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Simulators >> Circuit Simulators >> Reusing trimming from 25C in Monte Carlo runs for different temp.
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Message started by tempora123 on Nov 6^th, 2008, 5:23am

Title: Reusing trimming from 25C in Monte Carlo runs for different temp.
Post by tempora123 on Nov 6^th, 2008, 5:23am

Hello,

I have a question of a possibility to simulate the following:
I have an oscillator, which is trimmed in room temp. using binary search algorithm block (in veriloga) in a feedback loop. It works very well but the problem I have is that I would like to sweep temp in monte carlo tran analysis and use the same trimming value which was found in room temp for the same monte carlo run but in other temperatures. Is it possible?

Thank you for your answers.
BR

Title: Re: Reusing trimming from 25C in Monte Carlo runs for different temp.
Post by Tlaloc on Nov 6^th, 2008, 9:55am

I've thought a lot about this, and there are only two ways that I could think for this to work.

1) If your trimming was a different analysis than your main sim, e.g. a dc and a tran, then you could trim from a dc analysis and follow up with a tran. Here, you can code the veriloga to key off of the different analyzes to determine if you will allow the trim or not.

2) Other than that, you might have to run the monte for your trimming algorithm at room temp; write out the trim codes to a text file; then run the monte using the same seed, across temp, reading in the value from the file. This also has potential problems since I don't know if veriloga can find the information about the monte run itself. You may have to use the text file as a FIFO stack and delete the trim value as you are using them.