Continue to Site

Welcome to

Welcome to our site! is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

what different between post-sta and sign-off sta?

Not open for further replies.


Full Member level 4
Dec 13, 2002
Reaction score
Trophy points
Activity points
Before sign-off must do sign-off sta, and i want to know sign-off sta different from post-sta? what corner? thanks

I think: there is no difference .
sign-off sta must be post-layout sta. When layout is done , the spef parameter file is extracted and the sta is done to decide whether the layout is timing ok for tapeout.
what is the post-layout sta aim to do is also to determine whether the layout is timing ok for tapeout.

you only need to do post-layout STA. This is the STA before sign-off

As advice from synopsys, sign-off STA should be four times STA in two corner, slow corner and fast corner.
You should run STA by primetime. Use bc-wc analysis mode.
Set slow library, check setup time and hold time.
Set fast library, check setup time and hold time.

If all above four conditions are timing closured. You can sign-off. That is recommend flow.

But commonly, you can read both slow library and fast library in and check setup time with slow and hold time with fast. That is fine as well
  • Like
Reactions: ivlsi


    Points: 2
    Helpful Answer Positive Rating
As for the SetUp and Hold checks, should I run the tool twice each time for either SetUp Or Hold check? If the tool is able to read slow and fast SDF together, why not running it only once for all the related checks?

For Sign-Off STA we need to enable SI Analysis!

Not open for further replies.

Part and Inventory Search

Welcome to