A semiconductor memory device includes a memory cell array arranged in rows and columns, a row decoder and a control circuit. The row decoder drives word lines connected to the memory cell array by decoding a received row address and being synchronized with an internal clock signal. The control circuit receives a clock signal, a chip select signal and a mode signal, and generates the internal clock signal. The control circuit generates the internal clock signal so that the row decoder does not operate for a predetermined time in response to the chip select signal when the mode signal transitions from a power saving mode to a normal mode.