paramwidth.va

`include "disciplines.vams"
// Enhancement-91: parameter-dependent declaration widths. A net/port/array
// range whose bounds reference a parameter (`[0:N-1]`, `[0:bits-1]`) is folded
// to a literal range using the parameter's elaboration-time default, so the
// bus machinery (E-3) and array machinery (E-14) see a constant width. The
// width is fixed at the default -- a structural parameter (one OSDI descriptor
// per module), see Enhancement-91.md.

// (1) parameter-SIZED array + a runtime loop over the parameter (E-70): the
// harmonic sum  sum_{k=0}^{N-1} vref/(k+1).
module wsum4(out);
   parameter integer N = 4;
   parameter real vref = 1.0;
   output out; electrical out;
   real w[0:N-1];
   integer k;
   analog begin : b
      real acc;
      acc = 0.0;
      for (k = 0; k < N; k = k + 1) begin
         w[k] = vref / (k + 1);
         acc = acc + w[k];
      end
      V(out) <+ acc;
   end
endmodule

// (2) same source shape, a different default N -- the array width (and so the
// sum) tracks the parameter default.
module wsum8(out);
   parameter integer N = 8;
   parameter real vref = 1.0;
   output out; electrical out;
   real w[0:N-1];
   integer k;
   analog begin : b
      real acc;
      acc = 0.0;
      for (k = 0; k < N; k = k + 1) begin
         w[k] = vref / (k + 1);
         acc = acc + w[k];
      end
      V(out) <+ acc;
   end
endmodule

// (3) parameter-WIDTH node bus: `[0:bits-1]` folds from the default (4 bits).
module busout4(out);
   parameter integer bits = 4;
   output [0:bits-1] out;
   electrical [0:bits-1] out;
   analog begin
      V(out[0]) <+ 0.25; V(out[1]) <+ 0.5;
      V(out[2]) <+ 0.75; V(out[3]) <+ 1.0;
   end
endmodule

// (4) the same, a wider default -- the bus (and terminal count) tracks it.
module busout6(out);
   parameter integer bits = 6;
   output [0:bits-1] out;
   electrical [0:bits-1] out;
   analog begin
      V(out[0]) <+ 0.1; V(out[1]) <+ 0.2; V(out[2]) <+ 0.3;
      V(out[3]) <+ 0.4; V(out[4]) <+ 0.5; V(out[5]) <+ 0.6;
   end
endmodule