Fault tolerant implementation of a SpaceWire interface

Abstract

Due to cosmic radiation, semiconductor chips operating in space have to be protected particularly against Single Event Effects (SEE). The SpaceWire protocol is frequently used in space vehicles, connecting mission critical devices. To increase the reliability of a SpaceWire transceiver under these conditions, various fault tolerance concepts are presented, which protect the transceiver against Single Event Transients (SETs) and Upsets (SEUs). Within these concepts, the application of modular redundancy with information redundancy respectively with the error correction method at the SpaceWire protocol layer is combined to reduce the hardware overhead. This paper provides the evaluation of methods combining different circuit-level fault tolerant concepts with existing protocol-layer fault tolerance provided by SpaceWire standard. It will been shown that the concept utilizing Double Modular Redundancy is the most efficient one, while the application of hardware fault tolerance provides advantages only for high fault densities.