
12.0 Instruction Set
This section details the entire NSC800 instruction set in
terms of
#
Opcode
#
Instruction
#
Function
#
Timing
#
Addressing Mode
The instructions are grouped in order under the following
functional headings:
#
8-Bit Loads
#
16-Bit Loads
#
8-Bit Arithmetic
#
16-Bit Arithmetic
#
Bit Set, Reset, and Test
#
Rotate and Shift
#
Exchanges
#
Memory Block Moves and Searches
#
Input/Output
#
CPU Control
#
Program Control
12.1 Instruction Set Index
Alphabetical
Assembly
Mnemonic
Operation
Page
ADC A,m
1
ADC A,n
ADC A,r
ADC HL,pp
ADD A,m
1
ADD A,n
ADD A,r
ADD HL,pp
ADD IX,pp
ADD IY,pp
ADD ss,pp
AND m
1
AND n
AND r
Add, with carry, memory location contents to Accumulator
Add, with carry, immediate data n to Accumulator
Add, with carry, register r contents to Accumulator
Add, with carry, register pair pp to HL
Add memory location contents to Accumulator
Add immediate data n to Accumulator
Add register r contents to Accumulator
Add register pair pp to HL
Add register pair pp to IX
Add register pair pp to IY
Add register pair pp to contents of register pair ss
Logical ‘AND’ memory contents to Accumulator
Logical ‘AND’ immediate data to Accumulator
Logical ‘AND’ register r contents to Accumulator
40
38
36
43
40
38
36
43
43
43
43
41
39
36
BIT b,m
1
BIT b,r
Test bit b of location m
1
Test bit b of register r
45
44
CALL cc,nn
CALL nn
CCF
CP m
1
CP n
CP r
CPD
CPDR
Call subroutine at location nn if condition cc is true
Unconditional call to subroutine at location nn
Complement carry flag
Compare memory contents with Accumulator
Compare immediate data n with Accumulator
Compare register r to contents with Accumulator
Compare location (HL) and Accumulator, decrement HL and BC
Compare location (HL) and Accumulator, decrement HL and BC;
repeat until BC
e
0
Compare location (HL) and Accumulator, increment HL, decrement BC
Compare location (HL) and Accumulator, increment HL, decrement BC;
repeat until BC
e
0
Complement Accumulator (1’s complement)
56
56
38
42
40
37
50
51
CPI
CPIR
50
51
CPL
37
DAA
DEC m
1
DEC r
DEC rr
Decimal adjust Accumulator
Decrement data in memory location m
1
Decrement register r contents
Decrement register pair rr contents
38
42
37
44
28