求教： ISE PLACE报错 ，IBUFDS 问题

hongfeng575

ERROR: [PLACE 30-519] REFCLK pin of IDELAYCTRL instance ‘u_idelayctrl’ is driven by 'refclk_200Mhz_inst' {IBUFDS}.This will lead to unroutable situation,The REFCLK pin of a IDELAYCTRL insatance should be driven by a clock buffer.


可我代码明明用了IBUFGDS的啊：
IDELAYCTRL u_idelayctrl (
   .REFCLK  (ref_200MHz ),
   .RST  (!rst_n ),
   .RDY  ()
);

IBUFGDS #(
  .DIFF_TERM  ("TRUE"),
  .IOSTANDARD ("DEFAULT")
)  refclk_200MHz_inst  (
   .O   (ref_200MHz ),
  .I (refclk_200MHz_p ),  //直接从FPGA管脚输入
  .IB (refclk_200MHz_n )
);
先谢谢了！

albertcdy

确认一下IODELAY的REFCLK端能否用IBUFGDS来驱动
换句话说就是你这种时钟架构是否合理
供参考