z80:Opcodes:CPIR
From Learn @ Cemetech
Jump to navigationJump to searchRepeats CPI until either:
- BC=0
- A=HL
Contents
Syntax
No operands.
CPIR
Effects
The carry is preserved, N is set and all the other flags are affected as defined. P/V denotes the overflowing of BC, while the Z flag is set if A=(HL) before HL is decreased.
Uses
If you want to find the first occurrence of 124 in the valid memory space:
LD HL,0000h LD BC,0000h LD A,124 CPIR
Note if you used CPDR it would find the last occurrence of 124 in the valid memory space.
T-States
BC ≠ 0 and A ≠ (HL) | 21 |
BC = 0 or A = (HL) | 16 |
See Also
BIT,CALL,CP,CPD,CPDR,CPI,JP,JR