SBC - Z80 instruction reference

SZHP/VNC ●●●●1●

● set from the result
1 always 1

Forms

sbc a, 1 byte · 4 cycles

Subtracts r and the carry flag from A.
sbc a, 1 byte · 7 cycles

Subtracts (HL) and the carry flag from A.
sbc a, 2 bytes · 7 cycles

Subtracts nn and the carry flag from A.
sbc a, 3 bytes · 19 cycles

Subtracts the value pointed to by IX plus dd and the carry flag from A.
sbc hl, 2 bytes · 15 cycles

Subtracts rr and the carry flag from HL.

Pseudo-instructions

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

sbc 1 byte · 4 cycles

Subtracts r and the carry flag from A.
sbc 1 byte · 7 cycles

Subtracts (HL) and the carry flag from A.
sbc 2 bytes · 7 cycles

Subtracts nn and the carry flag from A.
sbc 3 bytes · 19 cycles

Subtracts the value pointed to by IX plus dd and the carry flag from A.

Undocumented 1 row

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

sbc a, 2 bytes · 8 cycles

Subtracts ixh/l and the carry flag from A.

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.

sbc 2 bytes · 8 cycles

Subtracts ixh/l and the carry flag from A.

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
rr: A register pair: bc, de, hl or sp.
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
        sbc a, b
        halt1
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