Implementation of a fault-tolerant, globally-asynchronous-locally-synchronous, inter-chip NoC communication bridge on FPGAs

Abstract

Network-on-Chip (NoC) architectures were introduced to help mitigate the bottleneck and scalability issues faced by the traditional bus interconnect in Multi-Processor System-On Chip (MPSoC). Nowadays, many embedded systems host a significant number of micro-controllers and processors (i.e. vehicles, airplanes, satellites, etc.) and as this number continues to increase, traditional bus solutions will start to fail on those platforms as well. NoCs not only offer a scalable solution for MPSoC interconnects but they can also provide a uniform platform of communication to embedded systems with multiple off-chip, often heterogeneous, processors. This leads to the need for investigation on inter-chip communication bridges suitable for transmitting flits/packets across chips and possibly across clock domains. This paper investigates an inter-chip communication link, of an MPSoC NoC architecture which is extended with an off-chip, heterogeneous processor (node) and proposes a scalable, fault-tolerant, globally asynchronous locally synchronous bridge for inter-chip communication. The proposed bridge is implemented on a prototype board of the SEUD KTH experiment where it successfully enables the communication of a NoC distributed over two FPGAs. The inter-chip bridge is verified in-circuit achieving transfer speeds up to 24 MByte/s (≈ 1.5 Mflit/s) and its ability to correct single bit errors is demonstrated in simulation.