File storage device, host apparatus, method for formatting nonvolatile semiconductor memory, and method of writing data in nonvolatile semiconductor memory

• US 20070226404A1
• Filed: 03/15/2007
• Published: 09/27/2007
• Est. Priority Date: 09/15/2004
• Status: Active Grant

• Current Assignee: Kioxia Corporation
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Ito, Takafumi, Sakamoto, Hiroyuki
• Granted Patent: US 7,822,931 B2
• Time in Patent Office: Days
• US Class Current: 711/103
• CPC Class Codes: G06F 3/061 Improving I/O performance
• CPC Class Codes: G06F 3/064 Management of blocks
• CPC Class Codes: G06F 3/0652 Erasing, e.g. deleting, data cleaning, moving of data to a wastebasket
• CPC Class Codes: G06F 3/0679 Non-volatile semiconductor memory device, e.g. flash memory, one time programmable memory [OTP]

Abstract

A file storage device includes a nonvolatile semiconductor memory which is accessed by a file system of a host apparatus. The nonvolatile semiconductor memory has a user data area. The user data area is accessible by the file system. Device information indicates that the nonvolatile semiconductor memory is a nonvolatile semiconductor memory and is written in the user data area.

Claims

1. A file storage device comprising a nonvolatile semiconductor memory which is accessed by a file system of a host apparatus, the nonvolatile semiconductor memory having a user data area which is accessible by the file system and in which device information indicating that the nonvolatile semiconductor memory is a nonvolatile semiconductor memory is written.

2. The device according to claim 1, wherein the device information is written into a boot sector in the user data area.

3. The device according to claim 1, wherein data in the nonvolatile semiconductor memory is erased by erasure block, and

block size information indicating a size of the erasure block is written in the user data area.

4. The device according to claim 3, wherein the block size information is written in a boot sector in the user data area.

5. The device according to claim 1, wherein data is written by write page into the nonvolatile semiconductor memory, and

page size information indicating a size of the write page is written in the user data area.

6. The device according to claim 5, wherein the page size information is written in a boot sector in the user data area.

7. The device according to claim 1, wherein

data is written by write page into the nonvolatile semiconductor memory,

the nonvolatile semiconductor memory receives a write command by a write unit which comprises write pages from a host apparatus which access the nonvolatile semiconductor memory,

the nonvolatile semiconductor memory is managed by the host apparatus by management unit which comprises write pages,

performance parameter information is written in the user data area,

the performance parameter information includes at least one of a size of the write unit, a size of the management unit, a write performance which indicates how fast the nonvolatile semiconductor memory writes data, and how fast the nonvolatile semiconductor memory moves data within the nonvolatile semiconductor memory.

8. The device according to claim 7, wherein the performance parameter information is written in a boot sector in the user data area.

9. A host apparatus into which a file storage device having a nonvolatile semiconductor memory whose data is erased by erasure block is inserted, the nonvolatile semiconductor device having a user data area which is accessible by a file system which manages data of the nonvolatile semiconductor memory, the host apparatus logically formatting the nonvolatile semiconductor memory in accordance with the file system, reading information of a size of the erasure block from the file storage device, and writing a block size information which indicates a size of the erasure block into the user data area during logical format.

10. The host apparatus according to claim 9, wherein the block size information is written in a boot sector in the user data area.

11. The host apparatus according to claim 9, wherein the nonvolatile semiconductor memory writes the data by write page,

the host apparatus further comprising a function of reading information of a size of the write page from the file storage device, and writing the page size information which indicates the size of the write page into the user data area during logical format

12. The host apparatus according to claim 11, wherein the page size information is written in a boot sector of the user data area.

13. A method of formatting a nonvolatile semiconductor memory in which data is written by write page and erased by erasure block and which has a user data area accessible by a file system, the method comprising:

reading information of a size of the erasure block from the nonvolatile semiconductor memory; and

writing a block size information which indicates the size of the erasure block in the user data area in accordance with the file system.

14. The method according to claim 13, wherein the block size information is written in a boot sector of the user data area.

15. The method according to claim 13, further comprising:

reading information of a size of the write page from the nonvolatile semiconductor memory; and

writing the page size information which indicates the size of the write page in the user data area.

16. The method according to claim 15, wherein the page size information is written in a boot sector of the user data area.

17. A method of writing data in a nonvolatile semiconductor memory in which data is erased by erasure block which comprises write areas and in which erasure block size information indicating a size of the erasure block is stored, the method comprising:

reading the erasure block size information; and

writing data in the write areas in accordance with the erasure block size information.

18. The method according to claim 17, wherein each of the write areas includes a first area in which data is written and a second area in which write completing information indicating that the data is written in the first area is written, and

writing data in the write areas includes writing the write completing information in the second area which is included in the write area including the first area in which the data is written, while writing data in the first area.

19. The method according to claim 18, further comprising:

searching, from erasure blocks, for a non-written block in which the write completing information is not written, with reference to a file system to manage data of the nonvolatile semiconductor memory, the erasure block size information, and the write completing information, wherein

writing the data in write areas includes writing the data preferentially from the write areas in the non-written block when the non-written block is found.