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Referencing a model, not a model instance

itos

Hello,

I found the post about disabling flicker noise with alter in this forum and I got it working:

turnOffFlicker1 alter mod=N15.xmmaster.lvtnfetacc param=nfalw value=0
turnOffFlicker2 alter mod=N15.xmmaster.lvtnfetacc param=nfblw value=0
turnOffFlicker3 alter mod=N15.xmmaster.lvtnfetacc param=nfclw value=0

If I reference the model (i.e. lvtnfetacc and masterlvtnfet from the model files) I get:

ERROR (SFE-1997): "disable_flicker.scs" 6: turnOffFlicker4: parameter `mod': Invalid model name `lvtnfetacc' was given as value of parameter `mod'.

I tried all possible variations. Unfortunately the model files are so nested that I don't know what's going on. Generally there is a subckt for "lvtnfet" which instantiates instance xmmaster of lvtnfetacc. lvtnfetacc itself is a subckt which instantiates m1. m1 is a reference to the model lvtnfetacc of type utsoi which has the parameter nfalw etc:

sub

Please help me to set nfalw to zero globally without listing all instances.

Also, is it possible to list multiple mod/param/value pairs at once so that I do not need to create thousands of turnOffFlickerXX lines that go up to 1000?

Thank you!

Parents
  • itos


    Hi Andrew,

    I again played around for an hour. I managed to get rid of the warning but the option still need to be ignored.

    I think the spectre version is correct, the noiseoff_type option is known in "spectre -h options". I read your reference and I am sure I am using it correctly.

    When I use noiseoff_type=flicker (or [flicker] or any other variation coming to my mind) all the noise is turned off (incl thermal). Without it, I get flicker. So it seems the option is still ignored.

    What I am wondering: Why does spectre log list my option as noiseoff_type=1? What does 1 mean?

    Cadence (R) Virtuoso (R) Spectre (R) Circuit Simulator
    Version 15.1.0.585.isr10 64bit -- 18 Aug 2016
    Copyright (C) 1989-2016 Cadence Design Systems, Inc. All rights reserved worldwide. Cadence, Virtuoso and Spectre are registered trademarks of Cadence Design Systems, Inc. All others are the property of their respective holders.

    Includes RSA BSAFE(R) Cryptographic or Security Protocol Software from RSA Security, Inc.
    [...]
    Notice from spectre during initial setup.
        The noise for all instances in this netlist has been turned on.
        The noise of the subckt instance `N1' is turned off.


    Global user options:
                 reltol = 0.001
                vabstol = 1e-06
                iabstol = 1e-12
                   temp = 27
                   gmin = 1e-12
                 rforce = 1
               maxnotes = 5
               maxwarns = 5
                 digits = 5
                   cols = 80
                 pivrel = 0.001
               sensfile = ../psf/sens.output
         checklimitdest = psf
          noiseoff_type = 1
          noiseoff_inst = N1
                   save = allpub
         subcktprobelvl = 2
                   tnom = 25
                 scalem = 1
                  scale = 1

    Scoped user options:

    Circuit inventory:
                  nodes 8
                 iprobe 16    
                 assert 12    
                   ccvs 1     
                  utsoi 2     
                vsource 5     

    Analysis and control statement inventory:
                     dc 1     
                   info 7     
                  noise 1     

    Output statements:
                 .probe 0     
               .measure 0     
                   save 0     

    Time for parsing: CPU = 79.988 ms, elapsed = 94.121 ms.
    Time accumulated: CPU = 439.932 ms, elapsed = 599.417 ms.
    Peak resident memory used = 59.1 Mbytes.

    ~~~~~~~~~~~~~~~~~~~~~~
    Pre-Simulation Summary
    ~~~~~~~~~~~~~~~~~~~~~~
    ~~~~~~~~~~~~~~~~~~~~~~

    Warning from spectre.
        WARNING (SPECTRE-16707): Only tran supports psfxl format, result of other analyses will be in psfbin format.
    [...]

    This is the relevant section of the netlist:

    simulatorOptions options reltol=1e-3 vabstol=1e-6 iabstol=1e-12 temp=27 \
        tnom=25 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 noiseoff_type=[flicker] noiseoff_inst=[ N1]
    dcOp dc write="spectre.dc" maxiters=150 maxsteps=10000 annotate=status
    dcOpInfo info what=oppoint where=rawfile
    noise ( vo 0 ) noise start=1 stop=1T iprobe=V1 annotate=status
    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 subcktprobelvl=2

    The circuit contains exactly one PMOS (not connected to output node) and one NMOS ("N1"). Both are utsoi, supposed to be supported for noiseoff_type according to spectre manual.

    I am starting to think about a bug ... ?

Reply
  • itos


    Hi Andrew,

    I again played around for an hour. I managed to get rid of the warning but the option still need to be ignored.

    I think the spectre version is correct, the noiseoff_type option is known in "spectre -h options". I read your reference and I am sure I am using it correctly.

    When I use noiseoff_type=flicker (or [flicker] or any other variation coming to my mind) all the noise is turned off (incl thermal). Without it, I get flicker. So it seems the option is still ignored.

    What I am wondering: Why does spectre log list my option as noiseoff_type=1? What does 1 mean?

    Cadence (R) Virtuoso (R) Spectre (R) Circuit Simulator
    Version 15.1.0.585.isr10 64bit -- 18 Aug 2016
    Copyright (C) 1989-2016 Cadence Design Systems, Inc. All rights reserved worldwide. Cadence, Virtuoso and Spectre are registered trademarks of Cadence Design Systems, Inc. All others are the property of their respective holders.

    Includes RSA BSAFE(R) Cryptographic or Security Protocol Software from RSA Security, Inc.
    [...]
    Notice from spectre during initial setup.
        The noise for all instances in this netlist has been turned on.
        The noise of the subckt instance `N1' is turned off.


    Global user options:
                 reltol = 0.001
                vabstol = 1e-06
                iabstol = 1e-12
                   temp = 27
                   gmin = 1e-12
                 rforce = 1
               maxnotes = 5
               maxwarns = 5
                 digits = 5
                   cols = 80
                 pivrel = 0.001
               sensfile = ../psf/sens.output
         checklimitdest = psf
          noiseoff_type = 1
          noiseoff_inst = N1
                   save = allpub
         subcktprobelvl = 2
                   tnom = 25
                 scalem = 1
                  scale = 1

    Scoped user options:

    Circuit inventory:
                  nodes 8
                 iprobe 16    
                 assert 12    
                   ccvs 1     
                  utsoi 2     
                vsource 5     

    Analysis and control statement inventory:
                     dc 1     
                   info 7     
                  noise 1     

    Output statements:
                 .probe 0     
               .measure 0     
                   save 0     

    Time for parsing: CPU = 79.988 ms, elapsed = 94.121 ms.
    Time accumulated: CPU = 439.932 ms, elapsed = 599.417 ms.
    Peak resident memory used = 59.1 Mbytes.

    ~~~~~~~~~~~~~~~~~~~~~~
    Pre-Simulation Summary
    ~~~~~~~~~~~~~~~~~~~~~~
    ~~~~~~~~~~~~~~~~~~~~~~

    Warning from spectre.
        WARNING (SPECTRE-16707): Only tran supports psfxl format, result of other analyses will be in psfbin format.
    [...]

    This is the relevant section of the netlist:

    simulatorOptions options reltol=1e-3 vabstol=1e-6 iabstol=1e-12 temp=27 \
        tnom=25 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 noiseoff_type=[flicker] noiseoff_inst=[ N1]
    dcOp dc write="spectre.dc" maxiters=150 maxsteps=10000 annotate=status
    dcOpInfo info what=oppoint where=rawfile
    noise ( vo 0 ) noise start=1 stop=1T iprobe=V1 annotate=status
    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 subcktprobelvl=2

    The circuit contains exactly one PMOS (not connected to output node) and one NMOS ("N1"). Both are utsoi, supposed to be supported for noiseoff_type according to spectre manual.

    I am starting to think about a bug ... ?

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