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Altera_Forum's avatar
Altera_Forum
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12 years ago

Dead process on SignalTap

Hi,

I am currently working on a personal project that I have successfully tested with ModelSim, but I have a problem when testing it with SignalTap.

One of the process that I'm running "freezes" at some time. The signals in it should be moving at each clock pulse but they're stuck to some value and they don't live up to that.

I have added a debug counter to this process that increments itself at each clock pulse but it doesn't increment up to some point.

I am running my design on a De0 Nano board with a 50MHz frequency clock.

I'm kinda stuck for the moment so if any of you have an advice to give that would be nice.

1 Reply

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

    I'm not sure you're giving us enough specific detail to work with. It simply sounds like both your design and the additional debug counter logic you've added fail to do anything.

    So, for the minute I suggest you consider the following:

    You suggest your design simulates correctly in ModelSim. First confirm that you're stimulating your simulation in exactly the same way as your real hardware is. Unless you do this you will not uncover potential conditions that cause your design to lock up - it could easily be something you've unintentionally designed into your logic.

    You must also confirm your design meets timing. A design that doesn't meet timing is unlikely to behave as you expect. Re-check your timing constraints (I trust you've added some) and confirm the design meets them.