SYSTEM AND METHOD FOR IMPROVED SYNCHRONIZATION BETWEEN DEVICES

• US 20150256329A1
• Filed: 03/06/2014
• Published: 09/10/2015
• Est. Priority Date: 03/06/2014
• Status: Active Grant

• Current Assignee: STMicroelectronics International N.V. (STMicroelectronics NV)
• Original Assignee: STMicroelectronics Asia Pacific Pte Limited (STMicroelectronics NV)
• Inventors: GUO, Dianbo, CHEONG, Chee Weng, DINU, Leonard Liviu, TAN, Kien Beng
• Granted Patent: US 9,971,421 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 2203/0384 Wireless input, i.e. hardware and software details of wireless interface arrangements for pointing devices
• CPC Class Codes: G06F 3/03545 Pens or stylus
• CPC Class Codes: G06F 3/038 Control and interface arrangements therefor, e.g. drivers or device-embedded control circuitry
• CPC Class Codes: G06F 3/041 Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
• CPC Class Codes: G06F 3/04162 for exchanging data with external devices, e.g. smart pens, via the digitiser sensing hardware
• CPC Class Codes: H04L 2027/0097 Adaptive synchronisation signals

Abstract

A system and method for synchronizing two devices in communication with each other. When communication between the two devices is to be established, a synchronization process may be invoked. In an embodiment, a first device may initiate sending synchronization signals having rising edge and falling edge pairs. The second device may include a controller configured to receive the synchronization signals. However, noise may inhibit the ability of the controller to correctly receive and/or interpret the synchronization signals. Noise may cause detection components to falsely detect noise as a synchronization signal or may cause detection components to miss detection of an actual synchronization signal. A window generator may be used to generate comparison windows for the controller to detect synchronization signals. Further, the detection window duration and start times may be adjusted based on previously detected (or undetected) synchronization signals in order to compensate for noise overshadowing synchronization signals.

Claims

1. A synchronization detector, comprising:

a receiver configured to receive a synchronization signal having edges from a remote device; and

a window generator configured to generate a window for detecting a subsequent synchronization signal edge in response to a first synchronization edge.

2. The synchronization detector of claim 1, wherein the first synchronization signal edge comprises a rising edge.

3. The synchronization detector of claim 1, wherein the synchronization signal comprises a period and the generated window comprises a duration related to the period.

4. The synchronization detector of claim 1, wherein the synchronization signal comprises a period and the generated window comprises a duration of approximately one tenth of the period plus a detection delay time.

5. The synchronization detector of claim 1, wherein the synchronization signal comprises a period and the window generator generates the window after a delay time equal to approximately half of the period.

6. The synchronization detector of claim 1, wherein the window generator is further configured to generate a second window in response to the subsequent synchronization signal edge.

7. The synchronization detector of claim 1, wherein the window generator is further configured to generate a second window in response to the subsequent synchronization signal edge after a delay time equal to approximately half the period.

8. The synchronization detector of claim 1, wherein the window generator is further configured to generate a second window in response to the first synchronization signal edge after a delay time equal to approximately the period in the absence of a detected subsequent synchronization signal edge.

9. A synchronization detector, comprising:

a receiver configured to receive a synchronization signal having a period from a remote device; and

a window generator configured to generate a window for detecting the synchronization signal, the generated window having a duration related to the period.

10. The synchronization detector of claim 9, wherein the synchronization signal comprises edges such that a first and second edge are within the period.

11. The synchronization detector of claim 9, wherein generated window comprises a duration of approximately one tenth of the period plus a detection delay time.

12. The synchronization detector of claim 9, wherein the window generator is further configured to generate the window after a delay time equal to approximately half of the period.

13. An integrated circuit, comprising:

a converter configured to receive a synchronization signal having edges from a remote device; and

a window generator configured to generate a window for detecting a subsequent synchronization signal edge in response to a first synchronization edge.

14. The integrated circuit of claim 13, wherein the converter comprises a charge-to-voltage converter.

15. The integrated circuit of claim 13, further comprising a comparator coupled to the converter and configured to generate a comparison signal for triggering the window generator.

16. The integrated circuit of claim 13, further comprising a single integrated circuit die.

17. The integrated circuit of claim 13, further comprising multiple integrated circuit dies.

18. The integrated circuit of claim 13, further comprising a processor.

19. A touch screen device, comprising:

a receiver configured to receive a synchronization signal having edges from a remote input device; and

a window generator configured to generate a window for detecting a subsequent synchronization signal edge in response to a first synchronization edge.

20. A system, comprising:

an input device configured to generate a synchronization signal;

a computing device configured to synchronize with the input device, the computing device;

having;

a receiver configured to receive a synchronization signal having edges from a remote device; and

a window generator configured to generate a window for detecting a subsequent synchronization signal edge in response to a first synchronization edge.

21. The system of claim 20, wherein the input device comprises a stylus and the computing device comprises a touch screen configured to capacitively communicate with the stylus.

24. The method of claim 21, further comprising detecting a first synchronization signal edge as a falling edge.

22. A method, comprising:

receiving, at a receiver, a synchronization signal having edges from a remote device; and

generating a window for detecting a subsequent synchronization signal edge in response to a first synchronization edge.

23. The method of claim 22, further comprising detecting a first synchronization signal edge as a rising edge.

25. The method of claim 22, further comprising generating the window having a duration related to a period of the synchronization signal.

26. The method of claim 25, further comprising generating the window having a duration of approximately one tenth of the period plus a detection delay time.

27. The method of claim 25, further comprising generating the window after a delay time equal to approximately half of the period.

28. The method of claim 22, further comprising generating a second window in response to the subsequent synchronization signal edge.

29. The method of claim 22, further comprising generating a second window in response to the subsequent synchronization signal edge after a delay time equal to approximately half the period.

30. The method of claim 22, further comprising generating a second window in response to the first synchronization signal edge after a delay time equal to approximately the period in the absence of a detected subsequent synchronization signal edge.