Adaptive scans of memory devices of a memory sub-system

Patent metadata

Field	Value
Publication number	US-12572298-B2
Application number	US-202217579923-A
Country	US
Kind code	B2
Filing date	Jan 20, 2022
Priority date	Dec 22, 2021
Publication date	Mar 10, 2026
Grant date	Mar 10, 2026

Abstract

One or more media scan parameters associated with a memory device are maintained. A number of program erase cycles associated with the memory device is identified. Responsive to determining that the number of program erase cycles satisfies a criterion, one or more adjusted media scan parameters are generated by adjusting the one or more media scan parameters. A media scan of the memory device is performed according to the one or more adjusted media scan parameters.

First claim

What is claimed is:

1 . A system comprising:
a memory device; and a processing device, operatively coupled with the memory device, to perform operations comprising:
maintaining one or more media scan parameters associated with the memory device, wherein the one or more media scan parameters are associated with a frequency for performing media scans of the memory device, and wherein the one or more media scan parameters comprise a wordline scan interval;
identifying a number of program erase cycles associated with the memory device;
responsive to determining that the number of program erase cycles satisfies a criterion, generating one or more adjusted media scan parameters by adjusting the one or more media scan parameters, wherein the one or more adjusted media scan parameters increase the frequency for performing the media scans of the memory device by decreasing the wordline scan interval as the number of program erase cycles increases; and
performing a media scan of the memory device according to the one or more adjusted media scan parameters.

2 . The system of claim 1 , wherein the media scan parameters comprise a wordline scan interval.

3 . The system of claim 2 , wherein the memory device comprises a plurality of wordlines, and wherein performing the media scan of the memory device according to the one or more adjusted media scan parameters further comprises:
dividing the plurality of wordlines into the number of scan groups corresponding to the one or more adjusted media scan parameters; determining, according to the wordline scan interval, a data state metric for the wordlines in each scan group; and responsive to determining that the data state metric associated with one of the wordlines exceeds a folding threshold value, performing a media management operation with respect to a block comprising the wordline.

4 . The system of claim 1 , wherein the media scan parameters comprise at least one of a bit error count per page value or a valley width value.

5 . The system of claim 4 , wherein the memory device comprises a plurality of wordlines, and wherein performing the media scan of the memory device according to the one or more adjusted media scan parameters further comprises:
dividing the plurality of wordlines into the number of scan groups corresponding to the one or more adjusted media scan parameters; determining, according to a wordline scan interval, a data state metric for wordlines in each scan group, wherein the data state metric comprises at least one of a bit error count per page or a valley width; and responsive to determining that the data state metric associated with one of the wordlines exceeds at least one of the bit error count per page value or the valley width value, performing a media management operation with respect to a block comprising the wordline.

6 . The system of claim 1 , wherein determining that the number of program erase cycles satisfies the criterion comprises:
maintaining a media scan lookup table, wherein an entry in the media scan lookup table comprises a program erase count value and one or more media scan parameter values; and determining that the number of program erase cycles matches the entry in the media scan lookup table.

7 . The system of claim 6 , wherein adjusting the one or more media scan parameters comprises:
setting the one or more media scan parameters to the one or more media scan parameter values in the entry associated with the number of program erase cycles.

8 . A method comprising:
maintaining one or more media scan parameters associated with a memory device, wherein the one or more media scan parameters are associated with a first entry in a scan frequency lookup table, wherein the one or more media scan parameters are associated with a frequency for performing media scans of the memory device corresponding to a wordline scan interval, and wherein the first entry comprises a first wordline scan interval; identifying a number of program erase cycles associated with the memory device; responsive to determining that the number of program erase cycles has reached a predetermined interval, determining a performance metric associated with the memory device; responsive to determining that the performance metric satisfies a criterion, generating one or more adjusted media scan parameters by adjusting the one or more media scan parameters to values associated with a second entry in the scan frequency lookup table, wherein the second entry comprises a second wordline scan interval, wherein the second wordline scan interval is less than the first wordline scan interval, and wherein the one or more adjusted media scan parameters increase the frequency for performing the media scans of the memory device by decreasing the wordline scan interval as the number of program erase cycles increases; and performing a media scan of the memory device according to the one or more adjusted media scan parameters.

9 . The method of claim 8 , wherein the one or more media scan parameters comprise a number of scan groups and the wordline scan interval.

10 . The method of claim 9 , wherein the memory device comprises a plurality of wordlines, and wherein performing the media scan of the memory device according to the one or more adjusted media scan parameters further comprises:
dividing the plurality of wordlines into the number of scan groups; determining, according to the second wordline scan interval, a data state metric for the wordlines in each scan group; and responsive to determining that the data state metric associated with one of the wordlines exceeds a folding threshold value, performing a media management operation with respect to a block comprising the wordline.

11 . The method of claim 8 , wherein determining that the number of program erase cycles satisfies the predetermined interval responsive to determining that the number of program erase cycles is a multiple of a predetermined value.

12 . The method of claim 8 , wherein the performance metric is an average raw bit error count associated with a number of blocks in the memory device.

13 . The method of claim 8 , wherein determining that the performance metric satisfies the criterion comprises:
identifying a threshold performance metric value associated with the number of program erase cycles; and determining that the performance metric exceeds the threshold performance metric value.

14 . A non-transitory computer-readable storage medium comprising instructions that, when executed by a processing device, cause the processing device to perform operations comprising:
maintaining one or more media scan parameters associated with a memory device, wherein the one or more media scan parameters are associated with a frequency for performing media scans of the memory device, and wherein the one or more media scan parameters comprise a wordline scan interval; identifying a number of program erase cycles associated with the memory device; responsive to determining that the number of program erase cycles satisfies a criterion, generating one or more adjusted media scan parameters by adjusting the one or more media scan parameters, wherein the one or more adjusted media scan parameters increase the frequency for performing the media scans of the memory device by decreasing the wordline scan interval as the number of program erase cycles increases; and performing a media scan of the memory device according to the one or more media adjusted scan parameters.

15 . The non-transitory computer-readable storage medium of claim 14 , wherein the media scan parameters compri

Assignees

• Micron Technology Inc

Inventors

• Liu Yang
• Xu Zhongguang
• Lang Murong
• Zhu Fangfang

Classifications

• G06F3/0614

  Improving the reliability of storage systems · CPC title

• G06F3/0679

  Non-volatile semiconductor memory device, e.g. flash memory, one time programmable memory [OTP] · CPC title

• G06F11/3409

  for performance assessment · CPC title

• G06F11/073

  in a memory management context, e.g. virtual memory or cache management (memory management G06F12/00; testing of static memory units G11C29/00) · CPC title

• G06F11/076

  by exceeding a count or rate limit, e.g. word- or bit count limit · CPC title