Erased sector detection mechanisms
AssigneeSanDisk Corporation
InventorSergey Gorobets
Life of this patent
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Abstract
The present invention presents a non-volatile memory and method for its operation that allows instant and accurate detection of erased sectors when the sectors contain a low number of zero bits, due to malfunctioning cells or other problems, and the sector can still be used as the number of corrupted bits is under the ECC correction limit. This method allows the storage system to become tolerant to erased sectors corruption, as such sectors can be used for further data storage if the system can correct this error later in the written data by ECC correction means.
Claims32
A method of determining whether a unit of data of a memory is erased, comprising:
- inverting the data content of the unit of data;
- generating a error correction code syndrome for the inverted data content;
- performing a data correction on the inverted data content using said syndrome;
- and
- based on the corrected, inverted data content, determining whether the data content of the unit of data was erased.
A method of treating a unit of data of a memory, comprising:
- quantifying the level of corruption of the content of the unit of data based upon its associated error correction code;
- determining whether the level of corruption is acceptable;
- in response to determining that the level of corruption is acceptable, correcting the data content;
- and
- based on the corrected data content, determining whether the data content of the unit of data was erased.
A method of treating a unit of data of a memory, comprising:
- determining and quantifying the level of corruption of the content of the unit of data relative to an erased state based upon its associated error correction code;
- and
- determining whether the level of corruption is acceptable.
Dependencies are inferred from the claim text.