Data transfer apparatus that performs retransmission control and transfers data in real time

摘要

A data transfer apparatus includes a reception unit for receiving data from the first external device; a storage unit for storing the data received by the reception unit; an output unit for receiving data and outputting the data to a second external device; a retransmission request receiving unit for receiving a retransmission request signal from the second external device; and a transfer control unit for having a first transfer performed when the receiving unit has received data from the first external device, the first transfer transferring the data using direct memory access (DMA) directly to both the output unit and the storage unit in parallel, and having a second transfer performed when retransmission request receiving unit has received the retransmission request signal, the second transfer transferring data, which has already been stored in the storage unit by the first transfer, to the output unit.