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Altera_Forum's avatar
Altera_Forum
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13 years ago

Good tutorial for SignalTap

Hi,

I am looking for good tutorial on SignalTap probably with a design example and step by step instructions.

Thanks

Bhargav

7 Replies

  • Altera_Forum's avatar
    Altera_Forum
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    Please advise how to change Time Units in SignalTapII.

    The problem is that fore any Time Units being set the waveforms remain the same.

    In the attached pictures you can see the same waveforms for Time Unit=1ps and 1s.

    Input clock is 50Mhz. The design is from the above tutorial.

    What am I doing wrong or is it a bug in SignalTapII?
  • Altera_Forum's avatar
    Altera_Forum
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    The time units aren't very useful in Timequest. IIRC it just changes the x axis legend. If you need to sample your signals at a different frequency, you need to change the frequency of the clock that you have defined in "setup" as sampling clock.

  • Altera_Forum's avatar
    Altera_Forum
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    I am working with SignalTapII, not Timequest.

    I dont need to sample signals at a different frequency, its just a simple 8-bit counter example with 50MHz clock input.

    I just want to set any valid Time Unit to see the length of the pulses in ns/ms, but I have the above problem.

    Only Sample Numbers mode ( just giving the number of the counted pulses ) is working correctly.
  • Altera_Forum's avatar
    Altera_Forum
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    Sorry I meant SignalTap, not Timequest.

    To be honest I've never used the timeunits. I've always counted the number of samples between two events and multiplied myself by the clock period.
  • Altera_Forum's avatar
    Altera_Forum
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    --- Quote Start ---

    I've always counted the number of samples between two events and multiplied myself by the clock period.

    --- Quote End ---

    But if the clock frequency is in question, then You never know it by doing so.

    I read "13. Design Debugging Using the SignalTap II Logic Analyzer" from Quartus Handbook, but Time Units are not even mentioned there.
  • Altera_Forum's avatar
    Altera_Forum
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    What do you mean? You must know at least the frequency of the clock you are using to sample your data in Signaltap. If you don't know that frequency, then you have no way of measuring any time related information from the signaltap output.