DATA UPDATING AND RECOVERING METHODS FOR A NON-VOLATILE MEMORY ARRAY

• US 20100306447A1
• Filed: 05/26/2009
• Published: 12/02/2010
• Est. Priority Date: 05/26/2009
• Status: Active Grant

• Current Assignee: MediaTek, Inc.
• Original Assignee: MediaTek, Inc.
• Inventors: Tu, Li-chun, Yang, Kun-chieh, Chiang, Chun-ying, Chen, Hong-ching, Lin, Tzu-chieh
• Granted Patent: US 8,296,503 B2
• Time in Patent Office: Days
• US Class Current: 711/103
• 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

Abstract

Methods for updating and recovering user data of a non-volatile memory array such as a flash memory are disclosed. An indication for indicating a mapping relationship for a logical address is established when original user data of the logical addresses is updated into new user data. The indication records new pointers, which record the mapping relationships between logical addresses and physical addresses storing the new user data of the logical addresses. Alternatively, the indication records memory positions of the non-volatile memory array which are defined as designated memory positions and a sequence for using these designated memory positions.

Claims

1. A method for updating user data, the user data being associated with a plurality of logical addresses and a plurality of physical addresses of a non-volatile memory array, a pointer table recording a plurality of mapping relationships between the logical addresses and the physical addresses being stored in the non-volatile memory, the method comprising:

writing new user data for a logical address to a memory position in the non-volatile memory array when original user data of the logical address is updated into the new user data, wherein the memory position is denoted by a new physical address; and

establishing an indication other than the point table, the indication indicating a mapping relationship between the logical address and the new physical address.

2. The method of claim 1, wherein the new user data of the logical address is written into the memory position denoted by the new physical address first, and then the indication is established.

3. The method of claim 1, wherein the indication is established first, and then the new user data of the logical address is written into the memory position denoted by the new physical address.

4. The method of claim 1, wherein writing the new user data of the logical address into the memory position denoted by the new physical address is executed in parallel with establishing the indication.

5. The method of claim 1, further comprising revising the pointer table based on the indication periodically.

6. The method of claim 1, wherein the indication is stored in a modification area located in the non-volatile memory.

7. The method of claim 6, further comprising revising the pointer table based on the indication when the modification area storing the indication is full.

8. The method of claim 7, further comprising cleaning the modification area after the revising step.

9. The method of claim 1, wherein the indication is stored in a modification area located in an additional non-volatile memory.

10. The method of claim 9, further comprising revising the pointer table based on the indication when the modification area storing the indication is full.

11. The method of claim 10, further comprising cleaning the modification area after the revising step.

12. A method for updating user data, the user data being associated with a plurality of logical addresses, the user data of each logical address being stored in a memory position of a non-volatile memory array, the method comprising:

establishing an indication about a plurality of memory positions of the non-volatile memory array defined as designated memory positions, and the indication indicating a predetermined sequence for using the designated memory positions; and

writing new user data of one of the logical addresses into one of the designated memory positions according to the indication when original user data of the logical address is to be updated into the new user data.

13. The method of claim 12, further comprising adjusting the predetermined sequence according to a condition of the non-volatile memory array.

14. The method of claim 12, further comprising adjusting the predetermined sequence according to a status bit indicating processing or completion of an operation of the non-volatile memory array.

15. The method of claim 12, wherein the indication is established to indicate that the designated memory positions are located in successive areas of the non-volatile memory array.

16. The method of claim 12, wherein the indication is established to indicate that the designated memory positions are located in discrete areas of the non-volatile memory array.

17. A method for recovering user data, the user data being associated with a plurality of logical addresses and a plurality of physical addresses of a non-volatile memory array, a pointer table recording a plurality of mapping relationships between the logical addresses and the physical addresses being stored in the non-volatile memory, the method comprising:

reading the pointer table from the non-volatile memory array;

reading an indication, the indication recording at least one modified mapping relationship for a logical address, original user data of the logical address having been updated into new user data, each modified mapping relationship indicating mapping relationship between the logical address and a new physical address, wherein the new physical address denotes a memory position of the non-volatile memory storing the new user data;

determining a valid mapping relationship between the logical addresses and the corresponding physical address according to the indication and the pointer table, the indication being considered in priority; and

reading the new user data from the memory position denoted by the new physical address according to the valid mapping relationship for the logical address.

18. The method of claim 17, further comprising checking whether the modification area is empty before reading the indication and suspending execution of the method if the modification area is empty.

19. The method of claim 17, wherein the last mapping relationship for the logical address is determined as the valid mapping relationship in the determining step.

20. The method of claim 17, wherein the pointer table is read and then the indication is read.

21. The method of claim 17, wherein the indication is read and then the pointer table is read.

22. The method of claim 17, where in reading the pointer table and reading the indication are executed in parallel.

23. A method for recovering user data, the user data being associated with a plurality of logical addresses, the user data of each logical address being stored in a memory position of a non-volatile memory array, the method comprising:

reading the pointer table from the non-volatile memory array;

reading an indication, the indication indicating that a plurality of memory positions of the non-volatile memory array are defined as designated memory positions, and the indication indicating a predetermined sequence for using the designated memory positions;

scanning the designated memory positions according to the indication; and

reading the new user data with the logical address recorded in the designated memory position.

24. The method of claim 23, wherein the pointer table is read and then the indication is read.

25. The method of claim 23, wherein the indication is read and then the pointer table is read.

26. The method of claim 23, where in reading the pointer table and reading the indication are executed in parallel.