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  3. Trouble netlising using analogLib Mosfet symbol [solved...

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Trouble netlising using analogLib Mosfet symbol [solved]

hesaliveJim
hesaliveJim over 1 year ago

I am trying to simulate a custom mosfet model utilising the analogLib Mosfet symbol. The circuit should form a simple inverter.

While the schematic looks good (see picture) the netlist does not and ADE says as much in the output log

Error found by spectre during hierarchy flattening.
    ERROR (CMI-2116): M2: Too few terminals given (0 < 3).
    ERROR (CMI-2116): M0: Too few terminals given (0 < 3).

I never have needed to do this before so I am unfamiliar with utilising the in built symbols but looking at the symbol it does have four appropriate terminals (see symbol properties picture)

Netlist produced for ADE:

// Generated for: spectre
// Generated on: May  2 19:02:26 2024
// Design library name: test
// Design cell name: INV
// Design view name: schematic
simulator lang=spectre
global 0
include "/home/Cadence/my_rundir/myPDK/models/hspice/my_TT.pm"

// Library name: test
// Cell name: INV
// View name: schematic
M2 pmos_lvt
M0 nmos_lvt
simulatorOptions options psfversion="1.4.0" reltol=1e-3 vabstol=1e-6 \
    iabstol=1e-12 temp=27 tnom=27 scalem=1.0 scale=1.0 gmin=1e-12 rforce=1 \
    maxnotes=5 maxwarns=5 digits=5 cols=80 pivrel=1e-3 \
    sensfile="../psf/sens.output" checklimitdest=psf
tran tran stop=10n errpreset=conservative write="spectre.ic" \
    writefinal="spectre.fc" annotate=status maxiters=5
finalTimeOP info what=oppoint where=rawfile
modelParameter info what=models where=rawfile
element info what=inst where=rawfile
outputParameter info what=output where=rawfile
designParamVals info what=parameters where=rawfile
primitives info what=primitives where=rawfile
subckts info what=subckts where=rawfile
saveOptions options save=allpub

I'll include only the first modified line of the model:

** My TT models

** Hspice modelcard
.model nmos_lvt nmos level = 72

I do not want to use hspice but I think spectre will read in an hspice file, in anycase the netlist is wrong therefore the schematic needs sorting first.

Obviously there may not be enough information but I'll add this as required not to make the post too long.

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  • Andrew Beckett
    Andrew Beckett over 1 year ago

    There is no component from analogLib called nmos_lvt, and as far as I can see no symbol that even looks like that. Are you sure it's the standard analogLib and not some locally modified copy?

    I'm guessing the CDF is not set up correctly.

    Andrew

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  • hesaliveJim
    hesaliveJim over 1 year ago in reply to Andrew Beckett

    "I'm guessing the CDF is not set up correctly."

    Andrew you were right and that pointed to what I was doing wrong.

    You have to edit the CDF itself, not just instance/object properties.

     CIW - Tools - CDF - Edit

    Looking again at that symbol it is indeed a locally modified copy but without the necessary CDF parameter in the spectre view that I created only the hspice view.

    Pleased to say with the CDF correctly set it netlists and simulates properly.

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  • hesaliveJim
    hesaliveJim over 1 year ago in reply to Andrew Beckett

    "I'm guessing the CDF is not set up correctly."

    Andrew you were right and that pointed to what I was doing wrong.

    You have to edit the CDF itself, not just instance/object properties.

     CIW - Tools - CDF - Edit

    Looking again at that symbol it is indeed a locally modified copy but without the necessary CDF parameter in the spectre view that I created only the hspice view.

    Pleased to say with the CDF correctly set it netlists and simulates properly.

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