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Pack_of_lone_wolves's avatar
Pack_of_lone_wolves
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1 year ago
Solved

Placement constraints for PLL in QPP

There is the feature called as logic lock which can fix placement of a node, I want to know if it is possible to use logic lock for fixing position of PLL? I get a warning in plan stage of fitter as "...
Hdl
  • AqidAyman_Altera's avatar
    AqidAyman_Altera
    1 year ago

    You can choose "Location" for that version of Quartus Prime.


AqidAyman_Altera's avatar
AqidAyman_Altera
Icon for Regular Contributor rankRegular Contributor
1 year ago

From my opinion, logic lock will reduce the flexibility for you on the timing side of the design. My suggestion is you need to change the PLL location through the qsf assignments.


  • Pack_of_lone_wolves's avatar
    Pack_of_lone_wolves
    Icon for Occasional Contributor rankOccasional Contributor
    1 year ago
    Will try this and let you know.
  • Pack_of_lone_wolves's avatar
    Pack_of_lone_wolves
    Icon for Occasional Contributor rankOccasional Contributor
    1 year ago
    I could see following cmd in qsf file:
    set_instance_assignment -name RESERVE_REGION "coordinates" -to PLL_instance.

    set_instance_assignment -name RESERVE_PLACE_REGION OFF -to PLL_instance

    For the second cmd, I changed it to ON and reran the Fit - Plan, but still same message is displayed.
  • Pack_of_lone_wolves's avatar
    Pack_of_lone_wolves
    Icon for Occasional Contributor rankOccasional Contributor
    1 year ago
    If I refer QPP settings file reference manual, what type of settings should be used to ensure desired PLL placement?