How do I lock a CLKDLL to a specified DLL in Virtex?
Users can lock a CLKDLL down in the UCF file.
In the UCF file, use the following syntax:
INST <DLL_instance> LOC = dll<x>
where <x> is the number 0 to 3.
EX: INST MY_DLL LOC = dll1
INST <DLL_instance> LOC = dll<xy>
where x is the number 0 to 3, and y is the letter p (for primary) or or
s (for secondary).
EX: INST MY_DLL LOC = dll1P