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Altera_Forum's avatar
Altera_Forum
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9 years ago

Number of IOPLLs in Arria 10 devices

I can instantiate more IOPLLs in my Arria 10 design (device 10AS016E4F29I3SG) than should be available. According to the documentation (https://documentation.altera.com/#/00035112-nt$nt00068592), the SX 160 has 6 IOPLLs. However, I was able to synthesize and fit a design with 8 IOPLLs. I have checked the fitter report: all 8 IOPLLs have different locations.

Are there really more than 6 IOPLLs in the target device? Or how can this discrepancy between documentation and fitter be explained?

2 Replies

  • Altera_Forum's avatar
    Altera_Forum
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    9 years ago

    You have 12 PLLs in that device - 6 fractional and 6 integer. Perhaps it's used a fractional PLL...

    However, I appreciate you're stating it's reporting "8 IOPLLs" - which doesn't particularly stack up.

    In which case, perhaps there is a discrepancy between the docs and the fitter - it does occasionally happen. Only Altera will be able to comment on that.

    Cheers,

    Alex
  • Altera_Forum's avatar
    Altera_Forum
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    9 years ago

    Thanks for your reply, Alex. I think the fitter merged several logical PLLs into one physical PLL. The fitter report was misleading as it reported the instantiation of IOPLLs in I/O banks that do not exist in the device used. When using pins as refclk input, the fitter was not able to fit 8 IOPLLs into the device anymore.