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Simulators >> Circuit Simulators >> Virtuoso/Wavescan calculator and mean derivative
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Message started by reinderien on Apr 2^nd, 2008, 6:59pm

Title: Virtuoso/Wavescan calculator and mean derivative
Post by reinderien on Apr 2^nd, 2008, 6:59pm

Hello all.

I've been fighting the Wavescan calculator for a while, and I can't seem to find a way to do this. So far, I have a voltage signal and its derivative (with 'deriv') successfully graphed from the results of the 'analog environment' simulation. I can also find the peak derivative ('ymax') and the voltage at which it occurs ('argmax').

I want to make calculator graph a new curve where the horizontal represents the distance to the left and right of the voltage at which the maximal derivative occurs, and the vertical represents the average of the derivative over that interval. I've tried all manner of different things, but it seems wavescan fails at even the most simple thing - like putting the current value of the swept (x-axis) variable into the calculator. Brilliantly, it neglects the current swept value and instead uses the default value entered in the 'analog environment' window.

This is in addition to a host of other inconceivable headaches, like the calculator often refusing to acknowledge the delete and backspace keys, and the analog environment adding dozens of extraneous parentheses to my expressions. If I can't resolve this in the next few days I'm looking for a new simulative environment for my project, because my experience with Cadence has been thoroughly poor.

Thanks for your help.

Title: Re: Virtuoso/Wavescan calculator and mean derivati
Post by RFICDUDE on Apr 3^rd, 2008, 4:53am

The "calculator" has been the weekest link in the Cadence Analog flow since its inception. Spectre is a fantasic simulator, but its potential is severly choked by the clunky clicky calculator.

If you just need a one off specialized caclution then you are much better off having the calculator print the simulation values in a table (printvs) and save the results to a text file for post processing using another tool.

OCEAN scripting can simplify the process of scheduling, collecting and saving Spectre results for large sets of simulations, but it takes a while to get used to the format.

At some point I thought they were going to build a measurement language into Spectre to make it much easier to set up measurement analysis directly within Spectre. Others on this forum are likely to be more in the know about this feature if it is available.

Title: Re: Virtuoso/Wavescan calculator and mean derivati
Post by reinderien on Apr 3^rd, 2008, 7:37am

If you're referring to MDL, I've heard of it but I have no idea how to use it. I suppose I could look up a tutorial.

Title: Re: Virtuoso/Wavescan calculator and mean derivati
Post by thechopper on Apr 7^th, 2008, 6:54pm

Hi reinderien,

Instead of using Wavescan try to use AWD calculator. It's older than wavescan but allows you to plot one variable vs any other one you want by simply choosing in the x axis menu the corresponding variable in the "plot vs" pop-up menu. The only requirement is having plotted such variable before choosing it from such menu

Hope this helps
Tosei