System and method of storing redundancy data

• US 9,348,695 B2
• Filed: 05/21/2014
• Issued: 05/24/2016
• Est. Priority Date: 05/21/2014
• Status: Active Grant

• Current Assignee: SanDisk Technologies LLC (Western Digital Corporation)
• Original Assignee: Sandisk Technologies Incorporated (Western Digital Corporation)
• Inventors: Sharon, Eran, Alrod, Idan
• Primary Examiner(s): Ton, David
• Application Number:
  US14/284,133
• Publication Number:
  US 20150339187A1
• Time in Patent Office: 734 Days
• Field of Search: 365/200, 714/763
• US Class Current: 1/1
• CPC Class Codes: G06F 11/10 Adding special bits or symbols to the coded information, e.g. parity check, casting out 9's or 11's
• CPC Class Codes: G06F 11/1012 using codes or arrangements adapted for a specific type of error G06F11/1048 takes precedence
• CPC Class Codes: G06F 11/1068 in sector programmable memories, e.g. flash disk G06F11/1072 takes precedence
• CPC Class Codes: G06F 11/108 Parity data distribution in semiconductor storages, e.g. in SSD
• CPC Class Codes: G11C 2029/0411 Online error correction
• CPC Class Codes: G11C 29/52 Protection of memory contents; Detection of errors in memory contents

Abstract

A data storage device includes a controller operatively coupled to a non-volatile memory. The non-volatile memory includes a plurality of blocks. When the controller is configured to operate according to a first mode, a portion of a first redundancy block of the plurality of blocks stores first redundancy data corresponding to a first group of multiple data portions. The multiple data portions stored in multiple blocks of the plurality of blocks. When the controller is configured to operate according to a second mode, the portion of the first redundancy block stores second redundancy data corresponding to a single block of the plurality of blocks.

Claims

1. A data storage device comprising:

a non-volatile memory including a plurality of blocks; and

a controller operatively coupled to the non-volatile memory, wherein, when the controller is configured to operate according to a first mode, a first portion of a first redundancy block of the plurality of blocks stores first redundancy data corresponding to a first group of multiple first data portions, the multiple first data portions stored in multiple blocks of the plurality of blocks, and wherein, when the controller is configured to operate according to a second mode, the first portion of the first redundancy block stores second redundancy data corresponding to a single block of the multiple blocks.

2. The data storage device of claim 1, wherein the first mode is associated with a first type of redundancy data, the first type of redundancy data corresponding to a redundant array of independent disks-type (RAID-type) to enable recovery of data from a defective block, wherein the second mode is associated with a second type of redundancy data, the second type of redundancy data corresponding to an error correcting code-type (ECC-type) to enable recovery of data from bit errors, and wherein the controller operates according to the first mode prior to operating according to the second mode.

3. The data storage device of claim 1, wherein the controller is further configured to transition from operating according to the first mode to the second mode based on a number of write/erase cycles, a bit error rate (BER) value, a defect detection rate, or a combination thereof.

4. The data storage device of claim 1, wherein the first redundancy data includes an exclusive-or (XOR) result generated based on the first group of the multiple first data portions being XORed together.

5. The data storage device of claim 1, wherein a second portion of a second redundancy block of the plurality of blocks stores third redundancy data corresponding to a second group of multiple second data portions, the multiple second data portions stored in the multiple blocks.

6. The data storage device of claim 5, wherein, when the controller is configured to operate according to the first mode, the first redundancy data includes a first exclusive-or (XOR) result generated based on the first group of the multiple first data portions combined via a XOR operation and the third redundancy data includes a second XOR result generated based on the second group of the multiple second data portions being XORed together.

7. The data storage device of claim 5, wherein the first redundancy data includes a first exclusive-or (XOR) result generated based on the first group of the multiple first data portions combined via a XOR operation and the third redundancy data is computed based on an error correcting code (ECC) code.

8. The data storage device of claim 1, wherein the non-volatile memory includes a three-dimensional (3D) memory configuration that is monolithically formed in one or more physical levels of arrays of memory cells having an active area disposed above a silicon substrate, and wherein the data storage device includes circuitry associated with operation of the memory cells.

9. A device comprising:

a non-volatile memory including a plurality of blocks; and

a controller coupled to the non-volatile memory, the controller configured to store redundant array of independent disks-type (RAID-type) data in a portion of a redundancy block and, in response to detecting a condition, to store error- correcting code-type (ECC-type) data in the portion of the redundancy block.

10. The device of claim 9, wherein the RAID-type data includes redundancy data for multiple blocks of the plurality of blocks, and wherein the ECC-type data includes redundancy data for a single block of the plurality of blocks.

11. The device of claim 9, wherein the condition corresponds to a number of write/erase cycles satisfying a threshold.

12. The device of claim 9, wherein the condition corresponds to a bit error rate (BER) value satisfying a threshold.

13. The device of claim 9, wherein the condition corresponds to a defect detection rate satisfying a threshold.

14. A method comprising:

in a data storage device including a controller and a non-volatile memory, wherein the non-volatile memory includes a plurality of blocks, performing;

storing, based on a first mode, first redundancy data into a first portion of a first redundancy block of the plurality of blocks, wherein the first redundancy data corresponds to multiple first data portions, the multiple first data portions stored in multiple blocks of the plurality of blocks; and

storing, based on a second mode, second redundancy data into the first portion of the first redundancy block, wherein the second redundancy data corresponds to a single block of the multiple blocks.

15. The method of claim 14, further comprising tracking which blocks of the plurality of blocks include data generated in accordance with the first mode or the second mode.

16. The method of claim 14, further comprising changing from the first mode to the second mode based on a determination that a number of write/erase cycles is greater than or equal to a threshold number of cycles.

17. The method of claim 14, further comprising changing from the first mode to the second mode based on a determination that a bit error rate (BER) value is greater than or equal to a threshold.

18. The method of claim 14, further comprising changing from the first mode to the second mode based on a determination that a defect detection rate associated with the non- volatile memory is less than or equal to threshold rate.

19. The method of claim 14, further comprising:

receiving first data to be stored at the non-volatile memory; and

when the controller operates according to the first mode, generating the first redundancy data based on the first data.

20. The method of claim 19, further comprising:

receiving second data to be stored at the non-volatile memory; and

when the controller operates according to the second mode, generating the second redundancy data based on the second data.

21. The method of claim 14, further comprising:

dividing a particular page of the single block into a plurality of sections; and

generating a particular portion of the second redundancy data based on combining each section of the plurality of sections via an exclusive-or (XOR) operation.

22. The method of claim 14, further comprising dividing a page of the first redundancy block into a plurality of sections, wherein each section of the page corresponds to a different page of the single block.

23. The method of claim 14, wherein each data portion of the multiple first data portions comprises an error correcting code (ECC) codeword having a first number of parity bits, and wherein the second redundancy data is associated with additional ECC parity bits to extend the ECC codeword to have a second number of parity bits greater than the first number of parity bits.

24. The method of claim 23, wherein the ECC codeword is a low-density parity check (LDPC) codeword.