A semiconductor memory device is capable of adjusting effective data period of data. The semiconductor memory device includes a buffering unit for buffering input data, a window adjusting unit, and a transmitting unit. The window adjusting unit is for adjusting a window of the buffered data outputted from the buffering unit in response to plural metal option. The window adjusting unit includes a first driving unit for driving an output node in response to the output signal from the buffering unit and a second driving unit for additionally driving the output node in response to the output signal from the buffering unit. Meanwhile, the transmitting unit delivers output of the window adjusting unit into a core block.