An access control device having a number-of-waits setting circuit determining a wait periodicity corresponding to an operating speed of peripheral devices connected to a second bus according to an address corresponding to an access request to the second bus sent from a first bus, responsive to the access request, and a count value generator generating a count value up to the wait periodicity set to the number-of-waits setting circuit. A control signal holding circuit holds a control signal for holding a state of the second bus at the setting of the wait periodicity by the number-of-waits setting circuit during a count period of the count value generator and maintains the access state of the status controller. A clock control circuit divides a clock for the first bus according to the wait periodicity set and outputs the result of division to the second bus.