FLASH MEMORY SCATTER-WRITE METHOD

• US 20070288685A1
• Filed: 06/09/2006
• Published: 12/13/2007
• Est. Priority Date: 06/09/2006
• Status: Abandoned Application

• Current Assignee: Phison Electronics Corporation
• Original Assignee: Phison Electronics Corporation
• Inventors: Chu, Chien-Hua
• Application Number:
  US11/423,148
• Publication Number:
  US 20070288685A1
• Time in Patent Office: Days
• US Class Current: 711/103
• CPC Class Codes: G06F 12/0246 in block erasable memory, e.g. flash memory
• CPC Class Codes: G06F 2212/1036 Life time enhancement
• CPC Class Codes: G06F 2212/7211 Wear leveling

Abstract

A flash memory scatter-write method divides a physical block of a flash memory into two areas, the first area includes a plurality of sub areas, and the second area is an area containing no data and provided for alternately writing data. If a data is written into a flash memory, a physical block in a non-predetermined sub area is selected from the first area first, and then a desired write-in physical block in the second area is selected, such that if the number of times of writing data at that particular time is a multiple of a predetermined value, then the write-in physical block is changed to another physical block in the second area for writing data, and then the data in the selected physical block of the first area is written into the physical block of the second area, and the selected physical block of the first area is moved to the second area, and the physical block of the second area containing the written data is moved to the first area, so as to scatter the number of times of writing data in each block and extend the life of the flash memory.

Claims

1. A flash memory scatter-write method, dividing a physical block of a flash memory into a first area and a second area, and said first area being a logical area containing data, and said first area comprising a plurality of sub areas, and said second area being an area containing no data and used for alternately writing data, such that data is written into said flash memory according to a procedure comprising the steps of:

(A) selecting a physical block in a non-predetermined sub area from said first area;

(B) selecting a physical block from said second area as a write-in physical block;

(C) determining whether or not the number of times of writing data at that particular time is a multiple of a predetermined value;

if yes, then execute Step (D), and if no, then execute Step (E);

(D) changing to another physical block as a physical block of said second area for writing data;

(E) writing the data contained in said selected physical block of said first area into said physical block of said second area; and

(F) moving said selected physical block of said first area to said second area, and moving said physical block of said second area containing the written data to said first area.

2. The flash memory scatter-write method of claim 1, wherein after said selected physical block of said first area is moved to said second area, said selected physical block becomes a physical block of said second area.

3. The flash memory scatter-write method of claim 1, wherein after said physical block of said second area containing the written data is moved to said first area, said physical block becomes a physical block of said first area.