Methods for data alignment in non-volatile memories with a directly mapped file storage system

• US 20070143567A1
• 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:
  US11/316,261
• Publication Number:
  US 20070143567A1
• Time in Patent Office: Days
• US Class Current: 711/202
• CPC Class Codes: G06F 12/0246 in block erasable memory, e.g. flash memory
• CPC Class Codes: G06F 12/0292 using tables or multilevel address translation means G06F12/023 takes precedence; address translation in virtual memory systems G06F12/10
• CPC Class Codes: G06F 2212/7202 Allocation control and policies

Abstract

In the file storage system, each portion belonging to a data file is identified by its file ID and an offset along the data file, where the offset is a constant for the file and every file data portion is always kept at the same position within a memory page to be read or programmed in parallel. In this way, every time a page containing a file portion is read and copy to another page, the data in it is always page-aligned, and each bit within the file portion can always be manipulated by the same sense amplifier and same set data latches within the same memory column. In a preferred implementation, the page alignment is such that (offset within a page)=(data offset within a file) MOD (page size). Any gaps that may exist in page can be padded with any existing page-aligned valid data.

Claims

1. In a memory system for storing data files created by a host, said memory system having memory accessible page by page, a method for storing file data belonging to a data file in the memory, comprising:

addressing each file data unit of the data file by a unique file identification and an offset within the file;

pre-assigning a fixed location within a page for each file data unit; and

storing each file data unit of the data file in a page according to its pre-assigned location.

2. The method according to claim 1, wherein:

the pre-assigned location within a page is given by the offset within the file times the modulus of the page size.

3. The method according to claim 1, further comprising:

filling any gaps within a page before the file data with a latest version of file data units having the same file identification and offsets appropriate for the gap.

4. The method according to claim 1, further comprising:

filling any remaining gap within a page of a previous block when the file data is written to a new block with any latest version of file data units having the same file identification and offsets appropriate for the remaining gap.

5. The method according to claim 1, wherein:

said page is organized from a row of memory cells of a memory array; and

each bit of the file data remains in the same column of the array when copied from one page to another.

6. The method according to claim 5, wherein:

said page is organized from linking individual pages of memory cells from multiple memory arrays; and

each bit of the file data remains in the same column of an array when copied from one page to another.

7. The method as in any one of claims 1-6, wherein the memory system includes an array of flash memory.

8. The method as in any one of claims 1-6, wherein the memory system is in the form of a removably memory card.

9. The method as in any one of claims 1-6, wherein the memory system includes memory cells that each store one bit of data.

10. The method as in any one of claims 1-6, wherein the memory system includes memory cells that each store more than one bit of data.