The Designer's Guide Community
Forum
Welcome, Guest. Please Login or Register. Please follow the Forum guidelines.
Apr 20th, 2024, 5:33am
Pages: 1
Send Topic Print
Spectre Turbo - Parasitic Reduction - Fmax (Read 5152 times)
Berti
Community Fellow
*****
Offline



Posts: 356

Spectre Turbo - Parasitic Reduction - Fmax
Feb 04th, 2011, 7:07am
 
When I enter a value smaller than 1 (e.g. 0.1) into the fmax option field of the spectre turbo parasitic reduction (using icfb 5.10.41), it get an error warning: "Invalid value specified for Fmax. Switching to default parasitic reduction mode."

Can the value of fmax be smaller than 1GHz? Is my formating wrong or is that just another bug? As usual, I haven't found anything in the documentation.

Thanks for help, Cheers


Back to top
 
 
View Profile   IP Logged
Geoffrey_Coram
Senior Fellow
******
Offline



Posts: 1998
Massachusetts, USA
Re: Spectre Turbo - Parasitic Reduction - Fmax
Reply #1 - Feb 4th, 2011, 10:57am
 
Are you sure that field has units of GHz, not Hz?
Back to top
 
 

If at first you do succeed, STOP, raise your standards, and stop wasting your time.
View Profile WWW   IP Logged
sheldon
Community Fellow
*****
Offline



Posts: 751

Re: Spectre Turbo - Parasitic Reduction - Fmax
Reply #2 - Feb 5th, 2011, 8:47am
 
Berti,

 Originally the minimum value of fmax was limited to 1GHz. In more
recent versions of MMSIM/IC, fractional values are supported.

                                                               Best Regards,

                                                                   Sheldon
Back to top
 
 
View Profile   IP Logged
Berti
Community Fellow
*****
Offline



Posts: 356

Re: Spectre Turbo - Parasitic Reduction - Fmax
Reply #3 - Feb 6th, 2011, 11:45pm
 
Thanks a lot Sheldon!

By the way, what is the actual meaning of fmax? What I mean is: Is the simulation accuracy guarantied for ≤fmax, or is fmax the maximum frequencies where parasitcs are taken into account (what would mean that my fmax in the simulation should be smaller)?

Thanks
Back to top
 
 
View Profile   IP Logged
boe
Community Fellow
*****
Offline



Posts: 615

Re: Spectre Turbo - Parasitic Reduction - Fmax
Reply #4 - Mar 7th, 2011, 9:39am
 
Berti,
"An important input to the parasitic reduction technology is the relevant frequency of interest. The parasitic reduction algorithm tries to preserve circuit accuracy up to this frequency."
 -- CadenceŽ VirtuosoŽ SpectreŽ Circuit Simulator and Accelerated Parallel Simulator User Guide, Product Version 10.1 (Sept 2010)

B O E
Back to top
 
 
View Profile   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.