Data reliability information in a non-volatile memory device

• US 10,459,793 B2
• Filed: 03/17/2016
• Issued: 10/29/2019
• Est. Priority Date: 03/17/2016
• Status: Active Grant

• Current Assignee: Sandisk Technologies Incorporated (Western Digital Corporation)
• Original Assignee: Western Digital Technologies Incorporated (Western Digital Corporation)
• Inventors: Bandic, Zvonimir Z., Gunnam, Kiran Kumar, Song, Seung-Hwan
• Primary Examiner(s): Tu, Christine T.
• Application Number:
  US15/073,409
• Publication Number:
  US 20170269992A1
• Time in Patent Office: 1,321 Days
• Field of Search: 714764, 714765, 714766, 714767, 714799, 714800, 714801, 714802
• CPC Class Codes: G06F 11/1048 using arrangements adapted for a specific error detection or correction feature
• CPC Class Codes: G06F 11/108 Parity data distribution in semiconductor storages, e.g. in SSD
• CPC Class Codes: G11C 29/52 Protection of memory contents; Detection of errors in memory contents

Abstract

A data storage device may include a non-volatile memory array and a controller. The non-volatile memory array may include a plurality of dies. Each die of the plurality of data dies may include a plurality of words, where a word is an access unit of a die. The controller may be configured to store user data to a respective first word of at least a first die and a second die of the plurality of data dies. A page of user data may include the user data stored at the respective first words of the at least first die and second die. The controller may also be configured to store parity data to a first portion of a first word of a third die. The controller may be further configured to store metadata to a second portion of the first word of the third die.

Claims

1. A data storage device comprising:

a non-volatile memory array comprising a plurality of dies, wherein each die of the plurality of dies includes a plurality of words; and

a controller coupled to the non-volatile memory array, the controller includes a writes module including a data management module, and address translation module, a read module, and a maintenance module, wherein the controller is configured to;

store user data to of at least a first die and a second die of the plurality of dies;

store parity data to a first portion of a third die of the plurality of dies; and

store metadata to a second portion of the third die, wherein the metadata stored to the second portion of the third die is self-correctable, the non-volatile memory array further comprises a RAID die associated with the plurality dies, wherein the controller is further configured to;

detect errors using parity data in the self-correctable metadata stored to the second portion of the third die;

responsive to detecting errors in the self-correctable metadata, correct the errors using parity data in the self-correctable metadata stored to the second portion the third die;

generate redundancy data by performing an XOR operation of the third die, the first die, and second die; and

store, to the RAID die, the redundancy data.

2. The data storage device of claim 1, wherein:

a size of the first portion of the third die is based on an ECC strength associated with the parity data stored at the third die; and

a size of the second portion of the third die is based on a difference between a total size of the third die and the size of the first portion of the third die.

3. The data storage device of claim 2, wherein:

the size of the first portion of the third die is different than the size of the second portion of the third die.

4. The data storage device of claim 1, wherein the metadata includes a cell error identifier that indicates a location of a particular bit of the at least first die and second die that includes an error.

5. The data storage device of claim 1, wherein the metadata includes a page flip indicator that indicates whether user data was flipped by the controller prior to writing the user data to the at least first die and second die.

6. The data storage device of claim 1, wherein the metadata includes a time-stamp that indicates a time when at least the first die and second die were most recently accessed.

7. The data storage device of claim 1, wherein the metadata includes a disturbance counter that indicates a number of times the at least first die and second die have been read or a number of times the at least first die and second die have been written.

8. The data storage device of claim 1, wherein the controller is further configured to store user data to the first portion of the third die.

9. A method comprising:

storing, by a controller, user data to a first die and a second die of a plurality of dies of a non-volatile memory array;

storing, by the controller, parity data to a first portion of a third die of the plurality of dies; and

storing metadata to a second portion of the third die, wherein the metadata stored to the second portion of the third die is self-correctable, the memory array further comprises a RAID die associated with the plurality of dies, the method further comprising;

detecting, by the controller, errors in the self-correctable metadata stored to the second portion of the third die;

responsive to detecting errors in the self-correctable metadata, correcting, by the controller, the errors in the self-correctable metadata stored to the second portion of the third die;

generating, by the controller, redundancy data by performing an XOR operation of the third die and from at least the first die and second die; and

storing, the redundancy data.

10. The method of claim 9, wherein:

a size of the first portion of the third die is based on an ECC strength associated with the parity data stored at the third die; and

a size of the second portion of the third die is based on a difference between a total size of the third die and the size of the first portion of the third die.

11. The method of claim 10, wherein:

the size of the first portion of the third die is different than the size of the second portion of the third die.

12. The method of claim 9, wherein the metadata includes a cell error identifier that indicates a location of a particular bit of the at least first die and second die of the plurality of dies that includes an error.

13. The method of claim 9, wherein the metadata includes a page flip indicator that indicates whether user data was flipped by the controller when the user data was written to the at least first die and second die.

14. The method of claim 9, wherein the metadata includes a time-stamp that indicates a time when the first die and second die were most recently accessed.

15. The method of claim 9, wherein the metadata includes a disturbance counter that indicates a number of times the first die and second die have been read or a number of times the first die and second die have been written.

16. A non-transitory computer-readable storage medium storing instructions that, when executed, cause a controller of a data storage device to:

store user data to a first die and a second die of a plurality of data dies of a non-volatile memory array;

store parity data to a first portion of a third die of the plurality of dies; and

store metadata to a second portion of the third die, wherein the metadata stored to the second portion of the third die is self-correctable, the non-volatile memory array further comprises a RAID die associated with the plurality of dies, the data storage device further comprising instructions that, when executed, cause the controller to;

detect errors in the self-correctable metadata stored to the second portion of the third die;

responsive to detecting errors in the self-correctable metadata, correct the errors in the self-correctable metadata stored to the second portion of the third die;

generate redundancy data by performing an XOR operation of the third die, the first die, and second die; and

store, to the RAID die, the redundancy data.

17. The non-transitory computer-readable storage medium of claim 16, wherein:

a size of the first portion of the third die is based on an ECC strength associated with the parity data stored at the third die; and

a size of the second portion of the third die is based on a difference between a total size of the third die and the size of the first portion of the third die.