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Saving a voltage value at a specific time to a file for a large array

Andrew Matthews

Hi,

I would like to save a voltage value at a specific time point during a transient simulation, for a large array of instance.

The array of instance are connected in a grid like fashion and I would like to save the net voltage in every instance of the array.

I have done some research, and found that I can accomplish this with a wildcard save in a separate spectre file.

For example, my spectre file (save.scs) looks like this:

simulator lang=spectre

save I0*.*net20 depth=5

I'm a little confused on the save function. I have depth=5 cause there is 5 levels of hierarchy between "I0" and "net20".

Also I believe this will save the entire waveform, while I just want a single voltage value at a specific time point.

Also I'm not sure where this is being saved to; Ideally I'd like to save the voltage value to a specified file.

Can anyone assist me with this?

Parents
  • Andrew Matthews

    An example of the net I am trying to save has a this hierarchy path:

    I0.I4.I5<0>.I18.I7.net20

    The I5, I18, and I7 can vary throughout the entire array which is why I am using the wildcard I0.I4*.*net20 to capture all the net20's at that level of the design.

Reply
  • Andrew Matthews

    An example of the net I am trying to save has a this hierarchy path:

    I0.I4.I5<0>.I18.I7.net20

    The I5, I18, and I7 can vary throughout the entire array which is why I am using the wildcard I0.I4*.*net20 to capture all the net20's at that level of the design.

Children
  • Andrew Beckett
    in reply to Andrew Matthews

    OK, it's slightly tricky to do this, but can be done as follows:

    1. The save statement doesn't need the depth=5 (that just asks it to also save nodes 5 levels below the matched subckt - the wildcards in your case will match the relevant node names)
    2. Create an info analysis as follows:
      myInfo info what=oppoint oppoint=node where=file file="dump.txt" save=selected
    3. Add these parameters to the tran analysis
      infotimes=[10.1n] infoname=myInfo

    That should tell it to dump to an ASCII file just the node voltages on the selected nodes at the specific time in the infotimes parameter.

    If you wanted the node voltages in a PSF database, you can do that with this instead:

    myInfo info what=oppoint oppoint=node where=rawfile save=selected

    Andrew

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