Klive Z80 Assembler
Z80 Instructions

Accepted Z80 Instructions

The Klive Assembler implements every officially documented Z80 instruction as well as the non-official ones. During the implementation, the ClrHome.org (opens in a new tab) was used as a reference.

Z80 instructions may start with a label. Labels are identifiers that can be terminated by an optional colon (:). The compiler accepts both labels in these samples:

Start: ld b,#f0
Wait   djnz Wait

Z80 Mnemonics

The compiler accepts these mnemonics:

ADC, ADD, AND, BIT, CALL, CCF, CP, CPD, CPDR, CPI, CPIR, CPL, DAA, DEC, DI, DJNZ, EI, EX, EXX, HALT, IM, IN, INC, IND, INDR, INI, INIR, JP, JR, LD, LDD, LDDR, LDDRX*, LDRX*, LDDX*, LDI, LDIR, LDIRX*, LIRX*, LDIX*, LDPIRX*, LPRX*, MIRROR*, MIRR*, MUL*, NEG, NEXTREG*, NREG*, NOP, OR, OTDR, OTIR, OUT, OUTINB*, OTIB*, OUTD, OUTI, PIXELAD*, PXAD*, PIXELDN*, PXDN*, POP, PUSH, RES, RET, RETI, RETN, RL, RLA, RLC, RLCA, RLD, RR, RRA, RRC, RRCA, RRD, RST, SBC, SCF, SET, SETAE*, STAE*, SLA, SLL SRA, SRL, SUB, SWAPNIB*, SWAP*, TEST*, XOR.

Note: The instructions marked with * can be used only with the ZX Spectrum Next model.

Z80 Registers

The compiler uses the standard 8-bit and 16-bit register names, as specified in the official Zilog Z80 documentation:

  • 8-bit registers: A, B, C, D, E, H, L, I, R
  • 16-bit registers: AF, BC, DE, HL, SP, IX, IY
  • For the 8-bit halves of the IX and IY index registers, the compiler uses these names: XL, XH, YL, YH. Alternatively, the compiler accepts these names, too: IXL, IXH, IYL, IYH. As a kind of exception to general naming conventions, these mixed-case names are also accepted: IXl, IXh, IYl, IYh.

JP Syntax

Z80 assemblers use two different syntax constructs for the indirect JP statements:

; Notation #1
jp hl
jp ix
jp iy

; Notation #2
jp (hl)
jp (ix)
jp (iy)

The Klive Assembler accepts both notations.

ALU operations syntax

Three standard ALU operations between A and other operands (ADD, ADC, and SBC) sign A as their first operand:

add a,b
adc a,(hl)
sbc a,e

However, the five other standard ALU operations between A and other operands (SUB, AND, XOR, OR, and CP) omit A from their notation:

sub e
and (hl)
xor e
or c
cp b

The Klive compiler accepts the second group of ALU operations using the explicit A operand, too:

sub a,e
and a,(hl)
xor a,e
or a,c
cp a,b
ExpressionsPragmas