There is provided a semiconductor device, which includes a calibration code generator circuit configured to generate a calibration code according to changes in external conditions, a first driver circuit configured to output a data signal with an impedance value controlled by the calibration code, an emphasis control circuit configured to generate an emphasis data signal using the data signal, and to change the calibration code according to an operating frequency to generate an emphasis code; and a second driver circuit configured to output the emphasis data signal with an impedance value controlled by the emphasis code.