Delay overhead in a memory device is eliminated.A command accepting unit accepts a read command requesting data reading from the memory device. A control unit selects, in accordance with a state of the memory device, one of a first mode in which a read request, requesting data reading from a memory cell array of the memory device and output of the read data, is issued to the memory device after completion of a preceding request and a second mode in which a sense request requesting data reading from the memory cell array is issued and then a data-out request requesting output of the data read by the sense request is issued to the memory device after a lapse of predetermined time from completion of the preceding request. A request issuing unit issues a request to the memory device in accordance with the first or the second mode selected by the control unit.