Redundancy circuit and method for replacing defective memory cells in a flash memory device

摘要

A method and circuit are disclosed for replacing defective columns of flash memory cells in a flash memory device. The circuit includes a plurality of sets of storage elements, each set of storage elements being capable of identifying a single addressed column of memory cells is to be replaced or a main column line and regular columns of memory cells associated therewith to be replaced. In the event a main column line and the associated regular columns are identified for replacement by a set of storage elements, the set additionally indicates whether the regular columns are regular columns in a single block of memory cells or multiple blocks. Redundancy circuitry performs the replacement operation during a memory access operation based upon the information stored in the sets of storage elements. <IMAGE>