Manipulate and export data from ViVa

To use the code, you can use the load() function to load it. Put it in a file (abGetCyclePeaks.il) and then in the CIW:

load("abGetCyclePeaks.il")

You can put this line in your .cdsinit too (put the full path to the file if necessary).

The code is written in SKILL - which is a LISP variant. In fact all your calculator expressions are SKILL too - so to actually use the function, you'd need to type the function call (as shown the comments) into the calculator buffer. It's possible to add it as a custom function in IC617 easily through the UI - I'll post how to do that a little later.

I tend to write my code using LISP syntax. To make it a bit easier to understand for those less familiar with SKILL, I've reformatted it into C-style below. This is equivalent, so there's no performance benefit in using either format - it's just the parser allows these alternative approaches to writing the code, because more engineers are probably familiar with a C-style than a LISP-style.

Regards,

Andrew.

/* abGetCyclePeaks.il

Author     A.D.Beckett
Group      Custom IC (UK), Cadence Design Systems Ltd.
Language   SKILL
Date       Mar 23, 2016 
Modified   
By         

Function to calculate the peak values (or times of peak values)
within each period. Has some tolerances built in so that it should
detects when it first reaches the peak and filters out numerical
noise.

Example - measure fall time (peak to peak) in each period:

abGetCyclePeaks(v("ramp" ?result 'tran) "rising" "max" ?yValues "x")-
    abGetCyclePeaks(v("ramp" ?result 'tran) "rising" "min" ?yValues "x")

***************************************************

SCCS Info: @(#) abGetCyclePeaks.il 03/23/16.22:27:05 1.1

*/

/*******************************************************************
*                                                                  *
*      (abGetCyclePeaks wave crossType minMax [?mode "auto"]       *
*         [?threshold 0.0] [?yValues "y"] [?xName "cycle"]         *
*                  [?reltol 1e-3] [?abstol 1e-6])                  *
*                                                                  *
*     For each cycle - identified by the rising or falling (or     *
*     either, but that's not so likely to be used) crossing of     *
*     the threshold (which is controlled by the ?mode argument     *
*  "auto" means automatic, "user" means as specified) - find the   *
* "min" or "max" value of the signal within the cycle. In order to *
* filter out numerical noise on the signal influencing the precise *
*     position of the peak, only look at changes bigger than a     *
*   reltol+abstol type delta from the previously found peak. The   *
*   resulting waveform can be plotted versus "cycle" or "time",    *
*    and the yValues can be either the y or x values at the peak.  *
*                                                                  *
*******************************************************************/

procedure(abGetCyclePeaks(wave crossType minMax @key (mode "auto") 
    (threshold 0.0) (yValues "y") (xName "cycle") 
    (reltol 1e-3) (abstol 1e-6) "gSSSfSSff")
  cond(
    (drIsWaveform(wave)
      let((xVec yVec len outX outY newXVec newYVec newWave cycleNum lastY 
          thisY localPeakX localPeakY direction func absdelta tolerance)
        ;----------------------------------------------------------------
        ; Validate the arguments to ensure they are valid strings
        ;----------------------------------------------------------------
        foreach(validInfo
          `(
            (crossType ,(crossType=get_string(crossType))
            ("rising" "falling" "either"))
            (minMax ,(minMax=get_string(minMax)) ("min" "max"))
            (?mode ,(mode=get_string(mode)) ("auto" "user"))
            (?xName ,(xName=get_string(xName)) ("cycle" "time"))
            (?yValues ,(yValues=get_string(yValues)) ("y" "x"))
          )
          unless(member(cadr(validInfo) caddr(validInfo))
            error("abGetCyclePeaks: %s argument must be one of \"%s\": %L\n"
              car(validInfo)
              buildString(caddr(validInfo) "\",\"")
              cadr(validInfo))
            )
        )
        when(mode=="auto"
          threshold=average(wave)
        )
        func=if(minMax=="max" 'greaterp 'lessp)
        xVec=drGetWaveformXVec(wave)
        yVec=drGetWaveformYVec(wave)
        len=drVectorLength(xVec)
        cycleNum=0
        lastY=drGetElem(yVec 0)
        localPeakY=lastY
        localPeakX=drGetElem(xVec 0)
        ;----------------------------------------------------------------
        ; Iterate through all the points
        ;----------------------------------------------------------------
        for(i 1 sub1(len)
          thisY=drGetElem(yVec i)
          ;--------------------------------------------------------------
          ; Determine if this is a transition, and if so, which direction
          ;--------------------------------------------------------------
          direction=
            cond( 
              (lastY<threshold && thisY>=threshold "rising")
              (lastY>=threshold && thisY<threshold "falling")
              (t nil)
            )
          ;--------------------------------------------------------------
          ; Assuming it's a crossing in the right direction, record
          ; the peak in that cycle (doesn't do it before the first
          ; transition though)
          ;--------------------------------------------------------------
          if(crossType==direction || crossType=="either" && direction then
            when(cycleNum>0
              outX=tconc(outX if(xName=="cycle" cycleNum localPeakX))
              outY=tconc(outY if(yValues=="y" localPeakY localPeakX))
            )
            localPeakX=drGetElem(xVec i)
            localPeakY=thisY
            cycleNum++
          else
            ;------------------------------------------------------------
            ; Otherwise see if the peak has been exceeded
            ;------------------------------------------------------------
            when(funcall(func thisY localPeakY)
              absdelta=abs(thisY-lastY)
              tolerance=max(abs(thisY) abs(lastY))*reltol+abstol 
              when(absdelta>tolerance
                localPeakX=drGetElem(xVec i)
                localPeakY=thisY
              )
            )
          )
          lastY=thisY
        ) ; for
        ;----------------------------------------------------------------
        ; Construct output vectors and waveforms with the right
        ; attributes
        ;----------------------------------------------------------------
        newXVec=drCreateVec(if(xName=="cycle" 'intlong 'double) car(outX))
        newYVec=drCreateVec('double car(outY))
        newXVec->units=if(xName=="cycle" "" xVec->units)
        newXVec->name=if(xName=="cycle" "cycle" xVec->name)
        newYVec->units=if(yValues=="y" yVec->units xVec->units)
        newYVec->name=if(yValues=="y" yVec->name xVec->name)
        newWave=drCreateWaveform(newXVec newYVec)
        famSetExpr(newWave 
          `abGetCyclePeaks(,famGetExpr(wave) crossType minMax 
             ?mode ,mode ?threshold ,threshold 
             ?yValues yValues ?xName ,xName 
             ?reltol ,reltol ?abstol ,abstol)
        )
        newWave
      )
    )
    (famIsFamily(wave)
      famMap('abGetCyclePeaks minMax ?mode mode ?threshold threshold 
        ?yValues yValues ?xName xName ?reltol reltol ?abstol abstol
      )
    )
    (t
      error("abGetCyclePeaks: Cannot handle %L\n" wave)
    )
  )
)

To use the code, you can use the load() function to load it. Put it in a file (abGetCyclePeaks.il) and then in the CIW:

load("abGetCyclePeaks.il")

You can put this line in your .cdsinit too (put the full path to the file if necessary).

The code is written in SKILL - which is a LISP variant. In fact all your calculator expressions are SKILL too - so to actually use the function, you'd need to type the function call (as shown the comments) into the calculator buffer. It's possible to add it as a custom function in IC617 easily through the UI - I'll post how to do that a little later.

I tend to write my code using LISP syntax. To make it a bit easier to understand for those less familiar with SKILL, I've reformatted it into C-style below. This is equivalent, so there's no performance benefit in using either format - it's just the parser allows these alternative approaches to writing the code, because more engineers are probably familiar with a C-style than a LISP-style.

Regards,

Andrew.

/* abGetCyclePeaks.il

Author     A.D.Beckett
Group      Custom IC (UK), Cadence Design Systems Ltd.
Language   SKILL
Date       Mar 23, 2016 
Modified   
By         

Function to calculate the peak values (or times of peak values)
within each period. Has some tolerances built in so that it should
detects when it first reaches the peak and filters out numerical
noise.

Example - measure fall time (peak to peak) in each period:

abGetCyclePeaks(v("ramp" ?result 'tran) "rising" "max" ?yValues "x")-
    abGetCyclePeaks(v("ramp" ?result 'tran) "rising" "min" ?yValues "x")

***************************************************

SCCS Info: @(#) abGetCyclePeaks.il 03/23/16.22:27:05 1.1

*/

/*******************************************************************
*                                                                  *
*      (abGetCyclePeaks wave crossType minMax [?mode "auto"]       *
*         [?threshold 0.0] [?yValues "y"] [?xName "cycle"]         *
*                  [?reltol 1e-3] [?abstol 1e-6])                  *
*                                                                  *
*     For each cycle - identified by the rising or falling (or     *
*     either, but that's not so likely to be used) crossing of     *
*     the threshold (which is controlled by the ?mode argument     *
*  "auto" means automatic, "user" means as specified) - find the   *
* "min" or "max" value of the signal within the cycle. In order to *
* filter out numerical noise on the signal influencing the precise *
*     position of the peak, only look at changes bigger than a     *
*   reltol+abstol type delta from the previously found peak. The   *
*   resulting waveform can be plotted versus "cycle" or "time",    *
*    and the yValues can be either the y or x values at the peak.  *
*                                                                  *
*******************************************************************/

procedure(abGetCyclePeaks(wave crossType minMax @key (mode "auto") 
    (threshold 0.0) (yValues "y") (xName "cycle") 
    (reltol 1e-3) (abstol 1e-6) "gSSSfSSff")
  cond(
    (drIsWaveform(wave)
      let((xVec yVec len outX outY newXVec newYVec newWave cycleNum lastY 
          thisY localPeakX localPeakY direction func absdelta tolerance)
        ;----------------------------------------------------------------
        ; Validate the arguments to ensure they are valid strings
        ;----------------------------------------------------------------
        foreach(validInfo
          `(
            (crossType ,(crossType=get_string(crossType))
            ("rising" "falling" "either"))
            (minMax ,(minMax=get_string(minMax)) ("min" "max"))
            (?mode ,(mode=get_string(mode)) ("auto" "user"))
            (?xName ,(xName=get_string(xName)) ("cycle" "time"))
            (?yValues ,(yValues=get_string(yValues)) ("y" "x"))
          )
          unless(member(cadr(validInfo) caddr(validInfo))
            error("abGetCyclePeaks: %s argument must be one of \"%s\": %L\n"
              car(validInfo)
              buildString(caddr(validInfo) "\",\"")
              cadr(validInfo))
            )
        )
        when(mode=="auto"
          threshold=average(wave)
        )
        func=if(minMax=="max" 'greaterp 'lessp)
        xVec=drGetWaveformXVec(wave)
        yVec=drGetWaveformYVec(wave)
        len=drVectorLength(xVec)
        cycleNum=0
        lastY=drGetElem(yVec 0)
        localPeakY=lastY
        localPeakX=drGetElem(xVec 0)
        ;----------------------------------------------------------------
        ; Iterate through all the points
        ;----------------------------------------------------------------
        for(i 1 sub1(len)
          thisY=drGetElem(yVec i)
          ;--------------------------------------------------------------
          ; Determine if this is a transition, and if so, which direction
          ;--------------------------------------------------------------
          direction=
            cond( 
              (lastY<threshold && thisY>=threshold "rising")
              (lastY>=threshold && thisY<threshold "falling")
              (t nil)
            )
          ;--------------------------------------------------------------
          ; Assuming it's a crossing in the right direction, record
          ; the peak in that cycle (doesn't do it before the first
          ; transition though)
          ;--------------------------------------------------------------
          if(crossType==direction || crossType=="either" && direction then
            when(cycleNum>0
              outX=tconc(outX if(xName=="cycle" cycleNum localPeakX))
              outY=tconc(outY if(yValues=="y" localPeakY localPeakX))
            )
            localPeakX=drGetElem(xVec i)
            localPeakY=thisY
            cycleNum++
          else
            ;------------------------------------------------------------
            ; Otherwise see if the peak has been exceeded
            ;------------------------------------------------------------
            when(funcall(func thisY localPeakY)
              absdelta=abs(thisY-lastY)
              tolerance=max(abs(thisY) abs(lastY))*reltol+abstol 
              when(absdelta>tolerance
                localPeakX=drGetElem(xVec i)
                localPeakY=thisY
              )
            )
          )
          lastY=thisY
        ) ; for
        ;----------------------------------------------------------------
        ; Construct output vectors and waveforms with the right
        ; attributes
        ;----------------------------------------------------------------
        newXVec=drCreateVec(if(xName=="cycle" 'intlong 'double) car(outX))
        newYVec=drCreateVec('double car(outY))
        newXVec->units=if(xName=="cycle" "" xVec->units)
        newXVec->name=if(xName=="cycle" "cycle" xVec->name)
        newYVec->units=if(yValues=="y" yVec->units xVec->units)
        newYVec->name=if(yValues=="y" yVec->name xVec->name)
        newWave=drCreateWaveform(newXVec newYVec)
        famSetExpr(newWave 
          `abGetCyclePeaks(,famGetExpr(wave) crossType minMax 
             ?mode ,mode ?threshold ,threshold 
             ?yValues yValues ?xName ,xName 
             ?reltol ,reltol ?abstol ,abstol)
        )
        newWave
      )
    )
    (famIsFamily(wave)
      famMap('abGetCyclePeaks minMax ?mode mode ?threshold threshold 
        ?yValues yValues ?xName xName ?reltol reltol ?abstol abstol
      )
    )
    (t
      error("abGetCyclePeaks: Cannot handle %L\n" wave)
    )
  )
)