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How to save transient operating point?

BaaB

This is an old answer to saving DC operating points. I am wondering if there is a similar way to do that with transient analysis. I would like to save all transient operating point parameters and then plot them with time.

I tried the solution here but that doesn't work. The transient directory doesn't have the needed info.

I am using IC6.61-64b.500.9 and MMSIM13.1.1.049 64 bit.

QUOTE: Answer by Andrew:

This is a very commonly asked question.

Create a text file (called, say, saveop.scs) with the following contents:

// include file to save op point data
save M0:all

where M0 is the name of the mosfet. See "spectre -h save" for more details on the save statement.

Then, in Setup->Model Libraries, reference this file (I gave it a .scs suffix so it is interpreted in spectre syntax).

Run your DC sweep, and then you can access the results via the results browser - or just use an expression such as:

getData("M0:vdsat" ?result 'dc)

This will then show vdsat versus the swept parameter. 

The same approach will work if you want to save operating point during a transient - you can always just save the specific op point information by doing:

save M0:gm M0:vdsat

for example.

Best Regards,

Andrew.

 

Parents

  • Thank you.

    I am not at schoo right now. It is night here so I can not take a picture or post the netlist file.

    However, I am having problem with subcircuit components. It is OK with components not in subcircuit.

    My circuit includes an instance I0 and I would like to save transient operating point (versus time) of the transistor inside the subcircuit named M0.

    To do this, I create a file saveop.scs with the content as below:

    save I0.M0:all

    Then I refer to that file from Model Libraries. I run the simulation and after that opened psf file.

    There is a folder "tran" that is empty.

    Also, I tried with IC6.17 version by choosing Outputs->To Be Saved->Save OP Parameters. 

    What should I do after choosing "Save OP Parameters". I clicked on a transistor but nothing happened. Normally with something like this (for example printing operating point) after I clicked a component there is a table with operating point parameters appears. 

    But I this case, I clicked a component and it just is something like I "select' the transistor.

    I also tried to continue to run the simulation but the "tran" folder still shows nothing at all.

Reply

  • Thank you.

    I am not at schoo right now. It is night here so I can not take a picture or post the netlist file.

    However, I am having problem with subcircuit components. It is OK with components not in subcircuit.

    My circuit includes an instance I0 and I would like to save transient operating point (versus time) of the transistor inside the subcircuit named M0.

    To do this, I create a file saveop.scs with the content as below:

    save I0.M0:all

    Then I refer to that file from Model Libraries. I run the simulation and after that opened psf file.

    There is a folder "tran" that is empty.

    Also, I tried with IC6.17 version by choosing Outputs->To Be Saved->Save OP Parameters. 

    What should I do after choosing "Save OP Parameters". I clicked on a transistor but nothing happened. Normally with something like this (for example printing operating point) after I clicked a component there is a table with operating point parameters appears. 

    But I this case, I clicked a component and it just is something like I "select' the transistor.

    I also tried to continue to run the simulation but the "tran" folder still shows nothing at all.

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