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AR# 25241

9.1.1 PlanAhead - Virtex-4 DRC error issued when more than 4 DCM outputs connect to a BUFG


When I run a DRC check on my Virtex-4 design in PlanAhead, I see the following error:

DCM dcm_0/Using_DCM_ADV.DCM_ADV_INST drives 5 BUFGs, it can only drive up to 4 BUFGs.


This is a known issue in the PlanAhead software at present and can be safely ignored.

As per the Virtex-4 User Guide:


"Any or all of the DCM's nine clock outputs can be used to drive a global clock network."

This issue is scheduled to be fixed in PlanAhead 9.2.

AR# 25241
Date Created 09/04/2007
Last Updated 12/15/2012
Status Active
Type General Article