Staged partitioned communication bus for a multi-port bridge for a local area network

Abstract

A staged partitioned communication bus for interconnecting the ports of a multi-port bridge for a local area network. The communication bus is partitioned into a plurality of data bus segments. Each data bus segment is coupled to one or more ports of the multi-port bridge and includes a same number of signal lines. A multiplexer is coupled to each data bus segment and to a memory device. A bus controller is coupled to each port and to the multiplexer. Each port requests access to the memory device from the bus controller for storing packets in the memory device and for retrieving packets therefrom. In response, the bus controller conditions the multiplexer to provide a signal path between the memory device to and the data bus segment which includes the requesting port. The memory device temporarily stores packets undergoing communication between the ports. Accordingly, a source port for a packet transfers the packet to the memory device via the multiplexer and, then, a destination port for the packet retrieves the packet from the memory device via the multiplexer. If the source port and the destination port are on a same data bus segment and the destination port is not currently busy, the destination port receives the packet directly from the source port as the source port stores the packet in the memory device. A look-up bus can be included, which is operable independently of the staged partitioned bus, for correlating destination addresses for packets to identifications of destination ports.