Variations of the impedance of each output driver of a semiconductor device can be reduced, and high-speed calibration is achieved. A calibration circuit including a replica circuit having the same configuration as each pull-up circuit or pull-down circuit included in an output driver of a semiconductor device is provided within a chip. During a first calibration operation, the replica circuit is provided with voltage conditions that allow the maximum current to flow through the output driver so that an impedance of the replica circuit is equal to a value of an external resistor. During a second calibration operation, table parameters obtained in the first calibration operation are used to adjust the impedance of the output driver without use of the replica circuit.