IBM 5150 PC Technical Reference (6025005, August, 1981) (PDF)

8088
REGISTER MODEL
AX: AH Al ACCUMULATOR
BX: BH Bl BASE
CX: CH CL COUNT
u..
OX: DH DL DATA ..Ja:
I
«W
SP STACK POINTER
a: I-­
W~
BP BASE POINTER
ZC!l
ww
C!la:
SI
~====================~ SOU RCE IN DEX
01 DESTINATION INDEX
~============~
I-------.----------lilNSTRU IP CTI ON POI NTE R
I FLAGSH I FLAGSL . STATUS FLAGS
t
~===============~====:
CS CODE SEGMENT } ~
OS DATA SEGMENT I-- ~
SS
:==========~==========: STAC K SE G M ENT
L-________ ~ ~
ES EXTRA SEGMENT ~~ Cl)a:
I
W
..J
Instructions which reference the flag register file as a 16-bit object
use the symbol FLAGS to represent the file:
15 7 0
'X , X IX I X , OF , OF 'IF ITF I SF I ZF t X IAF IX I PF IX ICF ,
X = Don't Care
AF: AUXILIARY CARRY - BCD }
CF: CARRY FLAG
PF: PARITY FLAG 8080 FLAGS
SF: SIGN FLAG
ZF: ZERO FLAG
OF: DIRECTION FLAG (STRINGS)}
IF: INTERRUPT ENABLE FLAG 8088 FLAGS
OF: OVERFLOW FLAG (CF E8 SF)
TF: TRAP - SINGLE STEP FLAG
B-2