SPEF PT flow - want to do STA in primetime at two coner

[synopsis]

SPEF PT flow

Hi, I only have got one nxtgrd file from foundry, so only one SPEF was extracted by STAR_RCXT. But I want to do STA in primetime at two coner (worst and best), what should I do?

 

[reasonable]

SPEF PT flow

I don't think corner information is included in your nxtgrd file. And I think STA use corner information (if it can) to calculate only gate delay, so the corner information is possibly ignored in interconnection delay calculation.

 

[jbeniston]

SPEF PT flow

Use the same SPEF with best and worst case timing libraries.

 

[synopsis]

Re: SPEF PT flow

I don't think corner information is included in your nxtgrd file. And I think STA use corner information (if it can) to calculate only gate delay, so the corner information is possibly ignored in interconnection delay calculation.

Thank you for your reply. But if I want to get the net corner information, what else I needed?

 

[psp_eee]

Re: SPEF PT flow

hotter wires are slower, so you need 2 spefs to conclude.

 

[Surfingbull]

Re: SPEF PT flow

Correct me if I'm wrong, but I think StarRC extraction and StarRC RC-netlisting are two different steps of the StarRC flow.

Only one nxtgrd file is needed for StarRC extraction. Then StarRC can produce RC netlists for multiple extraction corners (rcbest, rcworst, cbest, ...) using that same extraction.

The designer has to decide which extraction corner(s) to use to close min and max time.