METHODS FOR TAG-GROUPING OF BLOCKS IN STORAGE DEVICES

• US 20100131697A1
• Filed: 11/23/2008
• Published: 05/27/2010
• Est. Priority Date: 11/23/2008
• Status: Active Grant

• Current Assignee: SanDisk Technologies LLC (Western Digital Corporation)
• Original Assignee: SanDisk IL Ltd. (Western Digital Corporation)
• Inventors: ALROD, Idan, Sharon, Eran
• Granted Patent: US 9,141,475 B2
• Time in Patent Office: Days
• US Class Current: 711/103
• CPC Class Codes: G06F 11/1068 in sector programmable memories, e.g. flash disk G06F11/1072 takes precedence

Abstract

Embodiments described herein disclose methods, devices, and media for storing data. Methods including the steps of: receiving data to be stored in a memory that includes at least three blocks, wherein each block, for storing the data, has at least one metadata value, associated with each block, that is dependent upon a writing time of each block; grouping at least three blocks into at least two block groups, wherein at least one block group contains at least two blocks; associating a respective metadata value with each block group; and associating the respective metadata value of a respective block group with each block storing the data contained in the respective block group, without storing a dedicated copy of at least one metadata value for each block. In some embodiments, at least one metadata value is stored in a block-group table.

Claims

1. A method for storing data, the method comprising the steps of:

(a) receiving data to be stored in a memory that includes at least three blocks, wherein each said block, for storing said data, has at least one metadata value, associated with said each block, that is dependent upon a writing time of said each block;

(b) grouping said at least three blocks into at least two block groups, wherein at least one said block group contains at least two blocks;

(c) associating a respective metadata value with each said block group; and

(d) associating said respective metadata value of a respective block group with each block storing said data contained in said respective block group, without storing a dedicated copy of said at least one metadata value for each said block.

2. The method of claim 1, wherein said at least one metadata value is at least one value selected from the group consisting of:

a data age, an optimal-reading threshold-voltage, an optimal-verify threshold-voltage, a number of soft bits read, and data related to error correction.

3. The method of claim 1, wherein said at least one metadata value is stored in a block-group table.

4. The method of claim 1, wherein said step of grouping is based on a tag that is common to all blocks in a respective block group, wherein said tag is associated with an approximate relative time of writing said blocks of said respective block group.

5. The method of claim 4, wherein a time since power-up of said memory is divided into time intervals, and wherein two said blocks written during different said time intervals are associated with different tags.

6. The method of claim 5, wherein two said blocks written during two different power-up sessions of said memory are associated with different tags.

7. A method for storing data, the method comprising the steps of:

(a) receiving data to be stored in a memory that includes at least three blocks, wherein each said block, for storing said data, has at least one metadata value, associated with said each block, that is dependent upon a writing time of said each block;

(b) grouping said at least three blocks into at least two block groups, wherein at least one said block group contains at least two blocks;

(c) associating a sequential tag with each said block group, wherein a first block group having a previous sequential tag is indicative of being written to earlier in time than a second block group having a subsequent sequential tag; and

(d) associating a respective metadata value with each respective sequential tag.

8. The method of claim 7, wherein said at least one metadata value is at least one value selected from the group consisting of:

a data age, an optimal-reading threshold-voltage, an optimal-verify threshold-voltage, a number of soft bits read, and data related to error correction.

9. The method of claim 7, wherein said at least one metadata value is stored in a block-group table.

10. The method of claim 7, wherein a time since power-up of said memory is divided into time intervals, and wherein two said blocks written during different said time intervals are associated with different tags.

11. The method of claim 10, wherein two said blocks written during two different power-up sessions of said memory are associated with different tags.

12. A method for storing data, the method comprising the steps of:

(a) receiving data to be stored in a memory that includes at least three word-lines, and wherein each said word-line, for storing said data, has at least one metadata value, associated with said each word-line, that is dependent upon a writing time of said each word-line;

(b) grouping said at least three word-lines into at least two word-line groups, wherein at least one said word-line group contains at least two word-lines;

(c) associating a respective metadata value with each said word-line group; and

(d) associating said respective metadata value of a respective word-line group with each word-line storing said data contained in said respective word-line group, without storing a dedicated copy of said at least one metadata value for each said word-line.

13. The method of claim 12, wherein said at least one metadata value is at least one value selected from the group consisting of:

a data age, an optimal-reading threshold-voltage, an optimal-verify threshold-voltage, a number of soft bits read, and data related to error correction.

14. The method of claim 12, wherein said at least one metadata value is stored in a word-line-group table.

15. The method of claim 12, wherein each said word-line is contained in a block, and wherein at least one block contains two word-lines belonging to different word-line groups.

16. The method of claim 12, wherein said step of grouping is based on a tag that is common to all word-lines in a respective word-line group, wherein said tag is associated with an approximate relative time of writing said word-lines of said respective word-line group.

17. The method of claim 15, wherein a time since power-up of said memory is divided into time intervals, and wherein two said word-lines written during different said time intervals are associated with different tags.

18. The method of claim 16, wherein two said word-lines written during two different power-up sessions of said memory are associated with different tags.

19. A method for storing data, the method comprising the steps of:

(a) receiving data to be stored in a memory that includes at least three word-lines, and wherein each said word-line, for storing said data, has at least one metadata value, associated with said each word-line, that is dependent upon a writing time of said each word-line;

(b) grouping said at least three word-lines into at least two word-line groups, wherein at least one said word-line group contains at least two word-lines;

(c) associating a sequential tag with each said word-line group, wherein a first word-line group having a previous sequential tag is indicative of being written to earlier in time than a second word-line group having a subsequent sequential tag; and

(d) associating a respective metadata value with each respective sequential tag.

20. The method of claim 19, wherein said at least one metadata value is at least one value selected from the group consisting of:

a data age, an optimal-reading threshold-voltage, an optimal-verify threshold-voltage, a number of soft bits read, and data related to error correction.

21. The method of claim 19, wherein said at least one metadata value is stored in a word-line-group table.

22. The method of claim 19, wherein each said word-line is contained in a block, and wherein at least one block contains two word-lines belonging to different word-line groups.

23. A memory device comprising:

(a) a controller for storing data in a memory that includes at least three blocks, wherein each said block, for storing said data, has at least one metadata value, associated with said each block, that is dependent upon a writing time of said each block, said controller configured for;

(i) grouping said at least three blocks into at least two block groups, wherein at least one said block group contains at least two blocks;

(ii) associating a respective metadata value with each said block group; and

(iii) associating said respective metadata value of a respective block group with each block storing said data contained in said respective block group, without storing a dedicated copy of said at least one metadata value for each said block.

24. A memory device comprising:

(a) a controller for storing data in a memory that includes at least three blocks, wherein each said block, for storing said data, has at least one metadata value, associated with said each block, that is dependent upon a writing time of said each block, said controller configured for;

(i) grouping said at least three blocks into at least two block groups, wherein at least one said block group contains at least two blocks;

(ii) associating a sequential tag with each said block group, wherein a first block group having a previous sequential tag is indicative of being written to earlier in time than a second block group having a subsequent sequential tag; and

(iii) associating a respective metadata value with each respective sequential tag.

25. A memory device comprising:

(a) a controller for storing data in a memory that includes at least three word-lines, wherein each said word-line, for storing said data, has at least one metadata value, associated with said each word-line, that is dependent upon a writing time of said each word-line, said controller configured for;

(i) grouping said at least three word-lines into at least two word-line groups, wherein at least one said word-line group contains at least two word-lines;

(ii) associating a respective metadata value with each said word-line group; and

(iii) associating said respective metadata value of a respective word-line group with each word-line storing said data contained in said respective word-line group, without storing a dedicated copy of said at least one metadata value for each said word-line.

26. A memory device comprising:

(a) a controller for storing data in a memory that includes at least three word-lines, wherein each said word-line, for storing said data, has at least one metadata value, associated with said each word-line, that is dependent upon a writing time of said each word-line, said controller configured for;

(i) grouping said at least three word-lines into at least two word-line groups, wherein at least one said word-line group contains at least two word-lines;

(ii) associating a sequential tag with each said word-line group, wherein a first word-line group having a previous sequential tag is indicative of being written to earlier in time than a second word-line group having a subsequent sequential tag; and

(iii) associating a respective metadata value with each respective sequential tag.

27. A computer-readable storage medium having computer-readable code embodied therein, the computer-readable code comprising:

(a) driver code for a memory device having a memory that includes at least three blocks, wherein each said block, for storing data, has at least one metadata value, associated with said each block, that is dependent upon a writing time of said each block, said driver code configured for;

(i) grouping said at least three blocks into at least two block groups, wherein at least one said block group contains at least two blocks;

(ii) associating a respective metadata value with each said block group; and

(iii) associating said respective metadata value of a respective block group with each block storing said data contained in said respective block group, without storing a dedicated copy of said at least one metadata value for each said block.

28. A computer-readable storage medium having computer-readable code embodied therein, the computer-readable code comprising:

(a) driver code for a memory device having a memory that includes at least three blocks, wherein each said block, for storing data, has at least one metadata value, associated with said each block, that is dependent upon a writing time of said each block, said driver code configured for;

(i) grouping said at least three blocks into at least two block groups, wherein at least one said block group contains at least two blocks;

(ii) associating a sequential tag with each said block group, wherein a first block group having a previous sequential tag is indicative of being written to earlier in time than a second block group having a subsequent sequential tag; and

(iii) associating a respective metadata value with each respective sequential tag.

29. A computer-readable storage medium having computer-readable code embodied therein, the computer-readable code comprising:

(a) driver code for a memory device having a memory that includes at least three word-lines, wherein each said word-lines, for storing data, has at least one metadata value, associated with said each word-lines, that is dependent upon a writing time of said each word-lines, said driver code configured for;

(i) grouping said at least three word-lines into at least two word-line groups, wherein at least one said word-line group contains at least two word-lines;

(ii) associating a respective metadata value with each said word-line group; and

(iii) associating said respective metadata value of a respective word-line group with each word-line storing said data contained in said respective word-line group, without storing a dedicated copy of said at least one metadata value for each said word-line.

30. A computer-readable storage medium having computer-readable code embodied therein, the computer-readable code comprising:

(a) driver code for a memory device having a memory that includes at least three word-lines, wherein each said word-lines, for storing data, has at least one metadata value, associated with said each word-lines, that is dependent upon a writing time of said each word-lines, said driver code configured for;

(i) grouping said at least three word-lines into at least two word-line groups, wherein at least one said word-line group contains at least two word-lines;

(ii) associating a sequential tag with each said word-line group, wherein a first word-line group having a previous sequential tag is indicative of being written to earlier in time than a second word-line group having a subsequent sequential tag; and

(iii) associating a respective metadata value with each respective sequential tag.