Error correction circuit and method thereof

• US 8,533,573 B2
• Filed: 03/19/2008
• Issued: 09/10/2013
• Est. Priority Date: 03/22/2007
• Status: Active Grant

• Current Assignee: Realtek Semiconductor Corp.
• Original Assignee: Realtek Semiconductor Corp.
• Inventors: Lin, Tzuo-Bo
• Primary Examiner(s): Kramer, James
• Assistant Examiner(s): MILES, NEIL D
• Application Number:
  US12/051,641
• Publication Number:
  US 20080235551A1
• Time in Patent Office: 2,001 Days
• Field of Search: 714/774
• US Class Current: 714/774
• CPC Class Codes: H04L 2025/03356 Baseband transmission
• CPC Class Codes: H04L 2025/03598 Algorithms
• CPC Class Codes: H04L 25/03019 adaptive, i.e. capable of adjustment during data reception
• CPC Class Codes: H04L 25/4908 using mBnB codes

Abstract

An error correction circuit and method applicable to a DisplayPort receiver is disclosed. While decoding errors occur at a decoding stage, the invention actively adjusts settings of a physical layer by using an ANSI10B/8B decoder and performs data recovery by using a correcting unit that improves the reliability of input data.

Claims

1. A method for error correction, the method comprising the steps of:

determining whether a number of decoding errors of a decoding error signal is greater than a threshold value within a predetermined period of time;

adjusting a setting value of a digital display interface while the number of decoding errors is greater than the threshold value during a decoding stage; and

correcting a decoding error of a decoding control signal of a lane according to corresponding decoding control signals residing in other lanes.

2. The method according to claim 1, wherein the digital display interface is a DisplayPort interface.

3. The method according to claim 1, wherein the step of adjusting the setting value comprises:

adjusting a gain value to set an equalizer.

4. The method according to claim 1, wherein the step of adjusting the setting value comprises:

adjusting a charge pump current value to set a clock data recovery circuit.

5. The method according to claim 1, wherein the step of adjusting the setting value comprises:

comparing the setting value with a predetermined maximum value; and

raising the setting value while the setting value is less than the predetermined maximum value.

6. The method according to claim 5, wherein the step of adjusting the setting value further comprises:

setting the setting value to be equal to the predetermined maximum value while the setting value is greater than the predetermined maximum value.

17. The method according to claim 1, wherein the correcting step includes correcting the decoding error of the decoding control signal of the lane according to the pattern of the decoding control signal itself, and the method is applied to a digital display interface comprising a Main link with only one lane at a decoding stage.

18. The method according to claim 1, wherein the correcting step includes correcting the decoding error of the decoding control signal of the lane according to the corresponding decoding control signals residing in the other lanes, and the method is applied to a digital display interface comprising a Main link with at least two lanes at a decoding stage.

7. A method for error correction, the method comprising the steps of:

determining whether a number of decoding errors of a decoding error signal is greater than a threshold value within a predetermined period of time; and

correcting a decoding error of a decoding control signal of a lane according to corresponding decoding control signals residing in other lanes,

wherein the method is applied to a digital display interface comprising a Main link with at least two lanes at a decoding stage.

15. The method according to claim 7, wherein the digital display interface is a DisplayPort interface.

8. A method for error correction, the method comprising the steps of:

determining whether a number of decoding errors of a decoding error signal is greater than a threshold value within a predetermined period of time; and

correcting a decoding error of a decoding control signal of a lane according to a pattern of the decoding control signal itself,

wherein the method is applied to a digital display interface comprising a Main link with only one lane at a decoding stage.

9. The method according to claim 8, wherein the decoding control signal is a periodic signal.

10. The method according to claim 9, wherein the decoding control signal comprises a blanking start signal, a blanking end signal, a signal VB_ID signal or selected combinations thereof.

16. The method according to claim 8, wherein the digital display interface is a DisplayPort interface.

11. A method for error correction, the method comprising the steps of:

determining whether a number of decoding errors of a decoding error signal is greater than a threshold value within a predetermined period of time; and

correcting erroneous decoded video data signal or erroneous decoding audio data signal by interpolation or low-pass filtering,

wherein the method is applied to a digital display interface at a decoding stage, and

wherein the digital display interface is a DisplayPort interface.

12. An error correction circuit, comprising:

at least one converting circuit, each comprising;

an equalizer for amplifying a differential signal and generating an amplified signal;

a clock data recovery circuit for receiving the amplified signal and generating a recovered data;

a serial to parallel converter for generating a parallel data according to the recovered data;

a decoder of a digital display interface for generating a decoded data, a decoding control signal, a decoding error signal or selected combinations thereof according to the parallel data;

a microprocessor configured to adjust the equalizer, the clock data recovery circuit or both according to the decoding error signal if a number of decoding errors of the decoding error signal is greater than a threshold value within a predetermined period of time; and

a correcting unit configured to generate a correcting control signal correcting a decoding error of the decoding control signal of a lane to corresponding decoding control signals residing in other lanes.

13. The circuit according to claim 12, wherein the digital display interface is a DisplayPort interface.

14. The circuit according to claim 12, wherein one converting circuit is installed in one lane of the digital display interface.

19. The error correction circuit according to claim 12, wherein the correcting unit is configured to generate the correcting control signal correcting the decoding error of the decoding control signal of the lane according to the pattern of the decoding control signal itself, and the digital display interface comprises a Main link with only one lane at a decoding stage.

20. The error correction circuit according to claim 12, wherein the correcting unit is configured to generate the correcting control signal correcting the decoding error of the decoding control signal of the lane according to the corresponding decoding control signals residing in other the lanes, and the digital display interface comprises a Main link with at least two lanes at a decoding stage.

21. A method for error correction, the method comprising the steps of:

determining whether a number of decoding errors of a decoding error signal is greater than a threshold value within a predetermined period of time;

adjusting a setting value of a digital display interface while the number of decoding errors is greater than the threshold value during a decoding stage; and

correcting a decoding error of a decoding control signal of a lane according to a pattern of the decoding control signal itself, wherein the pattern of the decoding control signal is a periodic pattern.

23. The method according to claim 21, wherein the step of correcting the decoding error of the decoding control signal of the lane according to the pattern of the decoding control signal itself includes correcting the decoding error of the decoding control signal of the lane according to a missing part of the periodic pattern of the decoding control signal itself.

22. An error correction circuit, comprising:

at least one converting circuit, each comprising;

an equalizer for amplifying a differential signal and generating an amplified signal;

a clock data recovery circuit for receiving the amplified signal and generating a recovered data;

a serial to parallel converter for generating a parallel data according to the recovered data and; and

a decoder of a digital display interface for generating a decoded data, a decoding control signal, a decoding error signal or selected combinations thereof according to the parallel data; and

a microprocessor configured to adjust the equalizer, the clock data recovery circuit or both according to the decoding error signal if a number of decoding errors of the decoding error signal is greater than a threshold value within a predetermined period of time,

a correcting unit configured to generate a correcting control signal correcting a decoding error of the decoding control signal of a lane according to a pattern of the decoding control signal itself, wherein the pattern of the decoding control signal is a periodic pattern.

24. The circuit according to claim 22, wherein the correcting unit is configured to generate the correcting control signal correcting the decoding error of the decoding control signal of the lane according to a missing part of the periodic pattern of the decoding control signal itself.