N-bit logical shifter

module logical_shift (si, sel, so);

        parameter N=8;
//By varying the parameter value you can change the width of shift register

        input  [N-1:0] si;
        input  [1:0] sel;
        output reg [N-1:0] so;

        always @(si or sel)
                case (sel)
                        2’b00   : so = si;
                        2’b01   : so = si << 1;  //shifts by 1-bit
                        2’b10   : so = si << 2;  //shifts by 2-bit
                        default : so = si << 3; //shifts by 3-bit 
                endcase
        endmodule