Semiconductor memory device capable of refresh operation in burst mode

Abstract

A semiconductor memory device comprising a memory cell array, a row decoder, an input/output register train, a burst counter, an input/output bus, a refresh counter and a multiplexer. The memory cell array includes a plurality of word lines, a plurality of bit line pairs and a plurality of memory cells. The input/output register train has a plurality of registers corresponding to the bit line pairs. Each of the registers is connected to the corresponding bit line pair. The input/output bus inputs and outputs data to and from the register train in response to a signal from the burst counter. The multiplexer supplies the row decoder with an external address signal as an internal address signal. After data is transferred from any bit line pair to the register or before data is transferred from any register to the bit line pair, the multiplexer supplies the row decoder with a refresh address signal from the refresh counter in place of the external address signal. This allows a refresh operation to take place during a burst read/write operation of data.