Designer’s Guide Community

pipeline

Junior Member

Offline

Posts: 10

Problems with Hspice
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.

Back to top

err.png

learning to walk on the road of analog

IP Logged

spiceoracle

Junior Member

Offline

Posts: 21
USA

Re: Problems with Hspice
Reply #1 - 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.

Back to top

IP Logged

pipeline Junior Member Offline Posts: 10	Re: Problems with Hspice Reply #2 - 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!
Back to top	learning to walk on the road of analog IP Logged

mikki33

Community Member

Offline

Analog/Mixed
Signal/High Speed

Posts: 57
Israel

Re: Problems with Hspice
Reply #3 - 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)

Back to top

If you don't have time to do it good
you will find time to do it again

IP Logged

pipeline Junior Member Offline Posts: 10	Re: Problems with Hspice Reply #4 - 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
Back to top	learning to walk on the road of analog IP Logged

spiceoracle Junior Member Offline Posts: 21 USA	Re: Problems with Hspice Reply #5 - Jul 12^th, 2006, 12:21pm Without looking at your netlist, probably not.
Back to top	IP Logged