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Simulators >> Circuit Simulators >> saving oppoint in spectreS?
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Message started by oermens on Feb 20^th, 2009, 11:20am

Title: saving oppoint in spectreS?
Post by oermens on Feb 20^th, 2009, 11:20am

I am not too familiar with spectreS, just spectre. How can I save the dc operating point in spectreS? I am sweeping a dc voltage. In spectre I just make an .scs file with "save M0:oppoint" for as many transistors as I want to save and add it to my model files. In spectreS we have an init file with all include statements, so I told it to include the .scs file I made but I get this warning in output log:

Warning from spectre during initial setup.
`M0' is not a device or subcircuit instance name.
Ignoring invalid item `M0:oppoint' in save statement.

The "Save DC Operating point" doesn't do anything, my results browser for DC is empty. I want the results of the entire sweep.

Title: Re: saving oppoint in spectreS?
Post by Andrew Beckett on Feb 20^th, 2009, 11:28pm

Create the include file as usual (by the way, spectre supports wildcards these days, so you can do save *:oppoint - see "spectre -h save" for more details).

Then on the Setup->Environment form, reference the include file. Make sure that the Include/Stimulus File Syntax is set to "spectre" (the default is cdsSpice).

See the picture below.

Bear also in mind that spectreS will end up with all the instance names in lower case in the final netlist (check the final netlist that was created, and make sure you use the names used there). Perhaps that's what your issue was?

spectreS is obsolete (end-of-lifed), so I'd avoid using it unless you really have to!

Title: Re: saving oppoint in spectreS?
Post by oermens on Feb 21^st, 2009, 11:19am

Andrew Beckett wrote on Feb 20^th, 2009, 11:28pm:

spectreS is obsolete (end-of-lifed), so I'd avoid using it unless you really have to!

Thanks Andrew. We were using spectreS models for the past few years with the TSMC 0.18u kit for undergrad courses. I'm rewriting a lab manual and didn't want to switch it to spectre since the other lab manuals are written for spectreS. In light of spectreS being EOL, I'll pass this on to those concerned in our dept. and advise them to update their manuals to spectre.

Regarding save *:oppoint, it seems my spectre isn't liking that command. I get this error:

Error found by spectre during circuit read-in:
"/saveop.scs" 1: Unexpected operator "*". Expected end of file or end of line.

We're using the MMSIM stream.

vlsi:/opt/cmosp13> icfb -W
sub-version 5.10.41_USR5.90.69
vlsi:/opt/cmosp13> icfb -V
@(#)$CDS: icfb.exe version 5.1.0 06/20/2007 02:40 (cicsun11) $
vlsi:/opt/cmosp13> spectre -W
sub-version 6.1.1.424
vlsi:/opt/cmosp13> spectre -V
@(#)$CDS: spectre version 6.1.1 06/17/2007 07:20 (usim440-24) $

Title: Re: saving oppoint in spectreS?
Post by Andrew Beckett on Feb 21^st, 2009, 12:35pm

Wildcard support was added in MMSIM62 (I think) - it may have been the MMSIM62 update release, so 6.2.1. So your version is (unfortunately) too early...

Regards,

Andrew.