Re: A86: Parity Flag
[Prev][Next][Index][Thread]
Re: A86: Parity Flag
David Phillips wrote:
>
> The parity flag is also the overflow flag. It's context is determined by
> the last instruction that modified it. If it has a V, then it means that
> the instruction will set it if an overflow occurs. If it has a P, then the
> instruction will set or reset it depending on parity. It's probably not
> very useful, unless you're writing some _very_ optimized code, or an
> emulator, etc. I've never had a use for it in my code, but who knows, maybe
> you will.
LDI, CPIR, and similar instructions will return parity odd if bc hits
0. I use this a lot for optimization; often when you use bc as a
counter cpi / ret po will save a few bytes.
References: