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Simulators >> Circuit Simulators >> getting started with Monte Carlo simulations
https://designers-guide.org/forum/YaBB.pl?num=1311880592

Message started by seannnn on Jul 28^th, 2011, 12:16pm

Title: getting started with Monte Carlo simulations
Post by seannnn on Jul 28^th, 2011, 12:16pm

Hello all,
I'm getting started with MC simulations. I'm able to run the simulations, but don't know how to use the statistics blocks described in this PDF or the spectre documentation. So, my standard deviation currently comes out to be zero.

I'm using Cadence virtuoso ic 6.1.3

Can anyone please tell me how to insert statistics on a model and run the MC simulation? Can you tell me how I'd run the simulation in the PDF above?

Thanks.

Title: Re: getting started with Monte Carlo simulations
Post by Geoffrey_Coram on Jul 29^th, 2011, 5:42am

Did you try running the netlist given in that PDF as Listing 1?

I would expect you to see a non-zero std dev there. If you get 0, then you probably should re-read that document and try again.

I'll assume for now that you get non-zero for that example, and now you're trying to do something else. Do you have a foundry model file, and you want to add statistics to their models (which don't have them)? Or are there statistics blocks in the model file, and you don't know how to make a netlist that makes use of them?

Title: Re: getting started with Monte Carlo simulations
Post by seannnn on Jul 29^th, 2011, 5:50am

Thanks for the reply!

That part of my question actually was a lot more basic: how do I run the netlist? (Do I need to create a schematic and then run it?)

Title: Re: getting started with Monte Carlo simulations
Post by Geoffrey_Coram on Aug 1^st, 2011, 6:14am

You can copy&paste the netlist into a file and run spectre at the command line.

You could create the schematic, if you want to play with the design, but it isn't necessary.

Title: Re: getting started with Monte Carlo simulations
Post by seannnn on Aug 1^st, 2011, 10:00am

I'm not familiar with the command line/SKILL enough to run Spectre. Are there any tutorials you'd recommend?

Title: Re: getting started with Monte Carlo simulations
Post by Geoffrey_Coram on Aug 1^st, 2011, 1:05pm

Didn't you have to run spice or hspice in your undergrad circuits course?

Save the example into listing1.scs
Type
spectre listing1.scs
at the command line. Then bring up wavescan or your favorite waveform viewing tool.