用ISE10.1 Place&Route 后,出现如下警告: WARNING:Route:455-CLK Net:clk_200m may have excessive skew because 0 CLK pins and 1 NON_CLK pins failed to route using a CLK template.
若不管它进行后仿,就会出现: WARNING:Anno:67-NCD is not completely routed,some delays may be inaccurate.