Maximizing the Inner Resilience of a Network-on-Chip through Router Controllers Design

Reducing component size and increasing the operating frequency of integrated circuits makes the Systems-on-Chip (SoCs) more susceptible to faults. Faults can cause errors, and errors can be propagated and lead to a system failure. SoCs employing many cores rely on a Network-on-Chip (NoC) as the interconnect architecture. In this context, this study explores alternatives to implement the flow regulation, routing, and arbitration controllers of an NoC router aiming at minimizing error propagation. For this purpose, a router with Finite-State Machine (FSM)-based controllers was developed targeting low use of logical resources and design flexibility for implementation in FPGA devices. We elaborated and compared the synthesis and simulation results of architectures that vary their controllers on Moore and Mealy FSMs, as well as the Triple Modular Redundancy (TMR) hardening application. Experimental results showed that the routing controller was the most critical one and that migrating a Moore to a Mealy controller offered a lower error propagation rate and higher performance than the application of TMR. We intended to use the proposed router architecture to integrate cores in a fault-tolerant NoC-based system for data processing in harsh environments, such as in space applications.