Infopoints

What do you mean by a range of info points? If you are asking about infotimes - then this can be a list of discrete time points, but not a swept-range.

If you want to plot operating point parameters over time, there is now (from IC616 ISR10, i.e. 6.1.6.500.10) Outputs->To be Saved->Select OP Parameters which avoids you having to do the usual trick of creating an include file with save M1:oppoint type statements. Then you can access the results through the results browser.

Andrew.

Yeah, infotimes (I refer is at infopoints).Unfortunately we use IC616.101

So the trick that I use in transient analyses options is to define time points sequence in infotimes field of ANALYSIS DURING TRAN section.Somehow I cannot paste more than few hundred characters in that field. What's you say on this ?

The limitation of fields is about 8000 characters (I just checked - it complains if the string is too long, and truncates it; it was actually a bit over 8100).

There is an enhancement request to allow some kind of sweep mechanism here.

The alternative of saving the operating pont information during a transient is also viable (if you're just looking at a small number of devices) - you can do this with an include file with save M1:oppoint or save M1:gm etc. That will work in any Virtuoso version.

Regards,

Andrew

The problem : Lets say I want to observe Csg capacitance across NMOS during rising edge of clock signal.The way I would do is create info.scs file in my cadence directory with the following content :

save *:oppoints

Now that I have told Spectre I need discrete operating point values during my transient simulation, I will go to TransientAnalyses>Options>Output>AnalysisDuringTran and then check SaveFinalOpPt option.

Next, I will use MATLAB or perhaps a spreadsheet app to create my discrete time points (8000 limit like you said) and paste it in infotimes field.This was my way of using info points.

When I tried your suggested method, it didn't save transient info point parameters (I checked results browser to see if it had ran_info psf data and it didn't !).What's your say ?

OK, if you're using a recent enough version of spectre, you can get away with save *:oppoint (note, no "s" on the end). However, to be safe, you might want to use:

save *:oppoint sigtype=dev

Otherwise the wildcard won't necessarily find the devices (it used to only find nodes). The sigtype=dev doesn't do any harm though in newer versions.

If you do this, it will save the operating point parameters at every time point into the tran results.. No need to use infotimes. Note that the "Save Final Op Pt" option has nothing to do with this either. All that does is tell spectre to save a single operating point at the very end of the transient (saved in a different result database, the finalTimeOp (or something like that)).

The infotimes approach will save a complete operating point into a database at each of the time points you specify. It will end up in something like a tran_info database (I'm not doing this from ADE at the moment so I'm not sure what it gets called from ADE off the top of my head). That's separate from the tran results.

Regards,

Andrew.