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Using Montecarlo simulation for finding Rise and fall tile of a SETTLING waveform

RFQuery

 Dear All,

I want to do MONTE_CARLO simulation for my circuit for finding rise time and fall time.

The output is settling after 800u s.

I have to do some pre-processing before finding the last expression. The expressions I used as below.

But it did NOT work.

Can anybody tell how to find risetime and falltime of the waveform using MONTE-Carlo simulation if one needs some house-keeping processing of the waveform.

 .......

analysis('dc ?saveOppoint t  )
analysis('tran ?stop "1u"  ?errpreset "moderate"  ?maxstep "5p" 
        ?method "euler"  ?strobeperiod "5p"  )
desVar(      "frf" 6G    )
desVar(      "prf" -20    )
desVar(      "frf2" 6.1G    )
desVar(      "w" 20u    )
desVar(   "sigma" 3)
option(    'temp  "27.0"
    'iabstol  "1e-14"
    'vabstol  "1e-4"
)
saveOption( 'currents "selected" )
saveOption( 'save "all" )
temp( 27.0 )
monteCarlo( ?numIters "1" ?startIter "1"
    ?analysisVariation 'processAndMismatch ?sweptParam "None"
    ?sweptParamVals "27" ?saveData nil
    ?nomRun "yes" ?append nil
    ?saveProcessParams t
)
CLOCK_DUTY_PERIOD=2.5e-10
CLIP_START=0.8u
CLIP_END=0.9u

clip_I_P=clip( v("/MIXER_I_P" ?result 'tran) CLIP_START CLIP_END)
plot(clip_I_P)
MIN_VALUE=ymin(clip_I_P) + 0.02
MAX_VALUE=ymax(clip_I_P)- 0.03
UPPER_THRESOLD=MIN_VALUE + ( (MAX_VALUE-MIN_VALUE)*0.9 )
LOWER_THRESHOLD=MIN_VALUE + ( (MAX_VALUE-MIN_VALUE)*0.1 )
RISE_UPPER= cross( clip_I_P UPPER_THRESOLD 2 'rising )
RISE_LOWER= cross( clip_I_P LOWER_THRESHOLD 2 'rising )

monteExpr("RISE_TIME" "abs(RISE_UPPER-RISE_LOWER)")

monteRun()

  • Dear Andrew,

    I am really thankful to you for your time and patience.

    I have already filed a SR. 

    By the way, I tried with your testmonte.scs file with my ( what I have already posted) .artilinit code. It is showing the same error.

    I am wondering what is happening.

  •  testmonte.scs fails because your function has:

             CLIP_START = CLIP_START + (CLOCK_DUTY_PERIOD*1.5)
            clip_I_P=clip( v("/MIXER_I_P" ?result 'tran) CLIP_START CLIP_END)

    if instead it was:

             CLIP_START = CLIP_START + (CLOCK_DUTY_PERIOD*1.5)
            clip_I_P=clip( signal CLIP_START CLIP_END)

    It would be OK. This is because in the testmonte.scs case, it can't use "/MIXER_I_P" to look up the signal name because that's in the "schematic" namespace, and since the netlist was not produced from a schematic, you don't have any mapping data (e.g. in the amap directory) to tell it the mapping between schematic and netlist names. If you recall, in the testmonte.scs file I had:

     export RISE_TIME=oceanEval("MyRiseTime(v(\"MIXER_I_P\" ?result 'tran) \
        8e-07 9e-07)") 

    (no leading slash). If I make the above change to the code, and then change the export statement to:

     export RISE_TIME=oceanEval("MyRiseTime(v(\"MIXER_I_P\" ?result 'tran) \
        2.5e-10 8e-07 9e-07)")

    Then it works fine. Note that I know it's definitely in the "then" branch of the if() because I tried multipling the abs() by 0.0, and the RISE_TIME ended up being 0.0 for all points.

    So almost certainly this is due to some failing of the cross() calls with your specific data. This shows the need to program defensively...

    Regards,

    Andrew.

     

  • What's the SR number that you've logged? I wanted to point the AE who ends up dealing with this in the right direction before I leave for the Christmas holidays...

    Regards,

    Andrew.

  • Dear Andrew,

    Thanks a lot for pointing out the mistakes.

    Here is the story:-

     In tesmonte.scs, I have changed to 

    export RISE_TIME=oceanEval("MyRiseTime(v(\"MIXER_I_P\" ?result 'tran) \
        2.5e-10 8e-07 9e-07)")

    But THE CULPRIT-1 is:-

     I had NOT done ( I somehow couldn't cath that) 

     clip_I_P=clip( v("/MIXER_I_P" ?result 'tran) CLIP_START CLIP_END) to clip_I_P=clip( signal CLIP_START CLIP_END)

    Even if everything right there is another one -->

     THE CULPRIT-2 is:-

         I had NOT commented 

          w = newWindow() ( The complex command for .artilint )

     

    After fixing the above two CULPRITS ( of course I am the real culprit), things indeed worked.

    I really appreciate your help,time and patience.

    Kind Regards,

     

     

     

  •  

    Dear Andrew, 

    The SR NO. is  43205866.

    The AE has replied. I have given him the version of OCEAN I am using.

    Don't worry about that.

    Mery Christmas

    Kind Regards,

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