ASCII Adjust after Addition (aaa)

aaa

Operation

ASCII-adjust AL -> AL

Description

You use aaa only after executing the form of an add instruction that stores a two-BCD-digit byte result in the AL register. aaa then adjusts AL to contain the correct decimal result. The top nibble of AL is set to 0. To convert AL to an ASCII result, follow the aaa instruction with:

or %al, 0x30

Table 2-8 shows how aaa handles a carry.

Example

Adjust the AL register to contain the correct decimal result after an add instruction that stores a two-BCD-digit byte.

aaa