Block redundancy implementation in hierarchical RAMs

摘要

The present invention relates to a system and method for providing redundancy in a hierarchically memory, by replacing small blocks in such memory. The present invention provides such redundancy (i.e., replaces such small blocks) by either shifting predecoded lines (3202) or using a modified shifting predecoder circuit in the local predecoder block. In one embodiment, the hierarchal memory structure includes at least one active predecoder (3200A-3200D) adapted to be shifted out of use; and at least one redundant predecoder (3200E) adapted to be shifted in to use.