How to output/save gain, bandwidth, phase margin, gain margin in Spectre?

[Alex Liao]

Hi. Say I use command line to run simulation.
For example in Hspice my input stimuli is like this:
[section]

.op
.options ingold=2 list node post
.print ac vdb(6) vp(6)
.ac dec 100 0.001 10g 	

* net 6 = /out
.MEAS AC gain MAX vdb(6)                     		*gain
.MEAS AC bandwidth WHEN vdb(6)=0                    *Unity Gain Frequency (Bandwidth)
.MEAS AC PM FIND PAR('180+vp(6)') WHEN vdb(6)=0     *Phase Margin 180+phase
.MEAS AC GM FIND PAR('0-vdb(6)') WHEN vp(6)=0  		*Gain Margin

.end

By doing so, I have those four results saved in my local result file.

How can I do the same thing in Spectre/SpectreS? I guess the format is different.
I have attached a section of my stimuli file (spectreFinal) like this:

opBegin  dc  oppoint=rawfile  save=allpub  maxiters=150
+          maxsteps=10K  annotate=status  write="spectre.dc"
acSweep    ac  start=1.0  stop=1e9  annotate=status save=selected
                     		
modelParameter info what=model where=file file = "./info.what0"
element info what=models where=file file = "./info.what1"
outputParameter info what=output where=file file = "./info.what2"

What command should be inserted in order to do the same thing as Hspice?
Thanks.

 

[dick_freebird]

I'd suggest using Calculator to Print these results, in an
interactive session, save the memories, save the session
as an Ocean script and you can edit it to redirect output
to a file, add PVT loops and whatever else you want. The
foreground environment is pretty crappy for I/O unless
you want to screen-grab plots or save-as the output
text window.

 

[tompham]

Hi dick_freebird
The attached picture may help you

 

[Alex Liao]

Hi dick_freebird,

Thank you for this. I think your approach is dependent on ocean script which has something to do the the User Interface. What I want to find is spectre language based approach which is more like command based. Are you familiar with spectre language?

Alex

- - - Updated - - -

Hi tompham,

Do you have some knowledge on Spectre Language?

 

[Alex Liao]

How to output an result into file (say gain) using Spectre language?

As the title implied, using Graphic-based ADE tool as well as ocean script, result can be found. But what if I want to use Spectre language, how to achieve that. Screen display an simulation result (gain,bandwidth). I already have the formula copied from calculator in ADE. I tried to write the result in SpectreFinal which is the stimuli file used as the input of a simulation.
I only know the way of doing it using Hspice like this:

.op
.options ingold=2 list node post
.print ac vdb(6) vp(6)
.ac dec 100 0.001 10g 	

* net 6 = /out
.MEAS AC gain MAX vdb(6)                     		*gain
.MEAS AC bandwidth WHEN vdb(6)=0                    *Unity Gain Frequency (Bandwidth)
.MEAS AC PM FIND PAR('180+vp(6)') WHEN vdb(6)=0     *Phase Margin 180+phase
.MEAS AC GM FIND PAR('0-vdb(6)') WHEN vp(6)=0  		*Gain Margin

.end

My current Spectre based file (spectreFinal) with partial section displayed here:

opBegin  dc  oppoint=rawfile  save=allpub  maxiters=150
+          maxsteps=10K  annotate=status  write="spectre.dc"
acSweep    ac  start=1.0  stop=1e9  annotate=status save=selected
                     		
modelParameter info what=model where=file file = "./info.what0"
element info what=models where=file file = "./info.what1"
outputParameter info what=output where=file file = "./info.what2"

The gain from calculator is like this:

*Gain = value(dB20((VF("/vout") / (VF("/1") - VF("/2")))) 2)

How to edit the attached spectreFinal such that I could output the gain into a file using Spectre language?

Thanks,

 

[erikl]

You can find the syntax in the Spectre Circuit Simulator User Guide. G00GLE it!

 

[tompham]

Hi ALex Liao

Please seee this attached website and follows it. You can do what you want

**broken link removed**