OR - Z80 instruction reference

SZHP/VNC ●●0●00

● set from the result
0 always 0

Forms

or 1 byte · 4 cycles

Bitwise OR on A with r.
or 1 byte · 7 cycles

Bitwise OR on A with (HL).
or 2 bytes · 7 cycles

Bitwise OR on A with nn.
or 3 bytes · 19 cycles

Bitwise OR on A with the value pointed to by IX plus dd.

Pseudo-instructions

Other spellings the assembler accepts; each form shows the instruction it becomes.

or a, 1 byte · 4 cycles

Bitwise OR on A with r.
or a, 1 byte · 7 cycles

Bitwise OR on A with (HL).
or a, 2 bytes · 7 cycles

Bitwise OR on A with nn.
or a, 3 bytes · 19 cycles

Bitwise OR on A with the value pointed to by IX plus dd.

Undocumented 1 row

Left out of Zilog's manual, but the Z80 runs them, and so does this emulator.

or 2 bytes · 8 cycles

Bitwise OR on A with ixh/l.

Pseudo-instructions · Undocumented 1 row

Other spellings the assembler accepts; each form shows the instruction it becomes. Left out of Zilog's manual, but the Z80 runs them, and so does this emulator.

or a, 2 bytes · 8 cycles

Bitwise OR on A with ixh/l.

Operands

r: An 8-bit register: a, b, c, d, e, h or l.
(hl): The byte in memory at the address stored in hl. More
nn: An 8-bit immediate value, 0 to 255 or -128 to 127, written as a number, character constant or symbol. More
(ix+dd): The byte in memory at ix + dd, where dd is a signed displacement from -128 to 127, for example (ix+5) or (ix-3). (iy+dd) works the same way. More
ixh/l: The high or low byte of ix: ixh or ixl. For iy, use iyh or iyl. More

        .org 0x8000
        ld a, 5
        ld b, 3
        or b
        halt1
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