71. Arithmetic Logic Unit

How do you plan to solve it?

/*Write your code here*/
module alu4(input [3:0]a,b, input [2:0]op , output reg [3:0]y , output reg cf);
   
   reg bor;

   always @(*) begin

     case(op)
       
       3'b000 : {cf,y} = a + b;
       3'b001 : begin
            {cf,y} = a - b ;
            

       end
       3'b010 : begin
            y = a & b;
            cf = 0;
       end
       3'b011 : begin
            y = a | b;
            cf = 0;

       end
       3'b100 : begin
            y = a ^ b;
            cf = 0;

       end
       default : begin
            y = 4'b000;
            cf = 0;
       end

     endcase


   end


endmodule