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[pCell Error] Faulty pcell-schematic

Socks and Shoes

I Skill-coded two Pcells: A layout the schematic. The symbol is generated by the schematic-pcell. The LVS of the two pcells is clean.

BUT: Whenever I try to place my layout-Pcell into another layout and try the LVS, the LVS-Check stops after a short period of time and I get the following Errors from the LVS-console:


*Error*   Could not determine the node name for terminal '"D"'.  This may be caused by an error in the CDF specified on:
            component   : ne5
             named       : /I0
             in cellview : Test/schematic
             of library  : work_jw
"ERROR (OSSHNL-524): Netlisting failed because the function 'hnlNetNameOnTerm' was called with a non-existent terminal 'G' on the current instance 'I0' in the design 'work_jw/Test/schematic'. Provide a valid terminal name with this function and regenerate the netlist.\n\n"


*Error*   Could not determine the node name for terminal '"G"'.  This may be caused by an error in the CDF specified on:
             component   : ne5
             named       : /I0
             in cellview : Test/schematic
             of library  : work_jw
"ERROR (OSSHNL-524): Netlisting failed because the function 'hnlNetNameOnTerm' was called with a non-existent terminal 'S' on the current instance 'I0' in the design 'work_jw/Test/schematic'. Provide a valid terminal name with this function and regenerate the netlist.\n\n"


*Error*   Could not determine the node name for terminal '"S"'.  This may be caused by an error in the CDF specified on:
             component   : ne5
             named       : /I0
             in cellview : Test/schematic
             of library  : work_jw
"ERROR (OSSHNL-524): Netlisting failed because the function 'hnlNetNameOnTerm' was called with a non-existent terminal 'B' on the current instance 'I0' in the design 'work_jw/Test/schematic'. Provide a valid terminal name with this function and regenerate the netlist.\n\n"


*Error*   Could not determine the node name for terminal '"B"'.  This may be caused by an error in the CDF specified on:
             component   : ne5
             named       : /I0
             in cellview : Test/schematic
             of library  : work_jw
End netlisting Feb  1 14:31:20 2023
ERROR (OSSHNL-514): Netlist generation failed because of the errors reported above. The netlist might not have been generated at all, or the generated netlist could be corrupt. Fix the reported errors and regenerate the netlist.

I replaced the coded pcell schematic with a schematic I designed in the schematic editor, and ta da. The LVS is working now. So I strongly assume, that I forgot something in the skill-Code of the pcell - schematic.

Do you have an idea, what I did wrong? Skill-Code is posted below.

Parents

  • You didn't post the SKILL code of the Schematic PCell. Can you upload that please?

    (by the way, your original post went to moderation as the repeated text in the post triggers the "potential spam" check).

    Regards,

    Andrew

  • in reply to Andrew Beckett

    Hey Andrew, I posted the code, but it got flagged as SPAM again! I checked the community guidelines.  I didnt found any mistake of mine, regarding the guidelines. Did I do something wrong?

  • in reply to Socks and Shoes
    Socks and Shoes said:
    Hey Andrew, I posted the code, but it got flagged as SPAM again

    The forum automatically detects repeated text (particularly if there's a lot of it) as potential spam. It doesn't mean it is spam, just that it needs you to appeal the spam detection and then moderators get notified. We don't get notified of the initial spam alert (there would be way too many otherwise - there's an awful of spam attempts that are made, and we're much better at blocking spam and link-spam now by default), but when appealed we see it. I see the post with the code was approved by one of my colleagues who moderates a couple of the other forums and so I can see it above (BTW, adding the code as an attachment probably wouldn't trigger the repeated text check).

    Anyway, the issue is that your PCell creates the instance of the "ne" component, and the top level pins, and some graphical wires, but there is no connectivity to the instance itself - you need to use dbCreateInstTerm or dbCreateConn to connect up the instance. That's why it's failing. There's no "schematic extractor" run on PCells, so the wires are for visual inspection only - they won't do anything in terms of connectivity.

    This example below shows a simple case of creating a series-connected resistor and shows code which creates the instTerms too:

    /* respcell.il

Author     A.D.Beckett
Group      Custom IC (UK), Cadence Design Systems Ltd.
Language   SKILL
Date       Apr 07, 2014 
Modified   
By         

Example of a series resistor pcell.

Original version only contained connectivity - this one contains "graphics"
too so that if you descend into the schematic you can probe nets.

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

SCCS Info: @(#) respcell.il 04/07/14.11:02:22 1.2

*/
 
procedure(abCreateResPcell(libName cellName) 
  let( (pcellId)
    unless( ddGetObj(libName)
      error("Couldn't open library %L" libName)
    )

    pcellId =  pcDefinePCell(
      list( ddGetObj(libName) cellName "schematic" "schematic" )

      ;------------------------------------------------------------------
      ; Default Parameters
      ;------------------------------------------------------------------
      (
        (ns "1")
      )
      let(( pcCV masterCv instName instId netP netM numInsts y (resHeight 0.375)
        (wireLen 0.125) pinMaster pinFig wire lastCoord)

        pcCV = pcCellView

        ;------------------------------------------------------------------
        ; open master cellviews
        ;------------------------------------------------------------------
        masterCv = dbOpenCellViewByType( "analogLib" "res" "symbol" nil "r" )
        pinMaster=dbOpenCellViewByType("basic" "iopin" "symbol")

        numInsts=atoi(ns)
        when(numInsts<1 numInsts=1)

        ;----------------------------------------------------------------
        ; Create nets and terminals
        ;----------------------------------------------------------------
        netP=dbMakeNet(pcCV "PLUS")
        netM=dbMakeNet(pcCV "MINUS")
        dbCreateTerm(netP "PLUS" "inputOutput")
        dbCreateTerm(netM "MINUS" "inputOutput")
        y=0
        pinFig=dbCreateInst(pcCV pinMaster "" 0:y "R0")
        dbCreatePin(netP pinFig)
        lastCoord=0:y
        for(inst 1 numInsts
          ;--------------------------------------------------------------
          ; Create the nets connected to either side
          ;--------------------------------------------------------------
          if(inst==1 then
            netP=dbMakeNet(pcCV "PLUS")
          else 
            netP=dbMakeNet(pcCV sprintf(nil "net%d" inst-1))
          ) ; if
          if(inst==numInsts then
            netM=dbMakeNet(pcCV "MINUS")
          else 
            netM=dbMakeNet(pcCV sprintf(nil "net%d" inst))
          )
          sprintf(instName "R%d" inst)
          y=y-wireLen
          instId = dbCreateInst( pcCV masterCv instName (0:y) "R0" )
          dbCreateProp(instId "r" "string" "pPar(\"r\")/pPar(\"ns\")")
          ;--------------------------------------------------------------
          ; Connect up the instance
          ;--------------------------------------------------------------
          dbCreateInstTerm(netP instId dbFindTermByName(masterCv "PLUS"))
          dbCreateInstTerm(netM instId dbFindTermByName(masterCv "MINUS"))
          wire=dbCreateLine(pcCV list("wire" "drawing") list(lastCoord 0:y))
          dbAddFigToNet(wire netP)
          y=y-resHeight
          lastCoord=0:y
        )
        y=y-wireLen
        pinFig=dbCreateInst(pcCV pinMaster "" 0:y "R0")
        dbCreatePin(netM pinFig)
        wire=dbCreateLine(pcCV list("wire" "drawing") list(lastCoord 0:y))
        dbAddFigToNet(wire netM)

        dbSetConnCurrent(pcCV)

        dbClose( masterCv )
        ;; Always return true
        t
      ) ; ** let **
    )
    ; not sure if below is really necessary
    dbSave(pcellId)
    dbClose( pcellId ) 
  ) ; ** let **
)

    Regards,

    Andrew

Reply
  • in reply to Socks and Shoes
    Socks and Shoes said:
    Hey Andrew, I posted the code, but it got flagged as SPAM again

    The forum automatically detects repeated text (particularly if there's a lot of it) as potential spam. It doesn't mean it is spam, just that it needs you to appeal the spam detection and then moderators get notified. We don't get notified of the initial spam alert (there would be way too many otherwise - there's an awful of spam attempts that are made, and we're much better at blocking spam and link-spam now by default), but when appealed we see it. I see the post with the code was approved by one of my colleagues who moderates a couple of the other forums and so I can see it above (BTW, adding the code as an attachment probably wouldn't trigger the repeated text check).

    Anyway, the issue is that your PCell creates the instance of the "ne" component, and the top level pins, and some graphical wires, but there is no connectivity to the instance itself - you need to use dbCreateInstTerm or dbCreateConn to connect up the instance. That's why it's failing. There's no "schematic extractor" run on PCells, so the wires are for visual inspection only - they won't do anything in terms of connectivity.

    This example below shows a simple case of creating a series-connected resistor and shows code which creates the instTerms too:

    /* respcell.il

Author     A.D.Beckett
Group      Custom IC (UK), Cadence Design Systems Ltd.
Language   SKILL
Date       Apr 07, 2014 
Modified   
By         

Example of a series resistor pcell.

Original version only contained connectivity - this one contains "graphics"
too so that if you descend into the schematic you can probe nets.

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

SCCS Info: @(#) respcell.il 04/07/14.11:02:22 1.2

*/
 
procedure(abCreateResPcell(libName cellName) 
  let( (pcellId)
    unless( ddGetObj(libName)
      error("Couldn't open library %L" libName)
    )

    pcellId =  pcDefinePCell(
      list( ddGetObj(libName) cellName "schematic" "schematic" )

      ;------------------------------------------------------------------
      ; Default Parameters
      ;------------------------------------------------------------------
      (
        (ns "1")
      )
      let(( pcCV masterCv instName instId netP netM numInsts y (resHeight 0.375)
        (wireLen 0.125) pinMaster pinFig wire lastCoord)

        pcCV = pcCellView

        ;------------------------------------------------------------------
        ; open master cellviews
        ;------------------------------------------------------------------
        masterCv = dbOpenCellViewByType( "analogLib" "res" "symbol" nil "r" )
        pinMaster=dbOpenCellViewByType("basic" "iopin" "symbol")

        numInsts=atoi(ns)
        when(numInsts<1 numInsts=1)

        ;----------------------------------------------------------------
        ; Create nets and terminals
        ;----------------------------------------------------------------
        netP=dbMakeNet(pcCV "PLUS")
        netM=dbMakeNet(pcCV "MINUS")
        dbCreateTerm(netP "PLUS" "inputOutput")
        dbCreateTerm(netM "MINUS" "inputOutput")
        y=0
        pinFig=dbCreateInst(pcCV pinMaster "" 0:y "R0")
        dbCreatePin(netP pinFig)
        lastCoord=0:y
        for(inst 1 numInsts
          ;--------------------------------------------------------------
          ; Create the nets connected to either side
          ;--------------------------------------------------------------
          if(inst==1 then
            netP=dbMakeNet(pcCV "PLUS")
          else 
            netP=dbMakeNet(pcCV sprintf(nil "net%d" inst-1))
          ) ; if
          if(inst==numInsts then
            netM=dbMakeNet(pcCV "MINUS")
          else 
            netM=dbMakeNet(pcCV sprintf(nil "net%d" inst))
          )
          sprintf(instName "R%d" inst)
          y=y-wireLen
          instId = dbCreateInst( pcCV masterCv instName (0:y) "R0" )
          dbCreateProp(instId "r" "string" "pPar(\"r\")/pPar(\"ns\")")
          ;--------------------------------------------------------------
          ; Connect up the instance
          ;--------------------------------------------------------------
          dbCreateInstTerm(netP instId dbFindTermByName(masterCv "PLUS"))
          dbCreateInstTerm(netM instId dbFindTermByName(masterCv "MINUS"))
          wire=dbCreateLine(pcCV list("wire" "drawing") list(lastCoord 0:y))
          dbAddFigToNet(wire netP)
          y=y-resHeight
          lastCoord=0:y
        )
        y=y-wireLen
        pinFig=dbCreateInst(pcCV pinMaster "" 0:y "R0")
        dbCreatePin(netM pinFig)
        wire=dbCreateLine(pcCV list("wire" "drawing") list(lastCoord 0:y))
        dbAddFigToNet(wire netM)

        dbSetConnCurrent(pcCV)

        dbClose( masterCv )
        ;; Always return true
        t
      ) ; ** let **
    )
    ; not sure if below is really necessary
    dbSave(pcellId)
    dbClose( pcellId ) 
  ) ; ** let **
)

    Regards,

    Andrew

Children

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