Data equalizing circuit and data equalizing method

• US 8,520,725 B2
• Filed: 02/28/2012
• Issued: 08/27/2013
• Est. Priority Date: 12/29/2011
• Status: Active Grant

• Current Assignee: Industry-University Cooperation Foundation Hanyang University, Hynix Semiconductor Incorporated (SK Hynix Inc.)
• Original Assignee: SK Hynix Inc.
• Inventors: Jeong, Chun Seok, Lee, Jae Jin, Yoo, Chang Sik, Lee, Jang Woo, Kang, Seok Joon
• Primary Examiner(s): Flores, Leon
• Application Number:
  US13/407,546
• Publication Number:
  US 20130170537A1
• Time in Patent Office: 546 Days
• Field of Search: 375/226, 375/229, 375/230, 375/232, 375/233, 375/316, 375/324, 375/340, 375/346, 375/350, 375/371, 375/373, 375/376, 455/63.1, 455/67.13, 455/114.2, 455/260, 455/296, 455/501, 370/335, 370/342, 327/147, 327/156, 327/551, 333/18, 333/28.R, 708/300, 329/360
• US Class Current: 375/232
• CPC Class Codes: H04L 25/03038 with a non-recursive structure H04L25/03031 takes precedence

Abstract

A data equalizing circuit includes an equalizer configured to control a gain of data according to a value of a control code and output a controller gain; and a detection unit configured to divide n cycles of the data into N periods, count data transition frequencies for n/N periods while changing the value of the control code, calculate dispersion values of data transition frequencies for 1/N periods of the data from the data transition frequencies for the n/N periods, and finally output the value of the control code corresponding to a largest dispersion value, wherein n is equal to or greater than 2 and is set such that boundaries of the respective n/N periods of the data have different positions in the 1 UI data.

Claims

1. A data equalizing circuit comprising:

an equalizer configured to control a gain of data according to a value of a control code; and

a detection unit configured to divide n cycles of the data into N periods, count data transition frequencies for n/N periods while changing the value of the control code, calculate dispersion values of data transition frequencies for 1/N periods of the data from the data transition frequencies for the n/N periods, and finally output the value of the control code corresponding to a largest dispersion value,

wherein n is equal to or greater than 2 and is set such that boundaries of the respective n/N periods of the data have different positions in the 1 UI(unit interval) data, wherein the detection unit is implemented by hardware.

2. The data equalizing circuit according to claim 1, wherein the detection unit comprises:

a multi-phase locked loop configured to receive a reference clock and output N number of clocks having a frequency corresponding to 1/n times a frequency of the data with a phase difference of n/N;

a data latching section configured to store the data as N number of latched data in synchronization with the N number of clocks, respectively;

a data transition counting section configured to compare adjacent values of the N number of latched data and count the data transition frequencies for the n/N periods; and

a controller configured to calculate and store the dispersion values of the data transition frequencies for the 1/N periods from the data transition frequencies for the n/N periods while changing the value of the control code, and finally output the value of the control code corresponding to a largest dispersion value.

3. The data equalizing circuit according to claim 2, wherein the data transition counting section comprises:

a comparison part configured to compare adjacent values of the N number of latched data and generate N number of comparison signals; and

a counter part configured to respectively count the N number of comparison signals and output the data transition frequencies for the n/N periods.

4. The data equalizing circuit according to claim 3, wherein the comparison part outputs the comparison signal with a value of 1 when adjacent values of the latched data are the same, and the comparison part outputs the comparison signal with a value of 0 when the adjacent values of the latched data are not the same.

5. The data equalizing circuit according to claim 2, wherein the controller comprises:

a dispersion calculating part configured to receive the data transition frequencies for the n/N periods, and calculate and output the dispersion values of the data transition frequencies for the n/N periods; and

a control code setting part configured to store the dispersion values for respective values of the control code while changing the value of the control code, and finally output the value of the control code corresponding to a largest dispersion value.

6. The data equalizing circuit according to claim 5, wherein the data transition counting section initializes counted data transition frequencies for the n/N periods in response to a reset signal.

7. The data equalizing circuit according to claim 6, wherein the controller further comprises:

a reset signal generating part configured to output the reset signal which is activated when the control code setting part changes the value of the control code.

8. A data equalizing circuit comprising:

an equalizer configured to control a gain of data according to a value of a control code;

a multi-phase locked loop configured to receive a reference clock and output N number of clocks having a frequency corresponding to 1/n times a frequency of the data with a phase difference of n/N;

a data latching section configured to store the data as N number of latched data in synchronization with the N number of clocks, respectively;

a data transition counting section configured to compare adjacent values of the N number of latched data and count data transition frequencies for n/N periods;

a counting completion signal generating section configured to generate a counting completion signal when counting of the data transition frequencies for the n/N periods is completed; and

a controller configured to calculate and store dispersion values of data transition frequencies for 1/N periods from the data transition frequencies for the n/N periods in response to the counting completion signal while changing the value of the control code, and output the value of the control code corresponding to a largest dispersion value,

wherein n is equal to or greater than 2 and is set such that boundaries of respective n/N periods of the data have different positions in the 1_UI (unit interval) data.

11. The data equalizing circuit according to claim 8, wherein the counting completion signal generating section generates the counting completion signal which is activated, when a value of a most significant bit of any one of the data transition frequencies for the n/N periods is 1.

12. The data equalizing circuit according to claim 8, wherein the controller comprises:

a dispersion calculating part configured to receive the data transition frequencies for the n/N periods when an activated counting completion signal is inputted, and calculate and output the dispersion values of the data transition frequencies for the 1/N periods; and

a control code setting part configured to store the dispersion values for respective values of the control code while changing the value of the control code, and finally output the value of the control code corresponding to a largest dispersion value.

13. The data equalizing circuit according to claim 12, wherein the data transition counting section initializes counted data transition frequencies for the n/N periods in response to a reset signal.

14. The data equalizing circuit according to claim 13, wherein the controller further comprises:

a reset signal generating part configured to output the reset signal which is activated, when the control code setting part changes the value of the control code.

9. The data equalizing circuit according to claim B, wherein the data transition counting section comprises:

a comparison part configured to compare adjacent values of the N number of latched data and generate N number of comparison signals; and

a counter part configured to respectively count the N number of comparison signals and output the data transition frequencies for the n/N periods.

10. The data equalizing circuit according to claim 9, wherein the comparison part outputs the comparison signal with a value of 1 when the adjacent values of the latched data are the same and outputs the comparison signal with a value of 0 when the adjacent values of the latched data are not the same.

15. A data equalizing method for controlling a correction degree of a data eye in response to a value of a control code including a plurality of bits, comprising:

dividing n cycles of the data into N number of periods, and counting data transition frequencies for n/N periods while changing the value of the control code sequentially from a minimum value;

calculating dispersion values of data transition frequencies for 1/N periods of the data of 1 UI (unit interval) from the data transition frequencies for the n/N periods according to respective values of the control code; and

outputting the value of the control code when a dispersion value is largest among the dispersion values of the data transition frequencies for the 1/N periods, as a final control code,

wherein n is equal to or greater than 2 and is set such that boundaries of the respective n/N periods of the data have different positions in the 1_UI data, wherein the step of dividing is performed by hardware.

16. The data equalizing method according to claim 15, wherein the counting of the data transition frequencies for the n/N periods comprises:

receiving a reference clock and outputting N number of clocks having a frequency corresponding to 1/n times a frequency of the data with a phase difference of n/N;

storing the data as N number of latched data in synchronization with the N number of clocks, respectively; and

comparing adjacent values of the N number of latched data and counting the data transition frequencies for the n/N periods.

17. The data equalizing method according to claim 15, wherein, in the calculating of the dispersion values, the data transition frequencies for the n/N periods including the 1/N periods are summed for the respective 1/N periods of the data of 1 UI, and the dispersion values of summed results for the respective 1/N periods are calculated.