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Can the STB probe instance name be used as a variable?

dogman4

I have multiple op-amps in a single testbench and would like to run stability (STB) analysis on each loop by sweeping the setup.


Is it possible to make the STB probe instance a variable in assembler (IC618)?


If so, could you show me the exact setup steps?

My virtuoso version: "@(#)$CDS: virtuoso version 6.1.8-64b 09/03/2024 19:11 (sjfhw316) $"
My spectre version: Version19.1.0.063 64bit--10 Aug 2019

  • Andrew Beckett

    First of all, you're using a 7 year old version of Spectre. Why?

    More recent versions of Spectre and IC allow specifying multiple probes for stb analysis (IC23.1 ISR14/Spectre 23.1 ISR13 onwards). See:

    There's no simple support in ADE for the probe instance being a variable. There's a Cadence Change Request (CCR) for this, #2915598. It seems there's some limited support in Spectre for this (it honours the probe being a variable, but you can't sweep it or change it within the simulator - which is not what you'd need here).

    If you can't switch to a newer version, you could try:

    1. Create a variable PROBE which is assigned to the probes you want, e.g. IPRB0 IPRB1 IPRB2
    2. In the stb analysis select one of the probes in the probe instance in the UI
    3. On the stb options form, at the bottom in the additionalParams field, enter probe=PROBE

    This certainly works in more recent versions (I don't have time to try it out in the precise, old,  combination you're using). I added an output expression in ADE with the expression resultParam("probe" ?result 'stb) so that I can see which probe was being used for each sweep point.

    Andrew

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