Architecture of a reconfigurable low power gigabit ATM switch

Multistage switch interconnects like banyan switches are preferred in high speed networks for their cascadable structure and suitability for VLSI implementation. However most of these switch implementations are monolithic in nature and do not provide flexibility of dynamic re-routing of cells from active ports through idle ports. In this paper we take a critical look at a basic 8×8 benes switch from the perspective of identifying smaller blocks which can be pipelined in space and temporally multiplexed to exploit hardware reuse. A topological analysis of a 8×8 benes switch is carried out to identify mutually exclusive path sets that can be overlayed for hardware reuse. Based on this analysis we arrive at a basic building block called X-Structure, using which a 8×8 switch is constructed. The X-structure supports dynamic re-routing of cells and power down mode. A communication controller is designed using the the X-Structure based ATM switch at its core. A performance evaluation of the switch indicates a power saving of 66.66% due to hardware reuse, an 18.6% increase in hardware utilization and an aggregate throughput of 2.66 Gbps for a 8×8 switch