11.3 PlanAhead - DRC is allowing signals connected to IBUFGDS to be placed at non-clock pins

AR#	33367	Search For Another Answer
Topic	SW-PlanAhead
Last Updated	09/01/2009
Status	Active

Description

Keywords:global, cc, gc, dcm

I have a design with differential clock inputs driving an IBUFGDS, which have unintentionally been placed at general I/O sites instead of clock pins. I ran DRC in PlanAhead, but received no errors. I do get errors in the implementation tools. Should not PlanAhead's DRCs catch this?

Solution

Yes, PlanAhead should catch this and will in a future version of the software. Currently, PlanAhead DRCs are not intended to be a sign-off tool, but are intended to catch as many violations as possible. Refer to (Xilinx Answer 32379).