Transmission device and reception device

The present invention relates to a transmitter. More specifically, the present invention relates to a transmission device having a communication unit that performs communication using a communication path composed of predetermined lines of a transmission line.

In recent years, for example, from DVD (Digital Versatile Disc) recorders, set-top boxes, and other AV sources (Audio Visual sources) to TV receivers, projectors, and other displays, digital video signals, that is, uncompressed (uncompressed) As a communication interface for high-speed transmission of a video signal (hereinafter, appropriately referred to as "image data") of a base band) and a digital audio signal (hereinafter, appropriately referred to as "audio data") accompanying the video signal. HDMI (High Definition Multimedia Interface) is becoming widespread. For example, Patent Document 1 describes the details of the HDMI standard.<patcit num="1"><text>WO2002 / 078336</text></patcit>

<p> In the current HDMI standard, the transmitting device (source device) can determine whether or not the receiving device (sink device) is an eHDMI compatible device based on the voltage state of the reserve line of the HDMI cable. Here, the fact that the transmitting device or the receiving device is compatible with eHDMI means that the transmitting device or the receiving device communicates using a communication path composed of predetermined lines of an HDMI cable (for example, a reserve line and an HPD line). It means that it has a communication unit.</p><p> However, the receiving device cannot recognize whether or not the transmitting device is an eHDMI compatible device. Further, even if the transmitting device is an eHDMI compatible device, if the transmitting device is in a busy state, the receiving device cannot recognize the busy state. Therefore, the receiving device may send an unnecessary signal to a transmitting device that does not support eHDMI or a transmitting device that supports eHDMI in a busy state.</p><p> An object of the present invention is to enable a signal to be appropriately transmitted from a receiving device to a transmitting device.</p>

<p> The concept of this invention is A video signal transmitter that transmits video signals to external devices via a transmission line using multiple channels and differential signals. A communication unit that communicates with the external device via a communication path composed of predetermined lines of the transmission line. The external device is provided with a functional information transmission unit that transmits functional information indicating that the external device has the communication unit, and the communication path is a pair of differential transmission lines, and the pair of differential transmission lines At least one of them has a function of receiving a notification of the connection status from the external device by the DC bias potential. It is in the transmitter.</p><p> Moreover, the concept of this invention is A video signal receiver that receives video signals from an external device via a transmission line using multiple channels and differential signals. A communication unit that communicates with the external device via a communication path composed of predetermined lines of the transmission line. The communication path includes a function information receiving unit that receives functional information indicating that the communication unit has a communication unit that communicates via a communication path composed of the predetermined line sent from the external device. Is a pair of differential transmission lines, and at least one of the pair of differential transmission lines has a function of notifying the external device of the connection state of the own device by a DC bias potential. It is in the receiving device.</p><p> Functional information indicating that the communication unit is possessed is transmitted from the transmission device to the external device. This functional information can include, for example, information on the transmission format (application) supported by the transmitting device.</p><p> For example, the functional information is transmitted to an external device by being inserted during the blanking period of the video signal. In this case, the functional information is inserted in the blanking period of the video signal by using, for example, an HDMI AVI InfoFrame packet. Further, for example, functional information is transmitted to an external device via a control data line constituting a transmission line. In this case, for example, the control data line is the CEC line of the HDMI cable, and the functional information is transmitted to an external device as a CEC signal.</p><p> The receiving device includes a video signal receiving unit that receives a video signal from an external device (transmitting device) on a plurality of channels via a transmission line by a differential signal, and is, for example, an HDMI sink device. .. The receiving device is provided with a communication unit that communicates with an external device via a communication path composed of predetermined lines of the transmission line. For example, the communication path is a pair of differential transmission lines, and at least one of the pair of differential transmission lines has a function of notifying an external device of the connection state of the own device by a DC bias potential. Specifically, the predetermined lines of the transmission line are, for example, the reserve line and the HPD line constituting the HDMI cable.</p><p> The receiving device receives the above-mentioned functional information sent from the external device. For example, when the function information is inserted in the blanking period of the video signal received by the video signal receiving unit, the function information is extracted from the blanking period of the video signal to perform reception. Further, for example, functional information is received from an external device via a control data line constituting a transmission line.</p><p> As described above, when the transmitting device includes the communication unit, the transmitting device transmits the functional information indicating that the receiving device has the communication unit, and the receiving device receives the functional information. That is, the receiving device can receive the above-mentioned functional information when the transmitting device includes the communication unit, but cannot receive the above-mentioned functional information when the transmitting device does not include the communication unit. Therefore, the receiving device can recognize whether or not the external device (transmitting device) has a communication unit, and transmits an unnecessary signal to the external device that does not have the communication unit via the above-mentioned communication path. You can avoid that. Further, when the function information includes the corresponding transmission format information of the external device, the receiving device can easily know the transmission format supported by the external device from the information.</p><p> In the present invention, for example, the receiving device includes a transmission request transmitting unit that transmits a transmission request for functional information to an external device (transmitting device), and the transmitting device is a functional information transmitted from the external device (receiving device). The transmission request receiving unit may include a transmission request receiving unit for receiving the transmission request of the above, and the function information transmitting unit may be configured to transmit the function information to an external device when the transmission request is received by the transmission request receiving unit. In this case, the receiving device transmits a function information transmission request to the external device to determine whether or not the external device has a communication unit at an arbitrary timing (for example, at power-on, input switching, etc.). Can be confirmed.</p><p> The concept of this invention is A video signal receiver that receives video signals from an external device via a transmission line using multiple channels and differential signals. A communication unit that communicates with the external device via a communication path composed of predetermined lines of the transmission line. The external device is provided with a functional information transmission unit that transmits functional information indicating that the external device has the communication unit, and the communication path is a pair of differential transmission lines, and the pair of differential transmission lines At least one of them has a function of notifying the external device of the connection state of the own device by a DC bias potential. It is in the receiving device.</p><p> Moreover, the concept of this invention is A video signal transmitter that transmits video signals to external devices via a transmission line using multiple channels and differential signals. A communication unit that communicates with the external device via a communication path composed of predetermined lines of the transmission line. The communication path includes a function information receiving unit that receives functional information indicating that the communication unit has a communication unit that communicates via a communication path composed of the predetermined line sent from the external device. Is a pair of differential transmission lines, and at least one of the pair of differential transmission lines has a function of receiving notification of a connection state from the external device by a DC bias potential. It is in the transmitter.</p><p> Functional information indicating that the receiving device has a communication unit that communicates with an external device (transmitting device) via a communication path composed of predetermined lines of the transmission line is transmitted. The transmitting device receives the above-mentioned functional information sent from the external device (receiving device).</p><p> As described above, when the receiving device includes the communication unit, the receiving device transmits the functional information indicating that to the transmitting device, and the transmitting device receives the functional information. That is, the transmitting device can receive the above-mentioned functional information when the receiving device includes the communication unit, but cannot receive the above-mentioned functional information when the receiving device does not include the communication unit.</p><p> Therefore, the transmitting device can recognize whether or not the external device (receiving device) has a communication unit, and transmits an unnecessary signal to the external device that does not have the communication unit via the above-mentioned communication path. You can avoid that. Further, when the function information includes the corresponding transmission format information of the external device, the transmitting device can easily know the transmission format supported by the external device from the information.</p><p> In the present invention, for example, the transmitting device includes a transmission request receiving unit that transmits a transmission request requesting transmission of functional information to an external device (receiving device), and the receiving device is transmitted from the external device (transmitting device). A transmission request receiving unit for receiving a transmission request for incoming functional information is provided, and the functional information transmitting unit transmits the functional information to an external device when the transmission request is received by the transmission request receiving unit. Good. In this case, the transmitting device transmits a function information transmission request to the external device to determine whether or not the external device has a communication unit at an arbitrary timing (for example, at power-on, input switching, etc.). Can be confirmed.</p><p> The concept of this invention is A video signal transmitter that transmits video signals to external devices via a transmission line using multiple channels and differential signals. A communication unit that communicates with the external device via a communication path composed of predetermined lines of the transmission line. It is provided with a functional information transmission unit that changes the voltage of the first line constituting the transmission line to notify the external device that it has the communication unit, and the communication line is a pair of differential transmission lines. At least one of the pair of differential transmission lines has a function of receiving notification of the connection status from the external device by the DC bias potential. It is in the transmitter.</p><p> Moreover, the concept of this invention is A video signal receiver that receives video signals from an external device via a transmission line using multiple channels and differential signals. A communication unit that communicates with the external device via a communication path composed of predetermined lines of the transmission line. Functional information indicating that the external device has a communication unit that detects a voltage change of the first line constituting the transmission line and communicates via the communication line composed of the predetermined line. The communication path is a pair of differential transmission lines, and at least one of the pair of differential transmission lines is connected to the external device by a DC bias potential. Has a function to notify It is in the receiving device.</p><p> In the present invention, the transmission device includes a video signal transmission unit that transmits a video signal to an external device (reception device) via a transmission line by a differential signal on a plurality of channels, for example, HDMI. Source device. The transmission device is provided with a communication unit that communicates with an external device via a communication path composed of predetermined lines of the transmission line. For example, the communication path is a pair of differential transmission lines, and at least one of the pair of differential transmission lines has a function of receiving a notification of a connection state from an external device by a DC bias potential. Specifically, the predetermined lines of the transmission line are, for example, the reserve line and the HPD line constituting the HDMI cable.</p><p> The function information transmitting unit is made to change the voltage of the first line constituting the transmission line in order to convey to the external device that it has the communication unit. Further, for example, the format information transmission unit is made to change the voltage of the first line based on the transmission format corresponding to itself, and the transmission format (application) information is transmitted to the external device (receiver). To. Further, for example, information on the transmission format supported by the external device (receiver) is acquired based on the pulsed voltage change of the first line. The first line is, for example, a reserve line that constitutes an HDMI cable.</p><p> The receiving device includes a video signal receiving unit that receives a video signal from an external device (transmitting device) on a plurality of channels via a transmission line by a differential signal, and is, for example, an HDMI sink device. .. The receiving device is provided with a communication unit that communicates with an external device via a communication path composed of predetermined lines of the transmission line. For example, the communication path is a pair of differential transmission lines, and at least one of the pair of differential transmission lines has a function of notifying an external device of the connection state of the own device by a DC bias potential. Specifically, the predetermined lines of the transmission line are, for example, the reserve line and the HPD line constituting the HDMI cable.</p><p> By detecting the voltage change of the first line constituting the transmission line, the receiving device acquires functional information indicating that the external device has the above-mentioned communication unit. Further, for example, information on the transmission format (application) supported by the external device (transmitter) is acquired based on the pulsed voltage change of the first line. Further, for example, the format information transmitting unit makes the voltage of the first line change based on the transmission format corresponding to itself, and transmits the transmission format information to an external device (receiver).</p><p> In this way, when the transmitting device includes a communication unit, the voltage of the first line constituting the transmission line is changed by the transmitting device, and in the receiving device, the external device has the communication unit due to this voltage change. Function information indicating that the device is installed is acquired. That is, the receiving device can acquire the above-mentioned functional information when the transmitting device includes the communication unit, but cannot acquire the above-mentioned functional information when the transmitting device does not include the communication unit. Therefore, the receiving device can recognize whether or not the external device (transmitting device) has a communication unit, and transmits an unnecessary signal to the external device that does not have the communication unit via the above-mentioned communication path. You can avoid that.</p><p> In the present invention, for example, the receiving device changes the voltage of the second line or the first line constituting the transmission line before detecting the voltage change of the first line in the functional information acquisition unit, and externally. The device (transmitting device) is provided with a function requesting unit that requests transmission of functional information, and the transmitting device is provided with a voltage change detecting unit that detects a voltage change on the second line or the first line described above, and functional information. The transmission unit may be configured to change the voltage of the first line described above when a voltage change is detected by the voltage change detection unit. For example, the second line is the HPD line that constitutes the HDMI cable.</p><p> In this case, the receiving device changes the voltage of the second line or the first line constituting the transmission line to change the voltage of the external device (for example, at the time of power-on, at the time of input switching, etc.). It is possible to confirm whether or not the transmission device) has a communication unit. Further, in the case where the receiving device requests the function information from the external device (transmitting device) in this way, when there are a plurality of external devices, the request for the function information is requested to the plurality of external devices in a series. It becomes possible to do. In this case, it is expected that the number of pins (number of ports) of the microcomputer will be reduced.</p><p> When the receiving device cannot acquire the function information even after a certain period of time has passed since the function information was transmitted to the external device (transmitting device), the receiving device requests the external device to transmit the function information again. It may be configured.</p><p> The concept of this invention is A video signal receiver that receives video signals from an external device via a transmission line using multiple channels and differential signals. A communication unit that communicates with the external device via a communication path composed of predetermined lines of the transmission line. It is provided with a functional information transmission unit that changes the voltage of the first line constituting the transmission line to notify the external device that it has the communication unit, and the communication line is a pair of differential transmission lines. At least one of the pair of differential transmission lines has a function of notifying the external device of the connection state of the own device by a DC bias potential. It is in the receiving device.</p><p> Moreover, the concept of this invention is A video signal transmitter that transmits video signals to external devices via a transmission line using multiple channels and differential signals. A communication unit that communicates with the external device via a communication path composed of predetermined lines of the transmission line. Functional information indicating that the external device has a communication unit that detects a voltage change of the first line constituting the transmission line and communicates via the communication line composed of the predetermined line. The communication path is a pair of differential transmission lines, and at least one of the pair of differential transmission lines is notified of the connection status from the external device by a DC bias potential. Has a function to receive Transmitter.</p><p> In the receiving device, the function information transmitting unit is made to change the voltage of the first line constituting the transmission line in order to convey to the external device (transmitting device) that it has the communication unit. Further, in the transmission device, by detecting the voltage change of the first line constituting the transmission line, functional information indicating that the external device (reception device) has the above-mentioned communication unit is acquired.</p><p> In this way, when the receiving device includes a communication unit, the receiving device changes the voltage of the first line constituting the transmission line, and in the transmitting device, the external device has the communication unit due to this voltage change. Function information indicating that the device is installed is acquired. That is, the transmitting device can acquire the above-mentioned functional information when the receiving device includes the communication unit, but cannot acquire the above-mentioned functional information when the receiving device does not include the communication unit. Therefore, the transmitting device can recognize whether or not the external device (receiving device) has a communication unit, and transmits an unnecessary signal to the external device that does not have the communication unit via the above-mentioned communication path. You can avoid that.</p><p> In the present invention, for example, the transmitting device changes the voltage of the first line constituting the transmission line before detecting the voltage change of the first line in the functional information acquisition unit, and causes the external device (receiving device). The receiving device includes a voltage change detection unit that detects a voltage change in the first line described above, and the function information transmission unit has a voltage change detection unit that detects a voltage change. When is detected, the voltage of the first line described above may be changed.</p><p> In this case, the transmitting device changes the voltage of the first line constituting the transmission line, so that the external device (receiving device) communicates with the communication unit at an arbitrary timing (for example, at the time of power-on, at the time of input switching, etc.). It is possible to confirm whether or not the device is provided.</p><p> The concept of this invention is A video signal transmitter that transmits video signals to external devices via a transmission line using multiple channels and differential signals. A communication unit that communicates with the external device via a communication path composed of predetermined lines of the transmission line. A blocking judgment unit that determines whether or not to block communication by the above communication unit, When the cutoff determination unit determines that communication is cut off, the external device is provided with a communication information transmission unit that transmits communication information indicating communication cutoff, and the communication lines are a pair of differential transmission lines. At least one of the pair of differential transmission lines has a function of receiving notification of a connection state from the external device by a DC bias potential. It is in the transmitter.</p><p> Moreover, the concept of this invention is A video signal receiver that receives video signals from an external device via a transmission line using multiple channels and differential signals. A communication unit that communicates with the external device via a communication path composed of predetermined lines of the transmission line. It is provided with a communication information receiving unit that receives communication information indicating that communication is blocked by a communication unit that communicates via a communication path composed of the predetermined line, which is sent from the external device, and the communication paths are paired. At least one of the pair of differential transmission lines has a function of notifying the external device of the connection state of the own device by a DC bias potential. It is in the receiving device.</p><p> In the present invention, the transmission device includes a video signal transmission unit that transmits a video signal to an external device (reception device) via a transmission line by a differential signal on a plurality of channels, for example, HDMI. Source device. The transmission device is provided with a communication unit that communicates with an external device via a communication path composed of predetermined lines of the transmission line. For example, the communication path is a pair of differential transmission lines, and at least one of the pair of differential transmission lines has a function of receiving a notification of a connection state from an external device by a DC bias potential. Specifically, the predetermined lines of the transmission line are, for example, the reserve line and the HPD line constituting the HDMI cable.</p><p> The cutoff determination unit determines whether or not to block the communication by the communication unit. In the cutoff determination unit, for example, when it is in a busy state due to other processing, it is determined to shut off. When it is determined that the communication is blocked, communication information indicating that the communication is blocked is transmitted to the external device. For example, the communication information is transmitted to an external device by being inserted during the blanking period of the video signal. In this case, the communication information is inserted in the blanking period of the video signal by using, for example, an HDMI AVI InfoFrame packet. Further, for example, communication information is transmitted to an external device via a control data line constituting a transmission line. In this case, for example, the control data line is the CEC line of the HDMI cable, and the communication information is transmitted to an external device as a CEC signal.</p><p> The receiving device includes a video signal receiving unit that receives a video signal from an external device (transmitting device) on a plurality of channels via a transmission line by a differential signal, and is, for example, an HDMI sink device. .. The receiving device is provided with a communication unit that communicates with an external device via a communication path composed of predetermined lines of the transmission line. For example, the communication path is a pair of differential transmission lines, and at least one of the pair of differential transmission lines has a function of notifying an external device of the connection state of the own device by a DC bias potential. Specifically, the predetermined lines of the transmission line are, for example, the reserve line and the HPD line constituting the HDMI cable.</p><p> The receiving device receives the above-mentioned communication information sent from the external device. For example, when the communication information is inserted in the blanking period of the video signal received by the video signal receiving unit, the communication information is extracted from the blanking period of the video signal to perform reception. Further, for example, communication information is received from an external device via a control data line constituting a transmission line.</p><p> In this way, when the transmitting device blocks the communication by the communication unit, the transmitting device transmits the communication information indicating the blocking of the communication by the communication unit to the receiving device, and the receiving device receives this communication information. Therefore, the receiving device can avoid transmitting an unnecessary signal to the external device that blocks the communication by the communication unit via the above-mentioned communication path.</p><p> The concept of this invention is A video signal transmitter that transmits video signals to external devices via a transmission line using multiple channels and differential signals. A communication unit that communicates with the external device via a communication path composed of predetermined lines of the transmission line. A blocking judgment unit that determines whether or not to block communication by the above communication unit, When the cutoff determination unit determines that the communication is cut off, the communication is provided with a voltage control unit that changes the voltage of the first line constituting the transmission line in order to convey the cutoff of the communication to the external device. The lines are a pair of differential transmission lines, and at least one of the pair of differential transmission lines has a function of receiving notification of a connection state from the external device by a DC bias potential. It is in the transmitter.</p><p> Moreover, the concept of this invention is A video signal receiver that receives video signals from an external device via a transmission line using multiple channels and differential signals. A communication unit that communicates with the external device via a communication path composed of predetermined lines of the transmission line. It is provided with a communication information acquisition unit that detects a voltage change of the first line constituting the transmission line and acquires communication information indicating that communication is interrupted by the communication unit of the external device, and the communication path is a pair of differences. It is a dynamic transmission line, and at least one of the pair of differential transmission lines has a function of notifying the external device of the connection state of its own device by a DC bias potential. It is in the receiving device.</p><p> The cutoff determination unit determines whether or not to block the communication by the communication unit. In the cutoff determination unit, for example, when it is in a busy state due to other processing, it is determined to shut off. When it is determined to cut off, the voltage control unit causes the voltage of the first line constituting the transmission line to change in order to transmit the cutoff of communication to the external device. In this case, for example, the first line is the reserve line that constitutes the HDMI cable.</p><p> The receiving device includes a video signal receiving unit that receives a video signal from an external device (transmitting device) on a plurality of channels via a transmission line by a differential signal, and is, for example, an HDMI sink device. .. The receiving device is provided with a communication unit that communicates with an external device via a communication path composed of predetermined lines of the transmission line. For example, the communication path is a pair of differential transmission lines, and at least one of the pair of differential transmission lines has a function of notifying an external device of the connection state of the own device by a DC bias potential. Specifically, the predetermined lines of the transmission line are, for example, the reserve line and the HPD line constituting the HDMI cable. By detecting the voltage change of the first line constituting the transmission line, the receiving device acquires communication information indicating the interruption of communication by the communication unit of the external device. In this case, for example, the first line is the reserve line that constitutes the HDMI cable.</p><p> In this way, when the transmission device cuts off the communication by the communication unit, the voltage of the first line constituting the transmission line is changed by this transmission device. In the receiving device, the communication information indicating the interruption of communication by the communication unit of the external device is acquired by this voltage change. The receiving device can avoid transmitting an unnecessary signal to an external device that blocks communication by the communication unit via the above-mentioned communication path.</p>

<p> According to the present invention, when a communication unit that performs communication using a communication path composed of predetermined lines of a transmission line is provided, information about the communication unit can be recognized by an external device, and is external. The device can appropriately transmit signals, such as avoiding the transmission of unnecessary packets.</p>

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a configuration example of an AV (Audio Visual) system 200 as an embodiment. The AV system 200 has a disc recorder 210 as a source device and a television receiver 250 as a sink device. In this AV system 200, the disc recorder 210 and the television receiver 250 are eHDMI compatible devices. Here, the eHDMI compatible device means that it has a communication unit that performs communication using a communication path by a reserve line and an HPD line constituting an HDMI cable.

The disc recorder 210 and the television receiver 250 are connected via an HDMI cable 350. The disk recorder 210 is provided with an HDMI terminal 211 to which an HDMI transmission unit (HDMITX) 212 and a high-speed data line interface (I / F) 213 are connected. The television receiver 250 is provided with an HDMI terminal 251 to which an HDMI receiver (HDMIRX) 252 and a high-speed data line interface (I / F) 253 are connected. One end of the HDMI cable 350 is connected to the HDMI terminal 211 of the disc recorder 210, and the other end of the HDMI cable 350 is connected to the HDMI terminal 251 of the television receiver 250.

In the AV system 200 shown in FIG. 1, the video signal reproduced by the disc recorder 210 is supplied to the television receiver 250 via the HDMI cable 350, and the image is displayed on the television receiver 250. Further, the audio signal reproduced by the disc recorder 210 is supplied to the television receiver 250 via the HDMI cable 350, and the audio is output from the speaker of the television receiver 250.

FIG. 2 shows a configuration example of the disc recorder 210. The disk recorder 210 includes an HDMI terminal 211, an HDMI transmission unit 212, a high-speed data line interface 213, an antenna terminal 214, a digital tuner 215, a demultiplexer 216, an internal bus 217, a recording unit interface 218, and the like. DVD / BD drive 219, HDD (Hard Disk Drive) 220, CPU (Central Processing Unit) 221 and flash ROM (Read Only Memory) 222, DRAM (Dynamic Random Access Memory) 223, and Ethernet interface (Ethernet I /). It has F) 224, a network terminal 225, a DTCP (Digital Transmission Content Protection) circuit 226, an MPEG decoder 227, a graphic generation circuit 228, a video output terminal 229, and an audio output terminal 230. "Ethernet" and "Ethernet" are registered trademarks.

The HDMI transmission unit (HDMI source) 212 transmits baseband video (image) and audio data from the HDMI terminal 211 by HDMI-compliant communication. The details of the HDMI transmission unit 212 will be described later. The high-speed data line interface 213 is a bidirectional communication interface using a predetermined line (reserve line, HPD line in this embodiment) constituting the HDMI cable. Details of this high-speed data line interface 213 will be described later.

The antenna terminal 214 is a terminal for inputting a television broadcast signal received by a receiving antenna (not shown). The digital tuner 215 processes the television broadcast signal input to the antenna terminal 214 and outputs a predetermined transport stream. The demultiplexer 216 extracts a partial TS (Transport Stream) (TS packet of video data, TS packet of audio data) corresponding to a predetermined selected channel from the transport stream obtained by the digital tuner 215.

Further, the demultiplexer 216 extracts PSI / SI (Program Specific Information / Service Information) from the transport stream obtained by the digital tuner 215 and outputs the PSI / SI (Program Specific Information / Service Information) to the CPU 221. A plurality of channels are multiplexed in the transport stream obtained by the digital tuner 215. The process of extracting the partial TS of an arbitrary channel from the transport stream by the demultiplexer 216 can be performed by obtaining the packet ID (PID) information of the arbitrary channel from the PSI / SI (PAT / PMT). ..

The CPU 221 and the flash ROM 222, the DRAM 223, the demultiplexer 216, the Ethernet interface 224, and the recording unit interface 218 are connected to the internal bus 217. The DVD / BD drive 219 and the HDD 220 are connected to the internal bus 217 via the recording unit interface 218. The DVD / BD drive 219 and HDD 220 record the partial TS extracted by the demultiplexer 216. Further, each of the DVD / BD drive 219 and the HDD 220 reproduces the partial TS recorded on the recording medium.

The MPEG decoder 227 performs decoding processing on the video PES packets that constitute the partial TS extracted by the demultiplexer 216 or reproduced by the DVD / BD drive 219 or the HDD 220 to obtain video data. Further, the MPEG decoder 227 decodes the audio PES packets constituting the partial TS to obtain audio data.

The graphic generation circuit 228 performs a graphic data superimposition processing or the like on the video data obtained by the MPEG decoder 227 as necessary. The video output terminal 229 outputs video data output from the graphic generation circuit 228. The audio output terminal 230 outputs the audio data obtained by the MPEG decoder 227.

The DTCP circuit 226 encrypts the partial TS extracted by the demultiplexer 216 or the partial TS reproduced by the DVD / BD drive 219 or the HDD 220, if necessary. Further, the DTCP circuit 226 decrypts the encrypted data supplied from the network terminal 225 or the high-speed data line interface 213 to the Ethernet interface 224.

The CPU 221 controls the operation of each part of the disc recorder 210. The flash ROM 222 stores control software and data. The DRAM 223 constitutes a work area of the CPU 221. The CPU 221 expands the software and data read from the flash ROM 222 on the DRAM 223 to activate the software, and controls each part of the disk recorder 210.

The operation of the disc recorder 210 shown in FIG. 2 will be briefly described.

The television broadcast signal input to the antenna terminal 214 is supplied to the digital tuner 215. The digital tuner 215 processes the television broadcast signal to extract a predetermined transport stream, which is supplied to the demultiplexer 216. In this demultiplexer 216, partial TS (TS packet of video data, TS packet of audio data) corresponding to a predetermined channel is extracted from the transport stream. This partial TS is supplied to the DVD / BD drive 219 or the HDD 220 via the recording unit interface 218, and is recorded based on the recording instruction from the CPU 221.

Further, as described above, the partial TS extracted by the demultiplexer 216 or the partial TS reproduced by the DVD / BD drive 219 or the HDD 220 is supplied to the MPEG decoder 227. In this MPEG decoder 227, video data is obtained by performing decoding processing on a video PES packet composed of TS packets of video data. This video data is output to the video output terminal 229 after the graphics data is superimposed and processed by the graphic generation circuit 228. Further, in the MPEG decoder 227, the audio PES packet composed of the TS packet of the audio data is decoded to obtain the audio data. This audio data is output to the audio output terminal 230.

The video (image) data and audio data obtained by the MPEG decoder 227 corresponding to the partial TS reproduced by the DVD / BD drive 219 or the HDD 220 are supplied to the HDMI transmission unit 212 and are connected to the HDMI terminal 211. Delivered to the cable.

The high-speed data line interface 213 receives an IP packet including a remote control code transmitted through a predetermined line of the HDMI cable connected to the HDMI terminal 211. This IP packet is supplied to the CPU 221 via the Ethernet interface 224. When the remote control code included in the IP packet is related to the control of the disc recorder 210, the CPU 221 controls each part of the disc recorder 210 based on the remote control code.

Further, when the partial TS extracted by the demultiplexer 216 or the partial TS reproduced by the DVD / BD drive 219 or the HDD 220 is sent to the network, the partial TS is encrypted by the DTCP circuit 226. After that, it is output to the network terminal 225 via the Ethernet interface 224.

FIG. 3 shows a configuration example of the television receiver 250. The television receiver 250 includes an HDMI terminal 251, an HDMI receiver 252, a high-speed data line interface 253, an antenna terminal 257, a digital tuner 258, a demultiplexer 259, and an MPEG (Moving Picture Expert Group) decoder 260. , Video / graphic processing circuit 261, panel drive circuit 262, display panel 263, audio signal processing circuit 264, audio amplifier circuit 265, speaker 266, DTCP circuit 267, internal bus 270, CPU 271 and so on. It has a flash ROM 272, a DRAM 273, an Ethernet interface (Ethernet I / F) 274, a network terminal 275, a remote control receiver 276, and a remote control transmitter 277.

The antenna terminal 257 is a terminal for inputting a television broadcast signal received by a receiving antenna (not shown). The digital tuner 258 processes the television broadcast signal input to the antenna terminal 257 and outputs a predetermined transport stream corresponding to the user's selected channel. The demultiplexer 259 extracts a partial TS (Transport Stream) (TS packet of video data, TS packet of audio data) corresponding to the user's selected channel from the transport stream obtained by the digital tuner 258.

Further, the demultiplexer 259 extracts PSI / SI (Program Specific Information / Service Information) from the transport stream obtained by the digital tuner 258 and outputs the PSI / SI (Program Specific Information / Service Information) to the CPU 271. A plurality of channels are multiplexed in the transport stream obtained by the digital tuner 258. The process of extracting the partial TS of an arbitrary channel from the transport stream by the demultiplexer 259 can be performed by obtaining the packet ID (PID) information of the arbitrary channel from the PSI / SI (PAT / PMT). ..

The MPEG decoder 260 obtains video data by decoding a video PES (Packetized Elementary Stream) packet composed of TS packets of video data obtained by the demultiplexer 259. Further, the MPEG decoder 260 obtains audio data by performing decoding processing on an audio PES packet composed of TS packets of audio data obtained by the demultiplexer 259. If necessary, the MPEG decoder 260 performs decoding processing on the video and audio PES packets obtained by decoding with the DTCP circuit 267 to obtain video data and audio data.

The video / graphic processing circuit 261 performs multi-screen processing, graphics data superimposition processing, and the like on the video data obtained by the MPEG decoder 260, if necessary. The panel drive circuit 262 drives the display panel 263 based on the video data output from the video / graphic processing circuit 261. The display panel 263 is composed of, for example, an LCD (Liquid Crystal Display), a PDP (Plasma Display Panel), or the like. The audio signal processing circuit 264 performs necessary processing such as D / A conversion on the audio data obtained by the MPEG decoder 260. The audio amplifier circuit 265 amplifies the audio signal output from the audio signal processing circuit 264 and supplies it to the speaker 266.

The DTCP circuit 267 encrypts the partial TS extracted by the demultiplexer 259, if necessary. Further, the DTCP circuit 267 decrypts the encrypted data supplied from the network terminal 275 or the high-speed data line interfaces 253 and 256 to the Ethernet interface 274.

The CPU 271 controls the operation of each part of the television receiver 250. The flash ROM 272 stores the control software and data. The DRAM 273 constitutes the work area of the CPU 271. The CPU 271 expands the software and data read from the flash ROM 272 on the DRAM 273 to activate the software, and controls each part of the television receiver 250. The remote control receiver 276 receives the remote control signal (remote control code) transmitted from the remote control transmitter 277 and supplies the remote control signal (remote control code) to the CPU 271. The CPU 271, the flash ROM 272, the DRAM 273, and the Ethernet interface 274 are connected to the internal bus 270.

The HDMI receiving unit (HDMI sync) 252 receives baseband video (image) and audio data supplied to the HDMI terminal 251 by HDMI-compliant communication. The details of the HDMI receiving unit 252 will be described later. The high-speed data line interface 253 is a bidirectional communication interface using a predetermined line (reserve line, HPD line in this embodiment) constituting the HDMI cable. Details of this high-speed data line interface 253 will be described later.

The operation of the television receiver 250 shown in FIG. 3 will be briefly described.

The television broadcast signal input to the antenna terminal 157 is supplied to the digital tuner 258. The digital tuner 258 processes the television broadcast signal to output a predetermined transport stream corresponding to the user's selected channel, and the predetermined transport stream is supplied to the demultiplexer 259. In this demultiplexer 259, a partial TS (TS packet of video data, TS packet of audio data) corresponding to the user's selected channel is extracted from the transport stream, and the partial TS is supplied to the MPEG decoder 260.

In the MPEG decoder 260, the video PES packet composed of the TS packet of the video data is decoded to obtain the video data. This video data is supplied to the panel drive circuit 262 after the video / graphic processing circuit 261 performs multi-screen processing, graphics data superimposition processing, and the like as necessary. Therefore, an image corresponding to the user's selected channel is displayed on the display panel 263.

Further, in the MPEG decoder 260, the audio PES packet composed of the TS packet of the audio data is decoded to obtain the audio data. This voice data is supplied to the speaker 266 after being subjected to necessary processing such as D / A conversion by the voice signal processing circuit 264 and further amplified by the voice amplification circuit 265. Therefore, the speaker 266 outputs the sound corresponding to the user's selected channel.

When the partial TS extracted by the demultiplexer 259 is sent to the network at the time of receiving the above-mentioned television broadcast signal, the partial TS is encrypted by the DTCP circuit 267 and then is encrypted by the DTCP circuit 267, and then the network terminal is used via the Ethernet interface 274. It is output to 275.

The remote control receiver 276 receives the remote control code (remote control signal) transmitted from the remote control transmitter 277, and the remote control code is supplied to the CPU 271. When the remote control code is related to the control of the television receiver 250, the CPU 271 controls each part of the television receiver 250 based on the remote control code.

Further, the CPU 271 generates an IP packet including a remote control code supplied from the remote control receiving unit 276. This IP packet is output to the HDMI terminal 251 via the Ethernet interface 274 and the high-speed data line interface 253.

In addition, this IP packet is sent to the network as needed. In that case, the IP packet is output to the network terminal 275 via the Ethernet interface 274. Further, this IP packet is output to the HDMI terminal 251 via the Ethernet interface 274 and the high-speed data line interface 253.

The encrypted partial TS supplied from the network terminal 275 to the Ethernet interface 274 or supplied from the HDMI terminal 251 to the Ethernet interface 274 via the high-speed data line interface 253 is decrypted by the DTCP circuit 267. After being converted, it is supplied to the MPEG decoder 260. After that, the operation is the same as when the television broadcast signal is received, the image is displayed on the display panel 263, and the sound is output from the speaker 266.

Further, the HDMI receiving unit 252 acquires video (image) data and audio data input to the HDMI terminal 251 through the HDMI cable. The video data and the audio data are supplied to the video / graphic processing circuit 261 and the audio signal processing circuit 264, respectively. After that, the operation is the same as when the television broadcast signal is received, the image is displayed on the display panel 263, and the sound is output from the speaker 266.

FIG. 4 shows a configuration example of the HDMI transmission unit (HDMI source) 212 of the disc recorder 210 and the HDMI reception unit (HDMI sync) 252 of the television receiver 250 in the AV system 200 of FIG.

The HDMI source 212 is an effective image section (hereinafter, also appropriately referred to as an active video section) which is a section excluding the horizontal blanking interval and the vertical blanking interval from the section from one vertical synchronization signal to the next vertical synchronization signal. In the above, the differential signal corresponding to the pixel data of the image of one uncompressed screen is transmitted in one direction to the HDMI sink 252 by a plurality of channels, and at least the image in the horizontal blanking interval or the vertical blanking interval. Differential signals corresponding to voice data, control data, other auxiliary data, etc. accompanying the image are transmitted in one direction to the HDMI sink 252 via a plurality of channels.

That is, the HDMI source 212 has a transmitter 81. The transmitter 81 converts, for example, pixel data of an uncompressed image into a corresponding differential signal, and is connected via an HDMI cable 350 with three TMDS channels # 0, # 1, and # 2, which are a plurality of channels. Serial transmission is performed in one direction to the HDMI sink 252.

Further, the transmitter 81 converts audio data accompanying the uncompressed image, necessary control data and other auxiliary data into corresponding differential signals, and three TMDS channels # 0, # 1, #. Serial transmission is performed in one direction to the HDMI sink 252 connected via the HDMI cable 350 in 2.

Further, the transmitter 81 transmits the pixel clock synchronized with the pixel data transmitted through the three TMDS channels # 0, # 1, and # 2 to the HDMI sink 252 connected via the HDMI cable 350 via the TMDS clock channel. To do. Here, in one TMDS channel #i (i = 0,1,2), 10-bit pixel data is transmitted during one pixel clock.

The HDMI sync 252 receives the differential signal corresponding to the pixel data transmitted in one direction from the HDMI source 212 on a plurality of channels in the active video section, and in the horizontal blanking interval or vertical blanking interval. , Receives differential signals corresponding to audio data and control data transmitted in one direction from the HDMI source 212 on a plurality of channels.

That is, the HDMI sink 252 has a receiver 82. The receiver 82 is a differential signal corresponding to pixel data and audio data transmitted in one direction from the HDMI source 212 connected via the HDMI cable 350 on TMDS channels # 0, # 1 and # 2. And the differential signal corresponding to the control data is received in synchronization with the pixel clock transmitted from the HDMI source 212 on the TMDS clock channel.

In order to serially transmit pixel data and audio data in one direction from the HDMI source 212 to the HDMI sink 252 in the transmission channel of the HDMI system consisting of the HDMI source 212 and the HDMI sink 252 in synchronization with the pixel clock. In addition to the three TMDS channels # 0 to # 2 as transmission channels and the TMDS clock channel as a transmission channel for transmitting a pixel clock, there are transmission channels called DDC (Display Data Channel) 83 and CEC line 84.

The DDC 83 is composed of two signal lines (not shown) included in the HDMI cable 350, and the HDMI source 212 outputs an E-EDID (Enhanced Extended Display Identification Data) from the HDMI sink 252 connected via the HDMI cable 350. Used to read.

That is, the HDMI sink 252 has an EDID ROM (Read Only Memory) 85 that stores E-EDID, which is performance information related to its own performance (Configuration / capability), in addition to the HDMI receiver 81. The HDMI source 212 reads the E-EDID of the HDMI sink 252 from the HDMI sink 252 connected via the HDMI cable 350 via the DDC 83, and sets the performance of the HDMI sink 252 based on the E-EDID. That is, for example, an electronic device having an HDMI sink 252 recognizes an image format (profile) supported by, for example, RGB, YCbCr4: 4: 4, YCbCr4: 2: 2, and the like.

The CEC line 84 consists of a single signal line (not shown) included in the HDMI cable 350, and is used for bidirectional communication of control data between the HDMI source 212 and the HDMI sink 252.

Further, the HDMI cable 350 includes a line (HPD line) 86 connected to a pin called HPD (Hot Plug Detect). The source device can detect the connection of the sink device by using the line 86. The HDMI cable 350 also includes a line 87 used to supply power from the source device to the sink device. Further, the HDMI cable 351 includes a reserve line 88.

FIG. 5 shows a configuration example of the HDMI transmitter 81 and the HDMI receiver 82 of FIG.

The transmitter 81 has three encoders / serializers 81A, 81B and 81C corresponding to the three TMDS channels # 0, # 1 and # 2, respectively. Then, each of the encoder / serializers 81A, 81B, and 81C encodes the image data, auxiliary data, and control data supplied thereto, converts the parallel data into serial data, and transmits the differential signal. Here, when the image data has, for example, three components of R (red), G (green), and B (blue), the B component (B component) is supplied to the encoder / serializer 81A, and the G component (G component) is It is supplied to the encoder / serializer 81B, and the R component is supplied to the encoder / serializer 81C.

Further, the auxiliary data includes, for example, voice data and a control packet, the control packet is supplied to, for example, the encoder / serializer 81A, and the voice data is supplied to the encoder / serializer 81B, 81C.

Further, the control data includes a 1-bit vertical synchronization signal (VSYNC), a 1-bit horizontal synchronization signal (HSYNC), and 1-bit control bits CTL0, CTL1, CTL2, and CTL3, respectively. The vertical sync signal and the horizontal sync signal are supplied to the encoder / serializer 81A. The control bits CTL0 and CTL1 are supplied to the encoder / serializer 81B, and the control bits CTL2 and CTL3 are supplied to the encoder / serializer 81C.

The encoder / serializer 81A transmits the B component of the image data supplied thereto, the vertical synchronization signal and the horizontal synchronization signal, and the auxiliary data in a time division manner. That is, the encoder / serializer 81A sets the B component of the image data supplied therein as parallel data in units of 8 bits, which is a fixed number of bits. Further, the encoder / serializer 81A encodes the parallel data, converts it into serial data, and transmits it on TMDS channel # 0.

Further, the encoder / serializer 81A encodes the 2-bit parallel data of the vertical synchronization signal and the horizontal synchronization signal supplied therein, converts them into serial data, and transmits the serial data on the TMDS channel # 0. Further, the encoder / serializer 81A sets the auxiliary data supplied to the encoder / serializer 81A as parallel data in units of 4 bits. Then, the encoder / serializer 81A encodes the parallel data, converts it into serial data, and transmits it on TMDS channel # 0.

The encoder / serializer 81B transmits the G component of the image data supplied thereto, the control bits CTL0 and CTL1, and the auxiliary data in a time division manner. That is, the encoder / serializer 81B sets the G component of the image data supplied to the encoder / serializer 81B as parallel data in units of 8 bits, which is a fixed number of bits. Further, the encoder / serializer 81B encodes the parallel data, converts it into serial data, and transmits it on TMDS channel # 1.

Further, the encoder / serializer 81B encodes the 2-bit parallel data of the control bits CTL0 and CTL1 supplied to the encoder / serializer 81B, converts the data into serial data, and transmits the data on the TMDS channel # 1. Further, the encoder / serializer 81B sets the auxiliary data supplied to the encoder / serializer 81B as parallel data in units of 4 bits. Then, the encoder / serializer 81B encodes the parallel data, converts it into serial data, and transmits it on the TMDS channel # 1.

The encoder / serializer 81C transmits the R component of the image data supplied thereto, the control bits CTL2 and CTL3, and the auxiliary data in a time division manner. That is, the encoder / serializer 81C sets the R component of the image data supplied to the encoder / serializer 81C to parallel data in units of 8 bits, which is a fixed number of bits. Further, the encoder / serializer 81C encodes the parallel data, converts it into serial data, and transmits it on TMDS channel # 2.

Further, the encoder / serializer 81C encodes the 2-bit parallel data of the control bits CTL2 and CTL3 supplied to the encoder / serializer 81C, converts the data into serial data, and transmits the data on the TMDS channel # 2. Further, the encoder / serializer 81C sets the auxiliary data supplied to the encoder / serializer 81C as parallel data in units of 4 bits. Then, the encoder / serializer 81C encodes the parallel data, converts it into serial data, and transmits it on TMDS channel # 2.

The receiver 82 has three recovery / decoders 82A, 82B, 82C corresponding to the three TMDS channels # 0, # 1, # 2, respectively. Then, each of the recovery / decoders 82A, 82B, and 82C receives image data, auxiliary data, and control data transmitted by differential signals on TMDS channels # 0, # 1, and # 2. Further, each of the recovery / decoders 82A, 82B, and 82C converts image data, auxiliary data, and control data from serial data to parallel data, further decodes the data, and outputs the data.

That is, the recovery / decoder 82A receives the B component, the vertical synchronization signal, the horizontal synchronization signal, and the auxiliary data of the image data transmitted by the differential signal on the TMDS channel # 0. Then, the recovery / decoder 82A converts the B component of the image data, the vertical synchronization signal, the horizontal synchronization signal, and the auxiliary data from the serial data to the parallel data, decodes the data, and outputs the data.

The recovery / decoder 82B receives the G component of the image data transmitted by the differential signal on the TMDS channel # 1, the control bits CTL0 and CTL1, and the auxiliary data. Then, the recovery / decoder 82B converts the G component of the image data, the control bits CTL0, CTL1, and the auxiliary data from the serial data to the parallel data, decodes the data, and outputs the data.

The recovery / decoder 82C receives the R component of the image data transmitted by the differential signal on the TMDS channel # 2, the control bits CTL2 and CTL3, and the auxiliary data. Then, the recovery / decoder 82C converts the R component of the image data, the control bits CTL2 and CTL3, and the auxiliary data from the serial data to the parallel data, decodes the data, and outputs the data.

FIG. 6 shows an example of a transmission section (period) in which various transmission data are transmitted on the three TMDS channels # 0, # 1, and # 2 of HDMI. Note that FIG. 6 shows various transmission data sections when a progressive image having 720 × 480 pixels in width × length is transmitted in TMDS channels # 0, # 1 and # 2.

In the video field (Video Field) in which transmission data is transmitted through the three TMDS channels # 0, # 1 and # 2 of HDMI, a video data period and a data island section (Video Data period) and a data island section ( There are three types of sections: Data Island period) and Control period.

Here, the video field section is a section from the rising edge of a vertical synchronization signal to the rising edge of the next vertical synchronization signal, and is a horizontal blanking period (horizontal blanking) and a vertical blanking period (vertical blanking). , And the video field section is divided into an active video section (Active Video), which is a section excluding the horizontal blanking period and the vertical blanking period.

The video data section is assigned to the active video section. In this video data section, data of 720 pixels × 480 lines of active pixels constituting uncompressed image data for one screen is transmitted.

Data island sections and control sections are assigned to horizontal and vertical blanking periods. Auxiliary data is transmitted in the data island section and the control section.

That is, the data island section is allocated as part of the horizontal blanking period and the vertical blanking period. In this data island section, among auxiliary data, data not related to control, for example, voice data packets and the like are transmitted.

Control sections are assigned to the horizontal blanking period and the rest of the vertical blanking period. In this control section, data related to control among auxiliary data, for example, a vertical synchronization signal, a horizontal synchronization signal, a control packet, and the like are transmitted.

Here, in the current HDMI, the frequency of the pixel clock transmitted by the TMDS clock channel is, for example, 165 MHz, and in this case, the transmission rate of the data island section is about 500 Mbps.

FIG. 7 shows the pin arrangement of HDMI terminals 211 and 251. This pin arrangement is called type A (type-A).

The two lines that are the differential lines through which TMDS Data # i +, which is the differential signal of TMDS channel # i, and TMDS Data # i- are transmitted, are the pins to which TMDS Data # i + is assigned (pin number is 1). , 4, 7 pins) and the pins to which TMDS Data # i- are assigned (pins with pin numbers 3, 6, 9) are connected.

Further, the CEC line 84 through which the CEC signal which is the control data is transmitted is connected to the pin having the pin number 13, and the pin having the pin number 14 is a reserved pin. Further, a line through which an SDA (Serial Data) signal such as E-EDID is transmitted is connected to a pin having a pin number of 16 and is an SCL (Serial Clock) signal which is a clock signal used for synchronization at the time of transmission / reception of the SDA signal. Is connected to the pin whose pin number is 15. The above-mentioned DDC83 is composed of a line through which an SDA signal is transmitted and a line through which an SCL signal is transmitted.

Further, as described above, the HPD line 86 for the source device to detect the connection of the sink device is connected to the pin having the pin number 19. Further, as described above, the line 87 for supplying power is connected to the pin having the pin number 18.

FIG. 8 shows a configuration example of the high-speed data line interface 213 of the disk recorder 210 and the high-speed data line interface 253 of the television receiver 250 in the AV system 200 of FIG. These interfaces 213 and 253 constitute a communication unit that performs LAN (Local Area Network) communication. This communication unit is a pair of differential lines among a plurality of lines constituting the HDMI cable 350, and in this embodiment, a reserve line (Ether-line) corresponding to a reserve pin (14 pins). , And the HPD line (Ether + line) corresponding to the HPD pin (19 pin) is used for bidirectional communication.

The disk recorder 210 includes a LAN signal transmission circuit 411, a terminating resistor 412, an AC coupling capacitance 413, 414, a LAN signal reception circuit 415, and a subtraction circuit 416, which constitute a high-speed data line interface 213.

A series circuit of an AC coupling capacitance 413, a terminating resistor 412, and an AC coupling capacitance 414 is connected between pins 14 and 19 of the HDMI terminal 211. The connection points P1 of the AC coupling capacitance 413 and the terminating resistor 412 are connected to the positive output side of the LAN signal transmission circuit 411 and to the positive input side of the LAN signal reception circuit 415. Further, the connection points P2 of the AC coupling capacitance 414 and the terminating resistor 412 are connected to the negative output side of the LAN signal transmission circuit 411 and to the negative input side of the LAN signal reception circuit 415. A transmission signal (transmission data) SG411 is supplied to the input side of the LAN signal transmission circuit 411.

Further, the output signal SG412 of the LAN signal receiving circuit 415 is supplied to the positive terminal of the subtraction circuit 416, and the transmission signal (transmission data) SG411 is supplied to the negative terminal of the subtraction circuit 416. In this subtraction circuit 416, the transmission signal SG411 is subtracted from the output signal SG412 of the LAN signal reception circuit 415, and the reception signal (reception data) SG413 is obtained.

The television receiver 250 includes a LAN signal transmission circuit 441, a terminating resistor 442, an AC coupling capacitance of 443, 444, a LAN signal reception circuit 445, and a subtraction circuit 446, which constitute a high-speed data line interface 253. Further, the television receiver 250 has pull-up resistors 447 and 448.

A series circuit having an AC coupling capacitance 443, a terminating resistor 442, and an AC coupling capacitance 444 is connected between pins 14 and 19 of the HDMI terminal 251. The connection points P3 of the AC coupling capacitance 443 and the terminating resistor 442 are connected to the positive output side of the LAN signal transmission circuit 441 and to the positive input side of the LAN signal reception circuit 445. Further, the connection points P4 of the AC coupling capacitance 444 and the terminating resistor 442 are connected to the negative output side of the LAN signal transmission circuit 441 and to the negative input side of the LAN signal reception circuit 445. A transmission signal (transmission data) SG417 is supplied to the input side of the LAN signal transmission circuit 441.

Further, the output signal SG418 of the LAN signal receiving circuit 445 is supplied to the positive terminal of the subtraction circuit 446, and the transmission signal SG417 is supplied to the negative terminal of the subtraction circuit 446. In this subtraction circuit 446, the transmission signal SG417 is subtracted from the output signal SG418 of the LAN signal reception circuit 445, and the reception signal (reception data) SG419 is obtained.

Further, pin 19 of the HDMI terminal 251 is connected to the power supply line (+ 5.0V) via a pull-up resistor 447. Further, since the television receiver 250 is an eHDMI compatible device, pin 14 of the HDMI terminal 251 is connected to a power supply line (+ 5.0V) via a pull-up resistor 448.

The reserve line 501 and HPD line 502 included in the HDMI cable 350 form a differential twisted pair. The source side end 511 of the reserve line 501 is connected to pin 14 of the HDMI terminal 211, and the sink side end 521 of the reserve line 501 is connected to pin 14 of the HDMI terminal 251. Further, the source side end 512 of the HPD line 502 is connected to pin 19 of the HDMI terminal 211, and the sink side end 522 of the HPD line 502 is connected to pin 19 of the HDMI terminal 251.

Next, the operation of LAN communication by the high-speed data line interfaces 213 and 253 configured as described above will be described.

In the disk recorder 210, the transmission signal (transmission data) SG411 is supplied to the input side of the LAN signal transmission circuit 411, and the differential signal (positive output signal, negative output signal) corresponding to the transmission signal SG411 is supplied from the LAN signal transmission circuit 411. Is output. Then, the differential signal output from the LAN signal transmission circuit 411 is supplied to the connection points P1 and P2 and transmitted to the television receiver 250 through a pair of lines (reserve line 501, HPD line 502) of the HDMI cable 350. Will be done.

Further, in the television receiver 250, the transmission signal (transmission data) SG417 is supplied to the input side of the LAN signal transmission circuit 441, and the differential signal (positive output signal, negative) corresponding to the transmission signal SG417 from the LAN signal transmission circuit 441. Output signal) is output. Then, the differential signal output from the LAN signal transmission circuit 441 is supplied to the connection points P3 and P4, and is transmitted to the disk recorder 210 through a pair of lines (reserve line 501, HPD line 502) of the HDMI cable 350. To.

Further, in the disk recorder 210, since the input side of the LAN signal receiving circuit 415 is connected to the connection points P1 and P2, it is output from the LAN signal transmitting circuit 411 as the output signal SG412 of the LAN signal receiving circuit 415. An additional signal of a transmission signal corresponding to the differential signal (current signal) and a reception signal corresponding to the differential signal transmitted from the television receiver 250 as described above can be obtained. In the subtraction circuit 416, the transmission signal SG411 is subtracted from the output signal SG412 of the LAN signal reception circuit 415. Therefore, the output signal SG413 of the subtraction circuit 416 corresponds to the transmission signal (transmission data) SG417 of the television receiver 250.

Further, in the television receiver 250, since the input side of the LAN signal receiving circuit 445 is connected to the connection points P3 and P4, it is output from the LAN signal transmitting circuit 441 as the output signal SG418 of the LAN signal receiving circuit 445. An additional signal of a transmission signal corresponding to the differential signal (current signal) and a reception signal corresponding to the differential signal transmitted from the disc recorder 210 as described above can be obtained. In the subtraction circuit 446, the transmission signal SG417 is subtracted from the output signal SG418 of the LAN signal reception circuit 445. Therefore, the output signal SG419 of the subtraction circuit 446 corresponds to the transmission signal (transmission data) SG411 of the disc recorder 210.

In this way, bidirectional LAN communication can be performed between the high-speed data line interface 213 of the disc recorder 210 and the high-speed data line interface 253 of the television receiver 250.

In the television receiver 250, pin 19 of the HDMI terminal 251 is connected to the power supply line (+ 5.0V). Therefore, when the television receiver 250 is connected to the disc recorder 210 via the HDMI cable 350, the voltage Vhpd of pin 19 of the HDMI terminal 211 becomes high. Therefore, the disc recorder 210 can detect whether or not the television receiver 250 is connected to the disc recorder 210 via the HDMI cable 350 by monitoring the voltage Vrsv of pin 19 of the HDMI terminal 211.

Further, in the television receiver 250, pin 14 of the HDMI terminal 251 is connected to the power supply line (+ 5.0V). Therefore, when the television receiver 250 is connected to the disc recorder 210 via the HDMI cable 350, the voltage Vhpd of pin 14 of the HDMI terminal 211 becomes high. Therefore, the disc recorder 210 can recognize that the television receiver 250 is an eHDMI compatible device by monitoring the voltage Vhpd of pin 14 of the HDMI terminal 211.

In this embodiment, the television receiver 250 can recognize that the disc recorder 210 is an eHDMI compatible device. The method will be described below.

The disc recorder 210 is, for example, an eHDMI compatible device when the television receiver 250 is connected to the disc recorder 210 via the HDMI cable 350, that is, the disk recorder 210 is composed of a reserve line and an HPD line of the HDMI cable 350. Functional information indicating that it has a communication unit (high-speed data line interface 213, etc.) that uses a communication path is transmitted to the television receiver 250. Further, the disc recorder 210 includes information on a transmission format (application) that the disc recorder 210 can support in this functional information.

Here, the transmission format information is information on whether it corresponds only to the SPDIF (Sony Philips Digital InterFace) signal, only the Ethernet signal, or both the SPDIF signal and the Ethernet signal. ..

Here, the SPDIF signal will be briefly described. This SPDIF signal is a signal transmitted in the SPDIF standard. The SPDIF standard is an interface standard for transmitting digital audio signals in real time. Since the SPDIF signal is biphase mark modulated, it contains a clock component in the signal.

The configuration example of FIG. 8 described above shows a case where only the Ethernet signal is supported. When the SPDIF signal is also supported, the configuration example is as shown in FIG. The television receiver 250 has an SPDIF transmission circuit 449. The SPDIF signal output from the SPDIF transmission circuit 449 is transmitted in phase to the disc recorder 210 side by the adders 451 and 452 using the reserve line and the HPD line constituting the HDMI cable 350. Here, the SPDIF transmission circuit 449 constitutes a communication unit that communicates using a communication path composed of a reserve line and an HPD line, similarly to the high-speed data line interface 253.

Further, the disc recorder 210 has an SPDIF receiving circuit 417. The SPDIF signal transmitted in phase from the television receiver 250 side by the reserve line and the HPD line constituting the HDMI cable 350 is added by the adder 421 and supplied to the SPDIF receiving circuit 417. Here, the SPDIF receiving circuit 417 constitutes a communication unit that communicates using a communication path composed of a reserve line and an HPD line, similarly to the high-speed data line interface 213.

When only the SPDIF signal is supported, the configuration example shown in FIG. 9 excludes the high-speed data interfaces 213 and 253.

For example, the disc recorder 210 transmits the functional information to the television receiver 250 by inserting the functional information described above into the blanking period of the video signal transmitted to the television receiver 250 on the TMDS channel described above. Here, the disc recorder 210 inserts the above-mentioned functional information into the blanking period of the video signal by using, for example, an HDMI (Auxiliary Video Information) InfoFrame packet.

This AVI InfoFrame packet is placed in the data island section described above. FIG. 10 shows the data structure of an AVI InfoFrame packet. In HDMI, incidental information related to an image can be transmitted from a source device to a sink device by the AVIInfoFrame packet.

In this embodiment, the functional information includes, for example, 1 bit of E1 in the 4th byte (Data Byte 1) and E2 and E3 in the 8th byte (Data Byte 5), as shown in FIG. 10 showing the data structure of the AVI InfoFrame. It is arranged hierarchically in 2 bits of.

The 1-bit data E1 is an eHDMI compatible device having a communication unit (high-speed data interface 213, SPDIF receiving circuit 417) that communicates via a communication path composed of a reserve line of an HDMI cable 350 and an HPD line. It is data for identifying whether or not there is. Here, when E1 = 0, it indicates that the device is not an eHDMI compatible device, and when E1 = 1, it indicates that the device is an eHDMI compatible device.

Further, the bits for identifying whether the 2-bit data E2 and E3 correspond only to the SPDIF signal, only the Ethernet signal, or both the SPDIF signal and the Ethernet signal. It is data. For example, when E2 = 1 and E3 = 0, it indicates that only the SPDIF signal is supported, and when E2 = 0 and E3 = 1, it indicates that only the Ethernet signal is supported, and E2 = When 1 and E3 = 1, it indicates that both the SPDIF signal and the Ethernet signal are supported.

When the disc recorder 210 transmits the functional information to the television receiver 250 by inserting the functional information during the blanking period of the video signal transmitted to the television receiver 250 on the TMDS channel as described above, the television receiver In the 250, the functional information is received by extracting the above-mentioned functional information from the blanking period of the video signal received from the disc recorder 210 on the TMDS channel.

In the above description, the function information is inserted into the blanking period of the video signal using the AVIInfoFrame packet. Although detailed description is omitted, functional information can be inserted into the blanking period of the video signal by using other packets such as GCP packets.

Further, for example, the disc recorder 210 transmits the above-mentioned functional information to the television receiver 250 via the CEC line 84, which is the control data line of the HDMI cable 350. In this case, the television receiver 250 receives the functional information from the disc recorder 210 via the CEC line 84.

As described above, the television receiver 250 receives the functional information to determine whether or not the disc recorder 210 is an eHDMI compatible device, and a transmission format (application) that can be supported when the disk recorder 210 is an eHDMI compatible device. Can be recognized. As described above, when the functional information is transmitted from the disc recorder 210 to the television receiver 250, the HDMI transmitter 212 of the disc recorder 210 constitutes the functional information transmitter, and the HDMI receiver 252 of the television receiver 250 It constitutes a functional information receiver.

In the above description, when the TV receiver 250 is connected to the disc recorder 210 via the HDMI cable 350, the disc recorder 210 automatically transmits the function information to the TV receiver 250. However, the television receiver 250 transmits a transmission request for the functional information to the disc recorder 210, and the disc recorder 210 transmits the functional information to the television receiver 250 when the transmission request is received. May be good.

The television receiver 250 transmits the transmission request to the disc recorder 210 via the CEC line 84, for example, when the television receiver 250 switches the HDMI input at the time of power-on. In this case, the HDMI receiving unit 253 of the television receiver 250 constitutes a function information requesting unit, and the HDMI transmitting unit 213 of the disc recorder 210 constitutes a transmitting request receiving unit.

In this way, when the television receiver 250 transmits a transmission request to the disc recorder 210, the television receiver 250 uses the disc recorder 210 at an arbitrary timing (for example, when the power is turned on, when the input is switched, etc.). It is possible to confirm whether or not the device is an eHDMI compatible device, and further confirm the transmission format (application) supported by the disc recorder 210.

In the above description, an example of transmitting functional information from the disc recorder 210 to the television receiver 250 has been described. On the contrary, it is also conceivable to transmit the function information from the television receiver 250 to the disc recorder 210 in the same manner as described above. In this case, the functional information cannot be inserted and transmitted during the blanking period of the video signal, but the functional information can be transmitted via the CEC line 84, which is a control data line. In this case, the HDMI transmitter 212 of the disc recorder 210 constitutes the functional information receiver, and the HDMI receiver 252 of the television receiver 250 constitutes the functional information transmitter.

Here, transmission / reception of functional information using the CEC line (CEC channel) will be described. In this CEC line, control data can be transmitted in both directions between the source device and the sink device. In the present invention, the above-mentioned functional information is transmitted from the source device to the sink device or from the sink device to the source device as CEC (Consumer Electronics Control) data or CDC (Capability Discovery Channel) data.

FIG. 11 shows the structure of CEC data transmitted on the CEC line. On the CEC line, one block consisting of 10-bit data is transmitted in 4.5 ms. A start bit is arranged at the beginning, a header block is arranged after that, and then an arbitrary number (n) of data blocks including data actually to be transmitted are arranged. The functional information is contained in the data block.

FIG. 12 is a diagram showing a structural example of the header block. In the header block, the logical address (Logical Address) of the source (Initiator) and the logical address (Logical Address) of the destination (Destination) are arranged. Each logical address is set according to the type of each device.

FIG. 13 shows a logical address set according to the type of each device. As shown in FIG. 13, 16 types of address values from "0" to "15" are set for each type of device. A corresponding address value is arranged in 4 bits in the logical address of the source (Initiator) and the logical address of the destination (Destination) constituting the header block of FIG. 12.

Next, the CDC data will be described. The CDC is defined as having the same physical layer as the CEC, but different from the CEC. Although the structure of the CDC data is not shown, it has the same structure as the CEC data structure shown in FIG. 11, and the start bit is arranged at the beginning, the header block is arranged thereafter, and then the actual transmission is desired. The structure is such that an arbitrary number (n) of data blocks including data are arranged.

Although the structure of the CDC data header block is not shown, it is structurally the same as the CEC data header block shown in FIG. However, "15" is always used as the logical address of the source (Initiator) and the logical address of the destination (Destination) constituting the header block, regardless of the type of device. In other words, the source (Initiator) is unknown (Unregistered), and the destination (Destination) is broadcast (Broadcast).

In this way, in the transmission of CDC data, "15" is used as the logical address of the source and destination arranged in the header block, so it is necessary to acquire the logical address of each device. There is no. A message based on CDC data (CDC message) is a broadcast message whose source is unknown to the CEC, and it is unknown which device is the message addressed to which device.

Therefore, in the CDC message, in order to identify the physical connection path, the physical address (Physical Address) of the source (Initiator) and the destination (Target) must be included in the message placed in the data block. To be included. That is, when transmitting a CDC message, a physical address is used instead of a logical address.

The CEC cannot return the &lt;Feature Abort&gt; "It does not support" message for broadcast messages. Therefore, the CDC will always return a message in consideration of this situation.

[CDC message] Here, the &lt;Exchange Supported Channels Info&gt; message and the &lt;Activate Supported Channels&gt; message are defined as command messages to be placed in the data block of the CDC data. The &lt;Exchange SupportedChannels Info&gt; message is a message used when exchanging functional information between two devices. The &lt;Activate Supported Channels&gt; message is a message used when confirming the channels (transmission format) that are actually activated (activated) between the two devices and starting communication. Each message has the following data structure, for example.

<tables num="1"><img id="000002" he="78" wi="159" file="0005572929.tif" img-format="tif" img-content="drawing" /></tables>

Describes the &lt;ExchangeSupported Channels Info&gt; message. This &lt;Exchange Supported Channels Info&gt; message has the first to fifth five bytes of data. The physical address of the source (Initiator) is arranged in the first byte and the second byte, and the physical address of the destination (Target) is arranged in the third and fourth bytes. ..

Further, the function information of the source (Initiator) is arranged in the fifth byte. This functional information is information indicating that the device is an eHDMI compatible device, and includes information on a channel that the device can support, that is, a transmission format (application) that the device can support.

One bit of the 5th byte, for example, the 7th bit (most significant bit), is an eHDMI compatible device and supports the above-mentioned SPDIF signal transmission format (application), that is, [Audio Return Channel]. Indicates whether it is supported or not. One bit of the 5th byte is set to "1" when it is supported, and is set to "0" when it is not supported.

Further, the other 1 bit of the 5th byte, for example, the 6th bit, is an eHDMI compatible device and supports the above-mentioned Ethernet signal transmission format (application), that is, supports [Ethernet Channel]. Indicates whether or not it is. The other 1 bit of the 5th byte is set to "1" when it is supported, and is set to "0" when it is not supported.

Further, the remaining 6 bits of the 5th byte, for example, the 5th bit to the 0th bit are set as reserve bits and are all set to "0".

Next, the &lt;Activate Supported Channels&gt; message will be described. This &lt;Activate Supported Channels&gt; message has the first to fifth five bytes of data. The physical address of the source (Initiator) is arranged in the first byte and the second byte, and the physical address of the destination (Target) is arranged in the third and fourth bytes. ..

In addition, information on the channel (transmission format) that the source (Initiator) requests to start is arranged in the fifth byte. One bit of the fifth byte, for example, the seventh bit, indicates whether or not it requests communication of the SPDIF signal, that is, activation of the channel of [Audio Return Channel]. One bit of the 5th byte is set to "1" when the start is requested, and is set to "0" when the start is not requested.

Further, the other 1 bit of the 5th byte, for example, the 6th bit indicates whether or not the user requests the communication of the Ethernet signal, that is, the activation of the channel of [Ethernet Channel]. The other 1 bit of the 5th byte is set to "1" when the start is requested, and is set to "0" when the start is not requested.

Further, the remaining 6 bits of the 5th byte, for example, the 5th bit to the 0th bit are set as reserve bits and are all set to "0".

The rules for the &lt;Exchange Supported Channels Info&gt; and &lt;Activate Supported Channels&gt; messages described above are defined as follows: That is, when a CDC device broadcasts an &lt;Exchange Supported Channels Info&gt; message, the CDC device with the physical address of the destination included in the message contains its own information (parameters) &lt;Exchange Supported. Channels Info&gt; Broadcast the message.

Also, when a CDC device broadcasts an &lt;Activate Supported Channels&gt; message, the CDC device with the physical address of the destination included in the message contains its own information (parameters) &lt;Activate Supported Channels. &gt; Broadcast the message. Furthermore, when there is a channel (transmission format) supported by both of the [Audio Return Channel] and [Ethernet Channel] channels in the function information exchanged in the &lt;Exchange Supported Channels Info&gt; message, the two devices Communication via that channel is possible between them.

The CDC device means an eHDMI compatible device capable of supporting CDC data (Exchange Supported Channels Info&gt; message, &lt;Activate Supported Channels&gt; message, etc.). On the other hand, the Non-CDC device means an eHDMI compatible device that cannot support CDC data (Exchange Supported Channels Info&gt; message, &lt;Activate Supported Channels&gt; message, etc.).

Exchange Sequence Next, an example of using the &lt;Exchange Supported Channels Info&gt; message will be described with reference to the sequence diagram of FIG. In this case, the AV system 10 having the device configuration shown in FIG. 15 is assumed. That is, the AV system 10 includes CDC devices 11 and 12 and a Non-CDC device 13. The HDMI terminal 11a of the CDC device 11 and the HDMI terminal 12a of the CDC device 12 are connected via the HDMI cable 14. Further, the HDMI terminal 11b of the CDC device 11 and the HDMI terminal 13a of the Non-CDC device 13 are connected via the HDMI cable 15. Further, the physical address of the CDC device 11 is [0.0.0.0], the physical address of the CDC device 12 is [1.0.0.0], and the physical address of the Non-CDC device 13 (Physical). Address) is [2.0.0.0].

Returning to FIG. 14, (a) the CDC device 11 broadcasts an &lt;Exchange Supported Channels Info&gt; message in order to exchange functional information with the CDC device 12. The physical address of the source (Initiator) included in this &lt;Exchange Supported Channels Info&gt; message is [0.0.0.0], and the physical address of the destination (Target) is [1.0.0.0]. In addition, the CDC device 11 includes its own function information in this &lt;Exchange Supported Channels Info&gt; message. For example, this &lt;Exchange Supported Channels Info&gt; message indicates that it supports both AudioReturn Channel and Ethernet Channel channels.

(B) Since the physical address of the destination included in the &lt;Exchange Supported Channels Info&gt; message broadcast from the CDC device 11 is the own physical address [1.0.0.0], the CDC device 12 is &lt;Exchange Supported. ChannelsInfo&gt; Broadcast the message. The physical address of the source (Initiator) included in this &lt;Exchange Supported ChannelsInfo&gt; message is [1.0.0.0], and the physical address of the destination (Target) is [0.0.0.0]. In addition, the CDC device 12 includes its own function information in this &lt;ExchangeSupported Channels Info&gt; message. For example, this &lt;ExchangeSupported Channels Info&gt; message indicates that it supports both Audio Return Channel and Ethernet Channel channels.

In this way, the &lt;Exchange Supported Channels Info&gt; message is transmitted and received between the CDC device 11 and the CDC device 12, and the functional information of each other, that is, whether or not the device is an eHDMI compatible device, is determined by [Audio Return Channel]. ] And [Ethernet Channel] are exchanged to indicate whether or not they are supported.

(C) The CDC device 11 broadcasts an &lt;Exchange Supported Channels Info&gt; message in order to exchange functional information with the Non-CDC device 13. The physical address of the source (Initiator) included in this &lt;Exchange Supported Channels Info&gt; message is [0.0.0.0], and the physical address of the destination (Target) is [2.0.0.0]. In addition, the CDC device 11 includes its own function information in this &lt;Exchange Supported Channels Info&gt; message. For example, this &lt;Exchange Supported Channels Info&gt; message indicates that it supports both AudioReturn Channel and Ethernet Channel channels.

(D) The Non-CDC device 13 does not have any problem even if the physical address of the destination included in the &lt;Exchange Supported Channels Info&gt; message broadcast from the CDC device 11 is its own physical address [2.0.0.0]. no response. In this case, the CDC device 11 supports both [Audio Return Channel] and [Ethernet Channel] when there is no response after 2 seconds according to the 2-second Max rule. Recognize that you have not done so.

[Activate / De-Activate sequence] Next, an example of using the &lt;Activate Supported Channels&gt; message will be described with reference to the sequence diagram of FIG. In this case, in the AV system 10 having the device configuration shown in FIG. 15, communication is performed between the CDC device 11 and the CDC device 12 that exchanged functional information using the &lt;Exchange Supported Channels Info&gt; message as described above. It is supposed to be done.

(a) The CDC device 11 broadcasts an &lt;Activate Supported Channels&gt; message in order to confirm with the CDC device 12 the channels (transmission formats) for which activation is actually requested and to start communication. The physical address of the source (Initiator) included in this &lt;Activate Supported Channels&gt; message is [0.0.0.0], and the physical address of the destination (Target) is [1.0.0.0]. Further, the CDC device 11 arranges the information of the channel (transmission format) for which the CDC device 11 requests activation (Activate) in the &lt;ActivateSupported Channels&gt; message. For example, this &lt;Activate Supported Channels&gt; message indicates that both [AudioReturn Channel] and [Ethernet Channel] channels should be activated.

(B) The CDC device 12 has &lt;Activate Supported Channels&gt; because the physical address of the destination included in the &lt;Activate Supported Channels&gt; message broadcast from the CDC device 11 is its own physical address [1.0.0.0]. &gt; Broadcast the message. The physical address of the source (Initiator) included in this &lt;Activate Supported Channels&gt; message is [1.0.0.0], and the physical address of the destination (Target) is [0.0.0.0]. Further, the CDC device 12 arranges the information of the channel (transmission format) in which the CDC device 12 agrees to the request for activation in the &lt;ActivateSupported Channels&gt; message. For example, this &lt;Activate Supported Channels&gt; message indicates that you agree to the request to activate both the [AudioReturn Channel] and [Ethernet Channel] channels.

In this way, the &lt;Activate Supported Channels&gt; message is transmitted and received between the CDC device 11 and the CDC device 12, so that the channels (transmission format) that can be activated by both can be confirmed and communication can be performed. It will be started. In the example of FIG. 16, both the CDC device 11 and the CDC device 12 can activate [Audio Return Channel] and [Ethernet Channel], both channels (transmission format) are activated, and communication is started. To.

(C) After that, the CDC device 12 broadcasts the &lt;ActivateSupported Channels&gt; message when it wants to stop the communication of the [Ethernet Channel] in order to perform Ethernet communication through the network terminal, for example. The physical address of the source (Initiator) included in this &lt;ActivateSupported Channels&gt; message is [1.0.0.0], and the physical address of the destination (Target) is [0.0.0.0]. Further, the CDC device 12 indicates in this &lt;ActivateSupported Channels&gt; message that the channel (transmission format) for which it is requested to be activated is the channel of [AudioReturn Channel], and the channel of [Ethernet Channel] is excluded. ..

(D) The CDC device 11 has &lt;Activate Supported Channels&gt; because the physical address of the destination included in the &lt;Activate Supported Channels&gt; message broadcast from the CDC device 12 is its own physical address [0.0.0.0]. &gt; Broadcast the message. The physical address of the source (Initiator) included in this &lt;Activate Supported Channels&gt; message is [0.0.0.0], and the physical address of the destination (Target) is [1.0.0.0]. Further, the CDC device 11 arranges the information of the channel (transmission format) in which the CDC device 11 agrees to the request for activation in the &lt;Activate Supported Channels&gt; message. For example, this &lt;Activate Supported Channels&gt; message indicates that you agree to the AudioReturn Channel's request to activate the channel.

In this way, by transmitting and receiving &lt;Activate Supported Channels&gt; messages between the CDC device 11 and the CDC device 12, the transmission format (application) that can be started by both is reconfirmed, and [Ethernet] is confirmed. Communication by the channel of [Channel] is stopped, and communication by the channel of [AudioReturn Channel] is continued.

Next, another usage example of the &lt;Activate Supported Channels&gt; message will be described with reference to the sequence diagram of FIG. In this case, in the AV system 10 having the device configuration shown in FIG. 15, communication is performed between the CDC device 11 and the CDC device 12 that exchanged functional information using the &lt;Exchange Supported Channels Info&gt; message as described above. It is supposed to be done.

(A) The CDC device 11 broadcasts an &lt;Activate Supported Channels&gt; message in order to confirm the channels (transmission format) actually requested to be activated with the CDC device 12 and start communication. The physical address of the source (Initiator) included in this &lt;Activate Supported Channels&gt; message is [0.0.0.0], and the physical address of the destination (Target) is [1.0.0.0]. Further, the CDC device 11 arranges the information of the channel (transmission format) for which the CDC device 11 requests activation in the &lt;ActivateSupported Channels&gt; message. For example, this &lt;Activate Supported Channels&gt; message indicates that both [AudioReturn Channel] and [Ethernet Channel] channels should be activated.

(B) The CDC device 12 has &lt;Activate Supported Channels&gt; because the physical address of the destination included in the &lt;Activate Supported Channels&gt; message broadcast from the CDC device 11 is its own physical address [1.0.0.0]. &gt; Broadcast the message. The physical address of the source (Initiator) included in this &lt;Activate Supported Channels&gt; message is [1.0.0.0], and the physical address of the destination (Target) is [0.0.0.0]. Further, the CDC device 12 arranges the information of the channel (transmission format) in which the CDC device 12 agrees to the request for activation in the &lt;ActivateSupported Channels&gt; message. For example, this &lt;Activate Supported Channels&gt; message indicates that you agree to the AudioReturn Channel's request to activate the channel.

In this way, the &lt;Activate Supported Channels&gt; message is transmitted and received between the CDC device 11 and the CDC device 12, so that the channels (transmission format) that can be activated by both can be confirmed and communication can be performed. It will be started. In the example of FIG. 16, the CDC device 11 requires activation of both the [Audio Return Channel] and [Ethernet Channel] channels, but the CDC device 12 agrees only to activate the [Audio Return Channel] channel. Only the AudioReturn Channel channel is activated and communication is started.

The above-mentioned &lt;Activate Supported Channels&gt; message is transmitted and received, for example, after exchanging function information using the &lt;Exchange Supported Channels Info&gt; message and understanding both functions. After that, it is performed at an arbitrary timing such as when the channel for which communication is desired is changed.

[Improved effectiveness of CDC messages] As described above, the CDC message is made to always include the physical address of the source (Initiator) and the destination (Target). For example, when the sink device has a plurality of HDMI terminals, the physical address is indefinite for the source device in which the HPD signal is connected to a predetermined port (HDMI terminal) at "L". It becomes. When the physical address is indefinite in this way, the validity of the above-mentioned CDC message is reduced. Therefore, an example of improving the effectiveness of the CDC message in such a case will be described below.

[Example 1] In this example 1, the effectiveness of the CDC message is improved by providing the Direct Mode bit in the &lt;Activate Supported Channels&gt; message and the &lt;Exchange Supported Channels Info&gt; message. In this case, the &lt;Exchange Supported Channels Info&gt; message and the &lt;ActivateSupported Channels&gt; message have the following data structure, for example.

<tables num="2"><img id="000003" he="74" wi="159" file="0005572929.tif" img-format="tif" img-content="drawing" /></tables>

Describes the &lt;ExchangeSupported Channels Info&gt; message. This &lt;Exchange Supported Channels Info&gt; message has the first to fifth five bytes of data. The physical address of the source (Initiator) is arranged in the first byte and the second byte, and the physical address of the destination (Target) is arranged in the third and fourth bytes. ..

Further, the function information of the source (Initiator) is arranged in the fifth byte. This functional information has information indicating that it corresponds to the direct mode. In addition, this functional information has information indicating that it is an eHDMI compatible device, and includes information on a channel (transmission format) that it can support. That is, one bit of the fifth byte, for example, the seventh bit indicates whether or not it corresponds to the direct mode. One bit of the fifth byte is set to "1" when it is supported, and is set to "0" when it is not supported.

Further, the other 1 bit of the 5th byte, for example, the 6th bit, is an eHDMI compatible device and supports the above-mentioned SPDIF signal, that is, whether or not it supports [Audio Return Channel]. Shown. The other 1 bit of the 5th byte is set to "1" when it is supported, and is set to "0" when it is not supported.

Further, the other 1 bit of the 5th byte, for example, the 5th bit indicates whether or not the device itself is an eHDMI compatible device and supports the above-mentioned Ethernet signal, that is, whether or not it supports [Ethernet Channel]. .. The other 1 bit of the 5th byte is set to "1" when it is supported, and is set to "0" when it is not supported. Further, the remaining 5 bits of the 5th byte, for example, the 4th bit to the 0th bit are set as reserve bits and are all set to "0".

Next, the &lt;Activate Supported Channels&gt; message will be described. This &lt;Activate Supported Channels&gt; message has the first to fifth five bytes of data. The physical address of the source (Initiator) is arranged in the first byte and the second byte, and the physical address of the destination (Target) is arranged in the third and fourth bytes. .. Further, in the fifth byte, information indicating whether or not the message is in the direct mode and information on the channel (transmission format) for which the source (Initiator) requests activation are arranged.

That is, one bit of the fifth byte, for example, the seventh bit indicates whether or not the message is in the direct mode. One bit of the fifth byte is set to "1" when it is a message in direct mode, and is set to "0" when it is a normal message instead of a message in direct mode. The other 1 bit of the 5th byte, for example, the 6th bit indicates whether or not it requests the communication of the SPDIF signal, that is, the channel activation of [Audio Return Channel]. The other 1 bit of the 5th byte is set to "1" when the start is requested, and is set to "0" when the start is not requested.

Further, another 1 bit of the 5th byte, for example, the 5th bit indicates whether or not the user requests the communication of the Ethernet signal, that is, the channel activation of the [Ethernet Channel]. The other 1 bit of the 5th byte is set to "1" when the start is requested, and is set to "0" when the start is not requested. Further, the remaining 5 bits of the 5th byte, for example, the 4th bit to the 0th bit are set as reserve bits and are all set to "0".

As described above, the direct mode bit is provided for each message. In this case, for example, the operation is as follows. That is, when exchanging the function information by the &lt;Activate Supported Channels&gt; message, it is confirmed whether or not the HPD signal supports the communication in "L", that is, the direct mode. Then, if support for direct mode is confirmed, the &lt;Exchange Supported Channels Info&gt; message is sent and received in direct mode.

Between two CDC devices that support direct mode, the Initiator is allowed to send CDC messages in direct mode. The source (Initiator) does not send the same CDC message to other CDC devices, and the destination (Target) does not transfer the received CDC message to other CDC devices.

For example, consider a configuration example of the AV system 20 as shown in FIG. The source (Initiator) CDC device 21 has three ports 21a-21c. The target CDC device 22 has four ports 22a-22d. The port 21a of the CDC device 21 and the port 22a of the destination (Target) CDC device 22 are connected.

In this case, when the CDC device 21 of the source (Initiator) transmits the CDC message to the CDC device 22 of the destination (Target) in the direct mode, the CDC device 22 outputs the CDC message to the port 21a, but other Do not issue the same CDC message to ports 21b and 21c. Further, the CDC device 21 of the source (Initiator) does not transfer the CDC message sent to the port 22a in the direct mode to the other ports 22b to 22d.

As mentioned above, CDC devices that support direct mode have the ability to filter CDC messages. However, since the filtering method is a problem of processing in the device, it is not necessary to define it as a transmission standard.

As described above, by providing the direct mode, it is possible to send and receive the CDC message only between the two CDC devices. Therefore, the HPD signal is "L" and the physical address (Physical) of the source device side. Even if the Address) is indefinite, the validity of the CDC message is not reduced.

[Example 2] In this example 2, in addition to the &lt;Activate Supported Channels&gt; message and the &lt;Exchange Supported Channels Info&gt; message, a &lt;RequestHPD = H&gt; message requesting that the HPD signal be set to "H" is added, and the source device is a sink device. It is possible to read its own physical address (PhysicalAddress) from, and improve the effectiveness of CDC messages. The &lt;Request HPD = H&gt; message has the following data structure, for example.

<tables num="3"><img id="000004" he="18" wi="157" file="0005572929.tif" img-format="tif" img-content="drawing" /></tables>

A CDC device (source device) whose HPD signal is "L" and whose physical address is indefinite broadcasts the above-mentioned &lt;RequestHPD = H&gt; message. Upon receiving the &lt;Request HPD = H&gt; message, the CDC device sequentially sets the HPD signal of each port to "H" for at least a predetermined time, for example, 5 seconds. The CDC device that broadcasts the &lt;Request HPD = H&gt; message reads the E-EDID while the HPD signal of the port of the CDC device (sink device) to which it is connected is "H", and reads its own. Get the physical address.

In this way, the CDC device (source device) whose HPD signal is "L" and whose physical address is indefinite acquires and confirms its own physical address by using the &lt;Request HPD = H&gt; message. Therefore, the effectiveness of the CDC message can be enhanced.

[Example 3] In this example 3, in addition to the &lt;Activate Supported Channels&gt; message and the &lt;Exchange Supported Channels Info&gt; message, a &lt;RequestHPD = H&gt; message requesting that the HPD signal be set to "H" is added, and the source device is a sink device. It is possible to read its own physical address (PhysicalAddress) from, and improve the effectiveness of CDC messages.

In the case of Example 2 described above, each CDC device that has received the &lt;Request HPD = H&gt; message sequentially sets the HPD signal of each port to "H". Therefore, the CDC device (source device) that issued the &lt;Request HPD = H&gt; message needs to wait for the HPD signal of the port of the CDC device (sync device) to which it is connected to become "H". In this case, if the hierarchy of the CDC device to which it is connected is known and only the CDC device in that hierarchy sets the HPD signal of each port to "H", it is possible to quickly acquire the physical address. It becomes.

Therefore, the &lt;Request HPD = H&gt; message of Example 3 is added with data that specifies the hierarchy of physical addresses that require the HPD signal to be "H". Further, in this example 3, a &lt;Report HPD = H&gt; message is added. This &lt;Report HPD = H&gt; message is a CDC message broadcast by the CDC device that "H" the HPD signal, and includes the physical address of the CDC device. The &lt;Request HPD = H&gt; message and the &lt;Report HPD = H&gt; message have the following data structure, for example.

<tables num="4"><img id="000005" he="47" wi="159" file="0005572929.tif" img-format="tif" img-content="drawing" /></tables>

The &lt;RequestHPD = H&gt; message will be explained. This &lt;Request HPD = H&gt; message has 4-bit data of 3rd bit to 0th bit of data that specifies the hierarchy of physical addresses. By setting the third bit to "1" and the other bits to "0", the first layer (highest layer) of the physical address is specified. Further, by setting the second bit to "1" and the other bits to "0", the second layer of the physical address, or the first layer and the second layer are specified. Further, by setting the first bit to "1" and the other bits to "0" , the third layer of the physical address, or the first layer to the third layer is specified. Further, by setting the 0th bit to "1" and the other bits to "0", the 4th layer of the physical address or the 1st layer to the 4th layer is specified.

In addition, the &lt;Report HPD = H&gt; message will be described. This &lt;Report HPD = H&gt; message has 2 bytes of data. The physical address of the CDC device that "H" the HPD signal, that is, the physical address of the source (Initiator) is arranged in these 2 bytes.

[Example 4] This Example 4 is an example in which the HPD signal is requested to be "H" by changing the voltage of the power supply line without using the &lt;Request HPD = H&gt; message as in Examples 2 and 3 described above. Is. That is, as shown in FIG. 19B, the CDC device (source device) connected to the predetermined port (HDMI terminal) of the CDC device (sink device) whose HPD signal is "L" is of the power supply line. Reset the voltage to the ground voltage once, and then raise it to + 5V.

The CDC device (sink device) sets the HPD signal of the predetermined port to "H" for at least a predetermined time, for example, 5 seconds, as shown in FIG. 19A, in response to the voltage change of the power supply line. .. As a result, the CDC device (source device) reads the E-EDID from the CDC device (sink device) and acquires its own physical address during the period when the HPD signal of the predetermined port is "H".

In this way, the CDC device (source device) whose HPD signal is "L" and whose physical address is indefinite changes its own physical address from the CDC device (sink device) by changing the voltage of the power supply line. Can be obtained and confirmed, so that the validity of the CDC message can be enhanced.

In the above description, for example, the functional information is inserted and transmitted from the disc recorder 210 to the television receiver 250 during the blanking period of the video signal, or the functional information is transmitted via the CEC line 84 which is a control data line. By transmitting, the television receiver 250 can recognize whether or not the disc recorder 210 is an eHDMI compatible device.

However, by changing the voltage of the first line of the HDMI cable 350, for example, the reserve line, it is possible to transmit the functional information and the corresponding transmission format information.

"First example" The disc recorder 210 tells the television receiver 250 that it is an eHDMI compatible device by changing the voltage of the first line of the HDMI cable 350, for example, the reserve line.

The television receiver 250 acquires functional information indicating that the disc recorder 210 is an eHDMI compatible device by detecting a voltage change in the reserve line. In this case, the CPU 271 of the television receiver 250 constitutes a function information acquisition unit.

Further, the disc recorder 210 may automatically change the voltage of the reserve line when the television receiver 250 is connected via the HDMI cable 350, but the television receiver 250 has requested it. The voltage of the reserve line may be changed at the timing. The disc recorder 210 determines whether or not there is a request from the television receiver 250 side based on the voltage change of the second line of the HDMI cable 350, for example, the HPD line. In this case, the CPU 271 of the television receiver 250 constitutes a function information requesting unit, and the CPU 221 of the disc recorder 210 constitutes a voltage change detecting unit.

In addition to being an eHDMI compatible device, the disc recorder 210 also obtains information on the transmission format (application) that it supports by changing the voltage of the reserve line in a pulse shape. Can be told to. Here, the transmission format information is information such as whether it corresponds only to the SPDIF signal, only the Ethernet signal, or whether it corresponds to both the SPDIF signal and the Ethernet signal. In this case, the CPU 271 of the television receiver 250 constitutes a format information acquisition unit.

For example, the number of pulses 1 is defined as corresponding to only the SPDIF signal, the number of pulses 2 corresponds only to the Ethernet signal, and the number of pulses 3 corresponds to both the SPDIF signal and the Ethernet signal.

Further, for example, the number of pulses 1 corresponds to eHDMI (transmission format unknown), the number of pulses 2 corresponds to only SPDIF signals, the number of pulses 3 corresponds to only Ethernet signals, and the number of pulses 4 corresponds to both SPDIF signals and Ethernet signals. Is defined as.

Further, for example, the number of pulses 1 corresponds to eHDMI (transmission format unknown), the number of pulses 2 corresponds only to SPDIF signals, the number of pulses 3 corresponds only to Ethernet signals, and the number of pulses 4 corresponds to both SPDIF signals and Ethernet signals. The number of pulses 5 is defined as Reserve.

In this way, when the voltage of the reserve line is changed in a pulse shape on the disc recorder 210 side according to the corresponding transmission format, on the television receiver 250 side, the disc recorder 210 supports the transmission format based on the number of pulses. Information can be obtained. It is also conceivable that the corresponding transmission format (application) is represented by the voltage level or the pulse phase instead of the number of pulses.

As described above, FIG. 20 shows a configuration example of the disk recorder 210 and the television receiver 250 when the voltage of the reserve line and the HPD line is changed. In FIG. 20, the parts corresponding to those in FIG. 8 are designated by the same reference numerals, and detailed description thereof will be omitted.

In the disk recorder 210, pin 14 of the HDMI terminal 211 is grounded via a connection switch 418 made of a transistor or the like. The on / off of the connection switch 418 is controlled by the control signal SW1 from the CPU 221 (see FIG. 2). As a result, the voltage of the reserve line can be changed to notify the television receiver 250 that the disc recorder 210 is an eHDMI compatible device, and the change can be pulsed to support a transmission format (application). ) Can also be transmitted to the television receiver 250. In this case, the connection switch 418 and the CPU 221 constitute a function information transmission unit and a format information transmission unit.

Further, in the television receiver 250, pin 19 of the HDMI terminal 251 is grounded via a connection switch 450 made of a transistor or the like. The on / off of the connection switch 450 is controlled by the control signal SW2 from the CPU 271 (see FIG. 3). As a result, the voltage of the HPD line can be changed to request the disc recorder 210 to convey information on whether or not the disc recorder 210 is an eHDMI compatible device. In this case, the connection switch 450 and the CPU 271 form a function information requesting unit. In the television receiver 250, as described above, functional information indicating that the disc recorder 210 is an eHDMI compatible device and information on the corresponding transmission format can be acquired from the 14-pin voltage Vrsv of the HDMI terminal 251.

FIG. 21 shows an example of voltage control of the HPD line by the television receiver (sink device) 250 side and an example of voltage control of the reserve line by the corresponding disc recorder (source device) 210 side. In the case of this example, first, as shown in FIG. 21A, the connection switch 450 of the television receiver 250 is turned on for a predetermined time from the off state, and the voltage of the HPD (eHDMMI-) line is low. It will change to High. As a result, the television receiver 250 requests the disc recorder 210 to convey functional information and the like.

On the other hand, after the voltage of the HPD line returns to the high state, the connection switch 418 of the disc recorder 210 is changed from the off state to the on state, and as shown in FIG. 21B, the voltage of the reserve line is changed. Is changed from high to low, and functional information indicating that the device is an eHDMI compatible device is transmitted from the disc recorder 210 to the television receiver 250.

After that, for example, during 100 ms, the connection switch 418 of the disc recorder 210 is switched and controlled, and the voltage of the reserve line repeatedly changes from low (Low) to high (High) according to the transmission format that the disc recorder 210 can support. To be done. As a result, information on the transmission format that the disc recorder 210 can support is transmitted from the disc recorder 210 to the television receiver 250. Eventually, the connection switch 418 is returned to the off state.

As shown in FIG. 21 (b), since the voltage of the reserve line is changing, the television receiver 250 can detect the voltage of the reserve line, for example, the disk recorder 210 is an eHDMI compatible device, and a pulse is further generated. Since the number is 3, it is possible to obtain functional information that, for example, it corresponds to both the SPDIF signal and the Ethernet signal.

As described above, after the function information indicating that the device is an eHDMI compatible device and the corresponding transmission format information sent from the disc recorder 210 are confirmed by the TV receiver 250, between the TV receiver 250 and the disc recorder 210. The eHDMI transmission is started at.

"Second example" In the first example described above, by changing the voltage of the first line of the HDMI cable 350, for example, the reserve line, the disk recorder 210 corresponds to the TV receiver 250 with the functional information indicating that the device is an HDMI compatible device. Transmission format information is sent.

In this second example, further, by changing the voltage of the reserve line of the HDMI cable 350, information on the transmission format that the television receiver 250 can support is sent from the television receiver 250 to the disc recorder 210. In this second example, detailed description of the portion corresponding to the first example will be omitted.

The television receiver 250 detects the voltage change of the reserve line, acquires the function information indicating that the disc recorder 210 is an eHDMI compatible device, and the corresponding transmission format information, and then changes the voltage of the reserve line in a pulse shape. Then, the information of the transmission format corresponding to itself is transmitted to the disk recorder 210. In this case, the CPU 271 of the television receiver 250 constitutes a format information transmission unit. The disc recorder 210 detects the voltage change of the reserve line and acquires the information of the transmission format supported by the television receiver 250. In this case, the CPU 221 of the disc recorder 210 constitutes a format information acquisition unit.

As described above, FIG. 22 shows the disc recorder 210 and the case where the disc recorder 210 sends the function information and the corresponding transmission format information to the television receiver 250, and the television receiver 250 sends the corresponding transmission format information to the disc recorder 210. A configuration example of the television receiver 250 is shown. In FIG. 22, the parts corresponding to those in FIG. 20 are designated by the same reference numerals, and detailed description thereof will be omitted.

In the television receiver 250, pin 14 of the HDMI terminal 251 is grounded via a connection switch 451 made of a transistor or the like. The on / off of the connection switch 451 is controlled by the control signal SW3 from the CPU 271. As a result, the television receiver 250 can change the voltage of the reserve line in a pulse shape and transmit the information of the transmission format corresponding to the television receiver 250 to the disc recorder 210. In this case, the connection switch 451 and the CPU 271 form a format information transmission unit. Other configurations of the television receiver 250 in FIG. 22 are similar to those of the television receiver 250 in FIG.

The configuration of the disc recorder 210 in FIG. 22 is the same as the configuration of the disc recorder 210 in FIG. 20. In this disc recorder 210, information on the transmission format supported by the television receiver 250 can be acquired from the voltage Vrsv of pin 14 of the HDMI terminal 211 as described above. In this case, the CPU 221 of the disc recorder 210 constitutes a format information acquisition unit.

FIG. 23 shows an example of voltage control of the HPD line by the TV receiver (sink device) 250 side, and voltage control of the reserve line by the corresponding disc recorder (source device) 210 side and the TV receiver (sink device) 250 side. An example is shown.

In the case of this example, first, as shown in FIG. 23A, the connection switch 450 of the television receiver 250 is turned on for a predetermined time from the off state, and the voltage of the HPD (eHDMMI-) line is low. It will change to High. As a result, the television receiver 250 requests the disc recorder 210 to convey functional information and the like.

On the other hand, after the voltage of the HPD line returns to the high state, the connection switch 418 of the disc recorder 210 is changed from the off state to the on state, and as shown in FIG. 23 (b), the voltage of the reserve line is changed. Is changed from high to low, and functional information indicating that the device is an eHDMI compatible device is transmitted from the disc recorder 210 to the television receiver 250.

After that, for example, during 100 ms, the connection switch 418 of the disc recorder 210 is switched and controlled, and as shown in FIG. 23 (b), the voltage of the reserve line is lowered according to the transmission format that the disc recorder 210 can support. ) High is repeated. As a result, information on the transmission format that the disc recorder 210 can support is transmitted from the disc recorder 210 to the television receiver 250 (declaration of the transmittable format on the source side). Eventually, the connection switch 418 is returned to the off state.

After that, for example, during 100 ms, the connection switch 451 of the television receiver 250 is switched and controlled, and as shown in FIG. 23 (b), the voltage of the reserve line is adjusted according to the transmission format that the television receiver 250 can support. Is made to repeat the change from low to high. As a result, information on the transmission format that the television receiver 250 can support is transmitted from the television receiver 250 to the disk recorder 210 (declaration of the transmittable format on the sink side). Finally, the connection switch 451 is returned to the off state.

As described above, the TV receiver 250 confirms the functional information and the corresponding transmission format information indicating that the device is an eHDMI compatible device sent from the disc recorder 210, and the disc recorder 210 sends the information from the TV receiver 250. After the incoming corresponding transmission format information is confirmed, eHDMI transmission is started between the television receiver 250 and the disc recorder 210.

Here, a case where the television receiver 250 is provided with a plurality of HDMI terminals (HDMI ports) will be described. The television receiver 250 shown in FIG. 3 described above is provided with one HDMI terminal. FIG. 24 shows a television receiver 250 having a plurality of, for example, three HDMI terminals. In FIG. 24, the parts corresponding to those in FIG. 3 are designated by the same reference numerals, and detailed description thereof will be omitted.

The television receiver 250 has HDMI terminals 251a to 251c, an HDMI switcher 255, and high-speed data line interfaces 253a to 253c. The HDMI switcher 255 selectively connects the HDMI terminals 251a to 251c to the HDMI receiving unit 252. The HDMI receiving unit 252 acquires video (image) and audio data input to the HDMI terminal connected via the HDMI switcher 255 among the HDMI terminals 251a to 251c via the HDMI cable.

The high-speed data line interfaces 253a to 253c are bidirectional communication path interfaces composed of predetermined lines (reserve line and HPD line) of the HDMI cable connected to the HDMI terminals 251a to 251c described above. The high-speed data line interfaces 253a to 253c are inserted between the Ethernet interface 274 and the HDMI terminals 251a to 251c. The high-speed data line interfaces 253a to 253c are configured in the same manner as the high-speed data line interface 253 in FIG.

Others of the television receiver 250 of FIG. 24 are configured in the same manner as the television receiver 250 shown in FIG. 3, and perform the same operation.

As described above, the disc recorder 210 changes the voltage of the reserve line after receiving a transmission request (trigger) for functional information or the like from the television receiver 250 due to a voltage change on the HPD line, and receives the functional information or the like on the television. Send to machine 250.

Therefore, as shown in FIGS. 25 (a) to 25 (c), the television receiver 250 is a disk recorder 210 or the like connected to each HDMI terminal at an arbitrary timing via an HDMI cable. A series of requests for transmission of functional information, etc. can be made to the device. As a result, the number of pins of the microcomputer (CPU271) is expected to be reduced.

In FIGS. 25 (a) to 25 (c), "DDC5V" indicates the voltage of the power supply line, "HPD" indicates the voltage of the HPD line, and "Rsv" indicates the voltage of the reserve line. Regarding the input 3 of FIG. 25 (c), it is shown that the power of the device is turned on or the connection is made in the middle.

Further, "Source" indicates functional information and compatible transmission format information indicating that the device is an eHDMI compatible device transmitted from the source device (for example, the disk recorder 210) to the sink device (for example, the television receiver 250). Further, "Sink" indicates the corresponding transmission format information sent from the sink device (for example, the television receiver 250) to the source device (for example, the disc recorder 210).

The flowchart of FIG. 26 shows an example of a processing procedure when the CPU 271 of the television receiver (sink device) 250 performs a detection operation for a predetermined HDMI input.

The CPU 271 starts the process in step ST1, and then moves to the process in step ST2. In this step ST2, the CPU 271 determines whether or not the voltage of the power supply line (DDC 5V) is 5V.

When the voltage of the power supply line (DDC 5V) is 5V, the CPU 271 determines in step ST3 whether or not the detection operation of the function information, the corresponding transmission format information, etc. is being performed by another HDMI input. When the other input detection operation is in progress, the CPU 271 determines in step ST4 whether or not the detection of the other input is completed.

When the detection of the other input is completed, the CPU 271 moves to the process of step ST5. When the other input detection operation is not in progress in step ST3, the CPU 271 immediately shifts to the process of step ST5. In this step ST5, the CPU 271 changes the voltage of the HPD line from low (Low) to high (High), and requests the other party's source device (disk recorder 210 or the like) to transmit functional information or the like.

Next, in step ST6, the CPU 271 monitors the voltage of the reserve line and determines whether or not a response has been received from the source device, that is, whether or not functional information or the like has been sent. When no response is received, the CPU 271 determines in step ST7 whether or not 100 ms has elapsed since the transmission request was made in step ST5. When 100 ms has not passed, the CPU 271 returns to the process of step ST6. On the other hand, when 100 ms has elapsed, the CPU 271 determines in step ST8 that the source device on the other side is a non-eHDMI compatible device.

FIG. 27 shows an example of voltage changes of the HPD line and the reserve line when the CPU 271 determines that the source device on the other side is a non-eHDMI compatible device as described above. Note that FIG. 27 (a) shows the voltage of the power supply line (DDC 5V), FIG. 27 (b) shows the voltage of the HPD line, and FIG. 27 (c) shows the voltage of the reserve line.

As shown in FIG. 27 (b), the voltage of the HPD line is changed from low to high by the television receiver 250, and functional information and the like are transmitted to the other source device (disc recorder 210, etc.). A request has been made. However, as shown in FIG. 27 (c), the voltage of the reserve line remains high even after 100 ms has elapsed, and there is no response from the source device.

Returning to the flowchart of FIG. 26, when a response is received in step ST6, the CPU 271 recognizes that the source device on the other side is an eHDMI compatible device in step ST9, and from the voltage change of the reserve line, the other side Detects the supported transmission format of the source device.

Next, in step ST10, the CPU 271 changes the voltage of the reserve line in a pulse shape, and transmits the information of the transmission format (application) supported by the television receiver 250 to the source device on the other side. Then, in step ST11, the CPU 271 starts transmitting and receiving an eHDMI signal to and from the source device on the other side.

In the processing of the flowchart of FIG. 26, when the response from the source device does not arrive even after 100 ms has elapsed, the CPU 271 immediately determines that the device does not support eHDMI. However, as shown in FIG. 28 (b), when the response from the source device does not arrive even after 100 ms has elapsed, the CPU 271 is used several times (shown only once in FIG. 28 (b)) on the HPD line. The voltage may be changed from low (Low) to high (High), and a retry process may be performed to request the other party's source device (disk recorder 210 or the like) to transmit functional information or the like. As a result, when the source device cannot respond in a busy state, it is possible to avoid an error of immediately determining that the device does not support eHDMI.

Note that FIG. 28 (a) shows the voltage of the power supply line (DDC 5V), FIG. 28 (b) shows the voltage of the HPD line, and FIG. 28 (c) shows the voltage of the reserve line. 28 (a) and 28 (c) are the same as those of FIGS. 27 (a) and 27 (c).

The flowchart of FIG. 29 shows an example of the processing procedure of the CPU 221 of the disc recorder (source device) 210.

The CPU 221 starts the process in step ST21, and then moves to the process in step ST22. In this step ST22, the CPU 221 determines whether or not the voltage of the reserve line is in the high state. When the voltage of the reserve line is not high, the CPU 221 determines in step ST23 that the sink device (television receiver 250 or the like) on the other side is an eHDMI non-compliant device.

When the voltage of the reserve line is high, the CPU 221 moves to the process of step ST24. In this step ST24, the CPU 221 determines whether or not the voltage of the HPD line has changed in the order of high (High) low (Low) high (High). When such a change occurs, the CPU 221 determines that there is a request for transmission of functional information or the like from the sink device on the other side. Then, in step ST25, the CPU 221 changes the voltage of the reserve line and transmits the function information indicating that the device is an eHDM compatible device and the information of the corresponding transmission format (application) to the sink device on the other side.

Next, in step ST26, the CPU 221 monitors the voltage of the reserve line and determines whether or not a response has been received from the sink device, that is, whether or not information on a transmission format that the other sink device can handle has been sent. to decide. When no response is received, the CPU 221 determines in step ST27 whether or not 100 ms has elapsed since sending its own function information or the like in step ST25. When 100 ms has not passed, the CPU 221 returns to the process of step ST26. On the other hand, when 100 ms has elapsed, the CPU 221 determines in step ST28 that the sink device on the other side is a non-eHDMI compatible device or is in a busy state and cannot transmit.

When a response is received from the sink side in step ST26, the CPU 221 detects the corresponding transmission format of the sink device on the other side from the voltage change of the reserve line in step ST29. Then, in step ST30, the CPU 221 starts transmitting and receiving an eHDMI signal to and from the sink device on the other side.

"Third example" In the first and second examples described above, the voltage of the second line of the HDMI cable 350, for example, the HPD line, is changed from the television receiver (sink device) 250 to the disk recorder (source device) 210. A transmission request for function information, etc. is sent.

In this third example, the transmission request is made by changing the voltage of the first line of the HDMI cable 350, for example, the reserve line, as in the case of transmitting the functional information, the corresponding transmission format information, and the like. Further, in the third example, the transmission request for the functional information and the like can be issued from either the television receiver 250 or the disc recorder 210. In this third example, detailed description of the parts corresponding to the first example and the second example will be omitted.

The requesting side (sink device or source device) indicates to the responding side (source device or sink device) that the device is an HDMI compatible device by changing the voltage of the first line of the HDMI cable 350, for example, the reserve line. Request the transmission of function information (start of conditional transmission). Here, the CPU on the requesting side constitutes a function information requesting unit.

Next, the responding side monitors the voltage of the reserve line, and when the requesting side requests the transmission of functional information (start of conditional transmission), if it is an eHDMI compatible device, it reserves the HDMI cable 350. By changing the voltage of the line, function information (answer that conditional transmission is possible) is transmitted to the requesting side. The requesting side monitors the voltage of the reserve line and acquires the functional information sent from the responding side. In this case, the respondent constitutes a voltage change detection unit and a function information transmission unit. In addition, the requesting side constitutes a function information acquisition unit.

Next, the requesting side changes the voltage of the reserve line in a pulse shape, and transmits the transmission format information that it can correspond to to the responding side. The respondent monitors the voltage of the reserve line and the requester acquires the corresponding transmission format information. In this case, the requesting side constitutes a format information transmitting unit, and the responding side constitutes a format information acquiring unit.

Next, the responding side changes the voltage of the reserve line in a pulse shape and transmits the transmission format information that it can handle to the requesting side. The requesting side monitors the voltage of the reserve line, and the responding side acquires the corresponding transmission format information. In this case, the responding side constitutes a format information transmitting unit, and the requesting side constitutes a format information acquisition unit.

As described above, FIG. 30 shows the disc recorder 210 and the case where the disc recorder 210 sends the function information and the corresponding transmission format information to the television receiver 250, and the television receiver 250 sends the corresponding transmission format information to the disc recorder 210. A configuration example of the television receiver 250 is shown. In FIG. 30, the parts corresponding to those in FIG. 22 are designated by the same reference numerals, and detailed description thereof will be omitted.

In the television receiver 250, since the transmission request of the functional information is performed by changing the voltage of the first line of the HDMI cable 350, for example, the reserve line, the connection switch 450 in the television receiver 250 of FIG. 22 becomes unnecessary. .. Other configurations of the television receiver 250 in FIG. 30 are similar to those of the television receiver 250 in FIG. The configuration of the disc recorder 210 in FIG. 30 is the same as the configuration of the disc recorder 210 in FIG. 22.

FIG. 31 shows an example of voltage control of the reserve line. FIG. 31 (a) shows the voltage of the HPD line, and FIG. 31 (b) shows the voltage of the reserve line. The voltage on the HPD line remains high.

In the case of this example, first, the connection switch on the request side (connection switch 451 when the TV receiver 250 is on the request side, connection switch 418 when the disc recorder 210 is on the request side) is turned on for a predetermined time from the off state. As shown in FIG. 31 (b), the voltage of the reserve (eHDMMI +) line is changed from low (Low) to high (High). As a result, the requesting side is requested to the responding side to transmit the functional information indicating that the device is an eHDMI compatible device (start of conditional transmission).

Then, after a lapse of a maximum of 2 seconds, the connection switch on the answering side (connection switch 418 when the disk recorder 210 is on the answering side, connection switch 451 when the television receiver 250 is on the answering side) is off for a predetermined time. It is turned on, and as shown in FIG. 31 (b), the voltage of the reserve (eHDMMI +) line is changed from low (Low) to high (High). As a result, functional information (transmissible answer) indicating that the device is an eHDMI compatible device is transmitted from the responding side to the requesting side.

After that, for example, after 100 ms has elapsed, for example, during 100 ms, the connection switch is switched and controlled on the requesting side, and the voltage of the reserve line is changed from low to high depending on the transmission format that the requesting side can support. It is made to repeat the change of. As a result, information on the transmission format that the requester can handle is transmitted from the requester to the responder (declaration of the transmittable format on the requester side).

After that, for example, during 100 ms, the connection switch on the answering side is switched and controlled so that the voltage of the reserve line repeatedly changes from low (Low) to high (High) according to the transmission format that the answering side can support. Will be done. As a result, information on the transmission format that the respondent can handle is transmitted from the respondent to the requester (declaration of the transmittable format on the responder).

As described above, the requesting side confirms the function information and the corresponding transmission format information indicating that the device is an eHDMI compatible device sent from the responding side, and the responding side confirms the corresponding transmission format sent from the requesting side. After the information is confirmed, eHDMI transmission is started between the requesting side and the responding side.

Here, a case where the sink device is provided with a plurality of HDMI terminals (HDMI ports) will be described (see the television receiver 250 in FIG. 24).

As described above, the requesting side changes the voltage of the reserve line after the response side transmits the function information (answer that the condition transmission is possible), and sends the information of the corresponding transmission format to the responding side.

Therefore, as shown in FIGS. 32 (a) to 32 (c), the multi-input sink device (television receiver 250) transmits functional information from the source device at an arbitrary timing for each HDMI terminal (start of conditional transmission). Is requested, the transmission timing of the functional information (transmission possible answer) can be controlled, and the transmission / reception of the corresponding transmission format information at each HDMI terminal can be performed according to its own processing status.

In FIGS. 32 (a) to 32 (c), "DDC5V" indicates the voltage of the power supply line, "HPD" indicates the voltage of the HPD line, and "Rsv" indicates the voltage of the reserve line. Regarding the input 2 of FIG. 32 (b), it is shown that the power of the device is turned on or the connection is made in the middle.

The flowchart of FIG. 33 shows an example of a CPU (hereinafter, referred to as "CPUsi") processing procedure of the sink device when a request is issued from the sink device.

The CPUsi starts the process in step ST41, and then moves to the process in step ST42. In this step ST42, CPUsi determines whether or not the voltage of the power supply line (DDC 5V) is 5V.

When the voltage of the power supply line (DDC 5V) is 5V, the CPUsi determines in step ST43 whether or not the detection operation of the function information, the corresponding transmission format information, etc. is being performed by another HDMI input. When the other input detection operation is in progress, the CPUsi determines in step ST44 whether or not the detection of the other input is completed.

When the detection of the other input is completed, the CPUsi moves to the process of step ST45. When the other input detection operation is not in progress in step ST43, the CPUsi immediately shifts to the process of step ST45. In this step ST45, the CPUsi changes the voltage of the reserve line from low (Low) to high (High), and requests the source device to transmit functional information (start conditional transmission).

Next, in step ST46, the CPUsi monitors the voltage of the reserve line and determines whether or not a response has been received from the source device, that is, whether or not functional information (transmissionable answer) has been sent. When no response is received, the CPUsi determines in step ST47 whether or not 2 s has elapsed since the transmission request was made in step ST45. When 2s has not passed, CPUsi returns to the process of step ST46. On the other hand, when 2s has elapsed, the CPUsi determines in step ST48 that the source device on the other side is a non-eHDMI compatible device.

FIG. 34 shows an example of a voltage change of the reserve line when it is determined that the source device on the other side is a non-eHDMI compatible device as described above. Note that FIG. 25 (a) shows the voltage of the power supply line (DDC 5V), FIG. 34 (b) shows the voltage of the HPD line, and FIG. 34 (c) shows the voltage of the reserve line.

As shown in FIG. 34 (c), the voltage of the reserve line is changed from low to high in the sink device, and a request for transmission of functional information (start of conditional transmission) to the source device on the other side is requested. It has been issued. However, as shown in FIG. 34 (c), the voltage of the reserve line remains high even after 2 s has passed, and there is no response from the source device.

Returning to the flowchart of FIG. 33, when a response is received in step ST46, the CPUsi changes the voltage of the reserve line in a pulse shape in step ST49, and sends the information of the transmission format (application) supported by the sink device to the other party. Send to the source device on the side.

Next, CPUsi monitors the voltage of the reserve line in step ST50. Then, CPUsi detects the corresponding transmission format of the source device on the other side from the voltage change of the reserve line. Then, in step ST51, the CPUsi starts transmitting and receiving an eHDMI signal to and from the source device on the other side.

In the processing of the flowchart of FIG. 33, when the response from the source device does not arrive even after 2 seconds, the CPUsi immediately determines that the source device is a non-eHDMI compatible device. However, as shown in FIG. 35 (c), when the response from the source device does not arrive even after 2 seconds, the CPUsi has a reserve line several times (shown only once in FIG. 35 (c)). The voltage may be changed from low to high, and a retry process may be performed to issue a function information transmission request (conditional transmission start request) to the source device on the other side. As a result, when the source device cannot respond in a busy state, it is possible to avoid an error of immediately determining that the device does not support eHDMI.

Note that FIG. 35 (a) shows the voltage of the power supply line (DDC 5V), FIG. 35 (b) shows the voltage of the HPD line, and FIG. 35 (c) shows the voltage of the reserve line. 35 (a) and 35 (b) are the same as those of FIGS. 34 (a) and 34 (b).

The flowchart of FIG. 36 shows an example of the processing procedure of the CPUsi of the sink device when a request is issued from the source device.

The CPUsi starts the process in step ST61, and then moves to the process in step ST62. In this step ST62, the CPUsi determines whether or not the voltage of the power supply line (DDC 5V) is 5V.

When the voltage of the power supply line (DDC 5V) is 5V, the CPUsi monitors the voltage of the reserve line in step ST63 and detects a change from low (Low) to high (High). After that, the CPUsi determines that there is a request for transmission of functional information (start of conditional transmission) from the source side, and proceeds to the process of step ST64. In this step ST64, the CPUsi determines whether or not the detection operation of the function information, the corresponding transmission format information, etc. is being performed by another HDMI input.

When the other input detection operation is in progress, the CPUsi determines in step ST65 whether or not 2 s have elapsed since the reserve line low (Low) high (High) voltage change was detected in step ST63. .. When 2s has not elapsed, CPUsi returns to the process of step ST64. When 2s has elapsed, the CPUsi gives up the transmission of the functional information (transmissionable answer) in step ST66. If it is desired to transmit the function information (answer that transmission is possible), the sink side again requests the transmission of the function information (start of conditional transmission).

When the other input detection operation is not in progress in step ST64, the CPUsi moves to the process of step ST67. In this step ST67, the CPUsi changes the voltage of the reserve line from low (Low) to high (High), and transmits functional information (transmission possible answer) to the source device. Then, in step ST68, the CPUsi monitors the voltage of the reserve line and detects the corresponding transmission format of the source device on the other side from the voltage change of the reserve line.

Next, in step ST69, the CPUsi changes the voltage of the reserve line in a pulse shape and transmits the information of the transmission format (application) supported by the sink device to the source device on the other side. Then, in step ST70, the CPUsi starts transmitting and receiving an eHDMI signal to and from the source device on the other side.

The flowchart of FIG. 37 shows an example of the processing procedure of the CPUso of the source device when the request is issued from the source device.

The CPUso starts the process in step ST81, and then moves to the process in step ST82. In this step ST82, the CPUso determines whether or not the voltage of the reserve line is in the high state. When the voltage of the reserve line is not high, the CPUso determines in step ST83 that the sink device on the other side is a non-eHDMI compatible device.

When the voltage of the reserve line is high, the CPUso moves to the process of step ST84. In this step ST84, the CPUso determines whether or not the voltage of the reserve line remains high. If it does not remain high, the CPUso proceeds to the process of step ST85. In this step ST85, the CPUso determines whether or not the voltage of the reserve line returns to high after a certain period of time. If it does not return to High, the CPUso determines that the connection has been disconnected. On the other hand, when returning to High, the CPUso determines that a request from the sink device has occurred, and proceeds to the process of step ST104 in the flowchart of FIG. 38 to be described later.

When the voltage of the reserve line remains high in step ST84, the CPUso moves to the process of step ST88. In this step ST88, the CPUso changes the voltage of the reserve line from low (Low) to high (High), and requests the sink device to transmit functional information (start conditional transmission).

Next, in step ST89, the CPUso monitors the voltage of the reserve line and determines whether or not a response has been received from the sink device, that is, whether or not functional information (transmissionable answer) has been sent. When no response is received, the CPUso determines in step ST90 whether or not 2 s has elapsed since the transmission request was made in step ST88. When 2s has not passed, the CPUso returns to the process of step ST89. On the other hand, when 2s has elapsed, the CPUso determines in step ST91 that transmission to the sink device on the other side is impossible, and returns to the start of processing in step ST81.

When a response is received in step S89, the CPUso changes the voltage of the reserve line in a pulse shape in step ST92, and transmits the information of the transmission format (application) supported by the source device to the sink device on the other side.

Next, the CPUso monitors the voltage of the reserve line in step ST93. Then, the CPUso detects the corresponding transmission format of the sink device on the other side from the voltage change of the reserve line. Then, in step ST94, the CPUso starts transmitting and receiving an eHDMI signal to and from the sink device on the other side.

In the processing of the flowchart of FIG. 37, when the response from the sink device does not arrive even after 2 seconds, the CPUso immediately determines that transmission is impossible. However, when the response from the sink device does not arrive after 2 seconds, the CPUso changes the voltage of the reserve line from low to high several times, and causes the sink device on the other side to change the voltage. A retry process for issuing a function information transmission request (conditional transmission start request) may be performed. As a result, it is possible to avoid an error of immediately determining that transmission is impossible when the sink device cannot respond in a busy state.

The flowchart of FIG. 38 shows an example of the processing procedure of the CPUso of the source device when a request is issued from the sink device.

The CPUso starts the process in step ST101, and then moves to the process in step ST102. In this step ST102, the CPUso determines whether or not the voltage of the reserve line is in the high state. When the voltage of the reserve line is not high, the CPUso determines in step ST103 that the sink device on the other side is an eHDMI non-compliant device.

When the voltage of the reserve line is high, the CPUso moves to the process of step ST104. In this step ST104, the CPUso monitors the voltage of the reserve line and detects a change from low to high. In this case, the CPUso detects a request for transmitting functional information (request for starting conditional transmission) from the sink device.

Next, in step ST105, the CPUso changes the voltage of the reserve line from low (Low) to high (High), and transmits functional information (transmission possible answer) to the sink device on the other side. Then, in step ST106, the CPUso monitors the voltage of the reserve line and detects the corresponding transmission format of the sink device on the other side from the voltage change of the reserve line.

Next, in step ST107, the CPUso changes the voltage of the reserve line in a pulse shape and transmits the information of the transmission format corresponding to the source device to the sink device on the other side. Then, in step ST108, the CPUso starts transmitting and receiving an eHDMI signal to and from the sink device on the other side.

As described above, in the AV system 200 shown in FIG. 1, the disc recorder 210 receives a transmission request when the television receiver 250 is connected via the HDMI cable 350 or from the television receiver 250. At that time, the information indicating that the device itself is an eHDMI compatible device and the information of the corresponding transmission format (application) are transmitted to the television receiver 250.

On the other hand, for example, as shown in FIG. 39, in the AV system 200A in which the disc recorder 210A that does not support eHDMI and the TV receiver 250 are connected by the HDMI cable 350, the disc recorder 210A to the TV receiver The above-mentioned functional information and transmission format information are not transmitted to 250.

Therefore, the television receiver 250 can recognize whether or not the disc recorder 210 is provided with a communication unit (high-speed data interface, SPDIF receiving circuit), that is, whether or not it is an eHDMI compatible device, and is an eHDMI non-compatible device. It is possible to avoid transmitting unnecessary signals to the disc recorder 210A via a communication path composed of a reserve line and an HPD line.

Further, the television receiver 250 can acquire information on the transmission format supported by the disc recorder 210 from the disc recorder 210 which is an eHDMI compatible device, and therefore, it is easy to support the SPDIF signal and the Ethernet signal of the disc recorder 210. You can know.

As described in the above-described embodiment, the disc recorder 210, which is an eHDMI compatible device, transmits the functional information indicating that the device is an eHDMI compatible device to the television receiver 250. After recognizing that the disc recorder 210 is an eHDMI compatible device, the television receiver 250 may transmit the Ethernet signal and the SPDIF signal via the communication path composed of the reserve line of the HDMI cable 350 and the HPD line. it can.

However, the disk recorder 210 may determine that it wants to block the communication by the communication unit (high-speed data line interface 213, SPDIF receiving circuit 417). For example, when the network terminal 225 is connected to a network and priority is given to communication using the network, or when it is desired to allocate the power of the CPU 221 to another process in the device. For example, the CPU 221 determines whether or not to block the communication by the communication unit in this way. Here, the CPU 221 constitutes a cutoff determination unit.

When the disc recorder 210 determines that the communication by the above-mentioned communication unit is cut off, the disc recorder 210 transmits the communication information indicating the cutoff of the communication to the television receiver 250. For example, the disc recorder 210 inserts the above-mentioned communication information into the television during the blanking period of the video signal transmitted to the television receiver 250 on the above-mentioned TMDS channel in the same manner as the above-mentioned functional information. Send to receiver 250. Here, the disc recorder 210 inserts the above-mentioned communication information into the blanking period of the video signal by using, for example, an HDMI AVI InfoFrame packet, a GCP packet, or the like.

When the disc recorder 210 transmits the communication information to the television receiver 250 by inserting the communication information during the blanking period of the video signal transmitted to the television receiver 250 on the TMDS channel as described above, the television receiver In the 250, the communication information is received by extracting the above-mentioned communication information from the blanking period of the video signal received from the disc recorder 210 on the TMDS channel.

Further, for example, the disc recorder 210 transmits the above-mentioned communication information to the television receiver 250 via the CEC line 84, which is the control data line of the HDMI cable 350. In this case, the television receiver 250 receives the communication information from the disc recorder 210 via the CEC line 84.

As described above, the television receiver 250 can recognize that the disc recorder 210 is in the communication cutoff state by receiving the communication information. Therefore, the television receiver 250 can avoid transmitting an unnecessary signal to the disc recorder 250 that blocks communication by the communication unit via the above-mentioned communication path. As described above, when communication information is transmitted from the disc recorder 210 to the television receiver 250, the HDMI transmitter 212 of the disc recorder 210 constitutes an information transmitter, and the HDMI receiver 252 of the television receiver 250 provides information. Configure the receiver.

In the above description, by transmitting communication information from the disc recorder 210 to the television receiver 250, the television receiver 250 can recognize the interruption of communication by the communication unit of the disc recorder 210. However, the disc recorder 210 can notify the television receiver 250 that the communication is cut off by changing the voltage of the first line of the HDMI cable 350, for example, the reserve line. In this case, the disc recorder 210 changes the connection switch 418 (see FIG. 20) from the off state to the on state, and lowers the voltage of the reserve line.

By detecting the voltage change of the reserve line, the television receiver 250 can acquire the communication information indicating the interruption of the communication by the communication unit of the disc recorder 210. In this case, the CPU 271 of the television receiver 250 constitutes an information acquisition unit. As described above, the television receiver 250 can recognize that the disc recorder 210 is blocking the communication by the communication unit by detecting the voltage of the reserve line and acquiring the communication information. Therefore, the television receiver 250 can avoid transmitting an unnecessary signal to the disk recorder 210 in the communication cutoff state via the above-mentioned communication path.

In the above-described embodiment, the HDMI standard interface has been described as the transmission line for connecting the devices, but it can also be applied to other similar transmission standards. Further, although a disc recorder is used as a source device and a television receiver is used as a sink device, the present invention can be similarly applied to devices using other transmitters and receivers. Further, in the above-described embodiment, the electronic devices connected by the HDMI cable are shown, but the present invention can be similarly applied to the electronic devices connected wirelessly.

The present invention can appropriately transmit a signal from a receiving device to a transmitting device, and can be applied to an AV system or the like in which a source device and a sink device are connected via an HDMI cable.

<figref num="1">It is a block diagram which shows the structural example of the AV system as the embodiment of this invention.</figref><figref num="2">It is a block diagram which shows the configuration example of the disk recorder (source apparatus) which constitutes an AV system.</figref><figref num="3">It is a block diagram which shows the structural example of the television receiver (sink device) which constitutes an AV system.</figref><figref num="4">It is a block diagram which shows the structural example of the HDMI transmission part (HDMI source) and the HDMI receiving part (HDMI sink).</figref><figref num="5">It is a block diagram which shows the configuration example of the HDMI transmitter and the HDMI receiver.</figref><figref num="6">It is a figure which shows the structure of TMDS transmission data.</figref><figref num="7">It is a figure which shows the pin arrangement (type A) of the HDMI terminal.</figref><figref num="8">It is a connection diagram which shows the configuration example of the high-speed data line interface of a disk recorder and a television receiver.</figref><figref num="9">It is a connection diagram which shows the configuration example of the high-speed data line interface of a disk recorder and a television receiver.</figref><figref num="10">It is a figure which shows the data structure of AVI InfoFrame.</figref><figref num="11">It is a figure which shows the structure of the CEC data transmitted by a CEC line.</figref><figref num="12">It is a figure which shows the structural example of a header block.</figref><figref num="13">It is a figure which shows the logical address set according to the type of each device of HDMI.</figref><figref num="14">&lt;Exchange Supported Channels Info&gt; This is a sequence diagram for explaining a usage example of a message.</figref><figref num="15">It is a figure which shows the device configuration example of an AV system.</figref><figref num="16">It is a sequence diagram for demonstrating the use example of the &lt;Activate Supported Channels&gt; message.</figref><figref num="17">It is a sequence diagram for demonstrating the use example of the &lt;Activate Supported Channels&gt; message.</figref><figref num="18">It is a block diagram which shows the configuration example of an AV system.</figref><figref num="19">It is a figure for demonstrating an example of requesting that the HPD signal be set to "H" by changing the voltage of a power-source line without using the &lt;Request HPD = H&gt; message.</figref><figref num="20">It is a connection diagram which shows the configuration example of the high-speed data line interface of a disk recorder and a television receiver.</figref><figref num="21">It is a figure which shows the voltage change example of HPD line and reserve line.</figref><figref num="22">It is a block diagram which shows the configuration example of a disk recorder and a television receiver in the case where function information and corresponding transmission format information are sent from a disk recorder to a television receiver, and the corresponding transmission format information is sent from a television receiver to a disk recorder.</figref><figref num="23">It is a figure which shows the voltage control example of HPD line by a TV receiver (sink device) side, and the voltage control example of the reserve line by the disk recorder (source device) side and the TV receiver (sink device) side corresponding to it.</figref><figref num="24">It is a block diagram which shows the configuration example of the television receiver provided with a plurality of, for example, three HDMI terminals.</figref><figref num="25">It is a figure which shows the operation example when the sink device has multiple HDMI inputs.</figref><figref num="26">It is a flowchart which shows an example of the processing procedure when the CPU of a television receiver (sink device) performs a detection operation with respect to a predetermined HDMI input.</figref><figref num="27">It is a figure which shows the example of the voltage change of HPD line and reserve line when the CPU of a sink device determines that the source device of the other side is a device which does not support eHDMI.</figref><figref num="28">It is a figure for demonstrating the retry process which requests the source device of the other side to transmit the function information, etc. again when the response from the source device does not come even after 100 ms elapses.</figref><figref num="29">It is a flowchart which shows an example of the processing procedure of the CPU of a disk recorder (source device).</figref><figref num="30">It is a figure which shows the configuration example of a disk recorder and a television receiver in the case where function information and corresponding transmission format information are sent from a disk recorder to a television receiver, and the corresponding transmission format information is sent from a television receiver to a disk recorder.</figref><figref num="31">It is a figure which shows the voltage control example of the reserve line.</figref><figref num="32">It is a figure which shows the operation example when the sink device has multiple HDMI inputs.</figref><figref num="33">It is a flowchart which shows an example of the processing procedure of the CPU of the sink device at the time of making a request from a sink device.</figref><figref num="34">It is a figure which shows the example of the voltage change of the reserve line when the CPU of the sink device determines that the source device of the other side is a device which does not support eHDMI.</figref><figref num="35">It is a figure for demonstrating the retry process which requests the source device of the other side to transmit the function information again when the response from the source device does not come even after 2 seconds.</figref><figref num="36">It is a flowchart which shows an example of the processing procedure of the CPU of the sink device at the time of making a request from a source device.</figref><figref num="37">It is a flowchart which shows an example of the processing procedure of the CPU of the source device at the time of making a request from a source device.</figref><figref num="38">It is a flowchart which shows an example of the processing procedure of the CPU of the source device at the time of making a request from a sink device.</figref><figref num="39">It is a block diagram which shows the other configuration example of an AV system.</figref>

Code description

10 ... AV system, 11, 12 ... CDC device, 13 ... Non-CDC device, 11a, 11b, 12a, 13a ... HDMI terminal, 14, 15 ... HDMI cable, 200 .... AV system, 210 . . . Disc recorder, 211 . . . HDMI terminal, 212 . . . HDMI transmitter, 213 . . . High-speed data line interface, 250 . . . TV receiver, 251 . . . HDMI terminal, 252 ... HDMI receiver, 253 ... High-speed data line interface, 350 ... HDMI cable, 417 ... SPDIF receiving circuit, 449 ... SPDIF transmitting circuit