DAA DECIMAL ADJUST DAA

FOR ADDITION

Operation:

Flags Affected:

if ((AL) & OFH) > 9 or (AF) = 1 then

AF, CF, PF, SF, ZF

(AL) +- (AL) + 6

OF undefined'

(AF) +-1

 

if (AL) > 9FH or (CF) = 1 then

 

(AL) +- (AL) + 60H

 

(CF) +-1

 

Description:

DAA (Decimal Adjust for Addition) corrects the result of previously adding two valid packed decimal operands (the destination operand ml)st have been register AL). DAA changes the content of AL to a pair of valid packed decimal digits. It updates AF, CF, PF, SF and ZF; the content of OF is undefined following execution of DAA.

Encoding:

100100111 I

DAA Operands Clocks Transfers Bytes DAA Coding Example

(no operands)

4

-

1 DAA

2-70

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Intel 210200-002 manual DAA Decimal Adjust DAA For Addition