44. Bus Error Checker

How do you plan to solve it?

/*Write your code here*/
module error_checker_xz(
    input [0:7] bus,
    output all_known, has_unknown,
    output [7:0] bus_if_known
);
    wire any_xz =(^(bus ^ bus)) === 1'bx;

    assign all_known = any_xz ? 1'b0 : 1'b1;
    assign has_unknown = ~all_known;
    assign bus_if_known = all_known ? bus : 8'h00;
endmodule