manual/CHAPTER_StateOfTheArt/forgen02.v

   1 module uut_forgen02(a, b, cin, y, cout);
   2
   3 parameter WIDTH = 8;
   4
   5 input [WIDTH-1:0] a, b;
   6 input cin;
   7
   8 output [WIDTH-1:0] y;
   9 output cout;
  10
  11 genvar i;
  12 wire [WIDTH-1:0] carry;
  13
  14 generate
  15         for (i = 0; i < WIDTH; i=i+1) begin:adder
  16                 wire [2:0] D;
  17                 assign D[1:0] = { a[i], b[i] };
  18                 if (i == 0) begin:chain
  19                         assign D[2] = cin;
  20                 end else begin:chain
  21                         assign D[2] = carry[i-1];
  22                 end
  23                 assign y[i] = ^D;
  24                 assign carry[i] = &D[1:0] | (^D[1:0] & D[2]);
  25         end
  26 endgenerate
  27
  28 assign cout = carry[WIDTH-1];
  29
  30 endmodule