SEMICONDUCTOR MEMORY REDUNDUNCY

摘要

A redundancy device increases redundancy efficiency in a semiconductor memory device. Block select signals BLS each determined by a row address are applied to a fuse circuit MFB which also receives column addresses and generates redundancy signals REN. These are passed via selector circuits RS to redundant column decoders RCD, and to a circuit NDC for controlling normal column decoders NCD. Use of both a row address and column address for column redundancy control permits a decrease in the area of redundant cell array as well as an increase in the efficiency of the redundancy operation.