<p>A data transfer control system in a data transfer apparatus (3) including a plurality of data processing units (1) having different data transfer speeds and a temporarily holding circuit (5) provided between the data processing units for temporarily holding data transferred between the data processing units. The data transfer apparatus sends a transfer request of data corresponding to a data storage capacity of the temporarily holding circuit of the data transfer apparatus to the data processing unit on the side of sending data and sends a transfer request of data corresponding to the data storage capacity of the temporarily holding circuit after an elapse of a delivering time of data to an information processing unit on the data transferred side of the temporarily holding circuit from sending of the data transfer request while the requested data from the data processing unit on the data sending side reaches the temporarily holding circuit of the data transfer apparatus. <IMAGE></p>
