44. Bus Error Checker

How do you plan to solve it?

module error_checker_xz (
    input [7:0] bus,
    output all_known, has_unknown,
    output [7:0] bus_if_known
); 
    assign all_known = (^{bus, bus} === 1'b0) ? 1'b1 : 1'b0;
    assign has_unknown = ~all_known;
    assign bus_if_known = all_known ? bus : 8'h00;
endmodule