PURPOSE: To provide an event driving type wake-up system for controlling current consumption by a microcontroller for controlling a data input device to be used for entering data to a data processing system.

CONSTITUTION: The event driving type wake-up system has the data input device 16 such as a keyboard and the device 16 supplies a signal expressing the generation of an external event such as the depression of a key on the keyboard in response to the external event. The microcontroller 14 has a means for detecting the nonactivity of the device 16 and entering the controller 14 to a reduced current consumption mode. When the controller 14 is in the reduced current consumption mode, wake-up logic 12 supplies an wake-up signal WAKEUP for releasing the controller 14 from the reduced current consumption mode in response to input signals from the input device 16 and/or the system 10.