CTS的问题

妞儿

在place之后，做CTS时，check_clock_tree之后，报出了如下的warning，man 了一下，没有太理解，路过的大神求解~~~
Warning: The clock 'EMIF_clk' defined at port 'EMIF_clk_o_pad' loops to itself. (CTS-832)
  0:  EMIF_clk_o_pad
  1:  EMIF_clk_o_pad
Warning: The clock 'clk_o_fpa' defined at port 'clk_fpa_10' loops to itself. (CTS-832)
  0:  clk_fpa_10
  1:  clk_fpa_10
Warning: The clock 'clk_o_led' defined at port 'clk_o_10' loops to itself. (CTS-832)
  0:  clk_o_10
  1:  clk_o_10Warning: The clock 'EMIF_clk' defined at port 'EMIF_clk_o_pad' loops to itself. (CTS-832)
  0:  EMIF_clk_o_pad
  1:  EMIF_clk_o_pad
Warning: The clock 'clk_o_fpa' defined at port 'clk_fpa_10' loops to itself. (CTS-832)
  0:  clk_fpa_10
  1:  clk_fpa_10
Warning: The clock 'clk_o_led' defined at port 'clk_o_10' loops to itself. (CTS-832)
  0:  clk_o_10
  1:  clk_o_1


上面的port都是输出端口的port，定义在端口的时钟是第三个输出时钟，报出这个问题后，下面好像是要定义set_clock_tree_exception，但是怎么定义呢？？？