Dual mode access for non-volatile storage devices

• US 7,793,068 B2
• Filed: 12/21/2005
• Issued: 09/07/2010
• 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): Bataille; Pierre-Michel
• Assistant Examiner(s): PATEL, KAUSHIKKUMAR M
• Application Number:
  US11/314,842
• Publication Number:
  US 20070143571A1
• Time in Patent Office: 1,721 Days
• Field of Search: 711/203
• US Class Current: 711/203
• CPC Class Codes: G06F 3/0605 by facilitating the interaction with a user or administrator
• CPC Class Codes: G06F 3/0643 Management of files
• CPC Class Codes: G06F 3/0679 Non-volatile semiconductor memory device, e.g. flash memory, one time programmable memory [OTP]

Abstract

Method and mass storage memory system is provided. The system includes, re-programmable non-volatile memory cells, the memory cells being arranged in a plurality of blocks that are erasable together; and a controller including a microprocessor that is adapted to receive files of data identified by unique identifiers via a first interface and the controller causes a received data file to be stored in one or more memory blocks; and the controller receives data identified by logical addresses via a second interface and stores the received data in one or more memory blocks, wherein data written via the first interface is indexed using the unique identifiers so that data is accessible via the second interface or the first interface; and data received via the second interface is indexed so that data can be accessed via the first interface or the second interface.

Claims

1. A mass storage memory system, comprising:

a flash device for interfacing with a host, the flash device including re-programmable nonvolatile memory cells, the memory cells being arranged in a plurality of blocks that are erasable together; and

the flash device further including a controller including a microprocessor that is adapted to receive files of data identified by the host to the flash device using file identifiers via a first interface and the controller causes a received data file to be stored in one or more memory blocks; and

the controller receives data identified by the host to the flash device using logical addresses via a second interface and stores the received data in one or more memory blocks, wherein the data written via the first interface is indexed using the file identifiers so that the data is accessible via the second interface and the first interface; and

data received via the second interface is indexed so that the data can be accessed via the first interface and the second interface;

wherein the first interface is a direct data file storage (DFS) interface where data files received from the host are identified by the host to the flash device using the file identifiers and the second interface is a logical interface where data files received from the host are identified by the host to the flash device using the logical addresses.

2. The mass storage memory system of claim 1, wherein entries for a directory and a file allocation table (“

FAT”

) are created for a file written via the first interface.

3. The mass storage memory system of claim 2, wherein the directory and FAT entries are created after a host has completed writing the data via the first interface.

4. The mass storage memory system of claim 2, wherein the directory and FAT entries are created after a host issues a specific command.

5. The mass storage memory system of claim 1, wherein a unique file identifier for a file that is written via the first interface is associated with a cluster chain for the file, which is defined by the controller so that the file can be accessed via the second interface.

6. The mass storage memory system of claim 1, wherein logical to physical indexing is performed by the controller for the data that is received via the second interface so that the data written via the second interface can be accessed via the first interface.

7. The mass storage memory system of claim 6, wherein the controller identifies logical block address (“

LBA”

) runs for data received via the second interface and determines if the received data is for a new file, an existing file that has been updated, or for a file that has been deleted, and based on that an index table entry is updated.

8. The mass storage memory system claim 7, wherein the controller indexes file data identified by the LBA runs so that each LBA run has a unique file identifier.

9. A mass storage memory system, comprising:

a flash device for interfacing with a host, the flash device including re-programmable non-volatile memory cells, the memory cells being arranged in a plurality of blocks of memory cells that are erasable together; and

the flash device further including a controller including a microprocessor that is adapted to receive files of data identified by the host to the flash device using file identifiers via a first interface, and the controller causes a received data file to be stored in one or more memory blocks; and

the controller receives data via a second interface where the host identifies the data to the flash device using logical addresses and stores the received data in one or more memory cells;

wherein data written via the first interface can be accessed via the second interface and the first interface; and

data received via the second interface can be accessed via the first interface and the second interface;

wherein the first interface is a direct data file storage (DFS) interface where data files received the host are identified by the host to the flash device using the file identifiers and the second interface is a logical interface where data files received the host are identified by the host to the flash device using the logical addresses.

10. The mass storage memory system of claim 9, wherein entries for a directory and a file allocation table (“

FAT”

) are created for a file written via the first interface.

11. The mass storage memory system of claim 10, wherein the directory and FAT entries are created after a host has completed writing data via the first interface.

12. The mass storage memory system of claim 10, wherein the directory and FAT entries are created after a host issues a specific command.

13. The mass storage memory system of claim 9, wherein a unique file identifier for a file that is written via the first interface is associated with a cluster chain for the file, which is defined by the controller so that the file can be accessed via the second interface.

14. The mass storage memory system of claim 9, wherein a logical to physical indexing is performed by the controller for the data that is received via the second interface so that the data written via the second interface can be accessed via the first interface.

15. The mass storage memory system of claim 14, wherein the controller identifies logical block address (“

LBA”

) runs for the data received via the second interface and determines if the received data is for a new file, an existing file that has been updated, or for a file that has been deleted, and based on that an index table entry is updated.

16. The mass storage memory system of claim 15, wherein the controller indexes file data identified by the LBA runs so that each LBA run has a unique file identifier.

17. A method for transferring data between a host and a flash device including a reprogrammable non-volatile mass storage system having memory cells organized into blocks of memory cells that are erasable together, comprising:

at the flash device, receiving, from the host, unique file identifiers for individual files via a first interface;

at the flash device, translating file identifiers directly into physical addresses of blocks of memory cells in which data of the identified files are written, wherein the flash device translates the file identifiers; and

allocating a cluster chain within a logical block address (“

LBA”

) range to a file that is identified by a file identifier, so that the file can be read or updated via a second interface between the host system and the flash device, wherein the flash device performs the allocation and the first interface is a direct data file storage (DFS) interface wherein data files received from the host are identified by the host to the flash device using the file identifiers and the second interface is a logical interface wherein data files received from the host are identified by the host to the flash device using the logical address.

18. The method of claim 17, wherein the mass storage system receives the individual files with unique identifiers from the host system via the first interface.

19. The method of claim 17, wherein an index table is scanned to determine the length of a file for allocating the logical address space.

20. The method of claim 17, wherein a file allocation table (“

FAT”

) entries are updated so that the file is accessible via the second interface.

21. The method of claim 17, wherein allocation of the cluster chain occurs after the host system has completed a write operation using the unique file identifiers.

22. The method of claim 17, wherein the host system sends a command to the mass storage system to create entries for a directory and file allocation table (“

FAT”

) so that a file written via a first interface is accessible using the second interface.

23. The method of claim 22, wherein a logical write pointer in the FAT is incremented after a directory entry for the file is written.