Hi,
I have a input clock "i_clk_main", in my VHDL code, i divide this clk with factor 2, that means "clk_int" has the half frequenz as "i_clk_main", and i use "clk_int" to clock the output register.
Now, i must in the constraint file define, how much ns delays the output relative to "clk_int" may maximal have. What should i do? The following is the error report fomr ISE.
Checking timing specifications ... ERROR:XdmHelpers:634 - Signal "clk_int" is used as the clock in specification "OFFSET=OUT 7000 pS AFTER clk_int HIGH", but this clock signal is not connected directly to a pad. An OFFSET specification must use a pad signal to designate the clock.
Thanks, and have a nice weekend Cheng