PURPOSE: To attain normal access without altering an access cycle for an input device at a different access time by setting the frequency of the access for the input device according to the access time of the connected input device, and repeating the access in the set frequency.

CONSTITUTION: When a data processing means 105 accesses an input device 101 at the prescribed cycle, the access in the frequency corresponding to the access time of the input device 101 is repeated, and data sent from the input device 101 at prescribed timing are controlled so as to be read. Since the address data to designate the input device 101 are outputted at every access cycle, in an interface control means 107, its latch and the sending timing of the data from the input device 101 are controlled. Consequently, when the input device at the different access time is altered, it can be coped with by altering the frequency of its access. Thus, the alteration of hardware for the access cycle alteration can be made unnecessary.