【已解决】关于report_clock_tree和report_clock_timing报出的skew

Alicezw

report_clock_tree和report_clock_timing报出的skew有什么不同？我看有资料说如果no timing duration前者的skew会比后者大，否则前者的skew 会小一点。

Alicezw

自己顶一下。哎呀呀！求指点啊！谢谢啦！

joemool

不好意思，我没看到叫做report_clock_tree的命令

joemool

report_clock_timing
-type [skew | interclock_skew | jitter | summary | latency
      [ [-launch | -capture]
        [-rise | -fall]
        | [-histogram [-histogram_range interval size ]]
        [-logic_level [-source {clock_root | generated_clock}]]
        ]
      ]
[-early | -late]
[-clock clock_list ]
[-from_clock from_clock_list ]
[-to_clock to_clock_list ]
[-from from_list ]
[-to to_list ]
[-nworst worst_entries ]
[-greater_than lower_limit ]
[-view view_name ]
[-verbose]
[-format column_list ]
[-tcl_list]
[{> | >>} filename ]
Generates a clock skew report for the current design. The software generates a separate report for each specified clock or pair of clocks. You specify the clocks using the -clock parameter, and clock pairs using the -from_clock and -to_clock parameters. You can use the - nworst and -greater_than parameters with the -from_clock and - to_clock parameters to generate reports with skew to the specified sink pins. You can use the - early and -late parameters to specify the type of skew to be reported.

Note: To remove common path pessimism from the reported skew, use the setAnalysisMode -cppr both command before using the report_clock_timing command. The report contains a separate column for common path adjustment values.

You can use the report_clock_timing command to perform MMMC based SSTA analysis. In MMMC mode, the command reports the latency and clock skew for all individual views. You can use the report_clock_timing -view parameter to report clock timing for a user-specified view.

潇湘君

楼主比较的应该是ICC中的两条命令，dt的是，EDI中类似的命令可以将结果赋给tcl变量，但ICC的这种命令貌似不行，写script的时候总是要通过文件读写
这个要顶起！回头我也做实验去，楼主应该也做实验看看，光看文档不行。。。

陈涛

ICC也可以，比如get_timing_path

潇湘君

回复 6# 陈涛


    版主是跟我说话吗？？受宠若惊啊……
    这个命令都没怎么用过， 回头试试。
    要是能提供我要的信息并能在内存中处理那就perfect了~

shehuang1987

report_clock_timing报的是local skew
report_clock_tree报的是global skew

michaelll

report_clock_timing报的是local skew,有timing关系的两条路径之间的skew，考虑derate
report_clock_tree报的是global skew，任意两条路径之间的skew，不一定有timing关系，不考虑derate

Alicezw

回复 3# joemool


    有的啊，呵呵！