General Description: When I use the "INIT=S" attribute with the FDRSE flip-flop in a design that targets a Virtex device, MAP fails with the following error:
ERROR:MapLib:317 - Flop FDRSE symbol "u1" (output signal=N_output) has INITSTATE=1 and CLR dominates PRE. Virtex does not support this flop. To convert the flop into a FDPCE where PRE dominates CLR, set the environment variable XIL_MAP_FDCPE_I1_TO_FDPCE_I1.
(This message is misleading, as setting the variable actually converts the FDRSE to an FDSRE.)
解决方案
The message text will be corrected in the first major software release following 4.2i.