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Exceeded the blowup limit when running Monte Carlo analysis

aalbason

Hello there,

 

I am running MC analysis and I get this error due to an NPORT component which has the RLC files for a PCB output transmission line parameter model.

 

Error found by spectre at time = 14.0551 ns during transient analysis `tran', during Monte Carlo analysis `mc1'.

    ERROR (SPECTRE-16384): Signal V(NPORT0:int_Rn1) = -1.00013 GV has exceeded the blowup limit for the quantity `V' which is (1 GV). It is likely that the circuit is unstable. If you really want signals this large, set the `blowup' parameter of this quantity to a larger value.

 

To try to work around this since I cannot change the model file, I tried to have a larger blowup quantity and I used the script:

 

VoltQuant quantity name="V" blowup=10e9

 

Which I added to the maestro view under Setup → Simulation Files → Definition Files

 

Then I get an error when I run it again:

 

Error found by spectre during hierarchy flattening.

    ERROR (SFE-1997): "/home/team_proj/workareas/EIC2_LNR28LPP/al.albason/Quantity_Include_Statement.txt" 1: Cannot run the simulation, because VoltQuant in parameter `dc': Unknown parameter `V' has been specified in expression `V' Correct the expression and rerun the simulation.

 

Any advice? Hopefully it is just a minor error on the script used.

 

Thanks,

Alfonso

  • Andrew Beckett

    Alfonso,

    First of all, can you try setting the nport to have method=bbspice ? I don't know which version of Spectre you're using, but this might help ensure that it's a passive model being used. We also have the s-parameter checker (more details on our support site, but in recent IC versions this is available in the Tools menu in the CIW) to check for issues with the s-parameter file (of course, the garbage-in, garbage-out principle holds here...)

    In general, increasing the blowup limit is not that likely to fix things - if it's really got that large it may well just hit your even higher limit. 

    Anyway, I suspect this is a spectre syntax vs spice syntax thing. I'd start by giving your definition file a ".scs" suffix which will mean it's treated as Spectre syntax (the alternative is to put simulator lang=spectre before the quantity line, but the .scs suffix means the file is treated as Spectre syntax by default; .txt will be treated as SPICE).

    Andrew

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