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Usage of (* cds_inherited_parameter *)

chenchen

Hi all,

I try the simple case in Verilog-A document and I want to obtain "different" values of mismatch parameter in single Verilog-A module.

// I want to use "single" random variable for different parameters w/ mismatch

// variation.scs

section my_variation

parameters monteres=0

statistics {

  mismatch {
    vary monteres dist=gauss std=5
  }
}

endsection my_variation

//////////////////////////////////////////////////////////

// pseudo code 

include "variation.scs"  my_variation

(* cds_inherited_parameter *) parameter real monteres = 0;
parameter real r = 1k;

localparam real r1_effective = r + monteres; 

localparam real r2_effective = r + monteres; 

V(vp1, vn1) <+ (r1_effective)*I(vp1, vn1);

V(vp2, vn2) <+ (r2_effective)*I(vp2, vn2);

//////////////////////////////////////////////////////////

I expect two different random values of r1_effective and r2_effective, but I just got one random value during each Monte Carlo iteration ( r1_effective=r2_effective)

Anyone knows what is correct usage for such cases? (I want r1_effective != r2_effective)

Many thanks.

Parents

  • Why would you expect to have two different values? You'll have one value of monteres per instance of the Verilog-A module, so the value of both r1_effective and r2_effective will be the same of course. You will need to have two statistical parameters in the statistics block and cds_inherited_parameter for them both in the Verilog-A.

    Regards,

    Andrew.

Reply

  • Why would you expect to have two different values? You'll have one value of monteres per instance of the Verilog-A module, so the value of both r1_effective and r2_effective will be the same of course. You will need to have two statistical parameters in the statistics block and cds_inherited_parameter for them both in the Verilog-A.

    Regards,

    Andrew.

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