I have a question that is more theoretical than practical:
The DCM uses the feedback loop so that it can create a 360 (= 0) degree phaseshift from CLKIN to CLK0, CLK90 etc. (or that is how I understood it)
But why is this loop nessecary to create this behaviour?
I know it's a bit vague, but I didn't find to much detailed info on it...
Can someone please explain me the working of this system, or give me a link to a place on the net where I can find it?
I have the standard VirtexII-Pro manual, but it doesn't say much about the whole system itself...