Error CMP401: The reference clock pin of PLL <pin_name> cannot be driven by any CLKBUF cell.
Please replace it with an equivalent INBUF cell.

When driven by an external user PAD, the reference clock pin (CLKA) of any PLL core must be driven by a regular I/O macro, not a clock I/O macro.

Action

Replace the reference clock with an equivalent INBUF.