A electronic device includes a bus, two electronic elements connected to the bus, and a controller. Each of the two electronic element is designated a logic unit number (LUN) and a first temporary buffer identified by the LUN for storing messages transmitted from or to the corresponding electronic element by the bus. The controller for obtaining the LUN of the message transmitted from/to the at least two electronic element, determining the temporary buffer which the message is stored according to the obtained LUN, storing the message to the determined temporary buffer, and transmitting the message stored in the temporary buffer to the corresponding electronic element or processing the message stored in the temporary buffer.