A method of controlling processing in a mobile terminal comprising a plurality of controllers (180, 185), the method comprising: connecting with an external terminal; and synchronizing, by a second controller of the mobile terminal, data stored in the external terminal with data previously stored within the mobile terminal in response to a synchronization request received from the external terminal; characterized by: notifying, by the second controller, a first controller of the mobile terminal about the synchronization performed; displaying a synchronization screen on a display of the mobile terminal; continuing, by the second controller, the synchronization when a call signal is received during the synchronization; processing, by the first controller, the received call signal while the synchronization is processed by the second controller as a background process; displaying information related to the processing of the received call signal on the display while the received call signal is processed by the first controller; checking, by the first controller, whether the synchronization is being performed by the second controller (1859 upon completing the processing of the received call signal; continuing, by the second controller, the synchronization as a foreground process when the processing of the received call signal is completed; and re-displaying the synchronization screen on the display while the synchronization is continued as the foreground process. connecting with an external terminal; and synchronizing, by a second controller of the mobile terminal, data stored in the external terminal with data previously stored within the mobile terminal in response to a synchronization request received from the external terminal; characterized by: notifying, by the second controller, a first controller of the mobile terminal about the synchronization performed; displaying a synchronization screen on a display of the mobile terminal; continuing, by the second controller, the synchronization when a call signal is received during the synchronization; processing, by the first controller, the received call signal while the synchronization is processed by the second controller as a background process; displaying information related to the processing of the received call signal on the display while the received call signal is processed by the first controller; checking, by the first controller, whether the synchronization is being performed by the second controller (1859 upon completing the processing of the received call signal; continuing, by the second controller, the synchronization as a foreground process when the processing of the received call signal is completed; and re-displaying the synchronization screen on the display while the synchronization is continued as the foreground process. notifying, by the second controller, a first controller of the mobile terminal about the synchronization performed; displaying a synchronization screen on a display of the mobile terminal; continuing, by the second controller, the synchronization when a call signal is received during the synchronization; processing, by the first controller, the received call signal while the synchronization is processed by the second controller as a background process; displaying information related to the processing of the received call signal on the display while the received call signal is processed by the first controller; checking, by the first controller, whether the synchronization is being performed by the second controller (1859 upon completing the processing of the received call signal; continuing, by the second controller, the synchronization as a foreground process when the processing of the received call signal is completed; and re-displaying the synchronization screen on the display while the synchronization is continued as the foreground process.