Hello
I use Xilinx ISE Foundation 6.1.
Is it possible to use a signal as a clk source? The problem I got is: if I assign a special Pin (LOC constraints), the mapper tool claims:
"ERROR:MapLib:93 - Illegal LOC on IPAD symbol "IOSTRB_DSP" or BUFGP symbol "IOSTRB_DSP_BUFGP" (output signal=IOSTRB_DSP_BUFGP), IPAD-IBUFG should only be LOCed to GCLKIOB site"
(-> the signal_name is IOSTRB_DSP)
If I don't make a constraint for the signal, the report say: used: Type: GCLKIOB. Why does ISE not connect it to an GCLKIOB as I put in a LOC constraint for the signal IOSTRB_DSP?
I have to tell "place & route" where to connect the signal to. What should be filled in the constraint file? Or what should be chosen in PACE?
Thanks for any help.
Tobias Möglich