Failure logging mechanism to reduce garbage collection time in partially reused bad blocks
AssigneeSanDisk Technologies LLC
InventorsKaushik Kumar Bar, Chetan Agrawal, Dinesh Agarwal, Vimal Kumar Jain
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Abstract
A memory system logs failures to optimize garbage collection in partial bad blocks that are reused in non-volatile memory. A failure in a primary block may be logged in an inverse global address table. A garbage collection operation can reference the log in order to automatically avoid the failure in the primary block when the primary block is picked as the source block for garbage collection. Likewise, the garbage collection operation may scan only the logged wordlines in the secondary block when the secondary block is picked as the source block for garbage collection.
Claims20
A method for optimizing garbage collection in a memory device, the method comprising:
- identifying a program failure on a primary update block;
- recording the identified program failure and the primary update block with the identified program failure in a failure log;
- and
- operating the garbage collection by utilizing the failure log to avoid scanning portions of the primary update block with the program failure.
A method in a memory device with dual programming, the method comprising:
- identifying an error in a wordline of a primary update block;
- logging the identified error from the primary update block;
- and
- avoiding, during a garbage collection operation that utilizes the logging, a scan for fragments associated with the identified wordline.
A method comprising:
- identifying an error in a portion of a primary update block;
- updating an inverse global address table to include the identified error;
- and
- ignoring, during a garbage collection operation, a scan for the portion of the primary update block, wherein the garbage collection operation utilizes the inverse global address table to identify the error, further wherein a failure log that identifies the portion of the primary update block with the error.
Dependencies are inferred from the claim text.