When running Place and Route or the timing tools, I receive the following warning:
"ARNING:ConstraintSystem:12 - In file: maxskew_test.ucf(4): Loading a 'MaxSkew'
constraint from a UCF file is not supported at this time. This constraint
specification will be ignored."
Starting in 8.2i, the timing tools try to read the constraints file as part of a feature expansion that will allow, in 9.1i, the timing tools to change some of the constraints in the UCF file. This message can be safely ignored. For timing analysis, the ".pcf" and ".ncd" are used. Timing Analyzer does not support a ".ucf" constraint for MAXSKEW, only ".pcf". This should be updated for 9.1i.