A driving integrated circuit bonded to a mounting area of a display panel, the circuit including a plurality of connection contact pads electrically coupled to a plurality of signal pads in the mounting area, at least one test contact pad electrically coupled to at least one test pad in the mounting area, and a resistance measuring unit configured to charge an external capacitor electrically coupled to a bonding part of the test pad and the test contact pad and to measure a bonding resistance of the bonding part based on a magnitude or a discharging time of a charging voltage of the external capacitor.