Introduction - If you have any usage issues, please Google them yourself
DCM supports two frequency modes for the DLL. By default, the
DLL_FREQUENCY_MODE attribute is set to Low and the frequency of the clock
signal at the CLKIN input must be in the Low (DLL_CLKIN_MIN_LF to
DLL_CLKIN_MAX_LF) frequency range (MHz). See The Programmable Logic Data Book
for the current DLL_CLKIN_MIN_LF to DLL_CLKIN_MAX_LF frequency range
values. In Low frequency mode, the CLK0, CLK90, CLK180, CLK270, CLK2X,
CLKDV, and CLK2X180 outputs are available.