How to do a specific net Clock Tree Synthesis in Astro?

[mopansen]

Hi, everybody!
I want to specific a net (maybe a random net) to do CTS in Astro. How to do this?

 

[chyau]

Hi,

You can define a clock net in sdc(timing constraint) file.
The command is "creat_clock".

Best Regards,
Chyau

 

[luancao]

Hi, there,

You could use "create_clock -name ..." in sdc to specify a clock.

And you should also use the command "set_propagated_clock [all_clocks]"
and "remove_clock_uncertainty {*}" to specify it is NOT an ideal clock. Otherwise, Astro will treat all your clock as an ideal clock. When it exports back annotated and parasitic information in SDF, RSPF, DSPF & SPEF file, the clock latency and skew will not be included. To make things simple, you could export the sdc file from your STA environment by "write_sdf ...."