In ISE 13.x, theGTXEsimulation model is an extracted IC model for maximum functional accuracy. However, this model requires additional simulation time due to its complexity. This answer record provides a patch for this model in the 14.x ISE environment to allow for faster simulation times. This patch applies to the ISE environment only and is not be used in the Vivado tools.
Instructions:
1.) Navigate to the $Xilinx/ directory
2.) Copy the patch zip file to this directory
3.) Extract the contents of the zip file to this directory
4.) Note: the zip file contains contents in various subdirectories which willoverwrite existing contents. SelectYes when prompted if it is desired to overwrite these files.
5.) Re-run compxlib for your 3rd party simulation tool