A semiconductor memory device and method directed to performing a memory operation in a semiconductor memory device are provided. The method includes receiving a write command signal from a memory controller; receiving data from the memory controller, the data including n pieces of data, wherein the k-th piece of data comprises masking data to be masked; and receiving a data masking signal from the memory controller, the data masking signal including enable information that enables data masking, and non-enable information for not enabling data masking, wherein the enable information is used to mask the k-th piece of data. A latency between receiving the write command signal and receiving the enable information is less than a latency between receiving the write command and receiving the k-th piece of data.