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ThomasTessier
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2 years ago
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NCSIM of PLLs not generating correct output frequency

QuartusPrime 21.1 on CentOS7. Arria5 GX. I have a PLL which accepts 104MHz (from an upstream) and is suppose to generate 182MHz and 91MHz. That is a multiply by 7 with a divide by 8 and divide by ...
  • ThomasTessier's avatar
    2 years ago

    Aqid, no simulation error just the waveform frequency is incorrect. I modified the PLL to accept 104MHz but on the input I changed to multiple by 7 and divide by 2 and then changed my output stages to account for the VCO frequency difference to get the right frequencies I needed. This does simulate properly and generates the correct clocks. I cannot explain it but this was my solution and I am moving forward.