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

Abstract

A transparently 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 bus segments, each segment coupled to one or more ports of the multi-port bridge and including a same number (n) of signal lines. A controller pre-charges each signal line to a logic high voltage level by activating pre-charge transistors coupled between a voltage supply and a plurality of diodes, each diode coupled to a corresponding one of the signal lines. The pre-charging operation includes all the signal lines. The ports request access to the partitioned bus. A port having been granted access to the partitioned bus applies data to its associated bus segment. The transparent controller then senses the data applied by the port via sense lines. Then, the transparent controller replicates this data to each other bus segment by discharging appropriate ones of the signal lines of each other bus segment via appropriate ones of a plurality of discharge transistors. The discharge transistors are coupled to between each signal line and ground. This technique results in the data being quickly replicated to the other bus segments. Accordingly, the bus is “transparently” partitioned such that the bus segments, in conjunction with the controller, form a single logical bus by which the ports communicate data. A principle advantage is that the entire bus cycle can be made shorter than a bus cycle for a non-partitioned bus.