To carry out data processing with low load and at necessary timing even if a high performance device is not used, and to carry out precise data communication.
A first communication control part 132 converts a plurality of original data to be transmitted, into fixed length data packets by padding, and informs a second communication control part 122 of actual data lengths of these fixed length data packets, by a FIFO memory 146, and also, transmits these fixed length data to the second communication part 122 by DMA, and thereby, a CPU 123 of the second communication control part 122 restores original data from the fixed length data which was transmitted, at short times and with low load, on the basis of actual data lengths.