Hardening an AMBA-AXI Network Interface for a Reliable Network-on-Chip

Systems-on-chip (SoCs) used in space and critical environments feature increasing cores. Because of the environment in which these systems operate, they must use fault tolerance techniques to improve reliability. XINA (eXtensible Interconnect Network Architecture) is a reliable network-on-chip for space systems, which has already been verified and tested. However, a network interface (NI) must provide communication services for its effective use in real systems. Therefore, this work presents the development of a fault-tolerant NI compatible with the XINA that implements communication services commonly adopted in SoCs. The NI implements the AMBA-AXI 5 communication protocol to facilitate and accelerate the core integration process with XINA. We present a standard and a fault-tolerant version of the NI using TMR (Triple Modular Redundancy) and Hamming ECC (Error Correction Code) techniques in its internal components. The fault-tolerant interfaces reduced the error propagation by up to 16.7× compared to the standard versions, at a price of 82% more LUTs (Look-Up-Tables) and 23% more FFs (Flip-Flops) on average.