A method for controlling a portable device and which includes detecting one of a first unlock command for switching a state of a first display unit to an active state and maintaining a state of a second display unit in a locked state or a second unlock command for switching the state of the first display unit to the active state and switching the state of the second display unit to a ready-to-activate state; switching the states of the first and second display units to the active state and the ready-to-activate state, respectively, when the second unlock command is detected; detecting an unlock trigger; and switching the second display unit to the active state according to the detected unlock trigger.