AMD Am186 Series, Instruction Set

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Instruction Set 4-3
AAA AAA
Examples
This example adds two unpacked decimal numbers.
Tips
To convert an unpacked decimal digit to its ASCII equivalent, use OR after AAA to add 30h
(ASCII 0) to the digit.
ADC, ADD, SBB, and SUB set AF when the result needs to be converted for decimal
arithmetic. AAA, AAS, DAA, and DAS use AF to determine whether an adjustment is
needed. This is the only use for AF.
Related Instructions
If you want to See
Add two numbers and the value of CF ADC
Add two numbers ADD
Convert an 8-bit unsigned binary sum to its packed decimal equivalent DAA
UADDEND1 DB 05h ; 5 unpacked BCD
UADDEND2 DB 07h ; 7 unpacked BCD
; add unpacked decimal numbers
XOR AX,AX ; clear AX
MOV AL,UADDEND1 ; AL = 05h = 5 unpacked BCD
ADD AL,UADDEND2 ; AX = 000Ch = 12
AAA ; AX = 0102h = 12 unpacked BCD
; the AF and CF flags will be set, indicating the carry into AH