Hi all,

I'm running the latest HSPICE release from Synopsys: hspice-C-2009.03.
I have a model for a carbon nanotube transistor developed by a university. I am trying to simulate a basic inverter.  I run my the simulation as follows: 'hspice inv.sp >run.log'.

I'm getting an error. Upon examining run.log, I see the following errors:

**error** the output variable used in the algebraic equation of element
   7:gbtbt            does not exist.

**error** the output variable used in the algebraic equation of element
   7:g_qtotal         does not exist.

**error** the output variable used in the algebraic equation of element
   7:g_qchannel       does not exist.

When I dig in closely to the model, the above errors result from these lines (in cnfet.lib):

GCNT         Drain        Source        CUR='JFET(V(Drain,Source),photon,V(phib,Sub))'
GBTBT      Drain        Source          CUR='J_btbt(V(Drain,Source),I(GCNT),V(phib,Sub))'
G_Qtotal         Vdrain     phib        CUR='charge_channel(V(Vdrain),V(Vgate),V(Vsource),V(VsubM),V(phib,Sub))'
G_Qchannel       phib       Sub         CUR='charge_total(V(Vdrain),V(Vsource),V(phib,Sub))'
GCNT       Source       Drain           CUR='JFET(V(Vdrain,Vsource),photon,V(phib,Sub))'
GBTBT      Source       Drain           CUR='J_btbt(V(Vdrain,Vsource),I(GCNT),V(phib,Sub))'

The current version of HSPICE doesn't like the fact that CUR is not defined as a variable? Since I'm not an expert in SPICE, I'm not sure how I can fix this problem.

I was able to simulate this circuit fine in and older HSPICE release without any problems.

Can someone tell me how I fix the above  problem? I tried adding .PARAM CUR to the cnfet.lib file but that didn't fix it.

I'm also attaching the complete files if anyone wants to see

Thanks for any ideas.

Regards

It looks like it's not complaining about GCNT, which also uses CUR, so either you didn't put in all the errors (don't know why you put in 3 if not all), or else CUR isn't the problem.

Is J_btbt defined properly?  I see this in the lib file you uploaded:

.PARAM J_btbt(Vds,Ids,phib)='coeffj*kT*(Jbtbt_sub_1(Vds,Ids)*Tbtbt1(Vds,phib) + \\
                                       Jbtbt_sub_2(Vds,Ids)*Tbtbt2(Vds,phib))'

Maybe the new version doesn't like th \\ newline inside the 'quotes' ?

I'm not sure what the problem is.

I've run your testcase using HSPICE C-2009.03 on a number of different machines.  HSPICE runs successfully and does not give the error messages that you have seen.  The only difference I see is that the machine that I used that is similar to the one that you used is the OS version.