A dual mode display-port connector including a host-side auxiliary interface, a display-side auxiliary interface, and a cable. Each of the host-side auxiliary interface and the display-side auxiliary interface includes a bi-directional converter and a direct-current (DC) balancing codec. The bi-directional converter converts differential auxiliary signals received via one side thereof into a single auxiliary signal and a single auxiliary signal received via another side thereof into differential auxiliary signals. The direct-current (DC) balancing codec performs DC balancing encoding on a single auxiliary signal received via one side thereof, and decodes an encoded single auxiliary signal obtained through an encoding process and received via another side thereof.