MODEL BASED CONFIGURATION PARAMETER MANAGEMENT

• US 20160170871A1
• Filed: 02/02/2015
• Published: 06/16/2016
• Est. Priority Date: 12/12/2014
• Status: Active Grant

• Current Assignee: SanDisk Technologies LLC (Western Digital Corporation)
• Original Assignee: Sandisk Technologies Incorporated (Western Digital Corporation)
• Inventors: Perschon, Joshua, Hyun, Jea Woong, Lucky, Rick, Sun, Hairong, Peterson, James
• Granted Patent: US 9,916,237 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 12/0246 in block erasable memory, e.g. flash memory
• CPC Class Codes: G06F 2212/7201 Logical to physical mapping or translation of blocks or pages
• CPC Class Codes: G06F 2212/7202 Allocation control and policies
• CPC Class Codes: G06F 2212/7206 Reconfiguration of flash memory system
• CPC Class Codes: G06F 3/06 Digital input from, or digital output to, record carriers , e.g. RAID, emulated record carriers or networked record carriers
• CPC Class Codes: G06F 3/0631 by allocating resources to storage systems
• CPC Class Codes: G06F 3/0653 Monitoring storage devices or systems
• CPC Class Codes: G06F 3/0679 Non-volatile semiconductor memory device, e.g. flash memory, one time programmable memory [OTP]

Abstract

Apparatuses, systems, methods, and computer program products are disclosed for model based configuration parameter management. An association module is configured to group a plurality of erase blocks of a non-volatile memory medium based on an amount of time since data has been written to the plurality of erase blocks. A read module is configured to sample data of at least two word lines from at least one erase block from each of a plurality of groups of erase blocks. A configuration parameter module is configured to determine different read voltage thresholds for different word lines of groups of erase blocks using different read voltage threshold models for different groups based on sampled data.

Claims

1. A method comprising:

performing read operations for at least two sets of cells of a storage region of a non-volatile storage device in response to a trigger;

determining values for a configuration parameter for the at least two sets of cells based on the read operations; and

determining different values for the configuration parameter for other sets of cells of the storage region based on a behavior model of the values for the configuration parameter determined for the at least two sets of cells.

2. The method of claim 1, further comprising using values for the configuration parameter based on the behavior model for a group of one or more additional storage regions.

3. The method of claim 2, wherein the one or more additional storage regions are selected for the group based on an amount of time since data was written to the one or more additional storage regions.

4. The method of claim 1, wherein the behavior model comprises a linear model comprising a slope and an intercept determined based on the values for the configuration parameter determined for the at least two sets of cells.

5. The method of claim 4, wherein the slope comprises a negative slope such that values for the behavior model decrease as word line positions for the storage region increase.

6. The method of claim 1, further comprising determining different behavior models for different groups of storage regions grouped based on an amount of time since data was written to the storage regions of the different groups, read operations being performed for one or more storage regions from each of the different groups.

7. The method of claim 1, wherein the trigger comprises an age threshold being satisfied.

8. The method of claim 7, further comprising performing wear leveling for storage regions of the non-volatile storage device such that program/erase cycle counts for the storage regions are within a predefined range, the age threshold comprising a program/erase cycle count threshold.

9. The method of claim 1, wherein the at least two sets of cells comprise word lines and the storage region comprises an erase block of a non-volatile storage medium.

10. The method of claim 9, wherein the word lines are selected to be separated from ends of the erase block by at least one word line.

11. The method of claim 9, wherein the behavior model is determined based on read operations for at least two word lines from multiple different erase blocks of a die of the non-volatile storage medium and the behavior model is used for the configuration parameter for the entire die of the non-volatile storage medium.

12. The method of claim 1, wherein the configuration parameter comprises one or more read voltage thresholds for storage cells of the non-volatile storage device.

13. An apparatus comprising:

an association module configured to group a plurality of erase blocks of a non-volatile memory medium based on an amount of time since data has been written to the plurality of erase blocks;

a read module configured to sample data of at least two word lines from at least one erase block from each group of erase blocks; and

a configuration parameter module configured to determine different read voltage thresholds for different word lines of the groups of erase blocks using different read voltage threshold models for different groups based on the sampled data.

14. The apparatus of claim 13, further comprising a model module configured to determine the different read voltage threshold models for the different groups of erase blocks by interpolating read voltage thresholds for other word lines from the at least one sampled erase block from each group based on the sampled data from the at least two word lines from each group of erase blocks.

15. The apparatus of claim 14, further comprising a trigger module configured to determine that a trigger event has occurred, the read module configured to resample data from at least one erase block from each group of erase blocks and the model module configured to determine updated read voltage threshold models based on the resampled data, each in response to the trigger event.

16. The apparatus of claim 13, further comprising a trigger module configured to determine that a trigger event has occurred, the association module configured to regroup the plurality of erase blocks in response to the trigger event, the regrouping based on updated amounts of time since data has been written to the plurality of erase blocks.

17. The apparatus of claim 13, wherein the read module is configured to sample the data by rereading the data multiple times using different read voltage thresholds.

18. A system comprising:

a plurality of storage elements each comprising a plurality of storage regions; and

a controller for the storage elements, the controller classifying the storage regions by retention time, determining different read voltage threshold models for different retention time classifications, and using a read voltage threshold for a word line based on one of the read voltage threshold models and a position of the word line within one of the storage regions.

19. The system of claim 18, wherein the position of the word line within the storage region is between two word lines which the controller read to determine the one of the read voltage threshold models.

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