Concurrent error detection in asynchronous burst-mode controllers

We discuss the problem of concurrent error detection (CED) in a popular class of asynchronous controllers, namely burst-mode machines. We first outline the particularities of these clock-less circuits, including the use of redundancy to ensure hazard-free operation, and we explain how they limit the applicability and effectiveness of traditional CED methods, such as duplication. We then demonstrate how duplication can be enhanced to resolve these limitations through additional hardware for comparison synchronization and detection of error-induced hazards, which jeopardize the interaction of the circuit with its environment. Finally, we propose a transition-triggered CED method which employs a transition prediction junction to eliminate the need for hazard detection circuitry and hazard-free implementation of the duplicate. As indicated by experimental results, the proposed method reduces significantly the cost of CED, with an average of 22% in hardware savings.