The Designer's Guide Community
Forum
Welcome, Guest. Please Login or Register. Please follow the Forum guidelines.
Jul 20th, 2024, 2:29am
Pages: 1
Send Topic Print
Strange problem with Monte Carlo sim. in Spectre (Read 1894 times)
Roberto
New Member
*
Offline



Posts: 1

Strange problem with Monte Carlo sim. in Spectre
Jan 16th, 2006, 4:08am
 
Hello everyone,
I am using the Monte Carlo analysis within Spectre for transient simulations as well as PSS simulations. I found that for some of my schematics, the simulator is not able to correctly print the different result of each iteration. It actually presents all the iterations results as they were identical (for example while plotting family curves, all iterations are superimose to eachother). For some other schematics, it works properly, showing different results for each iteration. I did a lot of trials, I found that the only difference between the working schematic and the others are that in the working one the definition of the global source "VSS!" (my ground) is done by means of the Assura interface (Setup->Stimuli->global sources), while in the failling ones the VSS! is defined on the schematic by means of DC generator.
I tried to change the definition of my VSS! in the schematics where it was defined with the generator, and the problem get solved in some case, but not in all of them.

This looks pretty much like a bug, anyone has found that before?  

(In the cases where results are identical for each run, the histograms of the various parameters shown that the statistical choice of the parameters value is running properly, then the bug involve only the plotting of the results  I suppose)

Thank you very much for your kind help,
Roberto, University of Udine
Back to top
 
 
View Profile   IP Logged
Andrew Beckett
Senior Fellow
******
Offline

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

Posts: 1742
Bracknell, UK
Re: Strange problem with Monte Carlo sim. in Spect
Reply #1 - Jan 17th, 2006, 9:24pm
 
There are a couple of other explanations (which are probably more likely):

  • You're asking for mismatch variation, when the models are not set up to do mismatch (the models need to be in subckts; see http://www.designers-guide.org/Modeling/montecarlo.pdf
  • The expression you're calculating is referring to a fixed result directory (i.e. it has the ?resultsDir arg in the data access part of the expression) - and so is not seeing the monte carlo results.


Andrew.
Back to top
 
 
View Profile WWW   IP Logged
Pages: 1
Send Topic Print
Copyright 2002-2024 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.