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JuanEscobedo's avatar
JuanEscobedo
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8 months ago
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Issues debugging DDR3 controller using SignalTap on Quartus Prime Standard 23.1 with Arria V GZ FPGA

Hello, I have a simple design where a state machine writes synthetic data to DDR using the Avalon bus of the DDR3 controller and reads it back after some time, processes it, and writes new data to D...
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  • sstrell's avatar
    sstrell
    8 months ago

    In this situation, it doesn't matter, it's the same signal no matter what.

    Using pre-synth vs. post-fit comes more into play if you're trying to reduce recompile times (short ECO compilation with post-fit vs. full recomp with pre-synth even though in Standard edition, that isn't really a big thing either unless you are using incremental compilation).

    Short answer for you: it doesn't really matter.

sstrell's avatar
sstrell
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8 months ago

Can you clarify better what signals you can and cannot see? You say you "see the ones driven by the logic", but you can't see "the signals coming from the IP"? It's not clear what you mean by this. Like you can see the address bits (signals from logic to IP) but not readdata from the IP?

If you are talking about the memory signals that go out to the external memory, you can't tap those signals assuming you are using the hard controller.

JuanEscobedo's avatar
JuanEscobedo
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8 months ago
Hello. Yes, I am using the hard controller.

My issue is the the avalon bus signals that are outputs of the IP. Namely, readdata, datavalid, and ready. They do not show up in signaltap neither presynthesis nor post fitting. Signals used as input to the controller which are driven by RTL show up fine.
  • sstrell's avatar
    sstrell
    Icon for Super Contributor rankSuper Contributor
    8 months ago

    ready is not an Avalon signal. Do you mean waitrequest?

    Can you show your design instantiation or design in Platform Designer and screenshots of what you're seeing when you try to tap the nodes in Signal Tap? If you're leaving signals unconnected, they may have been optimized away.

    • JuanEscobedo's avatar
      JuanEscobedo
      Icon for New Contributor rankNew Contributor
      8 months ago

      Hello,

      I have attached the source RTL of my top level design and the top level RTL of the DDR3 controller generated by the wizard for your reference.

      As you can see, avl_ready is indeed one of the ports of the avl interface for the DDR3 controller.

      Below are the screenshots of the signals that show in post-fitting and pre-synthesis: