Fail safe refresh of data stored in NAND memory device

摘要

Methods, systems and devices provide for refreshing a data image stored on a NAND memory device. Aspects include sequentially copying each of a series of static data partitions into a scrub portion that does not store data image partitions identified in the partition table. The sequential copying begins with a last static data partition and proceeds sequentially to a first static data partition when the scrub portion occupies higher order addresses than the last address of the last static data partition. Alternatively, the sequential copying begins with the first static data partition and proceeds sequentially to the last static data partition when the scrub portion occupies addresses that are lower than the first address of the first static data partition. The partition table may be updated as each static data partition is stored to the scrub portion. Such operations enable fail-safe scrubbing and refreshing of data in a NAND device.

主权项

1. A method of refreshing a data image on a NAND memory device, wherein the data image is divided into series of partitions stored sequentially in the NAND memory device in which a first partition is stored in the NAND memory device beginning at a first address, a last partition is stored in the NAND memory device ending at a last address, and addresses of each partition are stored in a partition table, wherein the first address is a lower order address than the last address, the method comprising:
sequentially copying, as part of one refresh cycle, a series of static data partitions into a scrub portion of the NAND memory device that does not store data image partitions identified in the partition table, wherein sequentially copying the series of static data partitions into the scrub portion comprises:
individually copying each of the series of static data partitions beginning with a last static data partition and proceeding sequentially to a first static data partition when the scrub portion occupies one or more higher order addresses than the last address of the last static data partition in the series of static data partitions; andindividually copying each of the series of static data partitions beginning with the first static data partition and proceeding sequentially to the last static data partition when the scrub portion occupies one or more lower order addresses than the first address of the first static data partition of the series of static data partitions; and updating the partition table as each static data partition is stored to the scrub portion.