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Altera_Forum's avatar
Altera_Forum
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14 years ago

Help Please: FFT Simulation

I'm having a lot of trouble simulating a streaming architecture FFT megacore using the vector wave simulation. I'm using the FFT user guide and avalon interface specification as a reference.

At one point after several packets, source_ready and source_valid were asserted, followed by a source_error 3 I think. That is the closest I have come to getting an output stream.

While simulating I've asserted subtle differences to the signals in responce the the errors, I attached an image of one of the VWF simulations for reference. The input is arbitrary. Anyone think its a problem internally with the FFT? Help is really appreciated.

4 Replies

  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    Hi,

    Your signals sink_sop and sink_eop are high for too long, they should be high for only one clock cycle (look at figure 3-4 of the user guide for example).

    Jérôme
  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    Thanks, good eye

    that takes of my streaming errors. Can you look at this screen shot for me? After taking it I offset the clock so my sop and eop trigger on the rising edge, but still getting errors. I don't know why sink ready goes low and source ready and source valid only go high for that time. The quick error where source eop spikes twice was 3 I believe.

    Thanks, I feel like I'm chasing my tail in circles, I'm using this for a senior project and I need to make sure I can use the FFT.

    -Sam
  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    woops stupid error please disregard the last post I have an output now.

    My apologies thanks for the help