Auxiliary Carry Flag Help

Expand Post »

I am trying to find out if the Auxiliary carry flag only turns on when the 4th bit carries out from the 3rd bit or if it will turn on for the 7th to 8th bit aswell. This is what I did already:

mov ax, 0Fh ; this is the test for the 3rd to 4th
add ax, 1 ; AC=1

mov ax, 00F0h ; this is the test for the 7th to 8th
add ax, 0010h ; not sure if this should set AC=1

Similar Threads

assembly101

Reputation Points: 10

Solved Threads: 0

Newbie Poster

Offline

2 posts
since Oct 2009

Permalink

Oct 14th, 2009

Re: Auxiliary Carry Flag Help

The Auxiliary Carry (AF bit of Status Flags) is used for the carry out of bit 3 (0...7) into bit 4 for use in BCD operations! Think of it as a nibble carry!

wildgoose

Reputation Points: 546

Solved Threads: 99

Practically a Posting Shark

Offline

891 posts
since Jun 2009

This thread is solved

Either the thread starter or a moderator has marked this thread as solved. You can most likely trust the responses and answers given. There is most likely no reason for any further responses to be posted here. If you have a related question, please start a new thread in this forum instead.

This thread is more than three months old

No one has posted to this discussion for at least three months. Please let old threads die and do not reply to them unless you feel you have something new and valuable to contribute that absolutely must be added to make the discussion complete. Otherwise, please start a new thread in this forum instead.

Previous Thread in Assembly Forum Timeline: job

Next Thread in Assembly Forum Timeline: Help Printing Ascii Code

DaniWeb Message

Cancel Changes

User Name
Password