Method and apparatus to detect invalid data in a nonvolatile memory following a loss of power

• US 20060002197A1
• Filed: 06/30/2004
• Published: 01/05/2006
• Est. Priority Date: 06/30/2004
• Status: Abandoned Application

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Rudelic, John C.
• Application Number:
  US10/882,379
• Publication Number:
  US 20060002197A1
• Time in Patent Office: Days
• US Class Current: 365/189.90
• CPC Class Codes: G11C 16/102 External programming circuits, e.g. EPROM programmers; In-circuit programming or reprogramming; EPROM emulators
• CPC Class Codes: G11C 16/105 Circuits or methods for updating contents of nonvolatile memory, especially with 'security' features to ensure reliable replacement, i.e. preventing that old data is lost before new data is reliably written

Abstract

Briefly, in accordance with an embodiment of the invention, a method and apparatus to detect invalid data in a memory is provided. The method may include setting at least one power loss recovery (PLR) status bit in response to the writing to or erasing of a plurality of nonvolatile memory cells of a nonvolatile memory, wherein the at least one PLR status bit indicates whether the writing to or erasing of the plurality of memory cells was interrupted by a loss of power and wherein the setting of the at least one PLR status bit is performed by the nonvolatile memory. Other embodiments are described and claimed.

Claims

1. A method, comprising:

setting at least one power loss recovery (PLR) status bit in response to the writing to or erasing of a plurality of nonvolatile memory cells of a nonvolatile memory, wherein the at least one PLR status bit indicates whether the writing to or erasing of the plurality of memory cells was interrupted by a loss of power and wherein the setting of the at least one PLR status bit is performed by the nonvolatile memory.

2. The method of claim 1, wherein setting includes setting the at least one PLR status bit after completing the writing or erasing of the plurality of memory cells.

3. The method of claim 1, wherein the writing to the plurality of memory cells includes a write operation to write data to the plurality of memory cells and wherein setting includes setting only one PLR status bit for the write operation.

4. The method of claim 1, wherein the writing to the plurality of memory cells includes a write operation to write data to the plurality of memory cells and wherein setting includes setting a first PLR status bit and a second PLR status bit, wherein the first PLR status bit is set prior to beginning the write operation and wherein the second PLR status bit is set after the write operation is completed.

5. The method of claim 1, wherein the erasing of the plurality of memory cells includes an erase operation to erase the plurality of memory cells, wherein setting includes setting a first PLR status bit and a second PLR status bit, and wherein the first PLR status bit is set prior to beginning the erase operation and wherein the second PLR status bit is set after the erase operation is completed.

6. The method of claim 1, wherein setting the at least one PLR status bit includes storing the at least one PLR status bit in a PLR status cell linked to the plurality of nonvolatile memory cells and wherein the PLR status cell is a nonvolatile memory cell of the nonvolatile memory.

7. The method of claim 1, wherein setting the at least one PLR status bit includes storing two PLR status bits using two PLR status cells that correspond to the plurality of nonvolatile memory cells and wherein the two PLR status cells are nonvolatile memory cells of the nonvolatile memory.

8. The method of claim 1 further comprising determining whether the plurality of memory cells includes invalid data based on the at least one PLR status bit.

9. The method of claim 8, wherein the determining is performed upon power-up of the non-volatile memory or prior to reading information stored in plurality of nonvolatile memory cells and further comprising sending an address of the plurality of memory cells to a device external to the nonvolatile memory if the plurality of memory cells includes invalid data.

10. The method of claim 8, wherein the determining is performed by the nonvolatile memory and wherein determining comprises:

determining whether programmed data is stored in the plurality of nonvolatile memory cells; and

determining whether the at least one PLR status bit is set.

11. A nonvolatile memory, comprising:

a control circuit to set at least one power loss recovery (PLR) status bit in response to a write operation or an erase operation to a plurality of nonvolatile memory cells of the nonvolatile memory, wherein the at least one PLR status bit indicates whether the write operation or the erase operation was interrupted by a loss of power and wherein the at least one PLR status bit is set by the control circuit of the nonvolatile memory.

12. The nonvolatile memory of claim 11, wherein the nonvolatile memory is a flash electrically erasable programmable read-only memory (EEPROM) and the flash EEPROM includes at least one status cell to store the at least one PLR status bit, wherein status cell is a flash memory cell of the flash EEPROM.

13. The nonvolatile memory of claim 11, wherein the control circuit includes circuitry to write to, read from, or erase the plurality of nonvolatile memory cells.

14. The nonvolatile memory of claim 11, wherein the nonvolatile memory includes a plurality of memory blocks, wherein each block of the plurality of memory blocks includes a plurality of colonies, wherein each colony of the plurality of colonies includes a plurality of memory cells and wherein the control circuit sets the at least one PLR status bit after the completion of the write operation to the plurality of nonvolatile memory cells.

15. The nonvolatile memory of claim 14, wherein a colony of the plurality of colonies is at least about 512 bytes in size and wherein a block of the plurality of memory blocks is at least about 64 kilobytes in size.

16. The nonvolatile memory of claim 11, wherein control circuit includes circuitry to determine whether the plurality of memory cells includes invalid data based on the at least one PLR status bit and to send an address of the plurality of memory cells to a device external to the nonvolatile memory if the plurality of memory cells includes invalid data.

17. The nonvolatile memory of claim 11, wherein the control circuit is coupled to a memory array of the nonvolatile memory.

18. The nonvolatile memory of claim 11, wherein the nonvolatile memory is a ferroelectric random access memory (FRAM), a magnetic random access memory (MRAM), or a disk memory.

19. A system, comprising:

a processor;

an antenna coupled to the processor; and

a flash electrically erasable programmable read-only memory (EEPROM) coupled to the processor, wherein the flash EEPROM comprises a control circuit to set at least one power loss recovery (PLR) status bit in response to a write operation or an erase operation to a plurality of memory cells of the flash EEPROM, wherein the at least one PLR status bit indicates whether the write operation or the erase operation was interrupted by a loss of power and wherein the at least one PLR status bit is set by the control circuit of the flash EEPROM.

20. The system of claim 19, wherein the system is a wireless phone.

21. The system of claim 19, wherein control circuit includes circuitry to determine whether the plurality of memory cells includes invalid data based on the at least one PLR status bit and to send an address of the plurality of memory cells to the processor from the flash EEPROM if the plurality of memory cells includes invalid data.

22. A method, comprising:

setting at least one power loss recovery (PLR) status bit in response to the writing to a plurality of nonvolatile memory cells of a nonvolatile memory, wherein the at least one PLR status bit indicates whether the writing to the plurality of memory cells was interrupted by a loss of power and wherein the setting of the at least one PLR status bit is performed by the nonvolatile memory; and

receiving an address of the plurality of nonvolatile memory cells from the nonvolatile memory.

23. The method of claim 22, further comprising determining whether the plurality of memory cells includes invalid data based on the PLR status bit.