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Simulators >> Circuit Simulators >> Spectre models for MC and Corner sim
https://designers-guide.org/forum/YaBB.pl?num=1085573796

Message started by Paul on May 26^th, 2004, 5:16am

Title: Spectre models for MC and Corner sim
Post by Paul on May 26^th, 2004, 5:16am

Hello,

with respect to the discussion about Monte-Carlo simulation (http://www.designers-guide.com/Forum/?board=circuit;action=post;num=1066706959;quote=11;title=Post+reply;start=0) I have the following problem. Using the syntax suggested by EVI and also presented in the Spectre documentation, I cannot use my models anymore with the corner sim tool.

The workaround I'm trying to implement is the following:
I have a .lib.scs file with the corner info, which calls the .mdl.scs file containing the BSIM transistor models. In the .lib.scs, I create an additional corner called mc which contains the statistics section, all other corners don't contain any statistics part. As the .mdl.scs file contains some calculations (like u0_mis/sqrt(w*l)), I have to keep the inline subckt parts in all corners.

Spectre runs fine with that, but when I use the corner sim, I get the following error:
model `M15.n' (TYP.n.n): parameter `u0': Encountered error which may be related to a reference to an inherited parameter in a subcircuit, where the subcircuit definition (or any of the ancestor subcircuit definitions) were declared before the parameter being referenced. Ensure that all top-level netlist parameters are declared before any subcircuits are defined.

input.scs says
include "..../mos.lib.scs" section=tt
...circuit definition and analysis description...
TYP altergroup {
include \
"..../mos.lib.scs" \
section=tt
}
FF altergroup {
include \
"..../mos.lib.scs" \
section=tt
}

Any suggestion on this? Thanks for your help,

Paul

Title: Re: Spectre models for MC and Corner sim
Post by Paul on May 26^th, 2004, 5:49am

Sorry guys for bothering you... I gave up searching Sourcelink too quickly. The solution is here:
PCR 274399: Inline subcircuits cannot be used in altergroup
just some line to add to .cdsenv and it works

Paul

Title: Re: Spectre models for MC and Corner sim
Post by Chase Ng on Sep 24^th, 2005, 10:16pm

Hi, Just want a quick answer, wat to add in .cdsenv?

Title: Re: Spectre models for MC and Corner sim
Post by Andrew Beckett on Sep 25^th, 2005, 4:38am

Code:

spectre.envOpts useAltergroup boolean nil

Andrew.

Title: Re: Spectre models for MC and Corner sim
Post by chase.ng on Sep 25^th, 2005, 7:17am

Thanks... it works!

Chase