ELECTRONIC DEVICE FOR CONTENTION DETECTION OF BIDIRECTIONAL BUS AND RELATED METHOD

• US 20090254687A1
• Filed: 11/09/2008
• Published: 10/08/2009
• Est. Priority Date: 04/02/2008
• Status: Active Grant

• Current Assignee: Novatek Microelectronics Corporation (Novatek Microelectronics Corp Limited)
• Original Assignee: Novatek Microelectronics Corporation (Novatek Microelectronics Corp Limited)
• Inventors: Lin, Ching-Chun, Liu, Shang-I
• Granted Patent: US 8,074,004 B2
• Time in Patent Office: Days
• US Class Current: 710/107
• CPC Class Codes: G06F 13/376 using a contention resolving method, e.g. collision detection, collision avoidance

Abstract

An electronic device of detecting contention of a bidirectional bus for avoiding failing to drive a bidirectional bus due to bus contention includes: an output terminal, an input terminal and a data output unit, a timing comparing controller and a comparing unit. The output terminal is coupled to the bidirectional bus and used for outputting a data output signal to the bidirectional bus. The input terminal is coupled to the output terminal and the bidirectional bus and used for receiving a data reception signal from the bidirectional bus. The data output unit is used for providing the data output signal. The timing comparing controller is used for generating a timing comparison signal according to the data output signal. The comparing unit is used for comparing the data reception signal with the data output signal according to the timing comparison signal to determine a contention state of the bidirectional bus.

Claims

1. An electronic device of detecting contention of a bidirectional bus, the electronic device comprising:

an output terminal coupled to the bidirectional bus, for outputting a data output signal to the bidirectional bus;

an input terminal coupled to the output terminal and the bidirectional bus, for receiving a data reception signal from the bidirectional bus;

a data output unit for providing the data output signal;

a timing comparing controller for generating a timing comparison signal according to the data output signal; and

a comparing unit coupled to the input terminal, the data output unit and the timing comparing controller, for comparing the data reception signal with the data output signal according to the timing comparison signal to determine a contention state of the bidirectional bus.

2. The electronic device of claim 1 further comprising an input buffer coupled between the input terminal and the comparing unit, for determining a signal level of the data reception signal according to the plurality of predetermined signal levels.

3. The electronic device of claim 1 further comprising an output buffer coupled between the output terminal and the data output unit, for temporarily storing the data output signal.

4. The electronic device of claim 1, wherein the data output unit further detects a transition of the data output signal to generate a transition signal.

5. The electronic device of claim 4, wherein the timing comparing controller comprises a delay unit for delaying the transition signal for a delay time to generate the timing comparison signal.

6. The electronic device of claim 5, wherein the delay time is less than time difference between the transition of the data output signal and a next transition of the transition.

7. The electronic device of claim 1, wherein the bidirectional bus is a half-duplex bidirectional bus.

8. A method of detecting contention of a bidirectional bus used for transmitting a data output signal and receiving a data reception signal, the method comprising:

generating a timing comparison signal according to the data output signal before the bidirectional bus transmits the data output signal; and

comparing the data reception signal with the data output signal according to the timing comparison signal to determine a contention state of the bidirectional bus.

9. The method of claim 8 further comprising determining a signal level of the data reception signal according to a plurality of predetermined signal levels before comparing the data reception signal with the data output signal according to the timing comparison signal.

10. The method of claim 8 further comprising temporarily storing the data output signal before the bidirectional bus transmits the data output signal.

11. The method of claim 8 further comprising detecting a transition of the data output signal to generate a transition signal.

12. The method of claim 11 further comprising delaying the transition signal for a delay time to generate the timing comparison signal before the bidirectional bus transmits the data output signal.

13. The method of claim 12, wherein the delay time is less than time difference between the transition of the data output signal and a next transition of the transition.

14. The method of claim 8, wherein the bidirectional bus is a half-duplex bidirectional bus.

15. An electronic device of detecting contention of a bidirectional bus, the electronic device comprising:

an output terminal coupled to the bidirectional bus, for outputting a data output signal to the bidirectional bus;

an input terminal coupled to the output terminal and the bidirectional bus, for receiving a data reception signal from the bidirectional bus;

a data output unit for providing the data output signal;

a sampling timing generator coupled to the data output unit, for generating a sampling timing signal according to the data output signal;

a sampling unit coupled to the data output unit and the sampling timing generator, for sampling the data output signal according to the sampling timing signal, to generate a sample data signal;

a detection timing generator coupled to the data output unit, for generating a detection timing signal according to the data output signal; and

a comparing unit coupled to the input terminal, the sampling unit and the detection timing generator, for comparing the data reception signal with the sample data signal according to the detection timing signal, to determine a contention state of the bidirectional bus.

16. The electronic device of claim 15 further comprising an input buffer coupled between the input terminal and the comparing unit, for determining a signal level of the data reception signal according to the plurality of predetermined signal levels.

17. The electronic device of claim 15 further comprising an output buffer coupled between the output terminal and the data output unit, for temporarily storing the data output signal.

18. The electronic device of claim 15, wherein the detection timing generator generates the detection timing signal according to transitions of the data output signal.

19. The electronic device of claim 18, wherein the comparing unit neglects the detection timing signal generated according to a first transition of the data output signal.

20. The electronic device of claim 15, wherein the bidirectional bus is a half-duplex bidirectional bus.

21. A method of detecting contention of a bidirectional bus used for transmitting a data output signal and receiving a data reception signal, the method comprising:

generating a sampling timing signal according to the data output signal;

sampling the data output signal according to the sampling timing signal, to generate a sample data signal;

generating a detection timing signal according to the data output signal; and

comparing the data reception signal with the sample data signal according to the detection timing signal, to determine a contention state of the bidirectional bus.

22. The method of claim 21 further comprising determining a signal level of the data reception signal according to the plurality of predetermined signal levels before comparing the data reception signal with the sample data signal according to the detection timing signal.

23. The method of claim 21 further comprising temporarily storing the data output signal before the bidirectional bus transmits the data output signal.

24. The method of claim 21, wherein the step of generating the detection timing signal according to the data output signal comprises:

generating the detection timing signal according to transitions of the data output signal.

25. The method of claim 24, wherein the step of generating the detection timing signal according to transitions of the data output signal further comprises:

neglecting the detection timing signal generated according to a first transition of the data output signal.

26. The method of claim 21, wherein the bidirectional bus is a half-duplex bidirectional bus.