説明

When I create a Timespec PERIOD within PlanAhead, incorrect syntax is used which causes Constraint System errors similar to the following.  

"ERROR:ConstraintSystem - In file: floorplan_1.ucf(9): Constraint 'PERIOD' was 

applied to 'RISING FFS', but is only applicable to the following: 

design:NET or constraint:timegrp or global:clocknets 

Please see the Constraints Guide for more information on this constraint."

ソリューション

This will be fixed in a future release of PlanAhead.  

To create Timespec PERIOD constraints using predefined groups in the current release, use Constraints Editor.