US Patent 10187062 Semiconductor memory device, method, and program

According to one embodiment, a semiconductor memory device that is not equipped with an operating state notification terminal for providing notification of the operating state of the memory device includes a data bus comprising a plurality of signal lines and a controller configured to adjust an impedance of a signal line when the memory device is in a busy state and cannot receive signals transmitted thereto so as to provide notification of the operating state of the memory device during ZQ calibration.