COP424C NSC [National Semiconductor], COP424C Datasheet - Page 13

• Manufacturer Part Number: COP424C
• Description: Single-Chip 1k and 2k CMOS Microcontrollers
• Manufacturer: NSC [National Semiconductor]

Mnemonic
ARITHMETIC INSTRUCTIONS
ASC
ADD
ADT
AISC
CASC
CLRA
COMP
NOP
RC
SC
XOR
Instruction Set
Table II is a symbol table providing internal architecture in-
struction operan and operation symbols used in the instruc-
tion set table
Symbol
Internal Architecture Symbols
A
B
Br
Bd
C
D
EN
G
IL
IN
L
M
PC
Q
SA SB SC 11-bit 3-level subroutine stack
SIO
SK
SKL
T
TABLE II Instruction Set Table Symbols
Definition
4-bit accumulator
7-bit RAM address register (6-bit for COP424C)
Upper 3 bits of B (register address)
(2-bit for COP424C)
Lower 4 bits of B (digit address)
1-bit carry register
4-bit data output port
4-bit enable register
4-bit general purpose I O port
two 1-bit (IN0 and IN3) latches
4-bit input port
8-bit TRI-STATE I O port
4-bit contents of RAM addressed by B
11-bit ROM address program counter
8-bit latch for L port
4-bit shift register and counter
Logic-controlled clock output
1-bit latch for SK output
8-bit timer
Operand
y
Code
Hex
5
30
31
4A
10
00
40
44
32
22
02
b
0011 0000
0011 0001
0100 1010
0101
0001 0000
0000 0000
0100 0000
0100 0100
0011 0010
0010 0010
0000 0010
Language
TABLE III COP444C 445C Instruction Set
Machine
(Binary)
Code
y
A
Carry
A
A
A
A
Carry
0
A
None
‘‘0’’
‘‘1’’
A
a
a
a
a
a
Z
RAM(B)
C
RAM(B)
10
y
RAM(B)
13
Data Flow
a
A
A
10
RAM(B)
C
C
A
C
C
Table III provides the mnemonic operand machine code
data flow skip conditions and description of each instruc-
tion
Instruction Operand Symbols
d
r
a
y
RAM(x) RAM addressed by variable x
ROM(x) ROM addressed by variable x
Operational Symbols
a
b
e
A
Z
a
A
C
A
A
4-bit operand field 0– 15 binary (RAM digit select)
3(2)-bit operand field 0– 7(3) binary
(RAM register select)
11-bit operand field 0 – 2047 (1023)
4-bit operand field 0– 15 (immediate data)
Plus
Minus
Replaces
Is exchanged with
Is equal to
One’s complement of A
Exclusive-or
Range of values
A
A
Conditions
Carry
None
None
Carry
Carry
None
None
None
None
None
None
Skip
Add with Carry Skip on
Carry
Add RAM to A
Add Ten to A
Add Immediate Skip on
Carry (y
Complement and Add with
Carry Skip on Carry
Clear A
Ones complement of A to A
No Operation
Reset C
Set C
Exclusive-OR RAM with A
Description
i
0)