an apparatus and a method for setting a routing path in system - on - a - chip having an n × n net topology - based structure comprising a plurality of intellectual properties , each with a unique address , and a plurality of switches forming one - to - one correspondence to the ips , to transmit and receive data between the ips by using at least one of the switches . accordingly , an orthogonal code having orthogonality is assigned according to the direction of transmission of each data . then , an output port where the data is transmitted is determined , and the data is spread based on an orthogonal code assigned to the output ports of the at least one of the switches .