Forum Discussion

JMedi's avatar
JMedi
Icon for New Contributor rankNew Contributor
4 years ago

Clock generated by Fractional PLL Megawizard vs Timing analyzer

Hello, We have seen that it is different the clock configured/generated by Fractional PLL and the generated by the timing analyzer. They use different factor to generate VCO frequency: refCLK x...
Ash_R_Intel's avatar
Ash_R_Intel
Icon for Regular Contributor rankRegular Contributor
4 years ago

Hi,


I got some information from our team:

The Timing Analyzer numbers do have some inaccuracies, though they are consistent with each other & don't explain the PLL report's numbers:

  • Timing Analyzer stores clock periods, not their frequencies
  • Periods are only stored to three decimal places
  • The period of descendant clocks uses the mult & div factors of all of its ancestors, instead of using the mult & div factors of the truncated period of a parent clock


Regards.