Redundant-storage memory

Abstract

A memory incorporates redundancy in the form of one or more redundant columns. An applied binary address is first distributed between predecoders which form a 1-out-of-2.sup.n code from n bits received. For each non-redundant column there is available a part of a main decoder, each part receiving a different combination of the bits supplied by the predecoders, thus selecting the column. For each redundant column there is provided a redundancy decoder. The latter decoder receives all bits supplied by the predecoders, each time via a series connection of a activatable gating element and a fuse element. Per predecoder the outputs of the series connections are combined in a wired logic function. Each wired logic function forms an input signal of the actual redundancy decoder. When a redundant column is to be addressed, all fuse elements but one of a group are opened and the gating elements are activated. A memory column to be replaced is then uncoupled by way of another fuse element.