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Simulators >> Circuit Simulators >> Problems with Hspice
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Message started by pipeline on Jun 28^th, 2006, 10:53pm

Title: Problems with Hspice
Post by pipeline on Jun 28^th, 2006, 10:53pm

Dear all,
I encountered two problems when using Hspice, and have no idea with the causes.
1、There is some warnings : resistance is negative, it may cause instability problem. I wonder what this warning means, how it comes, and how to clear it.
2、When doing transient analysis of PLL, a run-time error occurs,as showed in the attachment. I don't know where to locate the problem.
So, would you please give some advices, thanks.

Title: Re: Problems with Hspice
Post by spiceoracle on Jun 29^th, 2006, 12:44pm

You are obviously using a Windows version of HSPICE but, you didn't mention which version you are using. Are you using any parameters or elements where the values are expressions? It could be a math problem with an expression. It could be a syntax error that is not being handled correctly (bug). Do you have access to HSPICE on another platform? Sometimes these things are platform dependent and sometimes a different platform will give you a different and sometimes more user friendly error message.

Title: Re: Problems with Hspice
Post by pipeline on Jun 29^th, 2006, 10:08pm

Yes, I am using Windows Version 2004.9. And it does exist a expression for calculating the value of capacitance in the netlist. So do I have to change platform, or are there any routines to handle such problems? And is the negative resistance warning all right? Thanks for help!

Title: Re: Problems with Hspice
Post by mikki33 on Jun 30^th, 2006, 2:22am

Regarding your err. message. It has nothing with HSPICE. This is run-time visual Fortran error!
The common case is the results can't be written to the disk. Do you have a disk space problem? Did you leave wave browser (AWAVES or like) opened. It may be also some user names - write/read protection etc.

Negative resistance warning happens quite offen. It is mostly the model issue. You have to find to which element it corresponds. If it is inside subcircuit of some transistor, you may just ignore it (the sourse is probably drain-source voltage inversion)

Title: Re: Problems with Hspice
Post by pipeline on Jul 2^nd, 2006, 9:07pm

I have solved problem 2 by setting OPTION gmindc to a bigger value 1e-10. But I still wonder what the real problem is. Can anybody give explanation? Thanks

Title: Re: Problems with Hspice
Post by spiceoracle on Jul 12^th, 2006, 12:21pm

Without looking at your netlist, probably not.