Xilinx ISE 中DCM的问题? ISE, DCM, Xilinx

wjingmei001

ERRORIT:65 - DCM symbol "physical_group_dll0/CLK0_BUF/dll0/DCM_INST" (output
signal=dll0/CLK0_BUF) CLKFB is driven by an input buffer, but neither CLK0,
CLK2X or CLKFX of the DCM is driving loads off-chip.

我编译的时候出现这个错误,无论怎么修改,都不行,各位高人有没有知道是怎么回事的?

帮忙解答一下,谢谢啦