Semiconductor memory device having redundant memory cells and circuit therefor

摘要

The semiconductor memory device includes at least one pair of redundant digit lines (RD,RDb), first input/output lines (IO,IOb) connected to a pair of digit lines (D,Db) via a respective sense amplifier (SA) and a switch (SW), second input/output lines (IO',IOb')connected to the redundant digit line pair (RD,RDb) via a sense amplifier (RSA) and switch (RSW), and selective amplifier means (IOSW, IOSW', RIOSW, RIOSW') for amplifying second input/output lines when redundant digit lines are selected. With this configuration, even when the redundant digit line pair is substituted for the digit line pair, it is possible to execute the redundancy operation by mere translation between these input/output line pairs.