Difference between revisions of "Z80 Instruction Set"
| Line 1: | Line 1: | ||
| − | + | Not a complete list, but most commonly used instructions are given. For a complete list with opcodes and number of clock cycles taken, go [http://nwps.ws/~dragonfire/Asmin28/lesson/toc.html here] | |
== Data Movement == | == Data Movement == | ||
| − | + | ===EX=== | |
Three possible arguments: | Three possible arguments: | ||
| Line 15: | Line 15: | ||
| − | + | ===EXX=== | |
Swap BC, DE and HL with their shadows | Swap BC, DE and HL with their shadows | ||
| − | + | ===LD=== | |
Four main arguments: | Four main arguments: | ||
| Line 33: | Line 33: | ||
''LD reg, (imm16)'' | ''LD reg, (imm16)'' | ||
Does the opposite of ''LD (imm16), reg'' | Does the opposite of ''LD (imm16), reg'' | ||
| + | |||
| + | |||
| + | ===LDIR=== | ||
| + | Copies a byte from (HL) to (DE), increments DE and HL, then decrements BC. The instruction is repeated if BC is not 0. Interrupts are allowed to trigger while this instruction is running. | ||
| + | |||
| + | |||
| + | ===PUSH=== | ||
| + | Used as ''PUSH reg16'' where reg16 is a register pair or index register. Decrements SP, copies regMSB to (SP), decrements SP again, then copies regLSB to (SP). | ||
| + | |||
| + | |||
| + | ===POP=== | ||
| + | Same syntax as PUSH. Copies (SP) to regLSB, increments SP, copies (SP) to regMSB, then increments SP again. The word based at the starting value of SP is zeroed. | ||
Revision as of 18:00, 21 February 2006
Not a complete list, but most commonly used instructions are given. For a complete list with opcodes and number of clock cycles taken, go here
Data Movement
EX
Three possible arguments:
EX DE, HL Swaps H with D and L with E
EX AF, AF' Swaps AF with its shadow
EX (SP), HL Swaps (SP) with L and (SP+1) with H. Index registers are also valid
EXX
Swap BC, DE and HL with their shadows
LD
Four main arguments:
LD reg, # Sets the eight or 16 bit contents of reg to #
LD reg2, reg1 Copies the contents of 8 bit reg1 to reg2
LD (imm16), reg Copies the value of 8 or 16 bit reg to 16 bit memory address imm16. Programmers should remember that 16 bit values are stored little-endian.
LD reg, (imm16) Does the opposite of LD (imm16), reg
LDIR
Copies a byte from (HL) to (DE), increments DE and HL, then decrements BC. The instruction is repeated if BC is not 0. Interrupts are allowed to trigger while this instruction is running.
PUSH
Used as PUSH reg16 where reg16 is a register pair or index register. Decrements SP, copies regMSB to (SP), decrements SP again, then copies regLSB to (SP).
POP
Same syntax as PUSH. Copies (SP) to regLSB, increments SP, copies (SP) to regMSB, then increments SP again. The word based at the starting value of SP is zeroed.
