Semiconductor memory device for determining operation state with detecting frequency of input clock signal

Abstract

A semiconductor memory device of the disclosure comprises a frequency detection circuit that detects the frequency of an input clock signal generated during a measurement time and generates a frequency confirmation data having the information on the frequency of the input clock signal; a status register that receives the frequency confirmation data and generates 1-st to m-th driving control signals; and a 1-st to an m-th operating circuit. In the semiconductor memory device of the disclosure, the operating state can be changed by detecting a frequency change of an input clock signal without an external mode register setting command. As a result, according to the semiconductor memory device of the disclosure, the time required to change the operating mode is reduced.