An SET Tolerant Tree Arbiter Cell

Due to their inherently in deterministic behavior arbiters cannot simply be made fault tolerant by replication. We present an in-depth analysis of a tree arbiter cell with respect to possible faults and failure modes. Based on these results we devise a fault tolerant implementation of this cell that carefully avoids all single points of failure and can hence withstand transient faults as well as bit flips in its stateful elements. We verify the fault tolerance of our implementation by means of model checking and compare its overheads and performance penalties with a TMR-based solution. While the validation confirms that our approach is indeed suitable for use within an overall fault tolerance concept, the penalties turn out to be lower than for a comparable TMR approach.