EEPROM-Karte mit Austauch von fehlerhaften Speicherzellen und Zwischenspeicher

摘要

A system of Flash EEPROM memory chips with controlling circuits serves as non-volatile memory such as that provided by magnetic disk drives. The memory cells of the Flash EEPROM are partitioned into a plurality of sectors that individually are erasable together as a unit. The individual sectors are provided with a user data portion and an overhead portion which allow for operations similar to that of a magnetic disk drive. In one embodiment, information about defect mapping of cells for a sector is maintained in the overhead portion and used to map defective cells or the whole sector to spare ones. In another embodiment, an error correction code of the data in the user data portion is maintained in the overhead portion.