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个人认为这样约束没问题,pll会自动为三个新生成的时钟生成约束。在static timing里会有如下信息,如:
INFO:XdmHelpers:851 - TNM " clk20_grp ", used in period specification "TS_clk20", was traced
into DCM instance "my_dcm". The following new TNM groups and period specifications were
generated at the DCM output(s):
如果有这个信息,就说明为新时钟生成了约束,如果没有,那就悲剧了。 ...