© Thomas Kunz 2000
SCE 574
83
8088 Flags
äFlag
values change as part of execution of the instructions
äGeneral
rules for 6 condition/status registers
äPF
- set if and only if (iff) lsbyte of result contains an even number of 1s
äZF
- zero flag - set iff result was zero
äSF
- sign flag - set equal to msbit of result
äAF
- auxiliary flag
äUsed
by decimal arithmetic instruction
äSet
iff there has been a carry from (or borrow to) the low nibble to
(from) the high nibble
äCF
- carry flag
äFor
unsigned arithmetic => overflow
äSet
iff carry out of (or borrow into) the msbit of the result
äCan
also be used in rotate instructions