Semiconductor memory device capable of selectively enabling/disabling a first input unit and a second input unit in response to a first and second internal clock in a gear-down mode

Abstract

A semiconductor memory device includes a clock signal generation unit suitable for dividing an external clock signal to generate a first internal clock signal corresponding to odd number periods of the external clock signal and a second internal clock corresponding to even number periods, a first input unit suitable for receiving an external command signal and an external address signal in response to the first internal clock signal, a second input unit suitable for receiving the external command signal and the external address signal in response to the second internal clock signal, and an operation control unit suitable for enabling one of the first input unit and the second input unit and disabling the other of the first input unit and the second input unit, during a gear-down mode.