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Grich

Mar 10th, 2008 6:56 PM

Flag Question

Another question from me. Although I am a noob at assembly, I love learning it.:D

My questions are:

What are flags?
When are they used?

Thanks in advance guys.

Benoit

Mar 10th, 2008 7:12 PM

Re: Flag Question

Flags are just a collection of bits that tell you different things about the current state of the processor. For example, if you do a byte addition and the result is greater than 255, then the carry flag will be set. The zero flag is also popular, to signify that the result of a computation is zero. The sign flag tells you if a number is interpreted as signed or unsigned. Most CPU's have atleast those three.

mrynit

Mar 10th, 2008 8:06 PM

Re: Flag Question

flags can be single bit registers, or memory mapped registers.
they are used in conditional operations. branch on negative/zero/positive

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