1. An image forming apparatus comprising: a communication interface configured to receive data; a buffer configured to store the data received by the communication interface; a main system configured to process the data stored in the buffer; a subsystem configured to be controlled by the main system to perform a function of the image forming apparatus; a system control unit configured to switch an operation status mode of the image forming apparatus between a normal status mode in which the main system and the subsystem are turned on and a deep sleep status mode in which the main system and the subsystem are turned off; and a data processing unit configured to, when the operation status mode is the deep sleep status mode, process the data received from the buffer if the data is determined to be processable by the data processing unit, and cause the system control unit to switch the operation status mode from the deep sleep status mode to the normal status mode if the data received from the buffer is determined not to be processable by the data processing unit.