Techniques for preventing read disturb in NAND memory
AssigneeIntel Corporation
InventorsArun Sitaram Athreya, Shankar Natarajan, Sriram Natarajan, Yihua Zhang, Suresh Nagarajan
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Abstract
Techniques for preventing read disturb in NAND memory devices are described. In one example, reads are tracked for sub-groups. When the number of reads to a sub-group meets a threshold, the data at the wordline on which the threshold was met is moved along with the data at neighboring wordlines to an SLC block without moving the entire block. The performance impact and write amplification impact of read disturb mitigation can be significantly reduced while maintaining some data continuity.
Claims18
A non-volatile storage device comprising:
- a NAND storage array including blocks of memory cells;
- logic to:
- receive a read request to access a wordline in a first NAND memory block, each memory cell at the wordline to store two or more bits;
- detect that a number of reads to the wordline exceeds a threshold;
- move data stored at the wordline to an SLC (single level cell) buffer;
- and
- update an address map pointer to direct subsequent read requests for the wordline to the SLC buffer.
A system comprising:
- a three-dimensional (3D) NAND array including blocks of NAND memory cells;
- a controller to access the 3D NAND array;
- and
- logic to:
- detect that a number of reads to a wordline in a first NAND memory block exceeds a threshold including to detect that a read counter for the wordline exceeds the threshold, each memory cell at the wordline to store two or more bits;
- and
- cause data stored at the wordline to be moved to an SLC (single level cell) buffer.
An article of manufacture comprising a computer readable storage medium having content stored thereon which when accessed causes processing circuitry to execute operations to perform a method comprising:
- receiving a read request to access a wordline in a first NAND memory block, each memory cell at the wordline to store two or more bits;
- detecting that a number of reads to the wordline exceeds a threshold;
- and
- moving data stored at the wordline to an SLC (single level cell) buffer, including moving second data stored at two or more neighboring wordlines without moving all the data stored in the first NAND memory block.
Dependencies are inferred from the claim text.