4 to 16 decoder AKA 74HC154

decoder_4to16.v

module decoder_4to16 (
	input  enable,
	input [3:0] binary_in,
	output reg [15:0] decoder_out
);

always @ (enable or binary_in)
begin
  if (enable) begin
    case (binary_in)
      4'h0 : decoder_out = 16'h0001;
      4'h1 : decoder_out = 16'h0002;
      4'h2 : decoder_out = 16'h0004;
      4'h3 : decoder_out = 16'h0008;
      4'h4 : decoder_out = 16'h0010;
      4'h5 : decoder_out = 16'h0020;
      4'h6 : decoder_out = 16'h0040;
      4'h7 : decoder_out = 16'h0080;
      4'h8 : decoder_out = 16'h0100;
      4'h9 : decoder_out = 16'h0200;
      4'hA : decoder_out = 16'h0400;
      4'hB : decoder_out = 16'h0800;
      4'hC : decoder_out = 16'h1000;
      4'hD : decoder_out = 16'h2000;
      4'hE : decoder_out = 16'h4000;
      4'hF : decoder_out = 16'h8000;
      default : decoder_out = 0;
    endcase
  end
  else begin
    decoder_out = 0;
  end
end

endmodule