Article ID: 000076092 Content Type: Troubleshooting Last Reviewed: 03/16/2023

Why do I see fitter or Timing Analyzer warnings about missing or ignored clocks when using UniPHY-based external memory interface IP in a Platform Designer (formerly Qsys) project?


  • Quartus® II Subscription Edition

    In the Platform Designer (formerly Qsys) project .qip file, the UniPHY external memory interface IP sdc files might not be in the correct order and this can be a reason for missing or ignored clock warnings or critical warnings. This is typically seen when the UniPHY IP is used with phase-locked loop (PLL) and delay locked loop (DLL) sharing between two interfaces.


    Two possible workarounds are :

    1. Comment out the sdc files in the Qsys .qip file and add them in the required order in the Quartus Project Settings -> Timing Analyzer  -> SDC files to include in the project.
    2. Modify the Qsys .qip file to put the sdc files in the required order.


    For each UniPHY IP instance, place the <UniPHY_IP_variation_name>_p0.sdc file before the other sdc files for that UniPHY IP.

    For the clock sharing timing flow to work correctly, the .qip file order (and hence timing sdc files) must be such that the master sdc files are listed before any associated slave sdc files.

    For further information, see the The DLL and PLL Sharing Interface” section in the Functional Description – UniPHY chapter in volume 3 of the External Memory Interface Handbook.

    This problem is fixed starting with the Quartus® II software version 12.0.

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