Decoding circuit arrangement for redundant semiconductor storage systems

摘要

A decoding process and a decoding circuit arrangement for a redundant semiconductor memory is described, wherein the advantages of parallelly selecting non-defective word lines and redundant word lines at a low level are utilized for the writing as well as for the reading current in such a manner that high speed reading and writing is not affected. This is achieved in that the decoder for the redundant word lines consists of a comparator circuit and fuse-controlled switches, and that the input addresses are applied to a conventional address decoder as well as to the comparator circuit. The output of the comparator circuit is directly connected to the input of a first driver circuit for the redundant word line, and furthermore to an OR circuit which is also controlled by a read/write control circuit, and which is connected to the decoder and to a clamp circuit that is directly connected to the input of a second word line driver circuit, and continuously maintains the potential following a deselect signal applied on that level, which requires a minimum of power.