Configuration parameter management for non-volatile data storage

• US 10,332,604 B2
• Filed: 11/30/2017
• Issued: 06/25/2019
• Est. Priority Date: 11/19/2014
• Status: Active Grant

• Current Assignee: SanDisk Technologies LLC (Western Digital Corporation)
• Original Assignee: SanDisk Technologies LLC (Western Digital Corporation)
• Inventors: Peterson, James, Janik, Gary, Hyun, Jea
• Primary Examiner(s): Yang, Han
• Application Number:
  US15/828,407
• Publication Number:
  US 20180090213A1
• Time in Patent Office: 572 Days
• Field of Search: 365200, 365201
• CPC Class Codes: G11C 11/5642 Sensing or reading circuits; Data output circuits
• CPC Class Codes: G11C 16/20 Initialising; Data preset; Chip identification
• CPC Class Codes: G11C 16/26 Sensing or reading circuits; Data output circuits
• CPC Class Codes: G11C 16/3418 Disturbance prevention or evaluation; Refreshing of disturbed memory data
• CPC Class Codes: G11C 16/349 Arrangements for evaluating degradation, retention or wearout, e.g. by counting erase cycles
• CPC Class Codes: G11C 2029/4402 Internal storage of test result, quality data, chip identification, repair information
• CPC Class Codes: G11C 2211/5641 Multilevel memory having cells with different number of storage levels
• CPC Class Codes: G11C 29/028 with adaption or trimming of parameters
• CPC Class Codes: G11C 8/12 Group selection circuits, e.g. for memory block selection, chip selection, array selection

Abstract

Apparatuses, systems, and methods are disclosed for managing configuration parameters for non-volatile data storage. A control module is configured to limit erase dwell times for blocks of a non-volatile memory medium to satisfy a threshold. A block classification module is configured to group blocks of a non-volatile memory medium based on retention times for the blocks. A block access module is configured to access at least one group of blocks using a read voltage threshold selected based on a grouping.

Claims

1. A method comprising:

programming and erasing blocks of a non-volatile storage medium such that variation of an erase dwell time for the blocks remains within a predetermined range;

grouping the blocks of the non-volatile storage medium based on retention times for the blocks; and

accessing at least one of the groups of blocks using a configuration parameter selected based on the grouping.

2. The method of claim 1, further comprising storing a single set of one or more configuration parameters per group such that the single set for a group is used for blocks of the group.

3. The method of claim 1, wherein the blocks are grouped using larger ranges of retention times for groups associated with larger retention times.

4. The method of claim 1, further comprising controlling variation for a program/erase cycle count for the blocks of the non-volatile storage medium.

5. The method of claim 1, wherein the erase dwell time comprises an elapsed time between erasing one of the blocks and writing data to the erased block.

6. The method of claim 1, wherein grouping the blocks is further based on one or more of one or more of die-to-die variation and a partially programmed state for one or more of the blocks of the non-volatile storage medium.

7. The method of claim 1, further comprising storing, for each group, a set of one or more threshold values for boundaries between discrete values stored by storage cells of the non-volatile storage medium.

8. The method of claim 1, further comprising updating the configuration parameter for a block in response to regrouping the block based on a change in a retention time for the block.

9. The method of claim 1, further comprising determining a new configuration parameter for at least one of the groups of blocks in response to a change in a program/erase cycle count.

10. The method of claim 9, wherein determining the new configuration parameter for one of the groups of blocks comprises:

sampling one or more blocks from the group;

accessing the sampled blocks multiple times with different values for the new configuration parameter; and

selecting a value from the different values for the new configuration parameter based on an error characteristic for the sampled blocks.

11. The method of claim 9, wherein determining the new configuration parameter for one of the groups of blocks comprises selecting the new configuration parameter from a set of predetermined configuration parameters based on the grouping.

12. The method of claim 9, wherein the change in the program/erase cycle count comprises the program/erase cycle count satisfying a threshold.

13. An apparatus comprising:

a control module configured to limit erase dwell times for blocks of a non-volatile memory medium to satisfy a threshold;

a block classification module configured to group blocks of a non-volatile memory medium based on retention times for the blocks; and

a block access module configured to access the at least one group of blocks using a read voltage threshold selected based on the grouping.

14. The apparatus of claim 13, further comprising a configuration parameter module configured to store a single set of one or more read voltage thresholds per group such that the single set for a group is used for blocks of the group.

15. The apparatus of claim 13, wherein an erase dwell time comprises an elapsed time between erasing a block and writing data to the block.

16. The apparatus of claim 13, wherein the block access module is configured to use a first read voltage threshold to access a fully programmed block and to use a second read voltage threshold, different from the first read voltage threshold, to access a partially programmed block.

17. A system comprising:

a non-volatile storage device comprising a non-volatile storage medium; and

a controller for the non-volatile storage device, that

manages variation of erase dwell times for blocks of the non-volatile storage medium,

categorizes the blocks into groups based on retention times, and

configures different groups to use different read voltage thresholds based on the retention times.

18. The system of claim 17, wherein the controller updates a read voltage threshold for a block in response to regrouping the block based on a change in a retention time for the block.

19. The system of claim 17, wherein the controller updates a read voltage threshold for at least one of the groups in response to a change in a program/erase count.

20. The system of claim 17, wherein the controller comprises one or more of a hardware controller for the non-volatile storage device and a device driver for the non-volatile storage device, the device driver comprising computer executable code stored on a non-volatile computer readable storage medium.