44. Bus Error Checker

How do you plan to solve it?

module error_checker_xz(
    input [7:0]bus,
    output all_known,output has_unknown,output [7:0] bus_if_known
);
assign has_unknown=(^(bus)===1'bx);
assign all_known=~has_unknown;
assign  bus_if_known=(all_known)?bus:8'b00;
endmodule