Methods for preventing fixed pattern programming

• US 20060181934A1
• Filed: 01/19/2006
• Published: 08/17/2006
• Est. Priority Date: 01/19/2005
• Status: Abandoned Application

• Current Assignee: Saifun Semiconductors Ltd. (Infineon Technologies AG)
• Original Assignee: Saifun Semiconductors Ltd. (Infineon Technologies AG)
• Inventors: Cohen, Guy, Eisen, Shai, Shappir, Assaf, Danon, Kobi
• Application Number:
  US11/335,316
• Publication Number:
  US 20060181934A1
• Time in Patent Office: Days
• US Class Current: 365/185.330
• CPC Class Codes: G06F 12/1408 by using cryptography for digital transmission H04L9/00
• CPC Class Codes: G11C 11/5635 Erasing circuits
• CPC Class Codes: G11C 16/0475 comprising two or more independent storage sites which store independent data
• CPC Class Codes: G11C 16/10 Programming or data input circuits
• CPC Class Codes: G11C 16/14 Circuits for erasing electrically, e.g. erase voltage switching circuits
• CPC Class Codes: G11C 16/16 for erasing blocks, e.g. arrays, words, groups
• CPC Class Codes: G11C 16/26 Sensing or reading circuits; Data output circuits
• CPC Class Codes: G11C 16/3404 Convergence or correction of memory cell threshold voltages; Repair or recovery of overerased or overprogrammed cells
• CPC Class Codes: G11C 16/344 Arrangements for verifying correct erasure or for detecting overerased cells
• CPC Class Codes: G11C 16/3445 Circuits or methods to verify correct erasure of nonvolatile memory cells
• CPC Class Codes: G11C 16/349 Arrangements for evaluating degradation, retention or wearout, e.g. by counting erase cycles
• CPC Class Codes: G11C 2216/18 Flash erasure of all the cells in an array, sector or block simultaneously

Abstract

A method for preventing fixed pattern programming, the method including programming data into a pattern of memory cells in a memory array, and preventing fixed pattern programming by periodically scrambling the data so that the data is stored in a different pattern of memory cells in the memory array.

Claims

1. A method for preventing fixed pattern programming, the method comprising:

programming data into a pattern of memory cells in a memory array; and

preventing fixed pattern programming by periodically scrambling the data so that the data is stored in a different pattern of memory cells in the memory array.

2. The method according to claim 1, wherein periodically scrambling the data comprises periodically inverting the data.

3. The method according to claim 1, wherein periodically scrambling the data comprises periodically rearranging a physical address of said data.

4. The method according to claim 1, wherein periodically scrambling the data comprises convolving said data with a mixing pattern during programming and de-convolving the convolved data during a read operation.

5. The method according to claim 1, wherein periodically scrambling the data comprises periodically scrambling the data in accordance with a program and erase cycle counter.

6. The method according to claim 1, wherein the data is periodically scrambled randomly.

7. The method according to claim 1, wherein the data is periodically scrambled pseudo-randomly.

8. The method according to claim 1, wherein periodically scrambling the data comprises scrambling as a function of a stored parameter inside the memory array.

9. The method according to claim 8, wherein said stored parameter is programmed in conjunction with said data

10. The method according to claim 1, wherein periodically scrambling the data comprises scrambling as a function of a logical address of said data.

11. The method according to claim 1, wherein periodically scrambling the data comprises scrambling as a function of a physical address of said data.