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Altera_Forum's avatar
Altera_Forum
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17 years ago

false path?

Hi,

I've got an internally generated page signal which changes state every few thousand clocks and the timing isn't particularly important. Am I best to treat this as a false path or use some form of multicycle constrain in TimeQuest.

If it's the latter please could you state which multi-cycle exception I should use as it is really confusing - I will read up in the mean time.

Thanks,

D.

2 Replies

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    17 years ago

    If the timing doesn't matter at all, use a set_false_path exception.

    If it's an asynchronous signal and your synchronizing logic assumes a maximum propagation delay, use set_max_delay.

    In my opinion, set_multicycle_path exceptions should be used only for synchronous signals for which the setup and/or hold relationship needs to be changed by a certain number of clock cycles.