Manipulating a single Instance Iterations in Virtuoso  

If you have an iterated instance, you can't set different properties on different members of that iterated instance. The whole point is that it's only a single component, but it's expanded to multiple instances when needed. So you can't do what you want - each would have to be drawn separately.

ilInst is a special variable used for label display; you should not try to use it for anything else.

Andrew.

 Hi Andrew

 I take from that that I can't do what I intend to in the schematic editor. To draw all instances and edit them by hand on the other hand seems a bit impractical for so many instances. Isn't there a way to perform the modification i need on a netlist level using netlist procedures in a skill script? Iam looking in to that, but havn't come up with a solution yet (it's my first time attempting something like that and I'm still a bit in the dark)

 Thanks for the input!

Samuel

 I have changed my approach a bit. I added the delay parameter i neet to change to the cell using pPar("delay"). In that way the netlister adds the parameter directly to the instance call instead of only the subcircuit. In that way all i need to manipulate is the value of the parameter for every instance. Since it's the first time doing netlist manipulations and the lack of good examples i wrote a custom PrintParameter function that simply overwrites the delay parameter with a fixed value to see if it works:

(defun MYPrintParameters (formatterId cvId)
    cellview_params = cvId->parameters
    (foreach param cellview_params           
        (if param->name == "delay" then
            param->value = "2u"
            cellview_params = nil
        );; if
    );; foreach
    amsPrintParameters(formatterId cvId)   
);; defun
netId = amsGetNetlister()                  
vlog = netId->vlog
vlog->parametersProc = `MYPrintParameters

I have made the according changes in the CDF editor (under Simulation Information in the spectre settings under netlistProcedures i added MYPrintParameters) for the cell and saved theMYPrintParameters function in the libInit.il file in the library folder and tried to generate the netlist. Unfortunatly it returns the error:

  *Error* MYPrintParameters: too few arguments (2 expected, 1 given) - (stdobj@0x15ecc170) 

Do I have to add another parameter in the CDF editor or where did I go wrong?

Thanks for the help,

Samuel

Samuel,

You appear to be creating a netlisting function using AMS netlisting functions (which are for the AMS cell-based netlister), but then using the netlist procedure for spectre (which uses the "nl" netlisting functions). So that's why it's not working.

Personally I would do this using a schematic pcell, then you don't need to worry about different custom netlist procedures for different simulators - the schematic would work in all ADE netlisters (except AMS cell-based, but would work in AMS OSS/irun flow).

Here's an example:

let( (CellLibrary pcellId)
  CellLibrary = "training"
  unless( ddGetObj(CellLibrary)
     error("Couldn't open library %L" CellLibrary)
  )
  
  pcellId =  pcDefinePCell(
     list( ddGetObj(CellLibrary) "rnsd" "schematic" "schematic" )
     
     /****************************************************************************
     /*
     /* Default Parameters
     /*
     /***************************************************************************/
     (
        (ns "1")
     )
     
     let(( pcCV masterCv instName instId netP netM numInsts)
       
       /*************************************************************************
       /*
       /* Get parameter values
       /*
       /************************************************************************/
       pcCV = pcCellView
       
       ;; open master cell view
       masterCv = dbOpenCellViewByType( "analogLib" "res" "symbol" nil "r" )

       ;; create the nets
       netP=dbMakeNet(pcCV "PLUS")
       netM=dbMakeNet(pcCV "MINUS")

       ;; create the terminals
       dbCreateTerm(netP "PLUS" "inputOutput")
       dbCreateTerm(netM "MINUS" "inputOutput")

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

          ;; create instance
          sprintf(instName "R%d" inst)
          instId = dbCreateInst( pcCV masterCv instName (0:0) "R0" )
          dbCreateProp(instId "r" "string" "pPar(\"r\")/pPar(\"ns\")")

          ;; create instTerms for the instance to connect it up
          dbCreateInstTerm(netP instId dbFindTermByName(masterCv "PLUS"))
          dbCreateInstTerm(netM instId dbFindTermByName(masterCv "MINUS"))

       ) ; for

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

Regards,

Andrew.

 Hi Andrew

I do like the approach using a schematic PCell.. It's quite elegant. I have tried it out and it seems to do the trick quite well. I will have to remember this approach for future projects!

Thank you very much for your valuable help!

Samuel