Memory controller and operating method of memory controller

• US 8,694,858 B2
• Filed: 05/09/2012
• Issued: 04/08/2014
• Est. Priority Date: 05/09/2011
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd. (Samsung Group)
• Original Assignee: Samsung Electronics Co. Ltd. (Samsung Group)
• Inventors: Kong, JaePhil, Cho, Yongwon
• Primary Examiner(s): Merant, Guerrier
• Application Number:
  US13/467,497
• Publication Number:
  US 20120290901A1
• Time in Patent Office: 699 Days
• Field of Search: None
• US Class Current: 714/763
• CPC Class Codes: G06F 1/3225 of memory devices
• CPC Class Codes: G06F 1/3275 Power saving in memory, e.g. RAM, cache
• CPC Class Codes: G06F 11/1048 using arrangements adapted for a specific error detection or correction feature
• CPC Class Codes: H03M 13/09 Error detection only, e.g. using cyclic redundancy check [CRC] codes or single parity bit
• CPC Class Codes: H03M 13/152 Bose-Chaudhuri-Hocquenghem [BCH] codes
• CPC Class Codes: H03M 13/1545 Determination of error locations, e.g. Chien search or other methods or arrangements for the determination of the roots of the error locator polynomial
• CPC Class Codes: H03M 13/3715 Adaptation to the number of estimated errors or to the channel state
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

A controller to control a memory system including a memory device. The controlling the memory system may include calculating an error location polynomial in a received read vector with a key equation solving unit of the memory system to read data from the memory device, estimating the number of errors in the received read vector with a control unit of the memory system according to at least one of the calculated error location polynomial and information on the error location polynomial, searching error locations of the received read vector according to the calculated error location polynomial with a chien search unit of the memory system with the control unit. A cycle-per power consumption of the chien search unit may be adjusted with the control unit. A maximum correction time may be adjusted according to the number of errors of the read vector.

Claims

1. A controller of a memory system to control a memory device, comprising:

a key equation solving unit to calculate an error location polynomial in a read vector received by the controller to read data from the memory device;

a control unit to estimate the number of errors in the received read vector according to at least one of the calculated error location polynomial and information on the error location polynomial; and

a chien search unit to search error locations of the received read vector according to the calculated error location polynomial,

wherein the control unit adjusts the cycle-per power consumption of the chien search unit.

2. The controller of claim 1, further comprising:

an error correcting unit to correct errors of the received read vector at the error locations determined by the chien search unit using the error location polynomial calculated by the key equation solving unit.

3. The controller of claim 1, wherein the control unit adjusts the cycle-per power consumption of the chien search unit by adjusting the number of bits to be searched at the same time in the received read vector according to the number of errors.

4. The controller of claim 3, wherein the control unit controls the chien search unit to operate in a full search mode to simultaneously search the bits of at least a data portion of the received read vector when the number of errors is less than or equal to a predetermined first error number.

5. The controller of claim 4, wherein the control unit controls the chien search unit to operate in a half search mode to simultaneously search half of the number of bits of the received read vector as a full search mode at the same time when the number of errors is greater than the predetermined first error number and less than a predetermined second error number.

6. The controller of claim 5, wherein the cycle-per-power consumption of the chien search unit operating in the half search mode is less than that of the full search mode.

7. The controller of claim 5, wherein the control unit controls the chien search unit to operate in a quarter search mode to simultaneously search one quarter of the number of bits of the received read vector at the same time as the full search mode when the number of errors is greater than the predetermined second error number.

8. The controller of claim 7, wherein the cycle-per-power consumption of the chien search unit operating in the quarter search mode is less than that of the half search mode.

9. The controller of claim 1, wherein the control unit controls the chien search unit to perform a chien search on only a data portion of the received read vector when the number of errors is less than or equal to a predetermined threshold value.

10. The controller of claim 1, wherein the control unit controls the chien search unit to perform a chien search on a data portion and a parity portion of the received read vector when the number of detected errors is greater than a predetermined threshold value.

11. The controller of claim 1, wherein the control unit adjusts a maximum correction time of the chien search unit according to the number of errors of the read vector.

12. The controller of claim 11, wherein the control unit adjusts the maximum correction time of the chien search unit to a first predetermined solving time when the number of errors is less than a first predetermined error number.

13. The controller of claim 12, wherein when the number of errors is less than the first predetermined error number, the control unit controls the chien search unit to operate in a full search mode to simultaneously search the bits of at least a data portion of the read vector.

14. The controller of claim 12, wherein when the number of errors is greater than the first predetermined error number and less than a second predetermined error number, the control unit controls the chien search unit to operate in a half search mode to simultaneously search half the number of the bits of at least a data portion of the read vector as when operating in a full search mode.

15. The controller of claim 14, wherein when the number of errors is greater than a second predetermined error number, the control unit controls the chien search unit to operate in a quarter search mode to simultaneously search one quarter the number of the bits of at least a data portion of the read vector as when operating in a full search mode.

16. The controller of claim 11, wherein the control unit adjusts the maximum correction time of the chien search unit to perform the chien search on a data portion and a parity portion of the received read vector when the number of detected errors is greater than a predetermined threshold value.

17. A method of controlling a memory system including a memory device, the method comprising:

calculating an error location polynomial in a received read vector with a key equation solving unit of the memory system to read data from the memory device;

estimating the number of errors in the received read vector with a control unit of the memory system according to at least one of the calculated error location polynomial and information on the error location polynomial; and

searching error locations of the received read vector according to the calculated error location polynomial with a chien search unit of the memory system with the control unit; and

adjusting the cycle-per power consumption of the chien search unit with the control unit.

18. The method of claim 17, further comprising:

correcting errors of the received read vector with an error correcting unit at the error locations determined by the chien search unit using the error location polynomial calculated by the key equation solving unit.

19. The method of claim 17, wherein the adjusting the cycle-per power consumption of the chien search unit comprises:

adjusting the number of bits to be searched at the same time in the received read vector with the control unit according to the number of errors.

20. The method of claim 19, further comprising:

operating the chien search unit in a full search mode to simultaneously search the bits of at least a data portion of the received read vector when the number of errors is less than or equal to a predetermined first error number.

21. The method of claim 20, further comprising:

operating the chien search unit in a half search mode to simultaneously search half of the number of bits of the received read vector as a full search mode at the same time when the number of errors is greater than the predetermined first error number and less than a predetermined second error number.

22. The method of claim 21, wherein the cycle-per-power consumption of the chien search unit operating in the half search mode is less than that of the full search mode.

23. The method of claim 21, further comprising:

operating the chien search unit in a quarter search mode to simultaneously search one quarter of the number of bits of the received read vector at the same time as the full search mode when the number of errors is greater than the predetermined second error number.

24. The method of claim 23, wherein the cycle-per-power consumption of the chien search unit operating in the quarter search mode is less than that of the half search mode.

25. The method of claim 17, further comprising:

controlling the chien search unit with the control unit to perform a chien search on only a data portion of the received read vector when the number of errors is less than or equal to a predetermined threshold value.

26. The method of claim 17, further comprising:

controlling the chien search unit with the control unit to perform a chien search on a data portion and a parity portion of the received read vector when the number of detected errors is greater than a predetermined threshold value.

27. The method of claim 17, further comprising:

adjusting a maximum correction time of the chien search unit with the control unit according to the number of errors of the read vector.

28. The method of claim 27, further comprising:

adjusting the maximum correction time of the chien search unit with the control unit to a first predetermined solving time when the number of errors is less than a first predetermined error number.

29. The method of claim 28, further comprising:

when the number of errors is less than the first predetermined error number, operating the chien search unit in a full search mode to simultaneously search the bits of at least a data portion of the read vector.

30. The method of claim 28, further comprising:

when the number of errors is greater than the first predetermined error number and less than a second predetermined error number, operating the chien search unit in a half search mode to simultaneously search half the number of the bits of at least a data portion of the read vector as when operating in a full search mode.

31. The method of claim 30, further comprising

when the number of errors is greater than a second predetermined error number, operating the chien search unit in a quarter search mode to simultaneously search one quarter the number of the bits of at least a data portion of the read vector as when operating in a full search mode.

32. The method of claim 27, further comprising:

adjusting the maximum correction time of the chien search unit with the control unit to perform the chien search on a data portion and a parity portion of the received read vector when the number of detected errors is greater than a predetermined threshold value.

33. A method of controlling a memory system having a controller coupled via at least one channel to at least one memory device, the method comprising:

determining an estimated number of errors and error location information of a read vector received by the controller to read data from the at least one memory device via the at least one channel; and

adjusting at least one of a cycle-per-power consumption and a maximum correction time of a chien search unit of the memory system that searches error locations of the read vector according to the estimated number of errors and the determined error location information.

34. A controller of a memory system having at least one memory device coupled to the controller via at least one channel, comprising:

an error correction code decoder of the controller to determine an estimated number of errors and error location information of a read vector received by the controller to read data from the at least one memory device via the at least one channel; and

a control unit of the error correction code decoder to adjust at least one of a cycle-per-power consumption and a maximum correction time of a chien search unit of the memory system that searches error locations of the read vector according to the estimated number of errors and the determined error location information.