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Altera_Forum's avatar
Altera_Forum
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15 years ago

NiosII intstruction clock period...??

hello;

i understand that to write a delay loop using Nios instruction set, i need to know how many clock cycles each instruction inside the loop takes...I am using the NiosII /e...anyone has the timing for all the instructions?

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  • Altera_Forum's avatar
    Altera_Forum
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    15 years ago

    They are in the documentation: for the /e version they are all 6, + the duration of any Avalon MM cycle.

    The /f does most ALU instructions in 1 clock, branches being 1, 2 or 4 (predicted not taken, predicted taken, mispredicted), results of non-ALU (and slow ALU) instructions are unusable in the next two instructions as they miss the 'fast path' and have to go via the register file.