System for transmitting data between systems using selected subsets of plural interconnecting bus lines and including selection of a compatible transmission speed

摘要

A method and apparatus for transmitting data between nodes connected to a communications bus, preferably a computer backbone, divides a full bus width into a plurality of sub-buses. Each sub-bus can be independently operated, and each node on the network can connect to one or more of the sub-buses. The apparatus provides, at a transmitting node, a determination of which sub-buses are available to transmit a data packet to one or more receiving nodes. The data words are divided into sub-words, thereby reducing the memory access time requirements and saving memory costs. In accordance with a particular embodiment, the header, at the beginning of the data packet, and the error check control, provided at the end of the data packet, are sent at a slower speed than the data information portion of the packet. The data information portion of the packet is sent at the highest speed compatible with the receiving node or nodes. In case one sub-bus fails, a node can transmit data over the other sub-buses available to it.