When I run TRCE on a Virtex, Virtex-E, Spartan-II, or Spartan-IIE design, the following warning message is reported:
"WARNING:SpeedCalc:42 - Cannot find referenced model "bel_d_min_period". This generally indicates that there is an inconsistency between versions of the speed and device data files. Please check to ensure that the XILINX environment variable is set correctly, if the MYXILINX variable is set, make sure that it is pointing to patch files that are compatible with the version of software to which the XILINX variable points."
This warning message may be safely ignored.
The bel_d_min_period was used in Virtex-II devices, but never for the Virtex, Virtex-E, Spartan-II, or Spartan-IIE device families.