The Designer's Guide Community
Forum
Welcome, Guest. Please Login or Register. Please follow the Forum guidelines.
May 17th, 2022, 6:36am
Pages: 1
Send Topic Print
Increasing the standard deviation of models in cadence (Read 485 times)
dnw
Junior Member
**
Offline



Posts: 25

Increasing the standard deviation of models in cadence
May 27th, 2020, 9:48am
 
Hi Is there a way to increase the sigma of stat models in cadence?
I am looking for a faster way to run 6,9 sigma cases
Thanks
Back to top
 
 
View Profile   IP Logged
Andrew Beckett
Senior Fellow
******
Offline

Life, don't talk to
me about Life...

Posts: 1740
Bracknell, UK
Re: Increasing the standard deviation of models in cadence
Reply #1 - Jun 7th, 2020, 6:43am
 
What are you aiming to achieve? There is a capability of the Virtuoso Variation Option used with ADE Explorer/Assembler for doing high-yield verification using an approach called Scaled Sigma Sampling which allows you to verify the yield with high sigma targets like six sigma. This approach (giving an over-simplified description) runs a monte carlo simulation with various scale factors of the sigma, and then from the results can then compute the yield. Because it scales up the sigma, it has the benefit of actually simulating points in the failure regions - trying to simulate 6-sigma or beyond in normal monte carlo is very unlikely to simulate anything in the tails because the probability of them happening is very small.

By the way, there is no tool called "cadence", so it helps if you can be precise about which tool/product you're using. Cadence is the name of the company providing EDA tools, not the name of a software suite (and Cadence produces a very wide range of EDA software, so you could be talking about many things).

Andrew.
Back to top
 
 
View Profile WWW   IP Logged
dnw
Junior Member
**
Offline



Posts: 25

Re: Increasing the standard deviation of models in cadence
Reply #2 - Jun 7th, 2020, 9:54am
 
Hi Andrew,
Sorry for loosely using Cadence name. I am using Virtuoso and running sims using ADEXL.
What I am trying to achieve is look at the tail with less number of simulation. I want to make sure I have enough margins on those corners.
Also to see if the startup is happening properly and if there is any failure case for that.

I think what you mentioned scaled sigma sampling is what I am looking for. I will try to google that also if you have some reference for that it will be really helpful.
Thanks
Back to top
 
 
View Profile   IP Logged
Pages: 1
Send Topic Print
Copyright 2002-2022 Designer’s Guide Consulting, Inc. Designer’s Guide® is a registered trademark of Designer’s Guide Consulting, Inc. All rights reserved. Send comments or questions to editor@designers-guide.org. Consider submitting a paper or model.