Method and system for accessing non-volatile storage devices

• US 7,747,837 B2
• Filed: 12/21/2005
• Issued: 06/29/2010
• Est. Priority Date: 12/21/2005
• Status: Active Grant

• Current Assignee: SanDisk Technologies LLC (Western Digital Corporation)
• Original Assignee: SanDisk Corporation (Western Digital Corporation)
• Inventors: Sinclair, Alan W., Gorobets, Sergey A.
• Primary Examiner(s): Kim; Matt
• Assistant Examiner(s): PATEL, KAUSHIKKUMAR M
• Application Number:
  US11/313,567
• Publication Number:
  US 20070143532A1
• Time in Patent Office: 1,651 Days
• Field of Search: None
• US Class Current: 711/203
• CPC Class Codes: G06F 3/0607 by facilitating the process of upgrading existing storage systems, e.g. for improving compatibility between host and storage device
• CPC Class Codes: G06F 3/0638 Organizing or formatting or addressing of data
• CPC Class Codes: G06F 3/0679 Non-volatile semiconductor memory device, e.g. flash memory, one time programmable memory [OTP]

Abstract

A mass storage memory system is provided. The memory system includes, re-programmable non-volatile memory cells arranged in a plurality of blocks of memory cells; and a controller that is adapted to receive data via a first interface, and/or a second interface, and data received via the first interface and the second interface is accessible via the first interface and the second interface even if a file name for the data is not provided by a host system or before a write operation is complete. The first interface is a file based interface and the second interface is a logical interface.

Claims

1. A mass storage memory system, comprising:

re-programmable non-volatile memory cells arranged in a plurality of blocks of memory cells;

a controller that receives files of data individually via a first host-system-accessible interface of the mass storage memory system, where the files are identified by unique identifiers, wherein the received file data is stored in one or more of the blocks of memory cells and indexed based on the unique identifiers;

wherein the controller assigns a plurality of logical block addresses to the received file data and updates directory and file allocation table (“

FAT”

) entries that are used by a host and that are stored in the one or more of the blocks of memory cells such that the file data received via the first host-system-accessible interface is accessible via a second host-system-accessible interface of the mass storage memory system;

wherein the first host-system-accessible interface is a direct data file storage (DFS) interface in which data to be written to or read from the re-programmable non-volatile memory cells is identified to the controller by using file identifiers defined in a first address space; and

wherein the second host-system-accessible interface is a logical interface in which data to be written to or read from the re-programmable non-volatile memory cells is identified to the controller by using logical addresses defined in a second address space distinct from the first address space.

2. The memory system of claim 1, wherein logical block address assignment and FAT update is performed by an embedded file system with a file output interface that is specific to a file storage back-end system.

3. The memory system of claim 2, wherein the embedded file system is a file to logical converter.

4. The memory system of claim 1, wherein data is stored as files in the plurality of non-volatile memory cells.

5. A mass storage memory system, comprising:

re-programmable non-volatile memory cells arranged in a plurality of blocks of memory cells;

a controller that receives, data identified by plurality of logical addresses via a first host-system-accessible interface of the mass storage memory system, which causes the data to be stored in one or more of the blocks of memory cells as a file and wherein the controller makes the data accessible via a second host-system-accessible interface of the mass storage memory system even if a file name for the data is not provided in a command received by the first host-system-accessible interface, by detecting a change made to directory and file allocation table entries that are used by a host and that are stored in the plurality of blocks of memory cells;

wherein the first host-system-accessible interface is a logical interface in which data to be written to or read from the re-programmable non-volatile memory cells is identified to the controller by using logical addresses defined in a first address space; and

wherein the second host-system-accessible interface is a direct data file storage (DFS) interface in which data to be written to or read from the re-programmable non-volatile memory cells is identified to the controller by using file identifiers defined in a second address space distinct from the first address space.

6. The memory system of claim 5, wherein the controller assigns internal file names to the data received via the first host-system-accessible interface and merges the internal file names to a single file name based on a file name that is provided via the first host-system-accessible interface or the second host-system-accessible interface.

7. The memory system of claim 6, wherein the internal file names are based on logical block addresses for the data.

8. A mass storage memory system, comprising:

re-programmable non-volatile memory cells arranged in a plurality of blocks of memory cells;

a controller that is adapted to receive data identified by a plurality of logical addresses via a first host-system-accessible interface of the mass storage memory system, which causes the data to be stored in one or more of the plurality of blocks of memory cells as a file, wherein the controller makes the data accessible via a second host-system-accessible interface of the mass storage memory system, even if a file name for the data is not provided by a host system in a command to the first host-system-accessible interface, by detecting a change made to directory and file allocation table entries that are used by a host and that are stored in the blocks of memory cells, and wherein the controller assigns internal file names to the data and merges the internal file names to a single file name based on a file name after a file name is provided via the first host-system-accessible interface or the second host-system-accessible interface;

wherein the first host-system-accessible interface is a logical interface in which data to be written to or read from the re-programmable non-volatile memory cells is identified to the controller by using logical addresses defined in a first address space; and

wherein the second host-system-accessible interface is a direct data file storage (DFS) interface in which data to be written to or read from the re-programmable non-volatile memory cells is identified to the controller by using file identifiers defined in a second address space distinct from the first address space.

9. The memory system of claim 8, wherein the internal file names are based on logical block addresses for the data.

10. The memory system of claim 8, wherein data is stored as files in the plurality of non-volatile memory cells.

11. A mass storage memory system, comprising:

re-programmable non-volatile memory cells arranged in a plurality of blocks of memory cells;

a controller that receives data occupying a plurality of logical block addresses via one or both of a first host-system-accessible interface of the mass storage memory system and a second host-system-accessible interface of the mass storage memory system, wherein the controller makes data for each logical block that is received via the first host-system-accessible interface and the second host-system-accessible interface is accessible via the first host-system-accessible interface and the second host-system-accessible interface, even if a file name for the data is not provided in a command received by the second host-system-accessible interface or before data occupying all of the plurality of logical block addresses has been received, by detecting a change made to directory and file allocation table entries that are used by a host and that are stored in the plurality of blocks of memory cells;

wherein the first host-system-accessible interface is a direct data file storage (DFS) interface in which data to be written to or read from the re-programmable non-volatile memory cells is identified to the controller by using file identifiers defined in a first address space; and

wherein the second host-system-accessible interface is a logical interface in which data to be written to or read from the re-programmable non-volatile memory cells is identified to the controller by using logical addresses defined in a second address space distinct from the first address space.

12. The memory device of claim 11, wherein data received via the first host-system-accessible interface is file data identified by unique identifiers and is stored in one or more memory blocks.

13. The memory system of claim 12, wherein the controller assigns the plurality of logical block addresses to the received file data and updates directory and file allocation table (“

FAT”

) entries that are stored in blocks of memory cells such that the file data received via the first host-system-accessible interface is accessible via the second host-system-accessible interface.

14. The memory system of claim 11, wherein the data received via the second host-system-accessible interface is identified by a plurality of logical addresses and the controller causes the data to be stored in one or more memory cells as a file.

15. The memory system of claim 13, wherein logical block address assignment and FAT update is performed by an embedded file system with a file output interface that is specific to a file storage back-end system.

16. The memory system of claim 15, wherein the embedded file system is a file to logical converter.

17. The memory system of claim 11, wherein the controller assigns internal file names to the data received via the second host-system-accessible interface and merges the internal file names to a single file name based on a file name provided by the host system that sends the data via the second host-system-accessible interface.

18. The memory system of claim 17, wherein the internal file names are based on logical block addresses for the data received via the second host-system-accessible interface.

19. The memory system of claim 11, wherein the data is stored as files in the plurality of non-volatile memory cells.

20. A mass storage memory system, comprising:

re-programmable non-volatile memory cells arranged in a plurality of blocks of memory cells;

a controller that receives files of data individually via a first host-system-accessible interface of the mass storage memory system, identified by unique identifiers, wherein the received file data is stored in one or more memory blocks and the controller assigns a plurality of logical block addresses to the received file data and updates directory and file allocation table (“

FAT”

) entries that are used by a host and that are stored in the blocks of memory cells, wherein the FAT update and logical block address assignment is performed in real time, and the file data received via the first host-system-accessible interface is accessible via second host-system-accessible interface of the mass storage memory system;

wherein the first host-system-accessible interface is a direct data file storage (DFS) interface in which data to be written to or read from the re-programmable non-volatile memory cells is identified to the controller by using file identifiers defined in a first address space; and

wherein the second host-system-accessible interface is a logical interface in which data to be written to or read from the re-programmable non-volatile memory cells is identified to the controller by using logical addresses defined in a second address space distinct from the first address space.

21. The memory system of claim 20, wherein the FAT update and logical block address allocation is performed after a write operation is completed via the first host-system-accessible interface, instead of being performed in real time.

22. The memory system of claim 20, wherein logical block address allocation and FAT update is performed by an embedded file system with a file output interface that is specific to a file storage back-end system.

23. The memory system of claim 22, wherein the embedded file system is a file to logical converter.

24. The memory of claim 20, wherein the controller is adapted to receive data identified by a plurality of logical addresses via the second host-system-accessible interface which causes the data to be stored in one or more memory cells as a file and is accessible via the first host-system-accessible interface even if a file name is not provided by the host system in a command received by the second host-system-accessible interface.

25. The memory system of claim 24, wherein the controller assigns internal file names to the data received via the second host-system-accessible interface and merges the internal file names to a single file name based on a file name that is provided by the host system that sends the data.

26. The memory system of claim 24, wherein indexing information for data written via the first host-system-accessible interface and the second host-system-accessible interface is stored in the memory cells and is continuously updated.

27. The memory system of claim 20, wherein any data written via the first host-system-accessible interface or the second host-system-accessible interface is uniquely identified by a logical block address and a file identifier and is accessible via the first host-system-accessible interface or the second host-system-accessible interface.

28. The memory system of claim 20, wherein a directory and FAT entries are created by a file system maintained by the memory system for a file written via the first host-system-accessible interface.

29. The memory system of claim 20, wherein data is stored as files in the plurality of non-volatile memory cells.