Apparatus and method to store a plurality of data having a common pattern and guarantee codes associated therewith in a single page

• US 8,352,676 B2
• Filed: 10/26/2010
• Issued: 01/08/2013
• Est. Priority Date: 10/26/2010
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Kawamura, Atsushi, Ogawa, Junji
• Primary Examiner(s): Parikh, Kalpit
• Application Number:
  US12/992,028
• Publication Number:
  US 20120102260A1
• Time in Patent Office: 805 Days
• Field of Search: 711/103, 711/156, 714/52, 714/766, 707/692
• US Class Current: 711/103
• CPC Class Codes: G06F 11/1044 with specific ECC/EDC distribution
• CPC Class Codes: G06F 11/108 Parity data distribution in semiconductor storages, e.g. in SSD
• CPC Class Codes: G06F 12/0246 in block erasable memory, e.g. flash memory
• CPC Class Codes: G06F 2212/7202 Allocation control and policies
• CPC Class Codes: G06F 3/0608 Saving storage space on storage systems
• CPC Class Codes: G06F 3/0616 in relation to life time, e.g. increasing Mean Time Between Failures [MTBF]
• CPC Class Codes: G06F 3/0641 De-duplication techniques
• CPC Class Codes: G06F 3/0679 Non-volatile semiconductor memory device, e.g. flash memory, one time programmable memory [OTP]
• CPC Class Codes: G06F 3/0688 Non-volatile semiconductor memory arrays
• CPC Class Codes: G11C 16/04 using variable threshold transistors, e.g. FAMOS
• CPC Class Codes: G11C 16/0483 comprising cells having several storage transistors connected in series

Abstract

Data capacity efficiency is improved by de-duplicating data assigned with a code that is different for each data.

A storage apparatus comprising a flash memory control device equipped with one or more flash memory modules, wherein the flash memory module comprises at least one flash memory chip for providing a storage area, and a controller for controlling writing/reading of data including user data and a guarantee code accompanying the user data to and from the storage area provided by the flash memory chip, wherein the controller respectively divides a plurality of the data having the common user data into the user data and the guarantee code, stores one of the user data in an area of a predetermined unit of the storage area, and links and stores each of the guarantee codes accompanying the plurality of user data in an area of a predetermined unit of the storage area.

Claims

1. A storage apparatus comprising:

one or more flash memory modules, each of the flash memory modules comprises a memory controller and at least one flash memory chip including a plurality of physical pages, each page of the plurality of physical pages is a unit for writing/reading data; and

a storage controller configured to send a plurality of user data and a plurality of guarantee codes, each of the plurality of guarantee codes is associated with one of the plurality of user data, to the flash memory module,

wherein the flash memory module is configured to receive the plurality of user data and the plurality of guarantee codes, and

wherein on the condition the plurality of user data received by the flash memory module have common pattern of data, the memory controller compresses the plurality of user data having the common pattern of data and stores the compressed user data with the plurality of guarantee codes associated with the plurality of user data into one page of the plurality of physical pages.

2. The storage apparatus according to claim 1,

wherein the memory controller:

provides a logical area, which is divided into plurality of logical pages in the flash memory module, to the storage controller,

manages the plurality of physical pages,

among the plurality of user data related to the logical pages, respectively divides the plurality of user data having the common pattern of data,

stores one of the plurality of user data in one physical page, and

links and stores each of the guarantee codes associated with the one of the plurality of user data in the one physical page.

3. The storage apparatus according to claim 2,

wherein the flash memory module comprises a memory for storing a management table which manages an association between the logical page and the physical page, and

wherein an address of the logical page storing data, an address of the physical page storing the user data corresponding to the data, and an address of the physical address storing the guarantee code corresponding to the data are associated and stored in the management table.

4. The storage apparatus according to claim 2,

wherein, among the plurality of user data stored in the logical pages, if three or more of the user data have the common pattern of data, the memory controller divides the plurality of user data and the plurality of guarantee codes and stores them in the physical pages which are respectively different.

5. The storage apparatus according to claim 2,

wherein, among the plurality of user data related to the logical pages, the memory controller respectively divides the plurality of user data having common pattern of data, and stores one of the compressed user data and a guarantee code group in which a plurality of guarantee codes are linked in the physical page.

6. The storage apparatus according to claim 1,

wherein, if a data size of the user data having the common pattern of data after compression is a predetermined size or smaller, the controller stores the compressed user data and the guarantee code in the physical page.

7. The storage apparatus according to claim 1,

wherein the storage controller is configured to issue format information to the flash memory module,

wherein the memory controller of the flash memory module creates the user data having a format pattern and the guarantee code associated with the user data based on the format information.

8. The storage apparatus according to claim 1,

wherein in one read process, the memory controller is configured to read the compressed user data with the plurality of guarantee codes stored in the one page of the plurality of physical pages.

9. The storage apparatus according to claim 1,

wherein each of the plurality of guarantee codes includes a bit error correction code and a logical address of the associated user data.

10. The storage apparatus according to claim 1,

wherein each of the plurality of guarantee codes indicates a different code.

11. The storage apparatus according to claim 1,

wherein the common pattern of data is 0.

12. A data control method using a storage apparatus comprising one or more flash memory modules and a storage controller, comprising:

receiving a plurality of user data and a plurality of guarantee codes;

compressing the plurality of user data on the condition the plurality of user data have a common pattern of data;

storing the compressed user data with the plurality of guarantee codes associated with the plurality of user data, into one page of a plurality of physical pages.

13. The data control method according to claim 12,

wherein in one read process, the flash memory module reads the compressed user data with the plurality of guarantee codes stored in the one page of the plurality of physical pages.

14. The data control method according to claim 12,

wherein each of the plurality of guarantee codes includes a bit error correction code and a logical address of the associated user data.

15. The data control method according to claim 12,

wherein each of the plurality of guarantee codes indicates a different code.

16. The data control method according to claim 12,

wherein the common pattern of data is 0.

17. A flash memory module comprising:

at least one flash memory chip including a plurality of physical pages, each page of the plurality of physical pages is a unit for writing/reading data; and

a memory controller configured to receive the plurality of user data and the plurality of guarantee codes, each of the plurality of guarantee codes is associated with one of the plurality of user data, to the flash memory module,

wherein if the plurality of user data received by the memory controller have common pattern of data, the memory controller compresses the plurality of user data having the common pattern of data and stores the compressed user data with the plurality of guarantee codes associated with the plurality of user data, into one page of the plurality of physical pages.

18. The flash memory module according to claim 17,

wherein in one read process, the memory controller is configured to read the compressed user data with the plurality of guarantee codes stored in the one page of the plurality of physical pages.

19. The flash memory module according to claim 17,

wherein the each of the plurality of guarantee codes includes a bit error correction code and a logical address of the associated user data.

20. The flash memory module according to claim 17,

wherein each of the plurality of guarantee codes indicates a different code.

21. The flash memory module according to claim 17,

wherein the common pattern of data is 0.