Haverstock & Owens LLP
Apparatus for and method of separating header information from data in an IEEE 1394-1995 serial bus network
An apparatus for and method of separating protocol header information from content data in an IEEE 1394-1995 serial bus network. A receiving node receives isochronous data packets from a transmitting node via a serial bus. Each packet can include a data portion in addition to protocol header information, although not every packet necessarily includes the data portion. Each incoming packet is loaded into a buffer in the receiver as the packet is being received. The protocol header information is removed and stored in sequence in a first block of memory. This is accomplished by placing an input_more direct memory access (DMA) instruction into a next instruction register and, then, executing the instruction. In addition, the receiver is conditioned for removing the data portion from the buffer by loading an input_last DMA instruction into the next instruction register. If examination of the 1394 header information reveals that the packet includes a data portion in addition to the protocol header information, the input_last instruction is executed. This removes the data portion of the packet from the buffer and stores it in sequence in a second block of memory. Upon execution of the input_last instruction, the receiver is conditioned to await a next packet. If the packet does not include a data portion, the input_last instruction is replaced with a no_operation instruction. The no_operation instruction does not initiate any operations. Upon execution of the no_operation instruction, the receiver is conditioned to await a next packet.
Sony Electronics, Inc. Sony Corporation
H G H
H04L G06F H04L
inventional inventional inventional
Bruce Chen-Chi
Fairman Chou