Symmetric crossbar arbiters for VLSI communication switches

The design and implementation of symmetric crossbar arbiters are addressed. Several arbiter designs are compared based on simulations of a multistage interconnection network. These simulations demonstrate the influence of the switch arbitration policy on network throughput, average latency, and worst-case latency. It is shown that some natural designs result in poor system performance and/or slow implementations. Two efficient arbiter implementations are proposed. Based on network simulations, VLSI implementation, and circuit simulation, it is shown that these arbiters achieve nearly optimal system performance without becoming the critical path that limits the system clock