Router switch applied to network-on-chip for supporting hard real-time communication

The invention provides a router switch applied to network-on-chip for supporting hard real-time communication. The router switch includes definition and recognition of message priorities and buffer, judge and output of the messages of different priorities. Different microchips of the messages can be stored in direction channels of a specific router switch input terminal. The direction channels are combined with the router and support that output of the microchips of high priorities is prior to output of the microchips of low priorities while the output of the microchips of the same priority follows a rule of order. Besides, the microchips in the same output direction are judged by a judging device in said direction based on fair turn and that output of the microchips of high priorities is prior to output of the microchips of low priorities in each corresponding channel is taken as the premise of the judgment. Therefore, by using the router switch based on buffer and judge of the microchips, the worst time of the messages with high priorities in each router is ensured and further a guarantee for meeting requirements for soft and hard real time communication at the same time is further provided.