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Problem saving intrinsic parameters using save statement save NM0:all

Bean1234

Hello all,

I know this has been addressed several times before as I've searched the forum before actually asking this question but I have tried the solutions but nothing seems to work. I'm trying to characterize an NMOS using the gm/Id technique which requires me to save the intrinsic parameters such as gm,gds,fT while the Vgs is being swept for a range of values. For this I have used the save NM0:all statement, saved it in a .scs file and have included it in the netlist as shown below. Spectre then gave a warning saying the following:

"WARNING: subcktInst:all is not supported.
WARNING (SPECTRE-8287): Ignoring invalid item `NM0:all' in save statement."

I then followed Andrew Beckett's advice on another post about saving Subcircuit stuff as per the following link [1] , and changed the save statement to save NM0.nm_hp:all, in which Spectre gives the following warning:-

"WARNING (SPECTRE-8282): `NM0.nm_hp' is not a device or subcircuit instance name.
WARNING (SPECTRE-8287): Ignoring invalid item `NM0.nm_hp:all' in save statement. "

I can confirm  that the transistor I am using is a subcircuit with the name nm_hp as the model file has the following lines, 

subckt nm_hp ( d g s b )
parameters

My question is, what am I doing wrong here? I have included all the appropriate model files and netlists and nothing seems to work. I can't for the life of me figure out what's wrong. I have attached the netlist below. Whelp?

Netlist:-

NM0 (vdd! net2 0 vdd!) nm_hp w=(4u) l=(130n) as=1.36p ad=1.36p ps=8.68u \
pd=8.68u m=1 sa=340n sb=340n sd=0 nf=1
V1 (vdd! 0) vsource dc=600.0m type=dc
V0 (net2 0) vsource dc=600.0m type=dc
simulatorOptions options 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 
dcOp dc write="spectre.dc" maxiters=150 maxsteps=10000 annotate=status
dcOpInfo info what=oppoint where=rawfile
dc dc dev=V0 param=dc start=0.2 stop=1.2 step=0.05 oppoint=rawfile \
maxiters=150 maxsteps=10000 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
save NM0.nm_hp:all
saveOptions options save=allpub

[1] community.cadence.com/.../26938;ReplyToContentTypeID=0

Parents
  • Andrew Beckett

    When you use save NM0.nm_hp:all the nm_np has to refer to the instance name within the subckt not the subckt name. So you need to look in the definition of nm_hp and see what the instance name is called, and use that.

    The error message clearly says there is no instance called nm_hp. Why is it the instance name? Well, there could be multiple instances of devices within the subckt - it needs to know which instance you're talking about.

    Regards,

    Andrew.

Reply
  • Andrew Beckett

    When you use save NM0.nm_hp:all the nm_np has to refer to the instance name within the subckt not the subckt name. So you need to look in the definition of nm_hp and see what the instance name is called, and use that.

    The error message clearly says there is no instance called nm_hp. Why is it the instance name? Well, there could be multiple instances of devices within the subckt - it needs to know which instance you're talking about.

    Regards,

    Andrew.

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