Data retention (DR) warning system
AssigneeWestern Digital Technologies, Inc.
InventorsLisha Wang, Jinyoung Kim, Andrew Yu-Jen Wang, Jinghuan Chen, Kroum Stoev
Life of this patent
Estimating the term…
Abstract
Aspects of a storage device including a memory and a controller are provided. The controller may determine to perform garbage collection on a superblock. During the garbage collection process, the controller will typically move the superblock into an erase pool for erasing the superblock. However, aspects of the disclosure are directed to a method of measuring a raw bit error rate (RBER) of the superblock prior to erasure. The measured RBER may be used to estimate a data retention time of the storage device and provide the customer with an early warning notification if a health metric of the storage devices reaches a threshold retention time.
Claims14
A storage device, comprising:
- a memory comprising a first superblock and a second superblock;
- and
- a controller coupled to the memory and configured to:
- select the first superblock for an audit, wherein the first superblock is selected from an active pool of superblocks if no superblocks are held in an inactive pool of superblocks, and wherein the first superblock is selected from the active pool of superblocks based on the first superblock having a lowest health metric relative to other superblocks from the active pool;
- audit the first superblock to determine whether an amount of invalid data contained in the first superblock satisfies a threshold condition;
- determine to perform garbage collection on the first superblock based on satisfaction of the threshold condition;
- and
- in response to the determination to perform garbage collection and prior to erasure of invalid data from the first superblock:
- copy valid data from the first superblock to the second superblock if the first superblock is selected from the active pool of superblocks;
- and
- measure a first raw bit error rate (RBER) of the first superblock;
- and
- estimate a data retention time of the storage device based on the first RBER and a second RBER measured from the second superblock prior to the first superblock measurement.
A method for self-testing by a storage device, the method comprising:
- selecting a first superblock for an audit, wherein the first superblock is selected from an active pool of superblocks if no superblocks are held in an inactive pool of superblocks, and wherein the first superblock is selected from the active pool of superblocks based on the first superblock having a lowest health metric relative to other superblocks from the active pool;
- auditing the first superblock of the storage device to determine whether an amount of invalid data contained in the first superblock satisfies a threshold condition;
- determining to perform garbage collection on the first superblock based on satisfaction of the threshold condition;
- and
- in response to the determination to perform garbage collection and prior to erasure of invalid data from the first superblock:
- copying valid data from the first superblock to a second superblock of the storage device if the first superblock is selected from the active pool of superblocks;
- and
- measuring a first raw bit error rate (RBER) of the first superblock;
- and
- estimating a data retention time of the storage device based on the first RBER and a second RBER measured from the second superblock prior to the first superblock measurement.
Dependencies are inferred from the claim text.