DAA -- Decimal Adjust AL after Addition

DAA -- Decimal Adjust AL after Addition Opcode Instruction Clocks Description 27 DAA 4 Decimal adjust AL after addition Operation IF ((AL AND 0FH) > 9) OR (AF = 1) THEN AL = AL + 6; AF = 1; ELSE AF = 0; FI; IF (AL > 9FH) OR (CF = 1) THEN AL = AL + 60H; CF = 1; ELSE CF = 0; FI; Description Execute DAA only after executing an ADD instruction that leaves a two-BCD-digit byte result in the AL register. The ADD operands should consist of two packed BCD digits. The DAA instruction adjusts AL to contain the correct two-digit packed decimal result. Flags Affected AF and CF as described above; SF, ZF, PF, and CF as described in Appendix C. Protected Mode Exceptions None Real Address Mode Exceptions None Virtual 8086 Mode Exceptions None