71. Arithmetic Logic Unit

How do you plan to solve it?

a simple alu

/*Write your code here*/
module alu4(
    input [3:0] a,b,
    input [2:0] op,
    output reg [3:0] y,
    output reg cf
);
    reg car,bor;
    always @(*) begin
        y = 4'd0;
        cf = 1'b0;
        case (op)
            3'b000 : begin
                {car,y} = a + b;
                cf = car;
            end
            3'b001 : begin
                {bor,y} = a + ~b + 1'd1;
                cf = bor;
            end
            3'b010 : y = a & b;
            3'b011 : y = a | b;
            3'b100 : y = a ^ b;
            default : {cf,y} = 5'd0;
        endcase
    end
    
endmodule