Communication node with a first bus configuration for arbitration and a

Abstract

A node for a communication system that has a plurality of nodes, each of which may be coupled to a local host. The nodes are coupled between themselves in a tree topology by a plurality of point-to-point links. The interconnected nodes provide a first bus configuration for arbitration like a single bus. Following arbitration, the interconnected nodes provide a second configuration for high speed unidirectional data transfer without the bandwidth limitations of a single bus. Each node includes an arbiter, a data bus, a plurality of ports, a first multiplexer to select either the arbiter or the data bus, and a second multiplexer to select either the arbiter or the data bus. The data bus includes a transmit bus and a receive bus that are coupled with a repeater circuit that can resynchronize the data. During arbitration, the multiplexers select the arbiter to provide the function of a single bus for all the nodes. During data transfer, the multiplexers are configured for transmission of data. Furthermore, a node can function as a repeater and resynchronizer even if it is not connected to a local host or if the local host is turned off or otherwise nonoperational.