Managing defective areas of memory

• US 9,026,721 B2
• Filed: 03/11/2013
• Issued: 05/05/2015
• Est. Priority Date: 07/31/1995
• Status: Expired due to Fees

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Estakhri, Petro, Iman, Berhanu
• Primary Examiner(s): THAI, TUAN V
• Application Number:
  US13/793,036
• Publication Number:
  US 20130262802A1
• Time in Patent Office: 785 Days
• Field of Search: 711/5, 711/100, 711/103, 711/154, 711/170, 711/200
• 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: G06F 12/0238 Memory management in non-volatile memory, e.g. resistive RAM or ferroelectric memory
• CPC Class Codes: G06F 12/0246 in block erasable memory, e.g. flash memory
• CPC Class Codes: G06F 3/0613 in relation to throughput
• CPC Class Codes: G06F 3/064 Management of blocks
• CPC Class Codes: G06F 3/0679 Non-volatile semiconductor memory device, e.g. flash memory, one time programmable memory [OTP]
• CPC Class Codes: G11C 16/08 Address circuits; Decoders; Word-line control circuits
• CPC Class Codes: G11C 16/102 External programming circuits, e.g. EPROM programmers; In-circuit programming or reprogramming; EPROM emulators
• CPC Class Codes: G11C 29/765 in solid state disks
• CPC Class Codes: G11C 29/82 for EEPROMs

Abstract

Methods of operating a memory, and memories for performing such methods, include determining that a particular area of the memory is defective, locating a free area of the memory, programming data intended for the particular area of the memory to the free area of the memory, checking the particular area of the memory for data previously programmed to the particular area of the memory, and moving any previously-programmed data from the particular area of the memory to the free area of the memory.

Claims

1. A method of operating a memory, comprising:

determining that a particular area of the memory is defective;

marking the particular area of the memory as defective;

locating a free area of the memory;

programming data intended for the particular area of the memory to the free area of the memory;

checking the particular area of the memory for data previously successfully programmed to the particular area of the memory; and

moving any previously successfully programmed data from the particular area of the memory to the free area of the memory.

2. The method of claim 1, wherein determining that a particular area of the memory is defective comprises determining that a write operation of the particular area of memory is not successfully verified.

3. The method of claim 2, wherein determining that a write operation of the particular area of memory is not successfully verified comprises determining that a write operation comprising one sector of data to a memory device of the memory and another sector of data to another memory device of the memory is not successfully verified.

4. The method of claim 3, wherein marking the particular area of the memory as defective comprises setting a flag of the particular area of the memory to a particular value.

5. The method of claim 4, wherein setting a flag of the particular area of the memory comprises setting a flag in only one of the memory devices of the memory.

6. The method of claim 2, wherein programming data intended for the particular area of the memory to the free area of the memory comprises programming data from the write operation that was not successfully verified to the free area of the memory.

7. The method of claim 1, further comprising marking the particular area of the memory as defective.

8. The method of claim 7, wherein marking the particular area of the memory as defective comprises setting a flag of the particular area of the memory to a particular value.

9. The method of claim 1, wherein determining that a particular area of the memory is defective comprises determining that a particular block of the memory is defective.

10. The method of claim 9, wherein checking the particular area of the memory for data previously successfully programmed to the particular area of the memory comprises checking for the presence of sector information that was previously written to the particular block of memory and successfully verified.

11. The method of claim 9, wherein locating a free area of the memory comprises locating a free block of the memory.

12. A method of operating a memory, comprising:

performing a write operation to a particular area of the memory;

determining whether the write operation is successful, wherein the particular area of the memory comprises a portion from each memory unit of a plurality of memory units of the memory, and wherein the write operation comprises data to be programmed to one or more of the portions of the particular area of the memory;

if the write operation is not successful;

marking the particular area of the memory as defective;

locating a free area of the memory;

programming the data of the write operation to the free area of the memory;

checking the particular area of the memory for data previously successfully programmed to the particular area of the memory; and

moving any previously successfully programmed data from the particular area of the memory to the free area of the memory.

13. The method of claim 12, further comprising marking the particular area of the memory as defective if the write operation is not successful.

14. The method of claim 12, wherein the write operation comprises data to be programmed to portions of the particular area of the memory from each of the memory units of the plurality of memory units.

15. The method of claim 12, wherein the write operation comprises data to be programmed to a portion of the particular area of the memory from only one memory unit of the plurality of memory units.

16. The method of claim 15, wherein moving any previously-programmed data from the particular area of the memory to the free area of the memory comprises moving data from memory units of the plurality of memory units other than the only one memory unit of the write operation.

17. A memory, comprising:

a memory bank comprising a plurality of memory units; and

a controller configured to perform operations on memory units of the memory bank, comprising;

performing a write operation to at least a portion of a particular area of the plurality of memory units in response to a command;

checking whether the write operation is successful;

if the write operation was not successful;

marking the particular area of the memory as defective;

locating a free area of the memory;

programming data of the write operation to the free area of the memory;

checking the particular area of the memory for data previously successfully programmed to the particular area of the memory; and

moving any previously successfully programmed data from the particular area of the memory to the free area of the memory.

18. The memory of claim 17, wherein performing a write operation to at least a portion of a particular area of the plurality of memory units comprises performing the write operation to a portion of at least one of the memory units of the plurality of memory units.

19. The memory of claim 17, wherein the particular area of the plurality of memory units comprises a portion from each memory unit of the plurality of memory units.

20. The memory of claim 19, wherein the controller is further configured to indicate that the particular area of the plurality of memory units is defective if the write operation is not successful.

21. The memory of claim 20, wherein the controller is further configured to indicate that the particular area of the plurality of memory units is defective by setting a flag in a particular portion of the particular area of the plurality of memory units.

22. The memory of claim 21, wherein the particular portion of the particular area of the plurality of memory units comprises a portion from only one memory unit of the plurality of memory units.