Description
Keywords: 6.1i, 5.2i, 5.1i , CPLD, TAEngine, timing constraint
Urgency: Hot
General Description:
The CPLD timing analysis tool of the TAEngine does not obey the "From" portion of a FROM:TO constraint. The constraint picks up only the "To" portion and, as a result, covers many more paths than expected.
Solution
Because more paths are covered by the constraint than intended, you can work around this issue by inspecting all paths to verify the validity of each path with respect to the starting point indicated in the timing constraint.
This problem has been fixed in the latest 6.1i Service Pack, available at:
http://support.xilinx.com/support/techsup/sw_updates The first service pack containing the fix is 6.1i Service Pack 1.