Isochronous packet transfer method, computer readable recording media recorded with control program for executing isochronous packet transfer, and bridge and packet transfer control lsi

Abstract

An isochronous packet transfer method is provided which can reduce a transmit buffer size required for isochronous packet transfer, and which can give a constant delay to an isochronous packet even if transmission of a cycle start packet is delayed. An isochronous packet received from an input side bus is input to a delay section, and this isochronous packet is delayed in accordance with delay information and is transmitted to an output side bus. Input side and output side cycle identification information generating sections respectively output cycle identification information which changes at a timing at which a cycle start packet is sent to the input side bus and the output side bus. Input side and output side reference cycle identification information generating sections sample the input side and output side cycle identification information at predetermined timing and output input side and output side reference cycle identification information. A delay information generating section adds a fixed delay to a difference in the elapsed cycle number for each bus from the predetermined timing, based on input side and output side cycle identification information and input side and output side reference cycle identification information to generate delay information.