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PravinKumar's avatar
PravinKumar
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1 year ago

Query in the Post Route results.

May I know how implemented frequency is calculated here and why the FMax is calculated in that way.

I am seeing the difference in calculating Fmax for the design.

Highlighted the considered values from reports and attached snapshots.

I have attached the project folder for your reference.

Can you help me to identify the issue.

7 Replies

  • ShengN_altera's avatar
    ShengN_altera
    Icon for Super Contributor rankSuper Contributor

    Hi,

    I had tried to extract the folder and open the design. However can't find the related files in screenshot:

    Could you provide the missing files as well?

    Thanks,

    Regards,

    Sheng

  • ShengN_altera's avatar
    ShengN_altera
    Icon for Super Contributor rankSuper Contributor

    Hi,


    May I know do you have any further concern or consideration?


    Thanks,

    Regards,

    Sheng


  • PravinKumar's avatar
    PravinKumar
    Icon for New Contributor rankNew Contributor

    Hi,

    Yes, I have attached the hdl_prj folder which is having hdlsrc and quartus_prj.

    Please let me know how to proceed.

    Thanks,

    Pravin

  • FvM's avatar
    FvM
    Icon for Super Contributor rankSuper Contributor

    Hi,

    your design fails timing analysis because Arria 10 maximum core clock frequency of 644 MHz is exceeded (timing analyser uses rounded value of 645.16MHz = 1/1.55ns). This causes a "minimum pulsewidth" violation for clk and a respective restricted Fmax value.
    Possible contradicting reported values in timing analysis are referred. You need to solve the minimum pulsewidth problem first.

    Regards
    Frank

  • FvM's avatar
    FvM
    Icon for Super Contributor rankSuper Contributor

    Hi,
    this .sdc passes timing analysis
    create_clock -name clk -period 1.56ns -waveform {0.0ns 0.78ns} [get_ports {clk}]
    derive_clock_uncertainty
    set_false_path -to [all_outputs]
    set_false_path -from [all_inputs]

    Presume NR_symbol_modulator is planned to be used inside an Arria 10 design with some kind of high speed interface. Consider that FPGA fabric side of the interface can't run above 644 MHz clock. If intended 780 MHz clock is required by interface throughput, you'll need more bits for the parallel data stream.

  • ShengN_altera's avatar
    ShengN_altera
    Icon for Super Contributor rankSuper Contributor

    Hi,


    May I know do you have any further update or concern?


    Thanks,

    Regards,

    Sheng