A <- A - (IY+d)
CP
(IY+d)
b7 | b6 | b5 | b4 | b3 | b2 | b1 | b0 | |
---|---|---|---|---|---|---|---|---|
1 | 1 | 1 | 1 | 1 | 1 | 0 | 1 | $FD |
1 | 0 | 1 | 1 | 1 | 1 | 1 | 0 | $BE |
d |
The contents of the Index (register pair IY) Register is added to a two's complement displacement d to point to an address in memory. A logical AND operation is performed between the contents of this address and the contents in the Accumulator, the result is stored in the Accumulator.
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 overflow, otherwise it is reset |
N | is set. |
C | is set if borrow, otherwise it is reset. |
If the Accumulator contains $63, Index Register IY contains $1000, and memory location $1005 contains $60, then upon the execution of
CP (IY+$05)
the P/V flag in the F register is reset.