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rmsNoise ocean command

pran

I have used rmsNoise command to calculate the total integrated rms noise over the desired band. But recently I am seeing wierd behaviour with this command and it throws me error:

 *Error* rms Noise data not available

Sample netlist::

    simulator lang=spectre
    global 0
    include "....../ahdlLib/quantity.spectre"
    C0 (VOUT VSS) capacitor c=1p
    R0 (VOUT VSS) resistor r=1M
    R1 (VOUT VDD) resistor r=1M
    V4 (VSS 0) vsource dc=0 type=dc
    V1 (VDD 0) vsource dc=1 type=dc
    noise (VOUT VSS) noise start=1 stop=1M

The ocean commands:

    openResults("psf")
    selectResults("noise-noise")      
    rmsnoise.sch = rmsNoise( 1 100K )

I am able to use noiseSummary('integrated) successfully.

Any idea what's going wrong.

Thanks

 

 

Parents

  • The rmsNoise() function expects the "runObjFile" to be present, which won't be the case if the simulation was run standalone.

    I don't see an enormously good reason for this. In fact even if you use wavescan/viva standalone on the data, it doesn't work - this is because it uses the ADE "VN2" function to retrieve the noise output.

    When you did the openResults, you'll have seen a message such as this:

     WARNING (OCN-6096): Could not find runObjFile under .../psf. Calculator data access functions will not work.

    and this is the reason why. The good news is that this is fixed in IC615 (I just tested it).

    As a workaround, you could use:

    procedure(CCSrmsNoise(from to @key result)
      sqrt(integ(clip(getData("out" ?result result) from to)**2))
    )

    Regards,

    Andrew.

     

Reply

  • The rmsNoise() function expects the "runObjFile" to be present, which won't be the case if the simulation was run standalone.

    I don't see an enormously good reason for this. In fact even if you use wavescan/viva standalone on the data, it doesn't work - this is because it uses the ADE "VN2" function to retrieve the noise output.

    When you did the openResults, you'll have seen a message such as this:

     WARNING (OCN-6096): Could not find runObjFile under .../psf. Calculator data access functions will not work.

    and this is the reason why. The good news is that this is fixed in IC615 (I just tested it).

    As a workaround, you could use:

    procedure(CCSrmsNoise(from to @key result)
      sqrt(integ(clip(getData("out" ?result result) from to)**2))
    )

    Regards,

    Andrew.

     

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