Data storage apparatus and method for writing data

• US 8,583,968 B2
• Filed: 04/14/2011
• Issued: 11/12/2013
• Est. Priority Date: 06/23/2010
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Sugita, Takami, Moro, Hiroyuki, Nango, Takahiro
• Primary Examiner(s): Lottich, Joshua P
• Application Number:
  US13/087,177
• Publication Number:
  US 20110320868A1
• Time in Patent Office: 943 Days
• Field of Search: 714/6.1, 714/6.11, 714/6.13, 714/54
• US Class Current: 714/54
• CPC Class Codes: G06F 11/1048 using arrangements adapted for a specific error detection or correction feature
• CPC Class Codes: G11C 2029/0411 Online error correction

Abstract

According to one embodiment, a data storage apparatus includes a read module, an error detector and a controller. The read module is configured to read data from a flash memory, more precisely from a rewrite area and a write-back area, both provided in the flash memory. The error detector is configured to detect errors, if any, in the data read. The controller is configured to keep rewriting data, without correcting the errors the error detector has detected in the rewrite area of the flash memory.

Claims

1. A data storage apparatus comprising:

a flash memory; and

a controller configured to;

read data stored in a flash memory, where the data is stored in a write-back area and a modified write area in the flash memory,

detect errors in the data read from the flash memory, and

perform a data writing process without correcting the detected errors in the data stored in the modify write area.

2. The data storage apparatus of claim 1, wherein the controller is configured to perform error notification when the controller detects errors in the data stored in either the modify write area or the write-back area.

3. The data storage apparatus of claim 2, wherein the controller is configured to manage statistics regarding accesses to the flash memory and error locations based on at least the error notification.

4. The data storage apparatus of claim 3, wherein the controller is configured to manage memory areas for prescribed access units designated by the error notification as unusable areas.

5. The data storage apparatus of claim 1, wherein when the controller detects an error in the data stored in the write-back area, the controller continues the data writing process after the error has been corrected.

6. The data storage apparatus of claim 1, wherein the controller is configured to stop the data writing process when the controller detects an error in the data stored in the write-back area and when the error cannot be corrected.

7. The data storage apparatus of claim 1, further comprising a buffer memory,

wherein the controller is configured to:

store data read from the flash memory into the buffer memory, wherein a first data portion is read from the write-back area; and

transfer the first data portion from the buffer memory to the modify write area of the flash memory;

wherein performing the data writing process comprises writing data to modify into the modify write area.

8. The data storage apparatus of claim 7, wherein when the controller detects an error in the data stored in the modify write area, the controller stores in the buffer memory the data stored in the modify write data containing the error.

9. The data storage apparatus of claim 7, wherein when the controller detects an error in the data stored in the write-back area, the controller stores, in the buffer memory, the data after the error has been corrected in the write-back area.

10. A method, implemented on an electronic device, for writing data in a data storage apparatus having a flash memory, the method comprising:

reading data from the flash memory, where the data is stored in a write-back area and a modify write area in the flash memory;

detecting errors in the data read from the flash memory; and

continuing a data writing process, without correcting the errors, when errors are detected in the data read held in the modify write area.

11. The method of claim 10, further comprising

performing error notification when errors are detected in the data stored in either the modify write area or the write-back area.

12. The method of claim 11, further comprising managing statistics regarding accesses to the flash memory and error locations based on at least the error notification.

13. The method of claim 12, further comprising managing memory areas for prescribed access units designated by the error notification as unusable areas.

14. The method of claim 10, further comprising continuing the data writing process, when an error in the data stored in the write-back area is detected, after the error has been corrected.

15. The method of claim 10, further comprising stopping the data writing process if an error is detected in the data stored in the write-back area and if the error cannot be corrected.

16. The method of claim 10, further comprising

storing data read from the flash memory into a buffer memory, wherein a first data portion is read from the write-back area;

and

transferring the first data portion from the buffer memory to the modify write area of the flash memory;

wherein performing the data writing process comprises writing data to modify into the modify write area.

17. The method of claim 16, further comprising, when an error is detected in the data stored in the modify write area, storing in the buffer memory the data stored in the modify write data containing the error.

18. The method of claim 16, further comprising, when an error is detected in the data stored in the write-back area, storing in the buffer memory the data after the error has been corrected in the write-back area.