Beneš Network-Based Efficient Data Concentrator for Triggerless Data Acquisition Systems

Abstract

The concentration of data from multiple links to a single output is an essential task performed by High-Energy Physics (HEP) Data Acquisition Systems (DAQs). At high and varying data rates combined with the large width of the concentrator’s output interface, this task is non-trivial. A high-speed dense packing of data from possibly non-continuous streams with preserving their time order requires complex and real-time adjustable routing. This paper presents a concentrator based on the Beneš network, which provides efficient concentration without using a high-frequency clock internally. It warrants that empty data are eliminated and does not disturb the data time-ordering if the data rates significantly differ between inputs. The concentrator uses simple data-routing primitives resulting in low resource consumption. If necessary, the pipeline registers may be added after each routing stage, shortening the critical path and increasing the maximum acceptable clock frequency. These features render the design well-suited to FPGA implementation.