In 9.1 (all service packs) if the dual-edge trigger register/flipflop is used and the CPLD fit option
Use Direct Input Registers is selected, the output of the post fit simulation is incorrect.
The data changes on only one edge.
This is a bug in the TSIM software that generates an .nga that is used by NetGEN to create
the postfit simulation netlist. The jedec file is correct.
The workaround to the issue is to edit the post fit simulation by hand to replace the FD
register with an FDD.