然后执行read_parasticts /...eua2308_dap_ram12_01_30.spef语句结果出现以下
warning:unconnected hierarchy pin'eua2308_dap_u/eua2308_dap_control_u/no_cycle'is missing in the RC annotation for net
'eua2308_dap_u/eua2308_dap_control_u/no.cycle'
warning:unconnected hierarchy pin'eua2308_dap_u/eua2308_dap_control_u/sck_pos_edge'is missing in the RC annotation for net
'eua2308_dap_u/eua2308_dap_control_u/sck_pos_edge'
net type total lumped RC pi RC network not annotated
internal nets 21933 0 0 21629 0
-driverless nets 0 0 0 231
-loadless nets 0 0 0 73
再运行report_timing -delay min
report_timing -delay max
后出现warning
warning:some timing arcs have been disaabled for breaking timing loops or because of constant propagation
下面的相类似的warning很多,我只列了一个
warning:failed to compute c_effective for the timing arc(data_ram_wc/data_ram)data_ram_u/ck-->DO2(max_falling retain_rising)because the library data indicates a non_positive drive resistance
warning:some timing arcs have been disaabled for breaking timing loops or because of constant propagation
一定要检查timing loops
warning:failed to compute c_effective for the timing arc(data_ram_wc/data_ram)data_ram_u/ck-->DO2(max_falling retain_rising)because the library data indicates a non_positive drive resistance
看看lib里面有什么特别的地方,或者PT有什么设置可以解决这种问题