reg/ Contents Contents
Memory Before After
PCU 01 Hex 01 Hex
PCL C4 Hex 32 Hex
Accumulator 26 Hex 26 Hex
Memory
COP8SG Family
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14.0 Instruction Set (Continued)
Reg/ Contents Contents
Memory Before After
Location 32 Hex 32 Hex
0126 Hex
The VIS instruction 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 program memory into the Program Counter in
order to jump to the associated interrupt service routine.
14.4 INSTRUCTION TYPES
The instruction set contains a wide variety of instructions.
The available instructions are listed below, organized into
related groups.
Some instructions test a condition and skip the next instruc-
tion if the condition is not true. Skipped instructions are
executed as no-operation (NOP) instructions.
14.4.1 Arithmetic Instructions
The arithmetic instructions perform binary arithmetic such as
addition and subtraction, with or without the Carry bit.
Add (ADD)
Add with Carry (ADC)
Subtract (SUB)
Subtract with Carry (SUBC)
Increment (INC)
Decrement (DEC)
Decimal Correct (DCOR)
Clear Accumulator (CLR)
Set Carry (SC)
Reset Carry (RC)
14.4.2 Transfer-of-Control Instructions
The transfer-of-control instructions change the usual se-
quential program flow by altering the contents of the Pro-
gram Counter. The Jump to Subroutine instructions save the
Program Counter contents on the stack before jumping; the
Return instructions pop the top of the stack back into the
Program Counter.
Jump Relative (JP)
Jump Absolute (JMP)
Jump Absolute Long (JMPL)
Jump Indirect (JID)
Jump to Subroutine (JSR)
Jump to Subroutine Long (JSRL)
Return from Subroutine (RET)
Return from Subroutine and Skip (RETSK)
Return from Interrupt (RETI)
Software Trap Interrupt (INTR)
Vector Interrupt Select (VIS)
14.4.3 Load and Exchange Instructions
The load and exchange instructions write byte values in
registers or memory. The addressing mode determines the
source of the data.
Load (LD)
Load Accumulator Indirect (LAID)
Exchange (X)
14.4.4 Logical Instructions
The logical instructions perform the operations AND, OR,
and XOR (Exclusive OR). Other logical operations can be
performed by combining these basic operations. For ex-
ample, complementing is accomplished by exclusiveORing
the Accumulator with FF Hex.
Logical AND (AND)
Logical OR (OR)
Exclusive OR (XOR)
14.4.5 Accumulator Bit Manipulation Instructions
The Accumulator bit manipulation instructions allow the user
to shift the Accumulator bits and to swap its two nibbles.
Rotate Right Through Carry (RRC)
Rotate Left Through Carry (RLC)
Swap Nibbles of Accumulator (SWAP)
14.4.6 Stack Control Instructions
Push Data onto Stack (PUSH)
Pop Data off of Stack (POP)
14.4.7 Memory Bit Manipulation Instructions
The memory bit manipulation instructions allow the user to
set and reset individual bits in memory.
Set Bit (SBIT)
Reset Bit (RBIT)
Reset Pending Bit (RPND)
14.4.8 Conditional Instructions
The conditional instruction test a condition. If the condition is
true, the next instruction is executed in the normal manner; if
the condition is false, the next instruction is skipped.
If Equal (IFEQ)
If Not Equal (IFNE)
If Greater Than (IFGT)
If Carry (IFC)
If Not Carry (IFNC)
If Bit (IFBIT)
If B Pointer Not Equal (IFBNE)
And Skip if Zero (ANDSZ)
Decrement Register and Skip if Zero (DRSZ)
14.4.9 No-Operation Instruction
The no-operation instruction does nothing, except to occupy
space in the program memory and time in execution.
No-Operation (NOP)
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
service routine.
COP8SG Family
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14.0 Instruction Set (Continued)
14.5 REGISTER AND SYMBOL DEFINITION
The following abbreviations represent the nomenclature
used in the instruction description and the COP8
cross-assembler.
Registers
A 8-Bit Accumulator Register
B 8-Bit Address Register
X 8-Bit Address Register
SP 8-Bit Stack Pointer Register
PC 15-Bit Program Counter Register
PU Upper 7 Bits of PC
PL Lower 8 Bits of PC
C 1 Bit of PSW Register for Carry
HC 1 Bit of PSW Register for Half Carry
GIE 1 Bit of PSW Register for Global Interrupt
Enable
Registers
VU Interrupt Vector Upper Byte
VL Interrupt Vector Lower Byte
Symbols
[B] Memory Indirectly Addressed by B Register
[X] Memory Indirectly Addressed by X Register
MD Direct Addressed Memory
Mem Direct Addressed Memory or [B]
Meml Direct Addressed Memory or [B] or
Immediate Data
Imm 8-Bit Immediate Data
Reg Register Memory: Addresses F0 to FF
(Includes B, X and SP)
Bit Bit Number (0 to 7)
←Loaded with
↔Exchanged with
14.6 INSTRUCTION SET SUMMARY
ADD A,Meml ADD A←A + Meml
ADC A,Meml ADD with Carry A←A+Meml+C,C
←
Carry,
HC←Half Carry
SUBC A,Meml Subtract with Carry A←A−MemI+C,C
←
Carry,
HC←Half Carry
AND A,Meml Logical AND A←A and Meml
ANDSZ A,Imm Logical AND Immed., Skip if Zero Skip next if (A and Imm) = 0
OR A,Meml Logical OR A←A or Meml
XOR A,Meml Logical EXclusive OR A←A xor Meml
IFEQ MD,Imm IF EQual Compare MD and Imm, Do next if MD = Imm
IFEQ A,Meml IF EQual Compare A and Meml, Do next if A = Meml
IFNE A,Meml IF Not Equal Compare A and Meml, Do next if A ≠Meml
IFGT A,Meml IF Greater Than Compare A and Meml, Do next if A >Meml
IFBNE #If B Not Equal Do next if lower 4 bits of B ≠Imm
DRSZ Reg Decrement Reg., Skip if Zero Reg←Reg − 1, Skip if Reg = 0
SBIT #,Mem Set BIT 1 to bit, Mem (bit = 0 to 7 immediate)
RBIT #,Mem Reset BIT 0 to bit, Mem
IFBIT #,Mem IF BIT If bit #, A or Mem is true do next instruction
RPND Reset PeNDing Flag Reset Software Interrupt Pending Flag
X A,Mem EXchange A with Memory A↔Mem
X A,[X] EXchange A with Memory [X] A↔[X]
LD A,Meml LoaD A with Memory A←Meml
LD A,[X] LoaD A with Memory [X] A←[X]
LD B,Imm LoaD B with Immed. B←Imm
LD Mem,Imm LoaD Memory Immed. Mem←Imm
LD Reg,Imm LoaD Register Memory Immed. Reg←Imm
XA,[B
±
] EXchange A with Memory [B] A↔[B], (B←B±1)
XA,[X
±
] EXchange A with Memory [X] A↔[X], (X←X±1)
LD A, [B±] LoaD A with Memory [B] A←[B], (B←B±1)
LD A, [X±] LoaD A with Memory [X] A←[X], (X←X±1)
LD [B±],Imm LoaD Memory [B] Immed. [B]←Imm, (B←B±1)
CLR A CLeaR A A←0
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14.0 Instruction Set (Continued)
INC A INCrement A A←A+1
DEC A DECrement A A←A−1
LAID Load A InDirect from ROM A←ROM (PU,A)
DCOR A Decimal CORrect A A←BCD correction of A (follows ADC, SUBC)
RRC A Rotate A Right thru C C→A7→…→A0→C
RLC A Rotate A Left thru C C←A7←…←A0←C, HC←A0
SWAP A SWAP nibbles of A A7…A4↔A3…A0
SC Set C C←1, HC←1
RC Reset C C←0, HC←0
IFC IF C IF C is true, do next instruction
IFNC IF Not C If C is not true, do next instruction
POP A POP the stack into A SP←SP + 1, A←[SP]
PUSH A PUSH A onto the stack [SP]←A, SP←SP − 1
VIS Vector to Interrupt Service Routine PU←[VU], PL←[VL]
JMPL Addr. Jump absolute Long PC←ii (ii = 15 bits, 0 to 32k)
JMP Addr. Jump absolute PC9…0←i (i = 12 bits)
JP Disp. Jump relative short PC←PC+r(ris−31to+32, except 1)
JSRL Addr. Jump SubRoutine Long [SP]←PL, [SP−1]←PU,SP−2, PC←ii
JSR Addr. Jump SubRoutine [SP]←PL, [SP−1]←PU,SP−2, PC9…0←i
JID Jump InDirect PL←ROM (PU,A)
RET RETurn from subroutine SP + 2, PL←[SP], PU←[SP−1]
RETSK RETurn and SKip SP + 2, PL←[SP],PU←[SP−1],
skip next instruction
RETI RETurn from Interrupt SP + 2, PL ←[SP],PU←[SP−1],GIE←1
INTR Generate an Interrupt [SP]←PL, [SP−1]←PU, SP−2, PC←0FF
NOP No OPeration PC←PC+1
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14.0 Instruction Set (Continued)
14.7 INSTRUCTION EXECUTION TIME
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 x number of cycles to be
skipped, where x equals the number of bytes in the skipped
instruction opcode.
See the BYTES and CYCLES per INSTRUCTION table for
details.
Bytes and Cycles per Instruction
The following table shows the number of bytes and cycles for
each instruction in the format of byte/cycle.
Arithmetic and Logic Instructions
[B] Direct Immed.
ADD 1/1 3/4 2/2
ADC 1/1 3/4 2/2
SUBC 1/1 3/4 2/2
AND 1/1 3/4 2/2
OR 1/1 3/4 2/2
XOR 1/1 3/4 2/2
IFEQ 1/1 3/4 2/2
IFGT 1/1 3/4 2/2
IFBNE 1/1
DRSZ 1/3
SBIT 1/1 3/4
RBIT 1/1 3/4
IFBIT 1/1 3/4
RPND 1/1
Instructions Using A & C
CLRA 1/1
INCA 1/1
DECA 1/1
LAID 1/3
DCORA 1/1
RRCA 1/1
RLCA 1/1
SWAPA 1/1
SC 1/1
RC 1/1
IFC 1/1
IFNC 1/1
PUSHA 1/3
POPA 1/3
ANDSZ 2/2
Transfer of Control Instructions
JMPL 3/4
JMP 2/3
JP 1/3
JSRL 3/5
JSR 2/5
JID 1/3
VIS 1/5
RET 1/5
RETSK 1/5
RETI 1/5
INTR 1/7
NOP 1/1
Memory Transfer Instructions
Register Direct Immed. Register Indirect
Indirect Auto Incr. & Decr.
[B] [X] [B+, B−] [X+, X−]
X A, (Note 18) 1/1 1/3 2/3 1/2 1/3
LD A, (Note 18) 1/1 1/3 2/3 2/2 1/2 1/3
LD B, Imm 1/1 (If B <16)
LD B, Imm 2/2 (If B >15)
LD Mem, Imm 2/2 3/3 2/2
LD Reg, Imm 2/3
IFEQ MD, Imm 3/3
Note 18: =>Memory location addressed by B or X or directly.
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14.0 Instruction Set (Continued)
14.8 OPCODE TABLE
Upper Nibble
FE D C BA98765 4 3 2 10
Lower Nibble
JP−15 JP−31 LD 0F0, #i DRSZ 0F0 RRCA RC ADC
A,#i ADC
A,[B] IFBIT
0,[B] ANDSZ
A, #i LD
B,#0F IFBNE 0 JSR
x000–x0FF JMP
x000–x0FF JP+17 INTR 0
JP−14 JP−30 LD 0F1, #i DRSZ 0F1 * SC SUBC
A, #i SUBC
A,[B] IFBIT
1,[B] *LD
B,#0E IFBNE 1 JSR
x100–x1FF JMP
x100–x1FF JP+18 JP+2 1
JP−13 JP−29 LD 0F2, #i DRSZ 0F2 X A,[X+] X
A,[B+] IFEQ
A,#i IFEQ
A,[B] IFBIT
2,[B] *LD
B,#0D IFBNE 2 JSR
x200–x2FF JMP
x200–x2FF JP+19 JP+3 2
JP−12 JP−28 LD 0F3, #i DRSZ 0F3 X A,[X−] X
A,[B−] IFGT
A,#i IFGT
A,[B] IFBIT
3,[B] *LD
B,#0C IFBNE 3 JSR
x300–x3FF JMP
x300–x3FF JP+20 JP+4 3
JP−11 JP−27 LD 0F4, #i DRSZ 0F4 VIS LAID ADD
A,#i ADD
A,[B] IFBIT
4,[B] CLRA LD
B,#0B IFBNE 4 JSR
x400–x4FF JMP
x400–x4FF JP+21 JP+5 4
JP−10 JP−26 LD 0F5, #i DRSZ 0F5 RPND JID AND
A,#i AND
A,[B] IFBIT
5,[B] SWAPA LD
B,#0A IFBNE 5 JSR
x500–x5FF JMP
x500–x5FF JP+22 JP+6 5
JP−9 JP−25 LD 0F6, #i DRSZ 0F6 X A,[X] X
A,[B] XOR
A,#i XOR
A,[B] IFBIT
6,[B] DCORA LD
B,#09 IFBNE 6 JSR
x600–x6FF JMP
x600–x6FF JP+23 JP+7 6
JP−8 JP−24 LD 0F7, #i DRSZ 0F7 * * OR A,#i OR A,[B] IFBIT
7,[B] PUSHA LD
B,#08 IFBNE 7 JSR
x700–x7FF JMP
x700–x7FF JP+24 JP+8 7
JP−7 JP−23 LD 0F8, #i DRSZ 0F8 NOP RLCA LD A,#i IFC SBIT
0,[B] RBIT
0,[B] LD
B,#07 IFBNE 8 JSR
x800–x8FF JMP
x800–x8FF JP+25 JP+9 8
JP−6 JP−22 LD 0F9, #i DRSZ 0F9 IFNE
A,[B] IFEQ
Md,#i IFNE
A,#i IFNC SBIT
1,[B] RBIT
1,[B] LD
B,#06 IFBNE 9 JSR
x900–x9FF JMP
x900–x9FF JP+26 JP+10 9
JP−5 JP−21 LD 0FA, #i DRSZ 0FA LD
A,[X+] LD
A,[B+] LD
[B+],#i INCA SBIT
2,[B] RBIT
2,[B] LD
B,#05 IFBNE 0A JSR
xA00–xAFF JMP
xA00–xAFF JP+27 JP+11 A
JP−4 JP−20 LD 0FB, #i DRSZ
0FB LD
A,[X−] LD
A,[B−] LD
[B−],#i DECA SBIT
3,[B] RBIT
3,[B] LD
B,#04 IFBNE 0B JSR
xB00–xBFF JMP
xB00–xBFF JP+28 JP+12 B
JP−3 JP−19 LD 0FC, #i DRSZ
0FC LD
Md,#i JMPL X A,Md POPA SBIT
4,[B] RBIT
4,[B] LD
B,#03 IFBNE 0C JSR
xC00–xCFF JMP
xC00–xCFF JP+29 JP+13 C
JP−2 JP−18 LD 0FD, #i DRSZ
0FD DIR JSRL LD A,Md RETSK SBIT
5,[B] RBIT
5,[B] LD
B,#02 IFBNE 0D JSR
xD00–xDFF JMP
xD00–xDFF JP+30 JP+14 D
JP−1 JP−17 LD 0FE, #i DRSZ
0FE LD A,[X] LD
A,[B] LD [B],#i RET SBIT
6,[B] RBIT
6,[B] LD
B,#01 IFBNE 0E JSR
xE00–xEFF JMP
xE00–xEFF JP+31 JP+15 E
JP−0 JP−16 LD 0FF, #i DRSZ 0FF * * LD B,#i RETI SBIT
7,[B] RBIT
7,[B] LD
B,#00 IFBNE 0F JSR
xF00–xFFF JMP
xF00–xFFF JP+32 JP+16 F
Where, iis the immediate data Md is a directly addressed memory location *is an unused opcode The opcode 60 Hex is also the opcode for IFBIT #i,A
COP8SG Family
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COP8SG Family
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15.0 Mask Options
See Section 5.5 ECON (CONFIGURATION) REGISTER.
16.0 COP8 Tools Overview
National is engaged with an international community of in-
dependent 3rd party vendors who provide hardware and
software development tool support. Through National’s inter-
action and guidance, these tools cooperate to form a choice
of tools 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.
16.1 SUMMARY OF TOOLS
COP8 Evaluation Software and Reference Designs
•COP8–NSEVAL: Software Evaluation package for Win-
dows. A fully integrated evaluation environment for
COP8. Includes WCOP8 IDE evaluation version (Inte-
grated Development Environment), COP8-NSASM (Full
COP8 Assembler), COP8-MLSIM (COP8 Instruction
Level Simulator), COP8C Compiler Demo, DriveWay™
COP8 Device-Driver-Builder Demo, Manuals, Applica-
tions Software, and other COP8 technical information.
•COP8–REF-xx: Reference Designs for COP8 Families.
Realtime hardware environment with a variety of func-
tions for demonstrating the various capabilities and fea-
tures of specific COP8 device families. Run Win 95 demo
reference software and exercise specific device capabili-
ties.
COP8 Starter Kits and Hardware Target Solutions
•COP8-EVAL-xxx: A variety of Multifunction Evaluation,
Design Test, and Target Boards for COP8 Families. Re-
altime target design environments with a selection of
peripherals and features including multi I/O, LCD display,
keyboard, A/D, D/A, EEPROM, USART, LEDs, and
bread-board area. Quickly design, test, and implement a
custom target system (some target boards are stand-
alone, and ready for mounting into a standard enclosure),
or just evaluate and test your code.
COP8 Software Development Languages and Integrated
Environments
•COP8-NSDEV: National’s COP8 Software Development
package for Windows on CD. A fully Integrated Develop-
ment Environment for COP8. Includes a fully licensed
WCOP8 IDE, COP8-NSASM. Plus Manuals,Applications
Software, and other COP8 technical information.
•COP8C: ByteCraft - C Cross-Compiler and Code Devel-
opment System. Includes BCLIDE (Integrated Develop-
ment Environment) for Win32, editor, optimizing C Cross-
Compiler, macro cross assembler, BC-Linker, and
MetaLinktools support. (DOS/SUN versions available.
•EWCOP8, EWCOP8-M, EWCOP8-BL: IAR - ANSI
C-Compiler and Embedded Workbench. (M version in-
cludes MetaLink debugger support) (BL version: 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.
COP8 Development Productivity Tools
•DriveWay-COP8: Aisys Corporation - COP8 Peripherals
Code Generation tool. Automatically generates tested
and documented C or Assembly source code modules
containing I/O drivers and interrupt handlers for each
on-chip peripheral. Application specific code can be in-
serted for customization using the integrated editor.
•COP8-UTILS: COP8 assembly code examples, device
drivers, and utilities to speed up code development. (In-
cluded with COP8-NSDEV and COP8-NSEVAL.)
COP8 Hardware Debug Tools
•COP8-EM-xx: Metalink COP8 Emulation Module for
OTP/ROM COP8 Families. Windows based development
and real-time in-circuit emulation tool, with 100 frame
trace, 32k s/w breaks, Enhanced User Interface, Met-
aLink Debugger. Includes COP8-NSDEV, power supply,
DIP emulation cables.
•COP8-DM-xx: Metalink COP8 Debug Module for
OTP/ROM COP8 Families. Windows based development
and real-time in-circuit emulation tool, with 100 frame
trace, 32k s/w breaks, Basic User Interface, MetaLink
Debugger, and COP8 OTP Programmer with sockets.
Includes COP8-NSDEV, power supply, DIP and/or SMD
emulation cables and adapters.
•COP8-IM: MetaLink iceMASTER®for OTP/ROM COP8
devices. Windows based, full featured real-time in-circuit
emulator, with 4k trace, 32k s/w breaks, and MetaLink
Windows Debugger. Includes COP8-NSDEV and power
supply. Package-specific probes and surface mount
adaptors are ordered separately. (Add COP8-PM and
adapters for OTP programming.)
COP8 Development and OTP Programming Tools
•COP8-PM: COP8 Development Programming Module.
Windows programming tool for COP8 OTP/Flash Fami-
lies. Includes 40 DIP programming socket, control soft-
ware, RS232 cable, and power supply. (Programming
adapters are extra.)
•Development: Metalink’s Debug Module includes devel-
opment device programming capability for COP8 de-
vices. Many other third-party programmers are approved
for development and engineering use.
•Production: Third-party programmers and automatic
handling equipment cover needs from engineering proto-
type and pilot production, to full production environments.
•Factory Programming: Factory programming available
for high-volume requirements.
COP8SG Family
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16.0 COP8 Tools Overview (Continued)
16.2 TOOLS ORDERING NUMBERS FOR THE COP8SGx FAMILY DEVICES
The COP8-IM/400 ICE can be used for emulation with the limitation of 10 MHz emulation speed maximum. For full speed
COP8SGx emulation, use the 15 MHz COP8-DM-SG or COP8-EM-SG.
Note: The following order numbers apply to the COP8 devices in this datasheet only.
Vendor Tools Order Number Cost Notes
COP8-NSEVAL COP8-NSEVAL VL Order from web site.
COP8-REF COP8-REF-SG VL Order from web site
COP8-EVAL COP8-EVAL-COB1 VL Order from web site
COP8-NSDEV COP8-NSDEV VL Included in EM. Order CD from web site
COP8-EM COP8-EM-SG M Included p/s, 28/40 pin DIP target cable, manuals,
software
EM Target Cables
and Converters COP8-EMC-44P VL 44 PLCC Target Cable
COP8-EMC-28CSP L 28 CSP Target Cable
COP8-EMA-xxSO L DIP to SOIC Cable Converter
COP8-EMA-44QFP L 44 pin PLCC to 44 QFP Cable Converter
Development
Devices COP8SGR7, COP8SGE7 VL 32k or 8k Eraseable/OTP devices
COP8-PM COP8-PM-00 L Included p/s, manuals, software, 16/20/28/40 DIP/SO
and 44 PLCC programming socket; add OTP adapter
or target adapter (if needed)
OTP Programming
Adapters COP8-PGMA-44QFP L For programming 44 QFP on any programmer
COP8-PGMA-28CSP L For programming 28 CSP on any programmer
COP8-PGMA-44CSP L For programming 44 CSP on any programmer
COP8-PGMA-28SO VL For programming 16/20/28 SOIC on any programmer
MetaLink COP8-DM DM5-KCOP8-SG M Included p/s (PS-10), target cables (DIP and PLCC),
16/20/28/40 DIP/SO and 44 PLCC programming
sockets. Add OTP adapter (if needed) and target
adapter (if needed)
DM Target
Adapters MHW-CNVxx (xx = 33, 34
etc.) L DM target converters for
16DIP/20SO/28SO/44QFP/28CSP; (i.e. MHW-CNV38
for 20 pin DIP to SO package converter)
OTP Programming
Adapters MHW-COP8-PGMA-DS L For programming 16/20/28 SOIC and 44 PLCC on the
EPU
MHW-COP8-PGMA-44QFP L For programming 44 QFP on any programmer
MHW-COP8-PGMA-28CSP L For programming 28 CSP on any programmer
COP8-IM 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
IM Probe Card PC-COP8SG44PW-AD-10 M 10 MHz 44 PLCC probe card; 2.5V to 6.0V
PC-COP8SG40DW-AD-10 M 10 MHz 40 DIP probe card; 2.5V to 6.0V
IM Probe Target
Adapters MHW-SOICxx (xx = 16, 20,
28) L 16 or 20 or 28 pin SOIC adapter for probe card
MHW-CONV33 L 44 pin QFP adapter for 44 PLCC probe card
KKD WCOP8-IDE WCOP8-IDE VL Included in DM and EM
IAR EWCOP8-xx See summary above L - H Included all software and manuals
Byte
Craft COP8C COP8C COP8CWIN M Included all software and manuals
Aisys DriveWay COP8 DriveWay COP8 L Included all software and manuals
OTP Programmers Go to:
www.national.com/cop8 L - H A wide variety world-wide
Cost: Free; VL =<$100; L = $100 - $300; M = $300 - $1k; H = $1k - $3k; VH = $3k - $5k
COP8SG Family
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16.0 COP8 Tools Overview (Continued)
16.3 WHERE TO GET TOOLS
Tools can be ordered directly from National, National’s e-store, a National Distributor, or from the tool vendor. Go to the vendor’s
web site for current listings of distributors.
Vendor Home Office Electronic Sites Other Main Offices
Byte Craft Limited 421 King Street North www.bytecraft.com Distributors Worldwide
Waterloo, Ontario info@bytecraft.com
Canada N2J 4E4
Tel: 1-(519) 888-6911
Fax: (519) 746-6751
IAR Systems AB PO Box 23051 www.iar.se USA:: San Francisco
S-750 23 Uppsala info@iar.se Tel: +1-415-765-5500
Sweden info@iar.com Fax: +1-415-765-5503
Tel: +46 18 16 78 00 info@iarsys.co.uk UK: London
Fax +46 18 16 78 38 info@iar.de Tel: +44 171 924 33 34
Fax: +44 171 924 53 41
Germany: Munich
Tel: +49 89 470 6022
Fax: +49 89 470 956
KANDA Systems
LTD. Unit 17 -18
Glanyrafon Enterprise Park,
Aberystwyth, Ceredigion,
SY23 3JQ, UK
www.kanda.com
support@kanda.com
usasupport@kanda.com
USA:
Tel: 800-331-7766
Fax: 303-456-2404
K and K
Development ApS Kaergaardsvej 42 DK-8355
Solbjerg Denmark Fax:
+45-8692-8500
www.kkd.dk kkd@kkd.dk
National 2900 Semiconductor Dr. www.national.com/cop8 Europe:
Semiconductor Santa Clara, CA 95051 support@nsc.com Tel: 49(0) 180 530 8585
USA europe.support@nsc.com Fax: 49(0) 180 530 8586
Tel: 1-800-272-9959 Hong Kong:
Fax: 1-800-737-7018 Distributors Worldwide
The following companies have approved COP8 programmers in a variety of configurations. Contact your vendor’s local office or
distributor and request a COP8FLASH update. You can link to their web sites and get the latest listing of approved programmers
at: www.national.com/cop8.
Advantech;American Reliance; BP Microsystems; Data I/O; Dataman; EE Tools, Hi-Lo Systems; ICE Technology; KANDA, Lloyd
Research; Logical Devices; Minato; MQP; Needhams; Phyton; SMS(Data I/O); Stag Programmers; System General; and Tribal
Microsystems.
17.0 REVISION HISTORY
Date Section Summary of Changes
October 2001 Electrical Characteristics Added spec. for comparator enable time.
Changed comparator response time to 600 ns.
Comparators Added note regarding comparator enable time.
COP8SG Family
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Physical Dimensions inches (millimeters) unless otherwise noted
Chip Scale Package CSP
Order Number COP8SGR7HLQ8
NS Package Number LQA44A
Molded SO Wide Body Package (WM)
Order Number COP8SGx528Mx,
NS Package Number M28B
COP8SG Family
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Physical Dimensions inches (millimeters) unless otherwise noted (Continued)
Molded Dual-In-Line Package (N)
Order Number COP8SGx728Nx
NS Package Number N28B
Molded Dual-In-Line Package (N)
Order Number COP8SGx540Nx
NS Package Number N40A
COP8SG Family
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Physical Dimensions inches (millimeters) unless otherwise noted (Continued)
44-Lead EPROM Leaded Chip Carrier (EL)
Order Number COP8SGR744J3
NS Package Number EL44C
COP8SG Family
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Physical Dimensions inches (millimeters) unless otherwise noted (Continued)
Molded Dual-In-Line Package (N)
Order Number COP8SGx544Vx
NS Package Number V44A
COP8SG Family
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Physical Dimensions inches (millimeters) unless otherwise noted (Continued)
Plastic Quad Flat Package (VEJ)
Order Number COP8SGx544VEJx
NS Package Number VEJ44A
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
Email: support@nsc.com
National Semiconductor
Europe Fax: +49 (0) 180-530 85 86
Email: europe.support@nsc.com
Deutsch Tel: +49 (0) 69 9508 6208
English Tel: +44 (0) 870 24 0 2171
Français Tel: +33 (0) 1 41 91 8790
National Semiconductor
Asia Pacific Customer
Response Group
Tel: 65-2544466
Fax: 65-2504466
Email: ap.support@nsc.com
National Semiconductor
Japan Ltd.
Tel: 81-3-5639-7560
Fax: 81-3-5639-7507
www.national.com
COP8SG Family, 8-Bit CMOS ROM Based and OTP Microcontrollers with 8k to 32k Memory, Two
Comparators and USART
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.
