METHOD OF CONTROLLING ERROR CHECK AND CORRECTION (ECC) OF NON-VOLATILE MEMORY DEVICE AND MEMORY SYSTEM PERFORMING THE SAME

• US 20190026181A1
• Filed: 02/21/2018
• Published: 01/24/2019
• Est. Priority Date: 07/19/2017
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: KIM, Ji-Suk, PARK, Sang-In, PARK, IL-Han, YOON, Sang-Yong, RHIM, Gyu-Seon, CHOI, Sung-Woon
• Granted Patent: US 10,635,532 B2
• Time in Patent Office: Days
• CPC Class Codes: G06F 11/1068 in sector programmable memories, e.g. flash disk G06F11/1072 takes precedence
• CPC Class Codes: G11C 16/0483 comprising cells having several storage transistors connected in series
• CPC Class Codes: G11C 16/26 Sensing or reading circuits; Data output circuits
• CPC Class Codes: G11C 16/28 using differential sensing or reference cells, e.g. dummy cells
• CPC Class Codes: G11C 29/52 Protection of memory contents; Detection of errors in memory contents
• CPC Class Codes: G11C 29/70 Masking faults in memories by using spares or by reconfiguring
• CPC Class Codes: G11C 7/1006 Data managing, e.g. manipulating data before writing or reading out, data bus switches or control circuits therefor
• CPC Class Codes: H03M 13/3707 Adaptive decoding and hybrid decoding, e.g. decoding methods or techniques providing more than one decoding algorithm for one code

Abstract

A method for controlling error check and correction (ECC) of a non-volatile memory device includes storing write data in a plurality of storing regions. The write data may be generated by performing ECC encoding. Individual ECC decoding may be performed based on each of a plurality of read data read out from the storing regions. Logic operation data may be provided by performing a logic operation of the read data when the individual ECC decoding fails with respect to all of the read data. Combined ECC decoding may be performed based on the logic operation data.

Claims

1. A method for controlling error check and correction (ECC) of a non-volatile memory device, the method comprising:

storing write data in a plurality of storing regions of the non-volatile memory device, the write data generated by performing ECC encoding;

performing individual ECC decoding based on each of a plurality of read data that are read out from the plurality of storing regions;

providing logic operation data by performing a logic operation of the plurality of read data when the individual ECC decoding fails with respect to all of the plurality of read data; and

performing a combined ECC decoding based on the logic operation data.

2. The method as claimed in claim 1, wherein providing the logic operation data includes at least one of:

providing OR data by performing a bit-by-bit OR operation of the plurality of read data; and

providing AND data by performing a bit-by-bit AND operation of the plurality of read data.

3. The method as claimed in claim 2, wherein the combined ECC decoding based on the OR data and the combined ECC decoding based on the AND data are performed regardless of an error type of the plurality of read data.

4. The method as claimed in claim 2, further comprising:

determining whether an error type of the plurality of read data is a first error type or a second error type, the first error type indicating that a ratio of 0-error is greater than a ratio of 1-error, the second error type indicating that the ratio of 1-error is greater than the ratio of 0-error, the 0-error indicating a case that a bit value of 1 is read out wrongly to a bit value of 0, the 1-error indicating a case that the bit value of 0 is read out wrongly to the bit value of 0.

5. The method as claimed in claim 4, wherein only one of the combined ECC decoding based on the OR data and the combined ECC decoding based on the AND data is performed based on a determination of the error type.

6. The method as claimed in claim 5, wherein:

when the error type is determined as the first error type, only the combined ECC decoding based on the OR data is performed.

7. The method as claimed in claim 5, wherein:

when the error type is determined as the second error type, only the combined ECC decoding based on the AND data is performed.

8. The method as claimed in claim 1, further comprising:

changing a read voltage to a correction read voltage when an error correction is determined as being failed by the combined ECC decoding;

reading out a plurality of correction read data from the plurality of storing regions based on the correction read voltage;

providing correction logic operation data by performing a logic operation of the plurality of correction read data; and

performing the combined ECC decoding based on the correction logic operation data.

9. The method as claimed in claim 8, wherein:

the read voltage is changed such that a ratio of 0-error is increased,

the 0-error indicates that a bit value of 1 is read out wrongly to a bit value of 0, and

the 1-error indicates that the bit value of 0 is read out wrongly to the bit value of 0.

10. The method as claimed in claim 9, wherein correction OR data are provided by performing a bit-by-bit OR operation of the plurality of correction read data and the combined ECC operation is performed based on the correction OR data.

11. The method as claimed in claim 8, wherein:

the read voltage is changed such that a ratio of 1-error is increased, and

the 1-error indicates that the bit value of 0 is read out wrongly to the bit value of 0.

12. The method as claimed in claim 11, wherein correction AND data are provided by performing a bit-by-bit AND operation of the plurality of correction read data and the combined ECC operation is performed based on the correction AND data.

13. The method as claimed in claim 1, wherein storing the write data in the plurality of storing regions includes storing the write data in different pages of the non-volatile memory device.

14. The method as claimed in claim 1, wherein storing the write data in the plurality of storing regions includes storing the write data in different portions of a page of the non-volatile memory device.

15. The method as claimed in claim 1, wherein performing the individual ECC decoding includes performing the individual ECC decoding sequentially using each of the plurality of read data until error correction is successful.

16. A memory system, comprising:

an error check and correction (ECC) encoder to perform an ECC encoding to generate write data;

a non-volatile memory device to store the write data in a plurality of storing regions of the non-volatile memory device; and

an ECC decoder to perform an individual ECC decoding based on each of a plurality of read data that are read out from the plurality of storing regions, provide logic operation data by performing a logic operation of the plurality of read data when the individual ECC decoding fails, and perform a combined ECC decoding based on the logic operation data.

17. The memory system as claimed in claim 16, wherein the ECC decoder includes:

a storage area including a plurality of buffers to store the plurality of read data;

a logic operator to perform the logic operation of the plurality of read data to provide the logic operation data;

a selector to select and output one of the plurality of read data and the logic operation data; and

an ECC decoder to perform the individual ECC decoding or the combined ECC decoding.

18. The memory system as claimed in claim 17, wherein the logic operator includes at least one of:

an OR operator to provide OR data by performing a bit-by-bit OR operation of the plurality of read data; and

an AND operator to provide AND data by performing a bit-by-bit AND operation of the plurality of read data.

19. The memory system as claimed in claim 18, wherein the ECC decoder determines whether an error type of the plurality of read data is a first error type or a second error type, the first error type indicating that a ratio of 0-error is greater than a ratio of 1-error, the second error type indicating that the ratio of 1-error is greater than the ration of 0-error, the 0-error indicating a case that a bit value of 1 is read out wrongly to a bit value of 0, the 1-error indicating a case that the bit value of 0 is read out wrongly to the bit value of 0, and the ECC decoder performs, based on a determination of the error type, only one of the combined ECC decoding based on the OR data and the combined ECC decoding based on the AND data.

20. A non-transitory computer-readable medium comprising code, which, when executed by a processor, causes the processor to control error check and correction (ECC) of a non-volatile memory device, the medium comprising:

code to store write data in a plurality of storing regions of the non-volatile memory device, the write data generated by performing ECC encoding;

code to perform individual ECC decoding based on each of a plurality of read data that are read out from the plurality of storing regions;

code to provide logic operation data by performing a logic operation of the plurality of read data when the individual ECC decoding fails with respect to all of the plurality of read data; and

code to perform a combined ECC decoding based on the logic operation data.