Article ID: 000074974 Content Type: Troubleshooting Last Reviewed: 04/08/2015

Cannot find PLL settings that allow for truncation-free problems in TimeQuest

Environment

  • Quartus® II Subscription Edition
  • BUILT IN - ARTICLE INTRO SECOND COMPONENT
    Description

    You may see this error in the MegaWizard message window in Quartus® II 12.0SP2 when generating Altera® UniPHY external memory interface IP with clock definitions which result in non integer values of clock period in ps.  The memory IP performs the following check:

    set period_ps [expr10^6/]
    if ([expr int(*2)] == [expr int()*2])

    If this is not true then the error will be reported in the MegaWizard message window.  For example where a 375MHz clock is used, int(*2) is 5333ps but int()*2 is 5334ps.

    Resolution

    Select a PLL reference clock frequency that results in a clock with a period which is an integer number of ps.

    This issue has been fixed in Quartus II 12.1

    Related Products

    This article applies to 1 products

    Intel® Programmable Devices