CPI¶
- CPI
- Compare and Increment
- Description
- Performs
cp a,(hl)
, then incrementsHL
and decrementsBC
.cp a,(hl) inc hl dec bc
- Uses
- This instruction is not very useful on its own, as
cp a,(hl)
is both smaller and faster than a singleCPI
, but more often used is the repeating version ofCPI
:CPIR
- This instruction is not very useful on its own, as
- Results
Register/Flag 16-bit (non-ADL) 24-bit (ADL) S
flagSet if result is negative; else reset Z
flagSet if A
=(HL)
; else resetH
flagSet if borrow from bit 4; else reset P/V
flagSet if BC
≠ 0 after the operation; else resetN
flagSet C
flagNot affected - Allowed Instructions
Instruction Opcode CC (ADL/non-ADL) CC (.S) CC (.L) cpi $ED, $A1 2F + 1R 3F + 1R 3F + 1R - Notes
- Although this instruction increments
HL
, it decrementsBC
.
- Although this instruction increments
- See Also
- CP, CPD, CPDR, CPIR, LDI