Abstract: A hardware frame modifier apparatus where the functions of the virtual device and virtual host are combined so that a single processor may perform them is provided. The hardware frame modifier apparatus may virtualize command and status frames without a store and forward operation. The modified command and status frames are sent to the physical host and physical device. The hardware frame modifier apparatus used a virtual table, updated by the virtual device/virtual host, to determine the appropriate mapping of the logical storage device of the frames to a physical storage device. Based on this mapping, the hardware frame modifier changes the frame header to direct the frame directly to the physical storage device and to determine the appropriate conversion of command and status type. In this way, the number of store and forward operations required to send data frames to, or read from, the physical storage devices is reduced or eliminated, thus reducing the delay or latency.

Abstract: A method and system for transmitting data among a plurality of cards in a crossbar interconnect network having a plurality of cards each having source paths and destination paths utilizes a plurality of source arbitrators and a plurality of destination arbitrators each associated with the cards. The source arbitrators generate connection request commands from the source paths requesting access to a desired destination path and broadcasts the request for receipt by all of the destination arbitrators. The destination arbitrator associated with the desired destination path captures the connection request command and processes the command based on whether or not the desired destination path is busy. If the desired destination path is not busy, the destination arbitrator generates a connection command requesting a connection be made between the source path and the desired destination path.