(IX+d) <- (IX+d) - 1
DEC
(IX+d)
| b7 | b6 | b5 | b4 | b3 | b2 | b1 | b0 | |
|---|---|---|---|---|---|---|---|---|
| 1 | 1 | 0 | 1 | 1 | 1 | 0 | 1 | $DD |
| 0 | 0 | 1 | 1 | 0 | 1 | 0 | 1 | $35 |
| d | ||||||||
The contents of Index Register IX (register pair IX) are added to the two's-complement displacement integer, d, to point to an address in memory. The contents of this address are then decremented.
| S | is set if result is negative, otherwise it is reset. |
| Z | is set if result is 0, otherwise it is reset. |
| H | is set if borrow from bit 4, otherwise it is reset. |
| P/V | is set if (IX+d) was $80 before operation, otherwise it is reset. |
| N | is set. |
| C | is not affected. |
If Index Register pair IX contains $2020 and memory location $2030 contains byte $34, then upon the execution of
DEC (IX+$10)
memory location $2030 contains $33