MoNoC: A monitored network on chip with path adaptation mechanism

Complex systems on chip containing dozens of processing resources with critical communication requirements usually rely on the use of networks on chip (NoCs) as communication infrastructure. NoCs provide significant advantages over simpler infrastructures such as shared busses or point to point communication, including higher scalability, more efficient energy management, higher bandwidth and lower average latency. Applications running on NoCs with more than 10% of bandwidth usage attest that the most significant portion of message latencies refers to buffered packets waiting to enter the NoC, whereas the latency portion that depends on the packet traversing the NoC is sometimes negligible. This work presents an adaptive routing architecture, named Monitored NoC (MoNoC), which is based on a traffic monitoring mechanism and the exchange of high priority control packets. This method enables to adapt paths by choosing less congested routes. Practical experiments show that the proposed path adaptation is a fast process, enabling to transmit packets with smaller latencies, up to 9 times smaller, by using non-congested NoC regions.