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How do condition codes work?

Hello,

I'm looking at the condition codes. However, I'm not entirely sure how they work. I've looked at the online manual on this site (e.g.http://www.keil.com/support/man/docs/armasm/armasm_dom1359731161338.htm)
but am still uncertain.

What exactly does something like

BGE NV + N'V' signed >=
mean?

Thank you

Parents
  • Combinations of codes determine if the instruction executes or not. It is cheaper than branching in a pipe-lined processor. If the condition is false, instruction acts like a NOP

    >>but am still uncertain

    If you are uncertain perhaps assemble a few examples and simulate them or single-step so it starts making sense. Get a teacher or colleague go over the logic with you.

    >> NV + N'V'

    (N AND V) OR (!N AND !V) // basically if (N == V) done with logic gates

Reply
  • Combinations of codes determine if the instruction executes or not. It is cheaper than branching in a pipe-lined processor. If the condition is false, instruction acts like a NOP

    >>but am still uncertain

    If you are uncertain perhaps assemble a few examples and simulate them or single-step so it starts making sense. Get a teacher or colleague go over the logic with you.

    >> NV + N'V'

    (N AND V) OR (!N AND !V) // basically if (N == V) done with logic gates

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