Abstract: A semiconductor memory device includes a plurality of sense amplifier groups, a sense amplifier drive circuit, a row decoder, and a memory array with a plurality of memory cells. Each sense amplifier group is activated according to a sense amplifier drive signal from the sense amplifier drive circuit. According to the timing of a word line selection in the row decoder and change in the sense amplifier drive signal, the semiconductor memory device has data of some memory cells connected to word line WLi copied speedily and selectively to other memory cells.