I would like to plot gm, gds, cgs, cgd, etc. as a function of time in my spectre transient sims using analog artist. How do I do this?
if these parameters are stored in the results / psf folder, you can use the OCEAN commands to plot them. Therefore you have to do the following steps:
Open the results:
- e.g. openResults("/myAbsolutePath/...../...../psf")
Select the results:
- e.g. selectResults('tran)
- you can use results() to display the selectable relults --> (dc tran ac)
Get the waveform Id:
e.g. wId = getData("net0815") --> waveform Id drwave:24234545
Plot the waveform:
If you have to calculate the parameters, you can use the OCEAN waveform calculator command described in the OCEAN reference.
In reply to haikom:
Thank you for your response. Unfortunately it does not answer my question. Let me try to be more specific:
I already know how to open results, view and plot voltages and currents in ocean and analog artist.
I want to plot the small signal parameters of the BSIM4 model of some transistors during a transient sim. Particularly, I want to track how the gm, cgd, and cgs change as a function of time. These are transistor parameters, not voltages and currents.
How do I:
1) save these in simulation
2) plot them as a function of time.
And just to be completely clear, I am NOT interested in the operating point of these devices at a single time step like you can access using the menu: Results -> Print -> Transient Operating Points OR the calculator expression: OPT("/dut2/MNP" "gm") which only give me these parameters at a SINGLE point in time, not as a waveform in time.
This is a trivial thing to do in HSPICE, so I assume it must be a trivial thing to do in Spectre and Analog Artist. I just can't find it.
In reply to Eric Gamble:
Found it in SourceLink solution number 11003524.
It turns out you need to create a text file that contains:
save M1:oppoint M2:oppoint
etc. for all the transistors and then access the data through the results browser.
Not as easy as I expected it to be, but at least it's possible.
I'm did not understand completely, what you want. The save statement "save M1:oppoint ..." seams to save the final operating point parameters. If you want to access theses values you can do this using the following way:
\o (tranOp subckts instance "tranViolations-violations" model "tran-info" variables output designParamVals tran primitives)
\o --> a huge list with all possible outputs :)
Now you can access the final operating point parameters (gm, gds, cgs ....) using the squiggle operator:
Here you just have one value for the final operating point. You can carry out a parametric analysis to get an parameter plot e.b. cgs vs. Vds.
Is this what you want?
I am also facing the same problem , can you please tell me weather you got solution of this problem or not.
Thanks & regards
In reply to jain205prateek:
The Forum Guidelines tell you not to post on old threads (and this one was VERY old - more than 4 years old).
And anyway, the answer was given by Eric in the thread, including a reference to a solution number on Cadence Online Support. This has been covered on numerous occasions on this forum too.