Time-slot interchanger for self-routing event building

An event builder based on a sorting network has been developed. The key components of the event builder are a comparator used as a node of the network, and a time slot interchanger (TSI), which arranges input data fragments. Since the data fragments determine their path in the network, no complicated software control is needed for the event builder. The sorting network has scalability for the size of the readout system, because of its recursive characteristics and capability of downsizing. In order to deduce these features, a time slot interchanger (TSI) was newly developed. The throughput of the data and scalability were examined for various speeds of the system clocks and the number of input channels. The TSI has sufficient scalability of the speed and the network-size.