US Patent 7640374 Data transfer apparatus by direct memory access controller

A DMA apparatus which reads data corresponding to a descriptor from memory, and a dividing unit in a descriptor management device divides one descriptor into a plurality of sub-descriptors. A plurality of DMA controllers produce a plurality of reading requests for reading data corresponding to the plurality of sub-descriptors from the memory. A memory controller reads the corresponding data from the memory according to the plurality of reading requests.