/*Write your code here*/
module error_checker_xz(
input [7:0] bus,
output all_known,
output has_unknown,
output [7:0] bus_if_known
);
assign xr = ^(bus);
assign has_unknown = (xr === 1'bx);
assign all_known = ~has_unknown;
assign bus_if_known = all_known ? bus : 8'h00;
endmodule