Hi,
since I updated to ISE 10.2 and regenerated my GTPs with coregen I have simulation problems. All output values from the GTP models are X although ALL input values driven by the toplevel module are defined (0 or 1).
Actually some input values are X but these are derived from a DCM which is again driven by the PLL lock detect (from the GTPs) so the main problem is that the PLL does not lock I guess. (however its X and not zero) The CLKIN and all resets are definitely fine.
Any ideas?