66. Demultiplexer

/*Write your code here*/
module demux1to4 (
    input d,
    input [1:0]s, 
    output reg [3:0]y
);

    always @(*) begin 
        y = 4'b0000;
        case(s)
            2'b00: y[0] = d;
            2'b01: y[1] = d;
            2'b10: y[2] = d;
            2'b11: y[3] = d;
        endcase
    end

endmodule