Random access memory device

Abstract

To realize a semiconductor memory which can be operated at a low frequency without reducing a data transfer rate, the semiconductor memory according to the invention is configured so that a series of operation can be finished in two clock cycles of row address strobe operation and column address strobe operation for operating DRAM. Timing for turning a sense amplifier activation signal SE at a high level after delay time determined by a first delay element since a leading edge of a clock pulse CLK that turns a row address strobe pulse (/RAS) at a low level and activating a sense amplifier sequence is generated. Also, timing for starting read operation and write operation since a leading edge of the clock pulse CLK at which a column address strobe pulse (/CAS) is turned at a low level, turning the sense amplifier activation signal SE at a low level, turning a bit line precharge signal EQPR at a high level and starting precharge operation when the termination of reading and writing is detected is acquired.