Encoding and/or decoding memory devices and methods thereof

• US 20090241009A1
• Filed: 09/12/2008
• Published: 09/24/2009
• Est. Priority Date: 03/18/2008
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Kong, Jun Jin, Kim, Yong June, Kim, Jae Hong
• Granted Patent: US 8,713,411 B2
• Time in Patent Office: Days
• US Class Current: 714/763
• CPC Class Codes: G06F 11/1072 in multilevel memories
• CPC Class Codes: H03M 13/03 Error detection or forward error correction by redundancy in data representation, i.e. code words containing more digits than the source words
• CPC Class Codes: H03M 13/05 using block codes, i.e. a predetermined number of check bits joined to a predetermined number of information bits H03M13/2906 takes precedence

Abstract

Encoding/decoding memory devices and methods thereof may be provided. A memory device according to example embodiments may include a memory cell array and a processor including at least one of a decoder and an encoder. The processor may be configured to adjust a redundant information rate of each channel, where each of the channels is a path of the memory cell array from which data is at least one of stored and read. The redundant information rate may be adjusted by generating at least one codeword based on information from a previous codeword. Therefore, example embodiments may reduce an error rate when data is read from and written to the memory device.

Claims

1. A memory device, comprising:

a memory cell array; and

a processor including at least one of a decoder and an encoder, wherein

the processor is configured to adjust a redundant information rate of each channel, where each of the channels is a path of the memory cell array from which data is at least one of stored and read, and

the redundant information rate is adjusted by generating at least one codeword based on information from a previous codeword.

2. The memory device of claim 1, wherein the processor includes the decoder, with the decoder configured to perform error-control code (ECC) decoding with respect to a first codeword generated from first data read from the memory cell array to estimate a first message, to combine the estimated first message and second data read from the memory cell array to generate a second codeword, and to perform ECC decoding with respect to the second codeword to estimate a second message.

3. The memory device of claim 2, wherein the memory cell array includes a plurality of multi-bit cells storing multi-bit data, and the decoder reads the second data from the plurality of multi-bit cells from which the first data is read.

4. The memory device of claim 2, wherein the second message includes a re-estimated value of the first message.

5. The memory device of claim 2, wherein the decoder substitutes at least a portion of the first message in the second data with the estimated first message to generate the second codeword.

6. The memory device of claim 2, wherein,

the decoder reads the first data from the memory cell array via a first channel, selects a first decoding scheme based on characteristics of the first channel, performs ECC decoding with respect to the first codeword based on the selected first decoding scheme, and wherein

the decoder reads the second data from the memory cell array via a second channel, and selects a second decoding scheme based on characteristics of the second channel, and performs ECC decoding with respect to the second codeword based on the selected second decoding scheme.

7. The memory device of claim 6, wherein the decoder includes,

a first decoding module corresponding to the first decoding scheme configured to perform ECC decoding with respect to the first codeword to estimate the first message;

and

a second decoding module corresponding to the second decoding scheme configured to perform ECC decoding with respect to the second codeword to estimate the second message.

8. The memory device of claim 6, wherein the decoder establishes a size of a message and redundant information of the first codeword based on the first decoding scheme to perform ECC decoding with respect to the first codeword, and establishes a size of a message and redundant information of the second codeword based on the second decoding scheme to perform ECC decoding with respect to the second codeword.

9. The memory device of claim 1, further comprising:

a programming unit storing a first and second codeword in the memory cell array, wherein

the processor includes the encoder, with the encoder configured to perform error-control codes (ECC) encoding with respect to a first message to generate a first codeword, and performing ECC encoding with respect to the first message and a second message to generate a second codeword.

10. The memory device of claim 9, wherein the memory cell array includes a plurality of multi-bit cells storing multi-bit data, and the programming unit stores the second codeword in the plurality of multi-bit cells storing the first codeword.

11. The memory device of claim 9, wherein,

the encoder selects a first encoding scheme based on characteristics of the first channel storing the first codeword and performs ECC encoding with respect to the first message based on the selected first encoding scheme, and wherein

the encoder selects a second encoding scheme based on characteristics of the second channel storing the second codeword and performs ECC encoding with respect to the second message based on the selected second encoding scheme.

12. The memory device of claim 11, wherein the encoder includes,

a first encoding module corresponding to the first encoding scheme configured to perform ECC encoding with respect to the first message to generate the first codeword;

and

a second encoding module corresponding to the second encoding scheme configured to perform ECC encoding with respect to the first and second message to generate the second codeword.

13. The memory device of claim 11, wherein the encoder establishes a size of a message and redundant information of the first codeword based on the first encoding scheme to perform ECC encoding with respect to the first message, and establishes a size of a message and redundant information of the second codeword based on the second encoding scheme to perform ECC encoding with respect to the second message.

14. A coding method, comprising:

performing at least one of error-control code (ECC) decoding and encoding, with a redundant information rate of each channel being adjusted, where each of the channels is a path of a memory cell array from which data is at least one of stored and read, and the redundant information rate is adjusted by generating at least one codeword based on information from a previous codeword.

15. The coding method of claim 14, further comprising:

performing error-control codes (ECC) decoding with respect to a first codeword generated from received first data to estimate a first message;

combining the estimated first message and received second data to generate a second codeword; and

performing ECC decoding with respect to the second codeword to estimate a second message.

16. The coding method of claim 15, wherein the second message includes a re-estimated value of the estimated first message.

17. The coding method of claim 15, wherein the performing ECC decoding with respect to the second codeword includes substituting at least a portion of the first message of the second data with the estimated first message.

18. A computer-readable storage medium encoded with a computer program for implementing the method of claim 15.

19. The coding method of claim 14, further comprising:

performing error-control codes (ECC) encoding with respect to a first message to generate a first codeword; and

performing ECC encoding with respect to the first message and a second message to generate a second codeword.

20. The coding method of claim 19, further comprising:

storing the first codeword in multi-bit cells of the memory cell array; and

storing the second codeword in the multi-bit cells storing the first codeword based on a multi-bit programming scheme.

21. A computer-readable storage medium encoded with a computer program for implementing the method of claim 19.