tests/simple/graphtest.v

   1 module graphtest (A,B,X,Y,Z);
   2
   3 input      [3:0] A;
   4 input      [3:0] B;
   5 output reg [3:0] X;
   6 output     [9:0] Y;
   7 output     [7:0] Z;
   8
   9 wire [4:0] t;
  10
  11 assign t[4] = 1'b0;                      // Constant connects to wire
  12 assign t[2:0] = A[2:0] & { 2'b10, B[3]}; // Concatenation of intermediate wire
  13 assign t[3] = A[2] ^ B[3];               // Bitwise-XOR
  14
  15 // assign Y[2:0] = 3'b111;
  16 // assign Y[6:3] = A;
  17 // assign Y[9:7] = t[0:2];
  18 assign Y = {3'b111, A, t[2:0]};          // Direct assignment of concatenation
  19
  20 assign Z[0] = 1'b0;                      // Constant connects to PO
  21 assign Z[1] = t[3];                      // Intermediate sig connects to PO
  22 assign Z[3:2] = A[2:1];                  // PI connects to PO
  23 assign Z[7:4] = {1'b0, B[2:0]};          // Concat of CV and PI connect to PO
  24
  25 always @* begin
  26   if (A == 4'b1111) begin                // All-Const at port (eq)
  27     X = B;
  28   end
  29   else begin
  30     X = 4'b0000;                         // All-Const at port (mux)
  31   end
  32 end
  33
  34 endmodule