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Altera_Forum's avatar
Altera_Forum
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12 years ago

Cyclone III - PLL

Hi,

I write for Elsys Design in association with SAFRAN Group.

I am working on a project where I need to get the Cyclone III PLL precision.

I would like to know how much the Cyclone III PLLs are accurate ? What is the uncertanity added to the clock outputs whereas the clock inputs (of 17.734573 MHz) ?

Thanks for your answer.

Antoine MASSON

Elsys Design

1 Reply

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    12 years ago

    There's no freqruency uncertainty. the PLL output frequencies have a rational (m/n) relation to the reference frequency, the exact frequency can be read from the Quartus MegaWizard or the compiler report files. In addition the PLL output has a phase jitter, see the device handbook for the specification.