When I implement an XC9500 design, I receive an error similar to the following:
"Unexpected error detected. Please report to Xilinx with reference: "../xc9500/s/nw95glb.c:108"
Tcl _cpldfit.tcl detected a return code of '2' from program 'cpldfit -f _cpldfit.rsp <xxx>.ngd'"
The failure is due to an internal conflict that occurs when the global OEs are assigned to their global nets. You can work around problem by using one of the following methods:
1. Choose "No Global OE Optimization" for the Implement Design Basic Process Properties from the GUI ("-nogtsopt" in the CPLDfit command line).
2. Apply a LOC constraint for the global OEs in the UCF file:
NET "My_OE" LOC = "P3";
(Please note that the first method by which to work around this issue will not create global OEs.)