icc clock routing rule fail

flowerah2

我cts之前定义了
define_routing_rule double_rule -default_reference_rule -multiplier_spacing 2 -multiplier_width 2
然后CTS的时候报错，
Warning: Incorrect routing rule specified for clock nets (CTS-202)

查了CTS-202:  the compile_clock_tree command has detected that the number of routing tracks required to place one global segment exceeds the capacity of the global cell. hence,it is not possible to use global routing for net delay and capacitance estimation.
我route 了 clock看到有些是double width，有些不是。看上面的意思是routing资源不够？