A semiconductor memory device is capable of securing margins of setup/hold times for receiving addresses. The device includes an address buffering unit, a data input/output line, a selecting unit and an output circuit. The address buffering unit buffers input addresses. The data input/output line transfers data with a cell array. The selecting unit selectively outputs the buffered addresses transferred from the address buffering unit and the data transferred through the data input/output line according to modes of the device. The output circuit latches an output of the selecting unit to be outputted from the device.