Multi-media digital interface systems and methods

• US 8,462,759 B2
• Filed: 02/11/2008
• Issued: 06/11/2013
• Est. Priority Date: 02/16/2007
• Status: Active Grant

• Current Assignee: Semtech Canada Corp. (Semtech Corporation)
• Original Assignee: Semtech Canada Corp. (Semtech Corporation)
• Inventors: Shakiba, Mohammad Hossein, Hudson, John, MacDougall, Jack, Rofheart, Martin, Lynch, David L.
• Primary Examiner(s): Perungavoor, Sath V
• Assistant Examiner(s): WILLIAMS, JEFFERY A
• Application Number:
  US12/029,053
• Publication Number:
  US 20080201756A1
• Time in Patent Office: 1,947 Days
• Field of Search: 370/344, 370/480
• US Class Current: 370/344
• CPC Class Codes: H04L 25/0264 Arrangements for coupling to transmission lines duplexing arrangements H04L5/14; line equalisers, line build-out devices H04L25/03878
• CPC Class Codes: H04L 25/0272 Arrangements for coupling to multiple lines, e.g. for differential transmission
• CPC Class Codes: H04L 25/03343 Arrangements at the transmitter end

Abstract

Systems and methods are provided herein for interfacing a first multi-media digital device with a second multi-media digital device. An exemplary method includes the steps of: (i) converting a plurality of differential digital content channels from the first multi-media digital device into a plurality of single-ended digital content channels; (ii) transmitting the plurality of single-ended digital content channels from the first multi-media digital device to the second multi-media digital device via one or more coaxial cables; and (iii) receiving the single-ended digital content channels from the one or more coaxial cables and converting the single-ended digital content channels back into a plurality of differential digital content channels that are supplied to the second multi-media digital device. Additional steps of the exemplary method may include: (i) transmitting one or more auxiliary channels between the first multi-media digital device and the second multi-media digital device; and (ii) combining the one or more auxiliary channels with at least one of the plurality of digital content channels to form a combined channel to be transmitted from the first multi-media digital device to the second multi-media digital device.

Claims

1. A method of interfacing a first multi-media digital device with a second multi-media digital device, comprising:

converting a plurality of differential digital content channels from the first multi-media digital device into a plurality of single-ended digital content channels, including combining, through frequency-multiplexing, one or more auxiliary channels with one or more of the plurality of single-ended digital content channels to form a combined channel;

transmitting the combined channel from the first multi-media digital device to the second multi-media digital device via one or more coaxial cables; and

receiving the combined channel from the one or more coaxial cables and converting the combined channel back into a plurality of differential digital content channels that are supplied to the second multi-media digital device.

2. The method of claim 1, further comprising:

combining a second auxiliary channel with one or more of the plurality of single-ended digital content channels to form a second combined channel.

3. The method of claim 1, further comprising:

separating the combined channel into the one or more auxiliary channels and the at least one of the plurality of digital content channels at the second multi-media digital device.

4. The method of claim 1, further comprising:

combining the plurality of single-ended digital content channels into a combined digital content channel; and

transmitting the combined digital content channel over a single coaxial cable coupling the first multi-media digital device to the second multi-media digital device.

5. The method of claim 1, further comprising:

combining one or more single-ended digital content channels with one or more second auxiliary channels to form a second combined channel; and

transmitting the second combined channel over a single coaxial cable coupling the first multi-media digital device to the second multi-media digital device.

6. The method of claim 5, further comprising:

separating the second combined channel into the one or more single-ended digital content channels and the one or more second auxiliary channels at the second multi-media digital device.

7. The method of claim 5, wherein the one or more second auxiliary channels includes a configuration and control channel, the method further comprising:

transmitting information on the configuration and control channel from the second multi-media digital device to the first multi-media digital device via the single coaxial cable.

8. The method of claim 7, wherein the configuration and control channel is a bidirectional configuration and control channel, the method further comprising:

transmitting information on the bidirectional configuration and control channel between the second multi-media digital device and the first multi-media digital device via the single coaxial cable.

9. The method of claim 7, wherein the configuration and control channel carries information regarding the configuration and operation of the second multi-media digital device.

10. The method of claim 1, wherein at least one digital content channel is a clock channel, the method further comprising:

combining the clock channel with the one or more auxiliary channels to form the combined channel; and

transmitting the combined channel over a single coaxial cable coupling the first multi-media digital device to the second multi-media digital device.

11. The method of claim 5, wherein the one or more auxiliary channels includes a status channel, the method further comprising:

transmitting information on the status channel from the second multi-media digital device back to the first multi-media digital device via the single coaxial cable.

12. The method of claim 11, wherein the status channel carries hot-plug detect information associated with the second multi-media digital device.

13. The method of claim 5, wherein the one or more auxiliary channels includes a supply channel for carrying power between the first multi-media digital device and the second multi-media digital device.

14. The method of claim 1, wherein the digital content channels or the one or more auxiliary channels carry encrypted data.

15. The method of claim 1, further comprising:

serializing the combined channel and the plurality of single-ended digital content signals channels except the one or more of the plurality of single-ended digital content channels into a single digital content bit stream;

modulating the digital content bit stream; and

transmitting the digital content bit stream from the first multi-media digital device to the second multi-media digital device via a single coaxial cable.

16. The method of claim 15, further comprising:

conditioning the digital content bit stream prior to transmitting it over the single coaxial cable.

17. The method of claim 16, wherein the conditioning step is based on information regarding the transmission characteristics of the single coaxial cable.

18. The method of claim 15, further comprising:

combining the digital content bit stream with one or more second auxiliary channels into the combined channel; and

transmitting the combined channel over the single coaxial cable.

19. The method of claim 18, further comprising:

separating the combined channel into the digital content bit stream and the one or more second auxiliary channels at the second multi-media digital device.

20. The method of claim 19, further comprising:

demodulating the digital content bit stream; and

deserializing the digital content bit stream to recover the plurality of single-ended digital content channels at the second multi-media digital device.

21. The method of claim 18, wherein the one or more second auxiliary channels includes a configuration and control channel, the method further comprising:

transmitting information on the configuration and control channel from the second multi-media digital device back to the first multi-media digital device via the single coaxial cable.

22. The method of claim 21, wherein the configuration and control channel is a bidirectional configuration and control channel, the method further comprising:

transmitting information on the bidirectional configuration and control channel between the second multi-media digital device and the first multi-media digital device via the single coaxial cable.

23. The method of claim 21, wherein the configuration and control channel carries information regarding the configuration and operation of the second multi-media digital device.

24. The method of claim 18, further comprising:

combining the second combined channel with a clock channel; and

transmitting the second combined channel and the clock channel over a single coaxial cable coupling the first multi-media digital device to the second multi-media digital device.

25. The method of claim 18, wherein the one or more second auxiliary channels includes a status channel, the method further comprising:

transmitting information on the status channel from the second multi-media digital device back to the first multi-media digital device via the single coaxial cable.

26. The method of claim 25, wherein the status channel carries hot-plug detect information associated with the second multi-media digital device.

27. The method of claim 18, wherein the one or more second auxiliary channels includes a supply channel for carrying power between the first multi-media digital device and the second multi-media digital device.

28. The method of claim 1, further comprising:

transmitting the plurality of single-ended digital content channels from the first multi-media digital device to the second multi-media digital device via a plurality of coaxial cables.

29. The method of claim 28, further comprising:

for each of the plurality of single-ended digital content channels, transmitting the single-ended digital content channel from the first multi-media digital device to the second multi-media digital device via a separate coaxial cable.

30. The method of claim 28, further comprising:

transmitting a differential clock signal from the first multi-media digital device to the second multi-media digital device.

31. The method of claim 30, wherein the differential clock signal is transmitted from the first multi-media digital device to the second multi-media digital device via a twisted-pair cable.

32. The method of claim 30, further comprising:

converting the differential clock signal into a single-ended clock signal; and

transmitting the single-ended clock signal from the first multi-media digital device to the second multi-media digital device via one of the one or more coaxial cables.

33. The method of claim 28, further comprising:

transmitting one or more auxiliary channels between the first multi-media digital device and the second multi-media digital device.

34. The method of claim 33, further comprising:

combining the one or more auxiliary channels with at least one of the plurality of digital content channels to form a combined channel and transmitting the combined channel from the first multi-media digital device to the second multi-media digital device.

35. The method of claim 34, further comprising:

separating the combined channel into the one or more auxiliary channels and the at least one of the plurality of digital content channels at the second multi-media digital device.

36. The method of claim 1, further comprising:

frequency multiplexing at least one of the single-ended digital content channels with one or more auxiliary channels to form a combined signal; and

transmitting the combined signal to the second multi-media digital device over at least one of the one or more coaxial cables.

37. The method of claim 36, further comprising:

receiving the combined signal from the coaxial cable; and

demultiplexing the single-ended digital content channel from the auxiliary channel.

38. The method of claim 36, further comprising:

frequency multiplexing at least one of the single-ended digital content channels with a plurality of auxiliary channels to form a combined signal; and

transmitting the combined signal to the second multi-media digital device over at least one of the one or more coaxial cables.

39. The method of claim 36, further comprising:

applying a high-pass filter to at least one single-ended digital content channel to form a high-pass content channel;

applying a low-pass filter to the auxiliary channel to form a low-pass auxiliary channel; and

combining the high-pass content channel with the low-pass auxiliary channel to form the combined signal.

40. The method of claim 38, further comprising:

applying a high-pass filter to the least one single-ended digital content channel to form a high-pass content channel;

applying a low-pass filter to one of the plurality of auxiliary channels to form a low-pass auxiliary channel;

applying a band-pass filter to one of the plurality of auxiliary channels to form a band-pass auxiliary channel; and

combining the high-pass content channel with the low-pass auxiliary channel and the band-pass auxiliary channel to form the combined signal.

41. The method of claim 36, wherein the one or more auxiliary channels includes a configuration and control channel, the method further comprising:

transmitting information on the configuration and control channel from the second multi-media digital device back to the first multi-media digital device via one of the one or more coaxial cables.

42. The method of claim 41, wherein the configuration and control channel is a bidirectional configuration and control channel, the method further comprising:

transmitting information on the bidirectional configuration and control channel between the second multi-media digital device and the first multi-media digital device via one of the one or more coaxial cables.

43. The method of claim 41, wherein the configuration and control channel carries information regarding the configuration and operation of the second multi-media digital device.

44. The method of claim 1, further comprising:

frequency multiplexing at least one of the single-ended digital content channels with a clock channel to form a combined signal; and

transmitting the combined signal to the second multi-media digital device over at least one of the one or more coaxial cables.

45. The method of claim 36, wherein the one or more auxiliary channels includes a status channel, the method further comprising:

transmitting information on the status channel from the second multi-media digital device back to the first multi-media digital device via one of the one or more coaxial cables.

46. The method of claim 45, wherein the status channel carries hot-plug detect information associated with the second multi-media digital device.

47. The method of claim 36, wherein the one or more auxiliary channels includes a supply channel for carrying power between the first multi-media digital device and the second multi-media digital device via one of the one or more coaxial cables.

48. The method of claim 36, further comprising:

providing a first and second filter hybrid for each of the plurality of single-ended digital content channels, the first filter hybrid positioned in proximity to the first multi-media digital device and the second filter hybrid positioned in proximity to the second multi-media digital device;

generating a plurality of combined signals using the first filter hybrids, each of the plurality of combined signals comprising one of the single-ended digital content channels and an auxiliary channel; and

transmitting the plurality of combined signals from the first multi-media digital device to the second multi-media digital device via the one or more coaxial cables.

49. The method of claim 48, further comprising:

extracting the single-ended digital content signals and the auxiliary channels using the second filter hybrids.

50. The method of claim 48, wherein the first filter hybrids comprise a high pass input for receiving the single-ended digital content channel, a low pass input for receiving the auxiliary channel, and a combined frequency-multiplexed output for outputting a combined signal.

51. The method of claim 48, wherein the first filter hybrids comprise a high-pass input for receiving the single-ended digital content channel, a low-pass input for receiving a first auxiliary channel, a band-pass input for receiving a second auxiliary channel, and a combined frequency-multiplexed output for outputting a combined signal.

52. The method of claim 48, wherein the first filter hybrids comprise a high-pass filter coupled between the high pass input and the combined frequency-multiplexed output, and a low-pass filter coupled between the low-pass input and the combined frequency multiplexed output.

53. The method of claim 51, wherein the first filter hybrids comprise a high-pass filter coupled between the high pass input and the combined frequency-multiplexed output, a low-pass filter coupled between the low pass input and the combined frequency multiplexed output, and a band-pass filter coupled between the band-pass input and the combined frequency multiplexed output.

54. The method of claim 1, wherein the plurality of differential digital content channels are HDMI content channels.

55. The method of claim 1, wherein the plurality of differential digital content channels are DisplayPort content channels.

56. The method of claim 7, wherein the configuration and control channel is a Consumer Electronics Control (CEC) channel.

57. The method of claim 7, wherein the configuration and control channel is a Display Data channel.

58. The method of claim 7, wherein the configuration and control channel is an Enhanced Display Data channel.

59. The method of claim 7, wherein the configuration and control channel is an Enhanced Extended Display Identification channel.

122. The method of claim 1, wherein the at least one of the plurality of digital content channels is modulated before being combined with the auxiliary channels.

60. An interface system for coupling a first multi-media digital device with a second multi-media digital device, comprising:

a plurality of differential to single-ended converters that convert a plurality of differential digital content channels from the first multi-media digital device into a plurality of single-ended digital content channels, including combining, through frequency-multiplexing, one or more auxiliary channels with one or more of the plurality of single-ended digital content channels to form a combined channel;

one or more coaxial cables for transporting the combined channel from the first multi-media digital device to the second multi-media digital device; and

a plurality of single-ended to differential converters that convert the combined channel from the one or more coaxial cables back into a plurality of differential digital content channels that are supplied to the second multi-media digital device.

61. The interface system of claim 60, further comprising:

interface circuitry for combining a second auxiliary channel with one or more of the plurality of single-ended digital content channels to form a second combined channel.

62. The interface system of claim 60, further comprising:

one or more separators for separating the combined channel into the one or more auxiliary channels and the at least one of the plurality of digital content channels at the second multi-media digital device.

63. The interface system of claim 60, further comprising:

circuitry for combining the plurality of single-ended digital content channels into a combined digital content channel; and

means for transmitting the combined digital content channel over a single coaxial cable coupling the first multi-media digital device to the second multi-media digital device.

64. The interface system of claim 60, further comprising:

one or more combiners for combining one or more single-ended digital content channels with one or more second auxiliary channels to form a second combined channel; and

means for transmitting the second combined channel over a single coaxial cable coupling the first multi-media digital device to the second multi-media digital device.

66. The interface system of claim 64, wherein the one or more second auxiliary channels includes a configuration and control channel, the system further comprising:

means for transmitting information on the configuration and control channel from the second multi-media digital device to the first multi-media digital device via the single coaxial cable.

67. The interface system of claim 66, wherein the configuration and control channel is a bidirectional configuration and control channel, the system further comprising:

means for transmitting information on the bidirectional configuration and control channel between the second multi-media digital device and the first multi-media digital device via the single coaxial cable.

68. The interface system of claim 66, wherein the configuration and control channel carries information regarding the configuration and operation of the second multi-media digital device.

69. The interface system of claim 60, wherein at least one of the digital content channels is a clock channel, the method further comprising:

circuitry for combining the combined digital content channel with one or more auxiliary channels to form the combined channel; and

means for transmitting the combined channel over a single coaxial cable coupling the first multi-media digital device to the second multi-media digital device.

70. The interface system of claim 64, wherein the one or more auxiliary channels includes a status channel, the system further comprising:

means for transmitting information on the status channel from the second multi-media digital device back to the first multi-media digital device via the single coaxial cable.

71. The interface system of claim 70, wherein the status channel carries hot-plug detect information associated with the second multi-media digital device.

72. The interface system of claim 64, wherein the one or more auxiliary channels includes a supply channel for carrying power between the first multi-media digital device and the second multi-media digital device.

73. The interface system of claim 60, wherein the digital content channels or the one or more auxiliary channels carry encrypted data.

74. The interface system of claim 60, further comprising:

a serializer coupled to the plurality of single-ended digital content channels for generating a single digital content bit stream; and

a modulator for modulating the digital content bit stream;

wherein the digital content bit stream is transported from the first multi-media digital device to the second multi-media digital device via a single coaxial cable.

75. The interface system of claim 74, further comprising:

circuitry for conditioning the digital content bit stream prior to transporting it over the single coaxial cable.

76. The interface system of claim 75, wherein the conditioning circuitry is coupled to a source of information regarding the transmission characteristics of the single coaxial cable.

77. The interface system of claim 74, further comprising:

at least one combiner for combining the digital content bit stream with one or more second auxiliary channels into the combined channel; and

means for transmitting the combined channel over the single coaxial cable.

78. The interface system of claim 77, further comprising:

at least one separator for separating the combined channel into the digital content bit stream and the one or more second auxiliary channels at the second multi-media digital device.

79. The interface system of claim 78, further comprising:

a demodulator for demodulating the digital content bit stream; and

a deserializer for deserializing the digital content bit stream to recover the plurality of single-ended digital content channels at the second multi-media digital device.

80. The interface system of claim 77, wherein the one or more second auxiliary channels includes a configuration and control channel, the system further comprising:

means for transmitting information on the configuration and control channel from the second multi-media digital device back to the first multi-media digital device via the single coaxial cable.

81. The interface system of claim 80, wherein the configuration and control channel is a bidirectional configuration and control channel, the system further comprising:

means for transmitting information on the bidirectional configuration and control channel between the second multi-media digital device and the first multi-media digital device via the single coaxial cable.

82. The interface system of claim 80, wherein the configuration and control channel carries information regarding the configuration and operation of the second multi-media digital device.

83. The interface system of claim 77, further comprising:

circuitry for combining the second combined channel with a clock channel; and

means for transmitting the second combined channel and the clock channel over a single coaxial cable coupling the first multi-media digital device to the second multi-media digital device.

84. The interface system of claim 77, wherein the one or more second auxiliary channels includes a status channel, the system further comprising:

means for transmitting information on the status channel from the second multi-media digital device back to the first multi-media digital device via the single coaxial cable.

85. The interface system of claim 84, wherein the status channel carries hot-plug detect information associated with the second multi-media digital device.

86. The interface system of claim 77, wherein the one or more second auxiliary channels includes a supply channel for carrying power between the first multi-media digital device and the second multi-media digital device.

87. The interface system of claim 60, further comprising:

a plurality of coaxial cables for transmitting the plurality of single-ended digital content channels from the first multi-media digital device to the second multi-media digital device.

88. The interface system of claim 87, wherein each of the plurality of single-ended digital content channels is coupled to a separate coaxial cable for separately transmitting the single-ended digital content channels from the first multi-media digital device to the second multi-media digital device.

89. The interface system of claim 87, further comprising:

means for transmitting a differential clock signal from the first multi-media digital device to the second multi-media digital device.

90. The interface system of claim 89, further comprising a twisted-pair cable for transmitting the differential clock signal from the first multi-media digital device to the second multi-media digital device.

91. The interface system of claim 89, further comprising:

a differential to single-ended converter for converting the differential clock signal into a single-ended clock signal; and

means for transmitting the single-ended clock signal from the first multi-media digital device to the second multi-media digital device via one of the one or more coaxial cables.

92. The interface system of claim 87, further comprising:

means for transmitting one or more auxiliary channels between the first multi-media digital device and the second multi-media digital device.

93. The interface system of claim 92, further comprising:

a combiner for combining the one or more auxiliary channels with at least one of the plurality of digital content channels to form a combined channel;

wherein the combined channel is transmitted from the first multi-media digital device to the second multi-media digital device.

94. The interface system of claim 93, further comprising:

a separator for separating the combined channel into the one or more auxiliary channels and the at least one of the plurality of digital content channels at the second multi-media digital device.

95. The interface system of claim 60, further comprising:

a frequency multiplexer coupled to at least one of the single-ended digital content channels and one or more auxiliary channels and forming a combined signal; and

means for transmitting the combined signal to the second multi-media digital device over at least one of the one or more coaxial cables.

96. The interface system of claim 95, further comprising:

a demultiplexer at the second multi-media digital device for demultiplexing the single-ended digital content channel from the auxiliary channel.

97. The interface system of claim 95, further comprising:

a frequency multiplexer coupled to at least one of the single-ended digital content channels and a plurality of auxiliary channels and forming a combined signal; and

means for transmitting the combined signal to the second multi-media digital device over at least one of the one or more coaxial cables.

98. The interface system of claim 95, wherein the frequency multiplexer further comprises:

a high-pass filter coupled to the least one single-ended digital content channel to form a high-pass content channel;

a low-pass filter coupled to the auxiliary channel to form a low-pass auxiliary channel; and

combining circuitry for combining the high-pass content channel with the low-pass auxiliary channel to form the combined signal.

99. The interface system of claim 97, wherein the frequency multiplexer further comprises:

a high-pass filter coupled to the least one single-ended digital content channel to form a high-pass content channel;

a low-pass filter coupled to one of the plurality of auxiliary channels to form a low-pass auxiliary channel;

a band-pass filter coupled to one of the plurality of auxiliary channels to form a band-pass auxiliary channel; and

circuitry for combining the high-pass content channel with the low-pass auxiliary channel and the band-pass auxiliary channel to form the combined signal.

100. The interface system of claim 95, wherein the one or more auxiliary channels includes a configuration and control channel, the system further comprising:

means for transmitting information on the configuration and control channel from the second multi-media digital device back to the first multi-media digital device via one of the one or more coaxial cables.

101. The interface system of claim 100, wherein the configuration and control channel is a bidirectional configuration and control channel, the system further comprising:

means for transmitting information on the bidirectional configuration and control channel between the second multi-media digital device and the first multi-media digital device via one of the one or more coaxial cables.

102. The interface system of claim 100, wherein the configuration and control channel carries information regarding the configuration and operation of the second multi-media digital device.

103. The interface system of claim 60, further comprising:

a frequency multiplexer for multiplexing at least one of the single-ended digital content channels with a clock channel to form a combined signal; and

means for transmitting the combined signal to the second multi-media digital device over at least one of the one or more coaxial cables.

104. The interface system of claim 95, wherein the one or more auxiliary channels includes a status channel, the system further comprising:

means for transmitting information on the status channel from the second multi-media digital device back to the first multi-media digital device via one of the one or more coaxial cables.

105. The interface system of claim 104, wherein the status channel carries hot-plug detect information associated with the second multi-media digital device.

106. The interface system of claim 95, wherein the one or more auxiliary channels includes a supply channel for carrying power between the first multi-media digital device and the second multi-media digital device via one of the one or more coaxial cables.

107. The interface system of claim 95, further comprising:

a first and second filter hybrid for each of the plurality of single-ended digital content channels, the first filter hybrid positioned in proximity to the first multi-media digital device and the second filter hybrid positioned in proximity to the second multi-media digital device;

the first filter hybrids generating a plurality of combined signals, each of the plurality of combined signals comprising one of the single-ended digital content channels and an auxiliary channel; and

means for transmitting the plurality of combined signals from the first multi-media digital device to the second multi-media digital device via the one or more coaxial cables.

108. The interface system of claim 107, further comprising:

circuitry in the second filter hybrids for extracting the single-ended digital content signals and the auxiliary channels.

109. The interface system of claim 107, wherein the first filter hybrids comprise a high pass input for receiving the single-ended digital content channel, a low pass input for receiving the auxiliary channel, and a combined frequency-multiplexed output for outputting a combined signal.

110. The interface system of claim 107, wherein the first filter hybrids comprise a high-pass input for receiving the single-ended digital content channel, a low-pass input for receiving a first auxiliary channel, a band-pass input for receiving a second auxiliary channel, and a combined frequency-multiplexed output for outputting a combined signal.

111. The interface system of claim 107, wherein the first filter hybrids comprise a high-pass filter coupled between the high pass input and the combined frequency-multiplexed output, and a low-pass filter coupled between the low-pass input and the combined frequency multiplexed output.

112. The interface system of claim 110, wherein the first filter hybrids comprise a high-pass filter coupled between the high pass input and the combined frequency-multiplexed output, a low-pass filter coupled between the low pass input and the combined frequency multiplexed output, and a band-pass filter coupled between the band-pass input and the combined frequency multiplexed output.

113. The interface system of claim 60, wherein the plurality of differential digital content channels are HDMI content channels.

114. The interface system of claim 60, wherein the plurality of differential digital content channels are DisplayPort content channels.

115. The interface system of claim 66, wherein the configuration and control channel is a Consumer Electronics Control (CEC) channel.

116. The interface system of claim 66, wherein the configuration and control channel is a Display Data channel.

117. The interface system of claim 66, wherein the configuration and control channel is an Enhanced Display Data channel.

118. The interface system of claim 66, wherein the configuration and control channel is an Enhanced Extended Display Identification channel.

119. The interface system of claim 60, wherein at least one of the differential digital content channels is a clock channel.

120. The interface system of claim 119, further comprising:

circuitry for combining the clock channel with at least one auxiliary channel to form a combined channel; and

means for transmitting the combined channel from the first multi-media digital device to the second multi-media digital device.

121. The interface system of claim 61, further comprising:

circuitry for conditioning the one or more auxiliary channels prior to being transmitted between the first multi-media digital device and the second multi-media digital device.

65. The interface system of 64, further comprising:

one or more separators for separating the second combined channel into the one or more single-ended digital content channels and the one or more second auxiliary channels at the second multi-media digital device.