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Altera_Forum's avatar
Altera_Forum
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14 years ago

Multiple PLL's in cyclone III

Greetings

I filled up one PLL in a cyclone III design and need to add another clock that is skewed -2.5 ns in another PLL. How close is PLL 1 to PLL2 and PLL3? Are they all accurate to one another or are they not to be trusted.

Thanks

3 Replies

  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    You can set the clock compensation mode on one of the PLL's output clocks.

    One of those modes should let you meet your needs.
  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    What does "Clock compensation" mean. I see it here in the PLL megawizard? can you digress? thank you

  • Altera_Forum's avatar
    Altera_Forum
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    14 years ago

    I would NOT trust different PLLs. Same PLL - OK, two different PLLs even if the source the same - not trustable.