Patent ID: 6742063
Filing Date: 2004-05-25
Classification: G06F,Y02D

Abstract:
A method for use in a data processing system for transferring a data packet between a data processing unit (DPU) having a first data bus of a first bus width operating at a first speed and a data device having a second data bus of a second bus width operating at a second speed, the data packet including a plurality of data bytes and a header including information about packet size, the system including (1) data packet transfer circuitry (DTC) providing a buffered packet path between the first bus and the second bus and (2) a direct data path between the first bus and the second bus separate from the buffered packet path, the method comprising:a) transferring, via the direct data path, packet size information from the data device to the DPU prior to transfer of packet data bytes associated with the packet size information over the buffered packet path; b) setting a DTC byte counter based on the packet size information; c) receiving from the data device, via the second data bus and the buffered packet path, receive data bytes and feeding the receive data bytes to a DTC receive buffer; d) decrementing the DTC byte counter according to the number of receive data bytes; e) repeating steps c) and d) until the DTC byte counter reaches a terminal count; f) transferring the receive data bytes from the DTC receive buffer to a DTC packing buffer having a byte-width corresponding to the first bus width until the packing buffer is filled or the DTC byte counter reaches the terminal count; and g) transferring from the DTC packing buffer to the DPU, via the first data bus and the buffered packet path, data bytes stored in the DTC packing buffer, wherein the DTC receive buffer and DTC packing buffer define the buffered data packet transfer path separate from the direct data path.