Non-volatile memories with adaptive file handling in a directly mapped file storage system

• US 20070143378A1
• Filed: 12/21/2005
• Published: 06/21/2007
• Est. Priority Date: 12/21/2005
• Status: Abandoned Application

• Current Assignee: SanDisk Technologies LLC (Western Digital Corporation)
• Original Assignee: SanDisk Technologies LLC (Western Digital Corporation)
• Inventors: Gorobets, Sergey
• Application Number:
  US11/316,110
• Publication Number:
  US 20070143378A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 12/0246 in block erasable memory, e.g. flash memory
• CPC Class Codes: G06F 2212/7205 Cleaning, compaction, garbage collection, erase control

Abstract

In a memory system with a file storage system, an optimal file handling scheme is adaptively selected from a group thereof based on the attributes of the file being handled. The file attributes may be obtained from a host or derived from a history of the file had with the memory system. In one embodiment, a scheme for allocating memory locations for a write operation is dependent on an estimated size of the file to be written. In another embodiment, a scheme for allocating memory locations for a relocation operation, such as for garbage collection or data compaction, is dependent on an estimated access frequency of the file in question. In this way, the optimal handling scheme can be used for the particular file at any time.

Claims

1. A memory system for storing data files created by a host, comprising:

an array of memory cells;

a memory controller for performing a memory operation on file data belonging to a data file created by a host;

a set of file attributes for the data file;

a plurality of predefined file data handling schemes;

an association between the set of file attributes with one of the plurality of predefined file data handling schemes; and

said memory controller in response to a file operating command to perform a memory operation on the file data selecting from the plurality of predefined file data handling schemes one associated with the set of file attributes for the data file to which the file data belongs and performing the memory operation on the file data by employing the selected predefined file data handling scheme.

2. A memory system as in claim 1, wherein the set of file attributes is obtained from the host.

3. The memory system as in claim 1, wherein the set of file attributes is obtained from the history of the data file with the memory system.

4. The memory system as in claim 1, wherein the set of file attributes includes a size for the data file and the associated predefined file data handling scheme is a scheme to pack file data among a set of one or more memory block during a write operation.

5. The memory system as in claim 1, wherein the set of file attributes includes an estimate for the frequency of file access for the data file and the associated predefined file data handling scheme is a scheme to direct file data selectively to a specific memory block during a relocation operation.

6. The memory system as in claim 1, wherein the set of file attributes includes a portion of the file name.

7. The memory system as in claim 1, wherein the set of file attributes includes an identification of the application that generated the data file.

8. The memory system as in claim 1, wherein the set of file attributes includes an identification of the host that provided the data file.

9. The memory system as in claim 1, wherein the set of file attributes includes a data modification performed on the file data either by the host or by the memory system.

10. The memory system as in claim 1, wherein the set of file attributes includes an update pattern detected previously by the memory system.

11. The memory system as in claim 1, wherein:

the memory operation includes writing file data; and

the predefined file data handling scheme is to write the file data of a new file into a new memory block when the set of file attributes includes a file size larger than that of a memory block, and to write the file data to an existing block following the file data of a last write when the set of file attributes includes a file size smaller than that of a memory block.

12. The memory system as in claim 1, wherein:

the memory operation includes a relocating file data; and

the predefined file data handling scheme is to write the file data selectively to a memory block containing data with similar file attributes.

13. The memory system as in claim 12, wherein:

the similar file attributes include an estimated file update frequency.

14. The memory system as in claim 1, wherein the memory system includes an array of flash memory.

15. The memory system as in claim 1, wherein the memory system is in the form of a removably memory card.

16. The memory system as in any one of claims 1-15, wherein the memory system includes memory cells that each store one bit of data.

17. The memory system as in any one of claims 1-15, wherein the memory system includes memory cells that each store more than one bit of data.

18. A memory system for storing data files created by a host, comprising:

an array of memory cells;

a memory controller for performing a memory operation on file data belonging to a data file created by a host;

a set of file attributes for the data file;

a plurality of predefined file data handling schemes;

an association between the set of file attributes with one of the plurality of predefined file data handling schemes; and

means for receiving a file operating command to perform a memory operation on the file data;

means for selecting from the plurality of predefined file data handling schemes one associated with the set of file attributes for the data file to which the file data belongs; and

means for performing the memory operation on the file data by employing the selected predefined file data handling scheme.

19. The memory system as in claim 18, wherein the memory system includes memory cells that each store one bit of data.

20. The memory system as in claim 18, wherein the memory system includes memory cells that each store more than one bit of data.