Update system for an audio amplifier

• US 20070009108A1
• Filed: 07/07/2005
• Published: 01/11/2007
• Est. Priority Date: 07/07/2005
• Status: Active Grant

• Current Assignee: Harman International Industries Incorporated (Samsung Electronics Co. Ltd.)
• Original Assignee: Harman International Industries Incorporated (Samsung Electronics Co. Ltd.)
• Inventors: Furge, Kenneth
• Granted Patent: US 8,050,418 B2
• Time in Patent Office: Days
• US Class Current: 381/86
• CPC Class Codes: G06F 8/65 Updates security arrangements therefor G06F21/57
• CPC Class Codes: H03F 2200/03 the amplifier being designed for audio applications
• CPC Class Codes: H03F 2200/321 Use of a microprocessor in an amplifier circuit or its control circuit
• CPC Class Codes: H03F 3/181 Low-frequency amplifiers, e.g. audio preamplifiers

Abstract

A system and method for updating the software of a digital audio amplifier. The digital data used to update the amplifier'"'"'s software is transmitted as an analog signal over analog audio channels to the amplifier. The amplifier is adapted to recognize when an audio signal should be used to update the amplifier'"'"'s software, instead of merely driving the speakers with the audio signal. Upon receiving such an audio signal, the amplifier decodes the analog signal into digital instructions. The digital instructions are processed to reconfigure the amplifier'"'"'s operation.

Claims

1. An audio system for a vehicle comprising:

an amplifier including an audio channel input, the amplifier including a processor adapted to switch between an audio mode and a reconfiguration mode,

a head unit including an audio channel output connected to the audio channel input of the amplifier, the head unit adapted to transmit an analog signal on the audio channel output to the audio channel input of the amplifier;

where the amplifier processes the analog signal received on the audio channel input for listening by a user when the processor is in the audio mode, and

where the processor reconstructs digital instructions from the analog signal received on the audio channel input when in the reconfiguration mode, the digital instructions adapted to reconfigure the operation of the amplifier.

2. The audio system of claim 1, where the processor switches to the reconfiguration mode in response to receiving a wake up signal from the head unit.

3. The audio system of claim 2, where the wake up signal is an analog signal with a frequency above the human audible range.

4. The audio system of claim 2, where the wake up signal is an analog signal with a frequency above 20 kHz.

5. The audio system of claim 1, where the processor recovers a clock signal embedded in the analog signal received from the head unit, the processor using the clock signal to reconstruct the digital instructions from the analog signal.

6. The audio system of claim 1, where the amplifier further comprises a second audio channel input adapted to receive a clock signal when the processor is in the reconfiguration mode, the processor using the clock signal to reconstruct the digital instructions from the analog signal.

7. The audio system of claim 1, where the processor reconstructs the digital instructions from the analog signal using a demodulation scheme selected from the group consisting of frequency shift keying, phase shift keying and quadature amplitude modulation.

8. The audio system of claim 7, where a carrier frequency for the demodulation scheme is between 3 kHz to 20.1 kHz.

12. The audio system as recited in claim 11, where the processor decodes the encoded digital data on the analog signal using the clock signal.

13. The audio system as recited in claim 12, where the processor converts the encoded digital data on the analog signal into instructions for changing at least one configuration setting of the amplifier.

9. An audio system for a vehicle comprising:

a head unit including a first audio channel output and a second audio channel output; and

an amplifier including a first audio channel input connected to the first audio channel output of the head unit and a second audio channel input connected to the second audio channel output of the head unit, the amplifier including a processor configured to reconstruct digital instructions from analog signals received on the first audio channel input and the second audio channel input, the digital instructions adapted to reconfigure the operation of the amplifier.

10. The audio system as recited in claim 9, where the head unit transmits a clock signal to the first audio channel input.

11. The audio system as recited in claim 10, where the head unit transmits encoded digital data on an analog signal to the second audio channel input.

14. The audio system as recited in claim 9, where the processor reconstructs digital instructions from analog signals received on the first audio channel input and the second audio channel input in response to receiving a wake up signal from the head unit.

15. The audio system as recited in claim 14, where the wake up signal is above the audible human range.

16. The audio system as recited in claim 14, further comprising at least two speakers connected to an output of the amplifier, the amplifier muting the output in response to the wake up signal.

17. An audio media for reconfiguring the operation of a digital audio device, the audio media having stored thereon an audio track comprising:

a first audio track including an analog signal representing digital instructions for reconfiguring the operation of a digital audio device according to a first set of operational parameters; and

a second audio track including an analog signal representing digital instructions for reconfiguring the operation of a digital audio device according to a second set of operational parameters.

18. The audio media as recited in claim 17, where the digital instructions are capable of being decoded using a serial clock.

19. The audio media as recited in claim 17, where the digital audio device is a digital amplifier.

20. The audio media as recited in claim 18, where the first audio track includes a first audio channel containing a signal representing a serial clock and a second audio channel containing a signal representing digital instructions for reconfiguring the operation of a digital audio device.

21. The audio media as recited in claim 19, where the digital instructions are configured to update software residing on the digital amplifier.

22. The audio media as recited in claim 19, where the digital instructions are configured to change the equalizer parameters of the digital amplifier.

23. The audio media as recited in claim 20, where the serial clock has a frequency of less than 40 kHz.

24. The audio media as recited in claim 20, where the serial clock has a frequency between approximately 1 kHz and 15 kHz.

25. The audio media as recited in claim 17, where the audio media is selected of the group consisting of an audio CD, an audio cassette and a compressed audio file.

26. A digital amplifier comprising:

an audio input;

an audio output;

memory configured to store operational parameters of a digital amplifier;

a power amplifier adapted to drive the audio output with an analog signal; and

a processor configured to reconstruct digital instructions from an analog signal received on the audio input, the digital instructions adapted to change the operational parameters stored in the memory.

27. The digital amplifier as recited in claim 26, where the audio input has a first audio channel input and a second audio channel input, the processor being configured to reconstruct digital instructions from analog signals received on the first audio channel input and the second audio channel input for reconfiguring the operation of the digital amplifier.

28. The digital amplifier as recited in claim 27, where the processor is configured to receive a clock signal on the first audio channel input and encoded digital data on an analog signal on the second audio channel input.

29. The digital amplifier as recited in claim 28, where the processor reconstructs the encoded digital data on the analog signal using the clock signal.

30. The digital amplifier as recited in claim 26, where the digital instructions include erasing the memory and writing a new amplifier configuration to the memory.

31. The digital amplifier as recited in claim 29, where the processor converts the encoded digital data on the analog signal into digital instructions for reconfiguring the operation of the digital amplifier.

32. The digital amplifier as recited in claim 26, where the processor forms the digital instructions into a plurality of data packets, each data packet having a header.

33. The digital amplifier as recited in claim 32, where the header includes a field representing the length of the data packet.

34. The digital amplifier as recited in claim 32, where the header includes a field representing an identification of the digital amplifier for which the digital instructions are intended.

35. The digital amplifier as recited in claim 32, where the header includes a field representing the version of the digital instructions.

36. The digital amplifier as recited in claim 32, where the header includes a field representing a modulation scheme for reconstructing analog signals received on the first audio channel input and the second audio channel input.

37. The digital amplifier as recited in claim 32, where the data packet includes a field representing a command to be performed by the processor.

38. The digital amplifier as recited in claim 26, where the processor is a digital signal processor.

39. The digital amplifier as recited in claim 27, where the processor reconstructs digital instructions from analog signals received on the first channel input and the second channel input in response to receiving a wake up signal.

40. The digital amplifier as recited in claim 39, where the wake up signal is above the audible human range.

41. The digital amplifier as recited in claim 40, where the audio output is muted in response to the wake up signal.

42. A method for changing at least one configuration setting of a digital amplifier comprising:

receiving an analog audio signal as an input to a digital amplifier, the analog audio signal representing instructions for reconfiguring the operation of the digital amplifier;

reconstructing the analog audio signal into a set of digital instructions for changing at least one configuration setting of the digital amplifier; and

processing the set of digital instructions to reconfigure the operation of the digital amplifier.

43. The method as recited in claim 42, where the receiving step includes receiving a first analog audio signal on a first channel of a digital amplifier and receiving a second analog audio signal on a second channel of the digital amplifier.

44. The method as recited in claim 43, where the first analog audio signal is a clock signal and the second analog audio signal is encoded digital data on an analog signal.

45. The method as recited in claim 43, where the reconstructing step includes converting the first analog audio signal and the second analog audio signal to digital data using an analog to digital converter.

46. The method as recited in claim 43, where the reconstructing step is performed by a digital signal processor.

47. The method as recited in claim 43, where the reconstructing step is performed in response to the digital amplifier receiving a wake up signal.

48. The method as recited in claim 43, further comprising the step of detecting whether the first analog audio signal is a clock signal.

49. The method as recited in claim 48, where the reconstructing step selects a channel used to decode responsive to the detecting step.

50. The method as recited in claim 43, further comprising the step of detecting a phase shift in the first analog audio signal and the second analog audio signal.

51. The method as recited in claim 42, where the reconstructing step compensates for a phase shift in the first analog audio signal and the second analog audio signal in response to the detecting step.

52. The method as recited in claim 42, further comprising the step of providing an audible indication during the processing step.

53. The method as recited in claim 42, further comprising the step of providing an audible indication upon completion of the processing step.

54. A method for changing at least one configuration setting of a digital device residing on a vehicle comprising:

receiving an analog audio signal representing a set of digital instructions on an audio input of a digital amplifier;

reconstructing the set of digital instructions from the analog audio signal; and

communicating the set of digital instructions to a destination device for changing at least one configuration setting of the destination device.

55. The method as recited in claim 54, where the digital amplifier and the destination device are connected by a CAN bus.

56. The method as recited in claim 55, where the reconstructing step includes converting the first analog audio signal and the second analog audio signal to digital data using an analog to digital converter.

57. The method as recited in claim 56, where the reconstructing step is performed by a digital signal processor.

58. The method as recited in claim 54, where the set of digital instructions includes header information containing an address for the destination device.

59. A digital amplifier comprising:

an audio input;

means for reconstructing digital instructions for reconfiguring the operation of the digital amplifier from an analog signal received on the audio input; and

means for processing the digital instructions to reconfigure the operation of the digital amplifier.

60. The digital amplifier as recited in claim 59, where the audio input has a first audio channel input and a second audio channel input, the reconstructing means being configured to reconstruct digital instructions for reconfiguring the operation of the digital amplifier from the analog signals received on the first audio channel input and the second audio channel input.

61. The digital amplifier as recited in claim 60, where the reconstructing means is configured to receive a clock signal on the first audio channel input and encoded digital data on an analog signal on the second audio channel input.

62. The digital amplifier as recited in claim 59, where the reconstructing means is a digital signal processor.