SEMICONDUCTOR MEMORY DEVICE, ZQ CALIBRATION OPERATION CONTROLLING CIRCUIT OF THE SAME AND METHOD FOR ZQ CALIBRATION OPERATION OF THE SAME

摘要

A semiconductor memory device, a ZQ calibration operation control circuit and a ZQ calibration method of the semiconductor memory device are provided to perform initial ZQ calibration operation of the semiconductor memory device properly. An auto calibration signal generation part(200) generates an auto calibration signal when a memory device is initialized. A ZQ calibration signal generation part(100) generates a ZQ calibration signal enabling the memory device to perform ZQ calibration operation in response to a ZQ calibration command. A calibration control part(300) controls ZQ calibration operation in response to the auto calibration signal and the ZQ calibration signal.