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Steve-Mowbray-ENL's avatar
Steve-Mowbray-ENL
Icon for Occasional Contributor rankOccasional Contributor
28 days ago

How to tell Quartus my Arria10 target system CLKUSR frequency is 100MHz?

Timing analyser reports CLKUSR at 125MHz but target system has 100MHz on this pin to accommodate AS in combination with transceiver calibration as per the manuals -- there doesn't seem to be any cons...
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AqidAyman_Altera's avatar
AqidAyman_Altera
Icon for Regular Contributor rankRegular Contributor
12 days ago

Hi Steve,

 

Please refer to the following explanation of the Warning that you see.

https://microsites.altera.com/microsites/psg_microsites_migration/quartushelp/current/index.htm#msgs/msgs/wcio_design_pin_assigned_to_clkusr_location.htm 

 

Based on the explanation, we would infer that Quartus detected transceivers in your design.

  • If transceivers are used in your design, then you need NOT do a pin assignment in the .qsf. However, it is must to provide a clock of 100-125 MHz at its input. No need to constraint it in the .sdc.
  • If you are not using transceivers, not using HMC, and not using this pin as a user-supplied configuration clock, instead want to use it as a GPIO, then you need to assign the logic port to the device CLKUSR pin location and constraint the pin in .sdc.

We hope this information helps.


Regards,

Aqid

Steve-Mowbray-ENL's avatar
Steve-Mowbray-ENL
Icon for Occasional Contributor rankOccasional Contributor
12 days ago

Hi Aqid

Thanks -- all understood -- my purpose is to identify why timing analyser reports CLKUSR at 125MHz when our design requires 100MHz -- and if there is a method to indicate to Quartus/Platform-Designer what CLKUSR frequency actually is or failing that if the incorrect CLKUSR frequency reported is in fact unimportant and can be ignored (our project does seem to mostly run as expected but there are some quirks which could be related to transceiver operation)

Regards, Steve