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How to use variable port width in VerilogA?

Qilong

Hi all, 

  Recently I am writing a simple verilog-A ADC and using variable-port width for the output bits. After I use "parameter integer nlevel=7" in the verilog-A file and finish the verilog-A parsing, I can only see out<0> instead of out<7:0> in the generated symbol. After reading  [SOLVED] Verilog-(AMS) PCell with variable bus width

Creating a component that allows setting a value on a bus in an analog simulation

and this 

Parametrized busses in Verilog-A

I start to build my symbol with SKILL. After loading the SKILL I can observe the port now can change with nlevel. But again, during spectre netlisting it throws out an error saying the verilog-A view is not synchronised with the symbol. After updating the symbol from verilog-A, the variable-port width again becomes out<0> only. 

  I think this issue must have been reported and discussed before. But can anyone provide some references to it? Thanks in advance. 

  PS: Attached are my verilog-A and SKILL code.

  PPS: Now I am using Virtuoso 6.1.6

Fullscreen VerilogA.txt Download 
// VerilogA for , verloga

`include "constants.vams"
`include "disciplines.vams"

module flash_nbit_pre_amp( inp, inn, clk, out );
parameter real FS=2;
parameter integer nlevel=7;  //input threshold level
parameter real gain=1;


input inp, inn;
input clk;
output  [nlevel:0]out;


electrical inp, inn,clk;
electrical [nlevel:0]out;



real LSB=FS/nlevel;
real td=0;
real tt=0;
real vdd=1.1;
real vth=vdd/2;
real dir=1;
real Vref_i=0;
real sample;
genvar i;
real result[nlevel:0];




analog begin
	@(cross(V(clk)-vth, +1) or initial_step) begin	
		sample = gain*(V(inp)-V(inn));
		for (i = nlevel; i >= 0; i =i -1) begin
			Vref_i=FS/2-LSB/2-(nlevel-i)*LSB;
			if (sample > Vref_i) begin
				 result[i] = vdd;
			end 
			else begin
			result[i] = 0;
			end 
		end	
	end
	for (i = nlevel; i >=0; i = i - 1) begin
		V(out[i])<+ transition(result[i], td, tt);
	end
end

endmodule
 
Fullscreen SKILL.txt Download 
let( (library cell pcellId)
    library="<XXXX>"
    cell="flash_nbit_pre_amp"
    unless(ddGetObj(library)
	error("Couldn't open library %L" library)
    )


    ;--------------------------------------------------------------------
    ; Now the symbol
    ;--------------------------------------------------------------------
    pcellId=pcDefinePCell(
	list(ddGetObj(library) cell "symbol" "schematicSymbol")

	;----------------------------------------------------------------
	; Formal parameters
	;----------------------------------------------------------------
	(
	    (FS 2)
	    (nlevel 7)
	    (gain 1)
	)

	;----------------------------------------------------------------
	; Code itself
	;----------------------------------------------------------------
	let(( cv netINP netINN netCLK netOUT 
		figINP figINN figINN figCLK netOUT hp ps pl bw lh
	    pxc label)

	cv = pcCellView

	;----------------------------------------------------------------
	; Various dimensions
	;----------------------------------------------------------------
	; half pin size
	hp=0.025
	; pin spacing
	ps=0.125
	; pin length
	pl=0.250
	; box width
	bw=1.4375
	; label height
	lh=0.0625
	; param label x coord
	pxc=0.5

	;----------------------------------------------------------------
	; create the shapes - first the pins
	;----------------------------------------------------------------
	figINP = dbCreateRect(cv list("pin" "drawing") list(-hp:-hp hp:hp)) 
	dbCreateLine(cv list("device" "drawing") list(0:0 pl:0))
	figINN = dbCreateRect(cv list("pin" "drawing") list(-hp:-ps-hp hp:-ps+hp))
	dbCreateLine(cv list("device" "drawing") list(0:-ps pl:-ps))
	figCLK = dbCreateRect(cv list("pin" "drawing") list(-hp:-3*ps-hp hp:-3*ps+hp))
	dbCreateLine(cv list("device" "drawing") list(0:-3*ps pl:-3*ps))
	figOUT = dbCreateRect(cv list("pin" "drawing") list(2*pl+bw-hp:-hp 2*pl+bw+hp:hp))
	dbCreateLine(cv list("device" "drawing") list(pl+bw:0 2*pl+bw:0))

	;----------------------------------------------------------------
	; Then the boxes
	;----------------------------------------------------------------
	dbCreateRect(cv list("device" "drawing") list(pl:-4*ps pl+bw:ps))
	dbCreateRect(cv list("instance" "drawing") list(0:-4*ps 2*pl+bw:ps))

	;----------------------------------------------------------------
	; create the nets
	;----------------------------------------------------------------
	netINP=dbMakeNet(cv "inp")
	netINN=dbMakeNet(cv "inn")
	netCLK=dbMakeNet(cv "clk")
	netOUT=dbMakeNet(cv sprintf(nil "out<%d:0>" nlevel))

	;----------------------------------------------------------------
	; create the terminals
	;----------------------------------------------------------------
	dbCreateTerm(netINP netINP~>name "input")
	dbCreateTerm(netINN netINN~>name "input")
	dbCreateTerm(netCLK netCLK~>name "input")
	dbCreateTerm(netOUT netOUT~>name "output")
	;----------------------------------------------------------------
	; create the pins
	;----------------------------------------------------------------
	dbCreatePin(netINP figINP)
	dbCreatePin(netINN figINN)
	dbCreatePin(netCLK figCLK)
	dbCreatePin(netOUT figOUT)
	
	;----------------------------------------------------------------
	; Put some labels for the pins
	;----------------------------------------------------------------
	dbCreateLabel(cv list("pin" "drawing") pl+ps/2:0
	    netINP~>name "centerLeft" "R0" "stick" lh)
	dbCreateLabel(cv list("pin" "drawing") pl+ps/2:-ps
	    netINN~>name "centerLeft" "R0" "stick" lh)
	dbCreateLabel(cv list("pin" "drawing") pl+ps/2:-3*ps
	    netCLK~>name "centerLeft" "R0" "stick" lh)
	dbCreateLabel(cv list("pin" "drawing") bw+pl-ps/2:0
	    netOUT~>name "centerRight" "R0" "stick" lh)

	;----------------------------------------------------------------
	; And other symbol labels
	;----------------------------------------------------------------
	label=dbCreateLabel(cv list("annotate" "drawing7") bw+pl-ps/2:ps*1.5
	    "cdsName()" "centerRight" "R0" "stick" lh)
	label~>labelType="ILLabel"
	label=dbCreateLabel(cv list("annotate" "drawing") pxc:0
	    "cdsParam(1)" "centerLeft" "R0" "stick" lh)
	label~>labelType="ILLabel"
	label=dbCreateLabel(cv list("annotate" "drawing") pxc:-ps
	    "cdsParam(2)" "centerLeft" "R0" "stick" lh)
	label~>labelType="ILLabel"
	label=dbCreateLabel(cv list("annotate" "drawing") pxc:-2*ps
	    "cdsParam(3)" "centerLeft" "R0" "stick" lh)
	label~>labelType="ILLabel"

	t
	) ; let
    )
    dbSave(pcellId)
    dbClose(pcellId) 

;------------------------------------------------------------------------
; Now create the CDF
;------------------------------------------------------------------------
    let( (cellId cdfId )
	unless( cellId = ddGetObj( library cell )
	    error( "Could not get cell %s." cell )
	)
	when( cdfId = cdfGetBaseCellCDF( cellId )
	    cdfDeleteCDF( cdfId )
	)
	cdfId  = cdfCreateBaseCellCDF( cellId )

	;;; Parameters
	cdfCreateParam( cdfId
	    ?name           "FS"
	    ?prompt         "Full Scale"
	    ?defValue       "2" 
	    ?type           "string"
	    ?display        "t"
	)
	cdfCreateParam( cdfId
	    ?name           "nlevel"
	    ?prompt         "nlevel"
	    ?defValue       " 7" 
	    ?type           "string"
	    ?display        "t"
	)
	cdfCreateParam( cdfId
	    ?name           "gain"
	    ?prompt         "Pre_amp Gain"
	    ?defValue       " 1" 
	    ?type           "string"
	    ?display        "t"
	)

	;;; Simulator Information
	cdfId->simInfo = list( nil )
	cdfId->simInfo->UltraSim = '( nil )
	cdfId->simInfo->ams = '( nil )
	cdfId->simInfo->auCdl = '( nil )
	cdfId->simInfo->auLvs = '( nil )
	cdfId->simInfo->cdsSpice = '( nil )
	cdfId->simInfo->hspiceD = '( nil )
	cdfId->simInfo->hspiceS = '( nil )
	cdfId->simInfo->spectre = '( nil )
	cdfId->simInfo->spectreS = '( nil )

	;;; Properties
	cdfId->formInitProc            = ""
	cdfId->doneProc                = ""
	cdfId->buttonFieldWidth        = 340
	cdfId->fieldHeight             = 35
	cdfId->fieldWidth              = 350
	cdfId->promptWidth             = 175
	cdfId->paramLabelSet           = "FS nlevel gain"
	cdfId->paramDisplayMode        = "parameter"
	cdfId->paramEvaluate           = "t nil nil nil nil"
	cdfSaveCDF( cdfId )
    ) ; let
) ; let

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