Data handling system

• US 7,000,064 B2
• Filed: 09/27/2002
• Issued: 02/14/2006
• Est. Priority Date: 09/28/2001
• Status: Expired due to Fees

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Lexar Media Incorporated (Micron Technology, Inc.)
• Inventors: Smith, Peter John, Payne, Robert Edwin
• Primary Examiner(s): Padmanabhan, Mano
• Assistant Examiner(s): Namazi, Mehdi
• Application Number:
  US10/260,180
• Publication Number:
  US 20030099140A1
• Time in Patent Office: 1,236 Days
• Field of Search: 711/103, 711/163, 711/217, 711/219, 713/168, 713/170, 380/28
• US Class Current: 711/103
• CPC Class Codes: G06F 11/1068 in sector programmable memories, e.g. flash disk G06F11/1072 takes precedence
• CPC Class Codes: G11C 7/1006 Data managing, e.g. manipulating data before writing or reading out, data bus switches or control circuits therefor

Abstract

In one embodiment of the present invention, there is disclosed, a method of handling data which is being written to and stored in flash memory, wherein input data, comprising information data and overhead data, undergoes a reversible transformation before being written to flash memory whereupon each bit stored in flash memory, as flash data, is a function of both information data and header data.

Claims

1. A data handling system for handling data being written to or stored in flash memory comprising:

means for receiving input data including bits forming bytes and bytes being

stored in sectors within the flash memory, said input data including information data and overhead data;

means for reversibly transforming the input data,

wherein the transforming means is an encoder;

means for writing the transformed input data into the flash memory,

wherein the encoder performs an encoding process of the input data by generating a data hiding key Q, performing an XOR operation, on a byte-by-byte basis, of the data hiding key Q with the information data, generating a header hiding key P, performing an XOR operation, on a byte-by-byte basis, of the header hiding key P with the header data; and

wherein each bit of the input data that is written into flash memory, as flash data, is a function of both information data and overhead data thereby enhancing security of the information data due to the bytes of the input data stored in the flash memory sector no longer being partitioned, and each byte no longer being identifiable as being an information data byte or an overhead data byte.

2. A data handling system as recited in claim 1 wherein the input data comprises 512 bytes of information data and 4 bytes of overhead data.

3. A data handling system as recited in claim 1 wherein the means for reversibly transforming the input data results in the flash data being an XOR function combining bytes of information data and overhead data.

4. A data handling system as recited in claim 1 further including means for producing 12 bytes of error detection and correction capability (ECC) for storage in the flash memory.

5. A data handling system as recited in claim 4 wherein the ECC is a function of the flash data.

6. A data handling system as recited in claim 1 the encoder comprises a plurality of XOR gates.

7. A data handling system as recited in claim 1 including a buffer memory wherein the input data being written first to a buffer memory without modification, the input data then being transferred from the buffer memory, via the encoder, to the flash memory.