Clock synchronous semiconductor memory device having current consumption

Abstract

A synchronous semiconductor memory device includes a clock pulse generator generating internal first and second clock pulses in synchronization with an external clock signal for application, respectively, to a word line select decoder selecting a row of memory cells, and to a bit line select decoder selecting a column of memory cells, a sense amplifier sensing and amplifying a data of selected memory cell and a write driver writing a data to the selected memory cell. Word line select decoder is enabled when the first clock pulse is active, and bit line select decoder, sense amplifier and write driver are activated when the second clock pulse is active. These circuits are activated only for a necessary minimum period, and current consumption is reduced.