Smart Reconfiguration Approach for Fault-Tolerant NoC Based MPSoCs

Newest technologies of integrated circuits fabrication allow billions of transistors arranged in a single chip enabling to implement a complex parallel system, which requires a high scalable and parallel communication architecture, such as a Network-on-Chip (NoC). These technologies are very close to physical limitations increasing faults in manufacture and at runtime. Thus, it is essential to provide a fault recovery mechanism for NoC operation in the presence of faults. The preprocessing of the most probable fault scenarios and flits retransmission capability enable to anticipate the calculation of deadlock-free routings, reducing the time necessary to interrupt the system in a fault occurrence and maintaining links operating with retransmission capability. This work proposes a smart decisions mechanism for errors on NoC links, which is composed of a hardware part implemented into the links and routers, and a software part implemented inside an operating system kernel of each processor. The mechanism defines thresholds where is better to reconfigure the NoC or to retransmit flits with errors. Experimental results, with several NoC sizes and some error models, suggest when is better to reconfigure the NoC and when is better to maintain some links operating with eventual faults.