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 CDF Parameter Passing to the Netlist 

Last post Mon, Apr 14 2014 3:21 PM by Andrew Beckett. 3 replies.
Started by gintel 12 Mar 2013 05:07 PM. Topic has 3 replies and 1222 views
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  • Tue, Mar 12 2013 5:07 PM

    • gintel
    • Not Ranked
    • Joined on Mon, Feb 4 2013
    • Posts 4
    • Points 65
    CDF Parameter Passing to the Netlist Reply

    Here is my problem:

     I would like to create the hspiceD (or spectre, doesn't really matter) netlist for a circuit, let us call it depth0. This circuit has a subblock, i0, which is an instance of cell depth1. Inside depth1, there is a resistor and a capacitor. In addition, depth1 has a parameter called myParam (defaults to 1) that I would like to pass to the netlist. In other words, I would like to create a netlist like this:

    .subckt depth1 in out
    * INPUT:  in
    * OUTPUT:  out
    * ----------------------------
    *.PININFO  in:I
    *.PININFO  out:O
    * ----------------------------
    r0 in out 1e3
    c0 out 0 1e-12
    .ends depth1

    .subckt depth0 in0 out0
    * INPUT:  in0
    * OUTPUT:  out0
    * ----------------------------
    *.PININFO  in0:I
    *.PININFO  out0:O
    * ----------------------------
    xi0 in0 out0 depth1 myParam=1

    .ends depth0
    .end

    To achieve this, I have edited the CDF parameters of depth1 (Scope:Cell, Layer:Base). I added a parameter called myParam, type:String, Default Value:1, Parse as CEL:yes, Parse as Number:yes, Store Default:yes. When I build the dept0 schematic and add the depth1 symbol, I can see the myParam parameter in the symbol view. In the Simulation Information of the CDF parameters window, in hspiceD simulator, I added myParam in instParameters section.

    When I netlist, I do get the netlist above without the myParam value. In other words, the bold line above in the actual netlist is this:

     xi0 in0 out0 depth1

    If in the stop view list, I put schematic, then I do get the bold line as I want, (i.e. xi0 in0 out0 depth1 myParam=1), but then the netlister does not descend into i0, and the netlist file does not include the depth1 subckt at all.

    Is there a way to keep both the parameter value and the subckt information in the netlist?

    Thanks.

     

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    • Post Points: 20
  • Wed, Mar 13 2013 4:26 PM

    Re: CDF Parameter Passing to the Netlist Reply

    You need something in the schematic to actually use the parameter - e.g. set the resistor value to 1e3*pPar("myParam") - and then it should get netlisted.

    Andrew.

    • Post Points: 20
  • Wed, Mar 19 2014 10:21 AM

    • gintel
    • Not Ranked
    • Joined on Mon, Feb 4 2013
    • Posts 4
    • Points 65
    Re: CDF Parameter Passing to the Netlist Reply

     Hi Andrew,

     I am having the same issue with spectre. If I use the parameter inside the lower level schematic, parameter shows up in the netlist. However, I want this netlist to include the defined parameter even if I don't use itin the lower level schematic. Is there a workaround? Is there a dummy block I can add to include these in the netlist?

     

    • Post Points: 20
  • Mon, Apr 14 2014 3:21 PM

    Re: CDF Parameter Passing to the Netlist Reply

    As I said, the workaround is to use the parameter. You can always set something like:

    r=1k+0*pPar("YoureTheOneThatIWant")
    c=1p+0*pPar("IGotChillsTheyreMultiplying")

    Andrew.

    • Post Points: 5
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Started by gintel at 12 Mar 2013 05:07 PM. Topic has 3 replies.