CONFIGURATION PARAMETER MANAGEMENT FOR NON-VOLATILE DATA STORAGE

• US 20160141042A1
• Filed: 01/21/2015
• Published: 05/19/2016
• Est. Priority Date: 11/19/2014
• Status: Active Grant

• Current Assignee: SanDisk Technologies LLC (Western Digital Corporation)
• Original Assignee: Sandisk Technologies Incorporated (Western Digital Corporation)
• Inventors: Peterson, James, Janik, Gary, Hyun, Jea
• Granted Patent: US 9,852,799 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• 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 manage differences in one or more storage characteristics for blocks of a non-volatile memory medium within one or more established limits. A block classification module is configured to group blocks of a non-volatile memory medium based on one or more other storage characteristics. A configuration parameter module is configured to use a configuration parameter for at least one group of blocks based on a grouping. A configuration parameter update module is configured to update a configuration parameter for at least one group in response to a change in one or more managed storage characteristics.

Claims

1. A method comprising:

programming and erasing blocks of a non-volatile storage medium such that variation of one or more factors affecting an error rate for the blocks remains within a predetermined range;

grouping the blocks of the non-volatile storage medium based on one or more additional factors affecting the error rate; 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 one or more additional factors comprise a retention time for the blocks of the non-volatile storage medium.

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

5. The method of claim 1, wherein the one or more factors comprise a program/erase cycle count for the blocks of the non-volatile storage medium.

6. The method of claim 1, wherein the one or more factors comprise an erase dwell time for the blocks of the non-volatile storage medium, the erase dwell time comprising an elapsed time between erasing one of the blocks and writing data to the erased block.

7. The method of claim 1, wherein the one or more additional factors comprise 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.

8. 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.

9. 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 the one or more additional factors.

10. 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 the one or more factors.

11. The method of claim 10, 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.

12. The method of claim 10, 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.

13. The method of claim 10, wherein the change in one or more of the factors comprises a program/erase cycle count satisfying a threshold.

14. An apparatus comprising:

a control module configured to manage differences in a program/erase count for blocks of a non-volatile memory medium within one or more established limits;

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

a configuration parameter update module configured to update a read voltage threshold for at least one of the groups in response to a change in the program/erase count.

15. The apparatus of claim 14, 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.

16. The apparatus of claim 14, wherein the control module is configured to limit an erase dwell time to satisfy a threshold, the erase dwell time comprising an elapsed time between erasing the block and writing data to the block.

17. The apparatus of claim 14, further comprising a block access module 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.

18. A system comprising:

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

a controller for the non-volatile recording device, the controller managing variation of a program/erase count for blocks of the non-volatile recording medium, categorizing the blocks into groups based on retention times, and configuring different groups to use different read voltage thresholds based on the retention times.

19. The system of claim 18, wherein the controller updates a read voltage threshold for at least one of the groups in response to a change in the program/erase count.

20. The system of claim 18, wherein the controller comprises one or more of a hardware controller for the non-volatile recording device and a device driver for the non-volatile recording device, the device driver comprising computer executable code stored on a non-volatile computer readable storage medium.