DATA RELIABILITY INFORMATION IN A NON-VOLATILE MEMORY DEVICE

• US 20170269992A1
• Filed: 03/17/2016
• Published: 09/21/2017
• Est. Priority Date: 03/17/2016
• Status: Active Grant

• Current Assignee: JP Morgan Chase Bank, N.A. (JP Morgan Chase & Co)
• Original Assignee: Western Digital Technologies Incorporated (Western Digital Corporation)
• Inventors: Bandic, Zvonimir Z., Gunnam, Kiran Kumar, Song, Seung-Hwan
• Granted Patent: US 10,459,793 B2
• Time in Patent Office: Days
• 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, wherein a word is an access unit of a die; and

a controller configured to;

store user data to a respective first word of at least a first die and a second die of the plurality of dies, wherein a page of user data comprises user data stored at the respective first words of the at least first die and second die;

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

store metadata to a second portion of the first word of the third die.

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

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

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

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

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

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

the size of the first portion of the first word of the third die is different than the size of the first portion of the second word 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 the respective first words of the at least 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 respective first words of the at least first die and second die have been read or a number of times the respective first words of the at least first die and second die have been written.

8. The data storage device of claim 1, wherein the metadata stored to the second portion of the first word of the third die is self-correctable, the non-volatile memory array further comprises a RAID die associated with the plurality dies, and the RAID die includes a plurality of words, wherein the controller is further configured to:

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

generate redundancy data by performing an XOR operation of the first word of the third die and the respective first words from the at least first die and second die; and

store, to a first word of the plurality of words of the RAID die, the redundancy data.

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

10. A method comprising:

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

each die of the plurality of dies includes a plurality of words

a word is an access unit of a die, and

a page of user data comprises user data stored at the respective first words of the at least first die and second die;

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

storing metadata to a second portion of the first word of the third die.

11. The method of claim 10, wherein:

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

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

12. The method of claim 11, wherein:

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

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

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

13. The method of claim 10, 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.

14. The method of claim 10, 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.

15. The method of claim 10, wherein the metadata includes a time-stamp that indicates a time when the respective first words of the at least first die and second die were most recently accessed.

16. The method of claim 10, wherein the metadata includes a disturbance counter that indicates a number of times the respective first words of the at least first die and second dive have been read or a number of times the respective first words of the at least first die and second die have been written.

17. The method of claim 10, wherein the metadata stored to the second portion of the first word of the third die is self-correctable, the memory device further comprises a RAID die associated with the plurality of dies, and the RAID die includes a plurality of words, the method further comprising:

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

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

storing, by the controller and to a first word of the plurality of words of the RAID die, the redundancy data.

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

store user data to a respective first word of at least a first die and a second die of a plurality of data dies of a non-volatile memory array, wherein;

the each die of the plurality of dies includes a plurality of words,

a word is an access unit of a die, and

a page of user data comprises user data stored at the respective first words of the at least first die and second die;

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

store metadata to a second portion of the first word of the third die.

19. The computer-readable storage medium of claim 18, wherein:

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

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

20. The computer-readable storage medium of claim 18, wherein the metadata stored to the second portion of the first word of the third die is self-correctable, the non-volatile memory array further comprises a RAID die associated with the plurality of dies, and the RAID die includes a plurality of words, the computer-readable storage medium further comprising instructions that, when executed, cause the controller to:

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

generate redundancy data by performing an XOR operation of the first word of the third die and the respective first words from the at least first die and second die; and

store, to a first word of the plurality of words of the RAID die, the redundancy data.