Patent ID: 7106463

Claim:
A data communication system comprising a first data communication unit, and a second data communication unit communicating with said first data communication unit, one of said first and second data communication units comprising: a deciding unit adapted to decide a fixed packet length based upon information related to an upper limit packet length in which a packet is capable of being transferred by said second data communication unit, and information related to an allowable packet length in which a packet is allowable of being transferred by said first data communication unit, wherein said first communication unit comprises: a generating unit adapted to generate a plurality of packets having said fixed packet length decided by said deciding unit, by dividing variable length data to be transferred from said first data communication unit to said second data communication unit into the plurality of packets; a storage unit adapted to store the plurality of packets generated by said generating unit; and a DMA controller adapted to control DMA transfer of the plurality of packets having said fixed packet length stored in said storage unit to said second data communication unit, and wherein said fixed packet length decided by said deciding unit is the smaller of said upper limit packet length and said allowable packet length.