Disclosed herein is a device that includes a replica buffer circuit that drives a calibration terminal, a reference-potential generating circuit that generates a reference potential, a comparison circuit that compares a potential appearing at the calibration terminal with the reference potential, and a control circuit that changes an output impedance of the replica buffer circuit based on a result of a comparison by the comparison circuit. The reference-potential generating circuit includes a first potential generating unit activated in response to an enable signal and a second potential generating unit activated regardless of the enable signal, and an output node of the first potential generating unit and an output node of the second potential generating unit are commonly connected to the comparison circuit.