Defective memory block remapping method and system, and memory device and processor-based system using same

• US 8,601,331 B2
• Filed: 05/20/2011
• Issued: 12/03/2013
• Est. Priority Date: 01/22/2007
• Status: Active Grant

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Nobunaga, Dean, Li, Hanqing
• Primary Examiner(s): Chung, Phung M
• Application Number:
  US13/112,707
• Publication Number:
  US 20110219260A1
• Time in Patent Office: 928 Days
• Field of Search: 714/819, 714/723, 714/736, 714/6.13, 714/6.2, 714/735, 714/763, 714/718, 714/719, 714/710, 714/799, 365/96, 365/200, 365/201, 365/185.33, 365/230.03
• US Class Current: 714/719
• CPC Class Codes: G11C 29/76 using address translation or modifications

Abstract

A non-volatile memory device includes a block remapping system that offsets an input block address by the addresses of non-functional blocks to provide an output block address that is used to address the memory device. The system generates the output block addresses by, in effect, adding to the input block address the addresses of all non-functional blocks of memory that are between an initial address and the output block address. The system performs this function be comparing the input block address to the address of any defective block. If the address of the defective block is less than or equal to the input block address, the addresses of all defective blocks starting at the block address are added to the input block address. The system then iteratively performs this process using each output block address generated by the system in place of the input block address.

Claims

1. A method of addressing a memory, comprising:

receiving an input address for access to the memory;

determining a number of non-functional memory blocks between an initial address of the memory and the input address;

incrementing the input address by the number of non-functional memory blocks to yield an output address; and

accessing the memory using the output address.

2. The method of claim 1 further comprising storing addresses in order from a lowest address of a non-functional memory block to a highest address of a non-functional memory block.

3. The method of claim 1 wherein determining the number of non-functional memory blocks between the initial address of the memory and the input address comprises:

comparing the input address to stored addresses of non-functional memory blocks of the memory.

4. The method of claim 3 wherein determining the number of bad addresses between the initial address of the memory and the input address further comprises:

summing respective sizes for all stored addresses that are less than the input address.

5. The method of claim 1 wherein incrementing the input address by the number of non-functional memory blocks comprises:

incrementing the input address by a sum of respective sizes for all stored addresses that are less than the input address.

6. The method of claim 1 wherein the determining and incrementing are iteratively performed until a stored address is greater than the input address.

7. A method of replacing bad memory blocks of an array, comprising:

mapping addresses for the bad memory blocks in the array to next available good memory blocks in the array; and

storing the addresses and respective sizes of the bad memory blocks in the array, the stored addresses and respective sizes of the bad memory blocks used in calculating remapped block addresses for the next available good memory blocks in the array.

8. The method of claim 7 wherein storing the addresses and the respective sizes of the bad memory blocks comprises:

programming the addresses and the respective sizes of the bad memory blocks in respective fuse sets.

9. The method of claim 7 wherein mapping the addresses for the bad memory blocks in the array to next available good memory blocks in the array comprises:

offsetting an input address by one or more of the addresses of the bad memory blocks to provide an output address used to access the array.

10. The method of claim 7 wherein mapping the addresses for the bad memory blocks in the array to next available good memory blocks in the array comprises:

when accessing an address for a bad memory block, accessing instead a memory block having an address that is the sum of the address for the bad memory block and a total number of bad memory blocks having addresses less than the address for the bad memory block.

11. The method of claim 7, further comprising storing a respective enable bit for each of the stored addresses, the enable bit indicative of whether the respective stored address is for a bad memory block.

12. A memory, comprising:

an array of memory blocks;

programmable memory configured to be programmed with addresses of bad memory blocks of the array and further configured to be programmed with respective sizes of bad memory blocks;

a remapping circuit coupled to the programmable memory and configured to determine a number of bad memory blocks between a memory block to which an input address is mapped and an initial block of memory and further configured to calculate a remapped address for the input address to access the memory block to which the input address is mapped based, at least in part, on the programmed addresses and respective sizes.

13. The memory of claim 12 wherein the remapping circuit is configured to remap addresses for bad memory blocks in an array to a next available good memory block in the array.

14. The memory of claim 12 wherein the programmable memory is configured to be programmed with the addresses of bad memory blocks in order from a lowest address to a highest address.

15. The memory of claim 12 wherein the array of memory blocks comprises an array of non-volatile memory blocks.

16. The memory of claim 12 wherein the remapping circuit is configured to add to the input address the number of all bad memory blocks of memory between an initial address and the remapped address.

17. The memory of claim 12 wherein the array of memory blocks comprises a plurality of memory blocks each having a respective physical address, the remapping circuit configured to calculate a remapped address for an input address corresponding to the physical address for the memory block to which the input address is mapped.

18. A memory, comprising:

redundancy fuse sets configured to be programmed with block addresses for non functional memory blocks and block sizes for the non-functional memory blocks;

a comparator coupled to the redundancy fuse sets and configured to compare an input block address with the block addresses programmed in the redundancy fuse sets;

an adder configured to add to the input block address the block sizes for non-functional memory blocks having addresses not greater than the input block address to provide a mapped block address; and

an address decoder coupled to the adder and configured to access a memory block corresponding to the mapped block address.

19. The memory claim 18, further

a first multiplexer configured to receive the input block address and the mapped block address and selectively provide an output block address;

an adder circuit coupled to the first multiplexer and configured to add a respective block size to the output block address from the first multiplexer to provide a temporary block address; and

a second multiplexer configured to receive the output block address and the temporary block address and further configured to selectively provide either as the mapped block address based on the input block address and the block address for a non-functional memory block.

20. The memory of claim 18, further comprising an output address register coupled to the adder and address decoder and configured to provide the mapped block address to the decoder from the adder.