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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
Icon for Super Contributor rankSuper Contributor
8 months ago

Have you tried searching on "afi_clk" instead of "avl_clk"? avl_clk does not appear in your tech map viewer screenshot even though you preserved it in your code.

JuanEscobedo's avatar
JuanEscobedo
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8 months ago

Afi_clk does appear, but only on pre-synthesis view in SignalTap

The signal is missing on post-fitting view

  • sstrell's avatar
    sstrell
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    8 months ago

    So tap it as pre-synthesis for use as the acquisition clock.

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

      What are the advantages/disadvantages of using pre synthesis vs post-fitting? Isn't the signal showing up in one but not the other a problem?

      • sstrell's avatar
        sstrell
        Icon for Super Contributor rankSuper Contributor
        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.