Flash memory directory virtualization

• US 20060253484A1
• Filed: 05/03/2005
• Published: 11/09/2006
• Est. Priority Date: 05/03/2005
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: McGinty, Patrick C., Tiso, William J. Jr., Bangalore, Kiran Kumar G.
• Granted Patent: US 7,634,494 B2
• 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 16/1847 specifically adapted to static storage, e.g. adapted to flash memory or SSD
• CPC Class Codes: G06F 2212/2022 Flash memory
• CPC Class Codes: Y10S 707/99943 Generating database or data structure, e.g. via user interface

Abstract

Directory virtualization may be achieved in semiconductor memories, such as flash memories, by providing a system in which files and directories are interchangeable. A directory may be stored at a virtual address which points to various files. From the user perspective, a tree hierarchy may be achieved. From a hardware standpoint, a series of entries in a table may be linked together by various pointers.

Claims

1. a method comprising:

storing a file system for a flash memory array in a separate random access memory.

2. The method of claim 1 including providing entries in said file system corresponding to files and file directories.

3. The method of claim 2 including enabling directories to point to files.

4. The method of claim 1 including populating a file system for the flash memory array using information obtained from a header within said flash memory array.

5. The method of claim 1 including storing file system data in said random access memory and said flash memory array.

6. The method of claim 5 including storing less file system data for each file in said flash memory array than is stored in said random access memory.

7. The method of claim 1 including storing actual files in said flash memory array and storing data, to enable said actual files to be accessed, in said random access memory.

8. The method of claim 7 including providing entries in said random access memory to enable files in said flash memory array to be accessed and indicating in connection with said entries in said random access memory whether the corresponding information stored in the flash memory array is a file or a directory.

9. The method of claim 1 including providing a file name hash stored in said random access memory which is translatable into a file name for a file stored in said flash memory array.

10. The method of claim 1 including enabling a file to be fragmented into portions, identifying said portions, and providing instance identifiers so that said portions can be accessed from data stored in said random access memory.

11. An article comprising a medium storing instructions that, if executed, enable a processor-based system to:

maintain a file system for a flash memory array in a separately accessible random access memory.

12. The article of claim 11 further storing instructions that, if executed, enable the processor-based system to provide entries in said flash memory array file system corresponding to files and file directories.

13. The article of claim 12 further storing instructions that, if executed, enable the processor-based system to enable directories to point to files.

14. The article of claim 11 further storing instructions that, if executed, enable the processor-based system to populate a file system for the flash memory array using information obtained from a header within said flash memory array.

15. The article of claim 11 further storing instructions that, if executed, enable the processor-based system to store file system data in the random access memory and said flash memory array.

16. The article of claim 15 further storing instructions that, if executed, enable the processor-based system to store less file system data for each file in the flash memory array than is stored in the random access memory.

17. The article of claim 11 further storing instructions that, if executed, enable the processor-based system to store actual files in flash memory array and store data, to enable said actual files to be accessed, in said random access memory.

18. The article of claim 17 further storing instructions that, if executed, enable the processor-based system to provide entries in said random access memory to enable files in said flash memory array to be accessed and to indicate in connection with said entries in said random access memory whether the corresponding information stored in the flash memory array is a file or a directory.

19. The article of claim 11 further storing instructions that, if executed, enable the processor-based system to provide a file name as stored in the random access memory which is translatable into a file name for a file stored in said flash memory array.

20. The article of claim 11 further storing instructions that, if executed, enable the processor-based system to fragment a file into portions, identify said portions, and provide instance identifiers so that said portions can be accessed from data stored in said random access memory.

21. A system comprising:

a processor;

a static random access memory coupled to said processor; and

a flash memory coupled to said processor, said flash memory including a controller and a flash array, said flash memory to store a file system for said flash array in said random access memory.

22. The system of claim 21 wherein said flash memory array includes headers storing the file data in said flash system and said random access memory stores some of the same but more information relating to files.

23. The system of claim 22 including storing information in said random access memory to enable files and directories of files to be located.

24. A flash memory comprising:

a controller;

a flash memory array coupled to said controller; and

a random access memory coupled to said controller to store a file system for said flash memory array.

25. The memory of claim 24 wherein said file system to store entries for files and file directories.

26. The memory of claim 25 wherein said file system data is stored in said flash memory array and said random access memory.

27. The memory of claim 26, said flash memory array to store less file system data than said random access memory array.

28. The memory of claim 24, said file system to enable a file to be fragmented into portions, identify said portions, and provide instance identifiers so that said portions can be accessed from data stored in said random access memory.