Ernst Bodenstorfer

Multiple Input Digital Arbiter with Timestamp Assignment for Asynchronous Sensor Arrays

This paper introduces a novel concept for arbitrating the access of multiple asynchronous data sources to a shared communication bus, while adding a timestamp, which represents high precision temporal information, to sensor information. This principle is based upon an arbiter serving uncorrelated inputs and generating a stream of data packets. The information contained in the data packets consists of the address information identifying the data source, data from the source and a timestamp value with respect to the occurrence of the bus request (event) generated by the corresponding data source. To enhance the adaptability to particular applications, the time resolution can be varied. The proposed concept has the advantage of delivering a sorted output data stream of nearly concurrent events (labeled with the same timestamp) which is very advantageous for consecutive data processing. Furthermore, this arbitration method is very efficient as it enables the utilization of the maximum output transfer rate for a given clock frequency. A potential usage in asynchronous vision chips is intended. This concept is demonstrated using an asynchronous vision chip containing 512 autonomous optical sensor elements.