14
Jul
17

Why am I getting timing results difference between PnR and STA?

This is a aged-old common question asked between the front-end design engineer and the PnR engineer.
It is lesser a tool issue, but more of a communication issue between the two entities.

Here’s a few items that might contribute to the difference:
– Is both using the same set of timing constraints used?
– Is both using the same derate factors?
– Is both running with SI?
– Any difference in the uncertainty setting between the two results?
– Is clock-gating/reset check turned on for both?
– Is both evaluating the same set of mode or corner?

If all the above are checked and yet still some difference, then there could be some parasitics extraction difference.
Double check if the SPEF extracted and used in timing closure is consistent with the PnR setup.
PVT definition; RC/R-only/C-only..

I hope this will help to align the prospective in debugging the differences.

Advertisements

0 Responses to “Why am I getting timing results difference between PnR and STA?”



  1. Leave a Comment

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s


HOME

My Gallery

Currently, I am posting my photographs on Imagekind. Their service provides international shipping. For more information, please refer to the links below.

========================

Buy my art at ImageKind.com.

Shipping

Return Policy

Contact Imagekind

Yosemite National Park Gallery

Alum Rock Park Gallery

Mono Lake

Some of my older postings