US 7,849,381 B2Granted

Method for copying data in reprogrammable non-volatile memory

AssigneeSanDisk Corporation

InventorAndrew Tomlin

Life of this patent

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Abstract

Methods are presented for improving data relocation operations. Rather than check data quality based on its associated error correction code (ECC) in every relocation operation, it can determine whether to check ECC based on predetermined selection criteria: if ECC checking is not selected, the memory can perform an on-chip copy of the data from a first location to a second location. If ECC checking is selected, the data is transferred to the controller and checked; when an error is found, a correction operation is performed and when no error is found, an on-chip copy is performed. Predetermined selection criteria may comprise a sampling mechanism, which may be random based or deterministic. Additionally, data transfer flags can be introduced to indicate data has been corrected and should be transferred back to the memory. Header and user data can be considered separately if each has a distinct associated ECC.

Claims14

Dependent claims

A method for copying data having an associated error correction code (ECC) from a first location to a second location of a reprogrammable non-volatile memory array of a system that includes a memory controller and a memory portion having said memory array, comprising:

reading the data from the first location into a cache on the memory portion;
determining whether to check the ECC based on predetermined selection criteria, and if ECC checking is not selected, causing the system to copy the data from the cache to the second location without transferring the data to the controller;
and
if ECC checking is selected, checking the ECC on the read data in the controller, including:
if an ECC error is found, correcting the ECC error on the read data in the controller and causing the controller to write the corrected data to the second location of the memory array;
and
if an ECC error is not found, causing the memory to copy the data from the cache to the second location without transferring the data to the controller.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 11/022,350Filed 21 Dec 2004
Published: US 2006/0156189 A113 Jul 2006
Granted: 7 Dec 2010
Term ends: Not estimatedThe source records don’t support an estimate.

Classification4 codes

G06F 12/0246
Memory management in non-volatile memory, e.g. resistive RAM or ferroelectric memory: in block erasable memory, e.g. flash memory
G06F 11/1068
In individual solid state devices: in sector programmable memories, e.g. flash disk
G06F 2212/7203
Details relating to flash memory management: temporary buffering, e.g. using volatile buffer or dedicated buffer blocks
G06F
Computing and data processing