Intel 210200-002 manual AAS Ascii Adjust AAS For Subtraction, 1001111111

AAS ASCII ADJUST AAS

FOR SUBTRACTION

Operation:	Flags Affected:
if ((AL) & OFH) >9 or (AF) = 1 then	AF,CF.
(AL) +- (AL) - 6	OF, PF, SF, ZF undefined
(AH) +- (AH)-1
(AF) +-1
(CF) +- (AF)
(AL) ~ (AL) & OFH

Description:

AAS (ASCII Adjust for Subtraction) corrects the result of a previous subtraction of two valid unpacked decimal operands (the destina- tion operand must have been specified as

register AL). AAS changes the content of AL to a valid unpacked decimal number; the high- order half-byte is zeroed. AAS updates AF and CF; the content of OF, PF, SF and ZF is undefined following execution of AAS.

Encoding:

1001111111

AAS Operands Clocks Transfers Bytes AAS Coding Example

(no operands) 4 - 1 AAS

2-52