输入时钟路径规则:
Clock-capable input > BUFG > global clock tree
Clock-capable input > BUFH > horizontal clock line
Clock-capable input > CMT > BUFG > global clock tree
Clock-capable input > CMT > BUFR/BUFH > regional clock tree/horizontalclock line
Clock-capable input > BUFR > regional clock tree
Clock-capable input > BUFMR > BUFR > regional clock tree
Clock-capable input> BUFIO > I/O clock tree
Clock-capable input > BUFMR >BUFIOs > I/O clock tree
另外详细说明可参考ug472和一位大侠的中文解析:http://blog.youkuaiyun.com/lg2lh/article/details/45374653