Zilog Z8F0130 - Manual (Page 142)

eZ8
™
CPU Core
User Manual
UM012820-0810 CPCX Instruction
127
CPCX
Definition
Compare with Carry using Extended Addressing.
Syntax
CPCX dst, src
Operation
dst - src - C
Description
For this new eZ8 extended addressing instruction, the source operand
with the C bit is compared to (subtracted from) the destination operand
and the appropriate flags are set accordingly. The contents of both oper-
ands are unaffected. For multiprecision operation, repeating this instruc-
tion enables multibyte compares. Only if the initial state of the Zero flag
is 1 and the result of the compare is 0 is the Zero flag set.
Flags
C Set if a borrow is required by bit 7; reset otherwise
Z Set if the result is zero and the initial Zero flag is 1; reset otherwise
S Set if the result is negative; reset otherwise
V Set if an arithmetic overflow occurs; reset otherwise
D Unaffected
H Unaffected