JP2008204267A - Transmission device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform power control in a short time not through an external control device by directly controlling an inner set register group based on a discrimination result in a cable connection detection circuit. <P>SOLUTION: This transmission device includes: a digital processing part 122 for processing video and voice data; a communication processing part 121 for transmitting data from the digital processing part 122 to a receiver 140 and discriminating the communication state (enable/disable) with the receiver 140; the connection state detecting circuit 114 for discriminating whether or not the connecting state with the receiver 140; the register group 113 for controlling the digital processing part 122 and the communication processing part 121; an interruption informing part 111 for informing the state of the register group 113 to an optional external control device 130; and an interface part 112 for communicating with the external control device 130. The connecting state detecting circuit 114 discriminates the connection state with the receiver 140, directly controls the register group 113 according to the results, and automatically controls the power of the transmission device. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a high-speed interface used for transmitting video and audio information between a transmission apparatus and a reception apparatus, and more particularly to a transmission device compliant with the HDMI (High Definition Multimedia Interface) standard.

  FIG. 5 is a block diagram showing a configuration related to a conventional HDMI transmission device. In the figure, reference numeral 540 indicates a receiving apparatus including an HDMI receiving device. Reference numeral 550 indicates an HDMI cable used for transmission of video / audio information, and reference numerals 550 a and 550 b indicate signal lines constituting the HDMI cable 550. Audio / video information and information indicating whether communication with the receiving device 540 is possible or not are transmitted to the signal line 550a, and information indicating whether the receiving device 540 is connected or not is transmitted to the signal line 550b. .

  Reference numeral 522 denotes a digital processing unit that performs digital processing of video / audio information. Reference numeral 521 denotes a communication processing unit that transmits video / audio information from the digital processing unit 522 to the receiving device 540. Reference numeral 523 denotes a communication state detection circuit that is installed in the communication processing unit 521 and determines whether communication with the receiving device 540 is possible or impossible. Reference numeral 520 denotes a video / audio processing unit including a communication processing unit 521 and a digital processing unit 522.

  Reference numeral 514 denotes a connection state detection circuit that determines whether the receiver 540 is connected via the HDMI cable 550.

  Reference numeral 513 denotes a register group for controlling the video / audio processing unit 520. Reference numeral 513 a denotes a connection state register that is provided in the register group 513 and holds information from the connection state detection circuit 514. Reference numeral 513b denotes a power control register provided in the register group 513 for performing power control of the video / audio processing unit 520. Reference numeral 513 c denotes a communication state register that is provided in the register group 513 and holds information from the communication state detection circuit 523.

Reference numeral 511 denotes an interrupt notification unit for notifying the outside of information change of an arbitrary register provided in the register group 513. Reference numeral 512 denotes an I ² C bus interface unit (I ² C I / F unit) that performs communication with an arbitrary external control device. Reference numeral 510 denotes a control unit including a connection state detection circuit 514, a register group 513, an interrupt notification unit 511, and an I ² C bus interface unit 512.

Reference numeral 560 indicates an I ² C bus.

Reference numeral 500 indicates a transmission device including a control unit 510 and a video / audio processing unit 520. Reference numeral 530 denotes an external control device connected to the transmission device 500 via the I ² C bus 560.

The external control device 530 makes a desired setting to the registers provided in the register group 513 via the I ² C bus 560. The digital processing unit 522 processes the input video / audio information in accordance with the set value of the register provided in the register group 513, and delivers it to the communication processing unit 521. The communication processing unit 521 transmits the video / audio information received from the digital processing unit 522 to the receiving device 540 via the HDMI cable 550. The receiving apparatus 540 displays the video / audio information received from the transmitting device 500 on an arbitrary apparatus or stores it on an arbitrary apparatus. Note that description of the receiving device 540 and subsequent processing will be omitted here.

  For example, the transmission device 500 receives video information and audio information with a resolution of 640 × 480 from an arbitrary external device (not shown), while the reception device 540 has a video with a resolution of 640 × 480 or 1920 × 1080. It can handle information and audio information. At this time, if the external control device 530 is set to transmit the video information with the resolution of 640 × 480, the digital processing unit 522 performs no processing on the input video information with the resolution of 640 × 480. Then, the communication processing unit 521 converts video information and audio information having a resolution of 640 × 480 into data packets conforming to the HDMI standard, and transmits the data packets to the receiving device 540.

  If the external control device 530 is set to transmit video information at a resolution of 1920 × 1080, the digital processing unit 522 changes the resolution (640 × 480 → 1920 × 1080), and the communication processing unit 521 The changed video information and audio information are converted into data packets conforming to the HDMI standard and transmitted to the receiving device 540.

  When the transmission device 500 and the reception device 540 are connected by the HDMI cable 550, the connection state detection circuit 514 writes High (hereinafter referred to as “H”) level information to the connection state register 513a and is connected. Low (hereinafter referred to as “L”) level information is written when the state is not connected (the HDMI cable 550 is not connected to either device or only one of them is not connected).

The connection status register 513a to which level information is written from the connection status detection circuit 514 notifies the external control device 530 of changes in level information via the interrupt notification unit 511 every time the level information is rewritten. In response to the notification from the interrupt notification unit 511, the external control device 530 reads the contents of the connection status register 513a via the I ² C bus 560.

When the information read from the connection status register 513a is “L” level after notification from the interrupt notification unit 511, the external control device 530 is not connected to the transmission device 500 and the reception device 540 via the HDMI cable 550. And the predetermined (“L” or “H”) level information in the control register (not shown) for the communication processing unit 521 provided in the register group 513 via the I ² C bus 560. , The transmission operation of the communication processing unit 521 is stopped, and the transmission of video / audio information to the receiving device 540 is stopped.

Furthermore, not being connected to the receiving device 540 means that the transmitting device 500 is not in use alone, and in this case, it is desirable to suppress the power of the transmitting device 500, so that the transmission device 500 does not pass through the I ² C bus 560. Then, the “L” level information is written in the power control register 513b, the operation of the video / audio processing unit 520 is stopped, and the power is suppressed.

If the information read from the connection status register 513a is “H” level after notification from the interrupt notification unit 511, it is determined that the transmission device 500 and the reception device 540 are connected via the HDMI cable 550, and I ² The “H” level information is written to the power control register 513b via the C bus 560, the stop of the video / audio processing unit 520 is released (the power suppression state is released), and the set value of the register provided in the register group 513 Process according to the.

In addition to using the notification from the interrupt notification unit 511, the external control device 530 reads the contents of the connection status register 513a via the I ² C bus 560 every arbitrary time, and the information is at the “H” level. Or “L” level, and there is a method of performing power control using the power control register 513b according to the result.

  When the transmission device 500 and the reception device 540 are connected via the HDMI cable 550 (when the content of the connection state register 513a is at “H” level), the reception device 540 is turned off, or the transmission device When communication with 500 becomes impossible, the predetermined signal of the signal line 550a becomes “L” level, and when communication becomes possible, the predetermined signal of the signal line 550a becomes “H” level.

  When the communication state detection circuit 523 detects that the predetermined signal of the signal line 550a is at the “L” level, the communication state detection circuit 523 writes the “L” level information to the communication state register 513c, and detects that the predetermined signal on the signal line 550a is at the “H” level. Write “H” level information to the status register 513c. Further, every time the state of the communication state register 513c changes, the interrupt notification unit 511 notifies the external control device 530 of the change of the communication state register 513c.

  After the notification from the interrupt notification unit 511, when the content of the communication status register 513c is “L” level, the external control device 530 writes “L” level information to the power control register 513b and stops the operation of the video / audio processing unit 520. Let the power be suppressed. This is a state in which the receiving device 540 is connected by the HDMI cable 550, but the transmitting device 500 that does not communicate with the receiving device 540 is the same as the single unused state. Perform power control. When the content of the communication status register 513c is “H” level, “H” level information is written in the power control register 513b. In this case, since the operation of the video / audio processing unit 520 does not stop, the video / audio transmission between the transmission device 500 and the reception device 540 is continued.

  Even in a field where such a transmission device 500 is applied, it is possible to reduce power consumption through accurate power control with respect to trivial matters such as cable insertion / extraction or changes in the state of a connected device, and environment such as energy saving / carbon dioxide emission. It is essential to tackle the problem.

For such a configuration, there is a device as disclosed in Patent Document 1 that realizes low power consumption.
Japanese Patent Laid-Open No. 2005-216046

However, in the configuration as described above, in the power control of the transmission device 500, the external control device 530 causes the “waiting for notification from the interrupt notification unit 511” → “reading contents of the connection status register 513a” → “contents of the connection status register 513a”. “Determination” → “Setting of power control register 513b” or “Reading contents of connection state register 513a (repeat until information changes)” → “Determination of contents of connection state register 513a” → “Setting of power control register 513b” Perform multiple processes. Furthermore, since reading and writing to the register group 513 is performed via the I ² C bus 560, taking this communication speed into consideration, the HDMI cable 550 is in a power-suppressed state after the HDMI cable 550 is disconnected, or the HDMI cable 550. It took time until the power suppression was released after the device became connected.

  Further, when the transmission device 500 and the reception device 540 are connected via the HDMI cable 550, the reception device 540 is turned off, or communication with the transmission device 500 becomes impossible and the communication state detection circuit 523 When the power suppression state is reached, the video / audio processing unit 520 is in the stopped state, so the communication state detection circuit 523 provided therein is also in the stopped state. The fact that the predetermined signal of the HDMI cable 550a has changed to the “L” level can be determined by notification from the interrupt notification unit 511 or by reading the contents of the communication status register 513c, but the predetermined signal of the HDMI cable 550a is “H”. Since the change to the “level” cannot be detected, the power suppression cannot be released.

  An object of the present invention is to provide a transmission device that can directly control a control unit and perform power control in a short time without using an external control device based on a determination result in a connection state detection circuit. .

  Another object of the present invention is to provide a transmission device that allows a communication state detection circuit to function in a state where it is cable-connected to an external device and can perform power control similar to that of the connection state detection circuit based on the determination result. It is to be.

  In order to solve the above problems, a transmitting device of the present invention includes a digital processing means for digitally processing video / audio data, a communication processing means for transmitting data from the digital processing means to an arbitrary external device, a communication processing means, Connection state determination means for determining whether or not the external device is in a connected state, control means for controlling the digital processing means and communication processing means including power control, and the state of the control means for any external control device A notification means for notification and an interface means for performing communication between the external control device and the control means, and the connection state determination means directly controls the control means based on the result of determining the connection state with the external device. This causes the control means to perform power control of the digital processing means and the communication processing means.

  According to this configuration, since the power control of the digital processing unit and the communication processing unit is performed by directly controlling the control unit by the connection state detection unit, the power control can be performed automatically and in a short time. In addition, since power control is not performed via the external control device, the external control device can allocate processing time related to power control to other processing, and the use efficiency of the external control device can be improved.

  In the above-described configuration, it is preferable to include a first power control switching unit that switches between enabling and disabling power control of the digital processing unit and the communication processing unit by directly controlling the control unit by the connection state determination unit.

  According to this configuration, by providing the first power control switching means, it becomes possible to select a control method according to the specification (situation), and usability can be improved.

  In the above configuration, the first power control switching means is preferably controlled to be switched by the control means.

  In the above configuration, the communication state determination unit is provided for determining whether the communication between the external device and the communication processing unit is possible or not. The communication state determination unit has a power source separated from the digital processing unit and the communication processing unit. The communication state determining means can cause the control means to perform power control of the digital processing means and the communication processing means by directly controlling the control means based on the result of determining the communication state with the external device. preferable.

  According to this configuration, since the power control of the digital processing unit and the communication processing unit is performed by directly controlling the control unit by the communication state control circuit, the power control can be performed automatically and in a short time. In addition, since power control is not performed via the external control device, the external control device can allocate processing time related to power control to other processing, and the use efficiency of the external control device can be improved.

  In the above configuration, it is preferable to include a digital processing unit by directly controlling the control unit by the communication state determination unit and a second power control switching unit that switches between enabling and disabling power control of the communication processing unit.

  According to this configuration, by providing the second power control switching means, it is possible to select a control method according to the specification (situation) and to improve usability.

  In the above configuration, it is preferable that the second power control switching unit is controlled to be switched by the control unit.

  With this configuration, when cable insertion / extraction occurs, power control can be performed in a short time without using an external control device, so that the power saving section is extended and power consumption can be further suppressed.

  Furthermore, similar power control is possible even in a state where the device is connected to the counterpart device (external device) by a cable, and similarly, the power saving section is extended and the power consumption can be further suppressed.

  Furthermore, by making it possible to switch the power control method, it is possible to flexibly cope with the specification (situation), so that the device is easy to use.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
Embodiment 1 of the present invention will be described below with reference to the drawings.

  FIG. 1 is a block diagram showing the configuration of the transmission device of the present invention. In the figure, reference numeral 140 denotes a receiving apparatus including an HDMI receiving device. Reference numeral 150 denotes an HDMI cable used for transmission of video / audio information, and reference numerals 150 a and 150 b denote signal lines constituting the HDMI cable 150. Audio / video information and information indicating whether communication with the receiving device 140 is possible or not are transmitted to the signal line 150a, and information indicating whether the receiving device 140 is connected or not is transmitted to the signal line 150b. .

  Reference numeral 122 denotes a digital processing unit that performs digital processing of video / audio information. Reference numeral 121 denotes a communication processing unit that transmits video / audio information from the digital processing unit 122 to the receiving device 140. Reference numeral 123 denotes a communication state detection circuit that is installed in the communication processing unit 121 and determines whether communication with the receiving apparatus 140 is possible or impossible. Reference numeral 120 denotes a video / audio processing unit including a communication processing unit 121 and a digital processing unit 122.

  Reference numeral 114 denotes a connection state detection circuit that determines whether or not the HDMI apparatus 150 is connected to the receiving device 140. Reference numeral 113 denotes a register group for controlling the video / audio processing unit 120. These register groups 113 function as control means. Reference numeral 113 a denotes a connection state register that is provided in the register group 113 and holds information from the connection state detection circuit 114. Reference numeral 113 b denotes a power control register provided in the register group 113 for performing power control of the video / audio processing unit 120. The power control register 113b is configured to be directly controllable from the connection state detection circuit 114. When the “L” level is written, the video / audio processing unit 120 is stopped and the “H” level is written into the power suppression state. The video / audio processing unit 120 is stopped and the power suppression state is also released. Reference numeral 113 c denotes a communication status register that is provided in the register group 113 and holds information from the communication status detection circuit 123. The register group 113 includes a register (not shown) for controlling the digital processing unit 122 and the communication processing unit 121 in addition to the above-described registers.

Reference numeral 111 denotes an interrupt notification unit for notifying the outside of a change in information of a register provided in the register group 113. Reference numeral 112 denotes an I ² C bus interface unit (I ² C I / F unit) that performs communication with an arbitrary external control device 130. Reference numeral 110 </ ^b > A denotes a control unit including a connection state detection circuit 114, a register group 113, an interrupt notification unit 111, and an I ² C bus interface unit 112.

Reference numeral 160 denotes an I ² C bus.

Reference numeral 100 denotes a transmission device including the control unit 110 </ b> A and the video / audio processing unit 120. Reference numeral 130 denotes an external control device connected to the transmission device 100 via the I ² C bus 160.

The external control device 130 makes a desired setting to the registers provided in the register group 113 via the I ² C bus 160. The digital processing unit 122 processes the input video / audio information in accordance with a set value of a register provided in the register group 113 and passes it to the communication processing unit 121. The communication processing unit 121 transmits the video / audio information received from the digital processing unit 122 to the receiving device 140 via the HDMI cable 150. The receiving apparatus 140 displays or saves the video / audio information received from the transmitting device 100 on an arbitrary apparatus. Note that description of the receiving device 140 and subsequent processing is omitted here.

  When the transmission device 100 and the reception device 140 are connected by the HDMI cable 150, the connection state detection circuit 114 writes “H” level information indicating the connection state in the connection state register 113a, and at the same time, the power control register “H” level information is also written in 113b. When the “H” level information is written, the power control register 113b has a specification that does not suppress the power of the transmission device 100, and thus the process according to the set value of the register group 113 is continued.

  When the transmitting device 100 and the receiving device 140 are not connected by the HDMI cable 150, or when only one of them is not connected, the connection state detection circuit 114 indicates the “L” level indicating the non-connection state in the connection state register 113a. At the same time that the information is written, the “L” level information is also written to the power control register 113b. When the “L” level information is written in the power control register 113b, the power control register 113b is designed to suppress the power of the transmitting device 100. Therefore, the video / audio processing unit 120 is stopped and the power control register 113b shifts to the power suppression state. Since the video / audio processing unit 120 is stopped, the transmission of video / audio information from the transmission device 100 to the reception device 140 is also stopped. At this time, the controller 110A does not stop.

  The connection state register 113a to which level information indicating the current connection state is written from the connection state detection circuit 114 is an interrupt notification unit every time the level information changes (“H” → “L” or “L” → “H”). A change in level information is notified to the external control device 130 via 111.

In response to the notification from the interrupt notification unit 111, the external control device 130 reads the contents of the connection state register 113a via the I ² C bus 160 and obtains the current power control state. Alternatively, the current power control state may be obtained by continuously reading the contents of the connection state register 113a via the I ² C bus 160 regardless of the notification from the interrupt notification unit 111.

  As described above, according to the first embodiment, by directly controlling the power control register 113b for power control by the connection state detection circuit 114, the power control of the transmission device 100 can be performed automatically and in a short time. it can.

  Furthermore, it becomes possible for the external control device 130 to allocate processing time related to power control to other processing, and the use efficiency of the external control device 130 can be improved. Further, the power control state can be notified to the external control device 130 at any time.

  The definition of the information level and the stop control specification of each part in the power suppression state are not limited to those in the first embodiment.

(Embodiment 2)
Embodiment 2 of the present invention will be described below with reference to the drawings.

  FIG. 2 is a block diagram showing a configuration of control unit 110B provided in the transmission device according to the second embodiment of the present invention. The control unit 110B is used in place of the control unit 110A in FIG. 1, and the configuration of the other transmission devices is the same as that of the first embodiment shown in FIG. To do.

  Reference numeral 114a denotes a first switch for switching whether to directly control the power control register 113b using level information ("H" or "L") indicating the connection state of the HDMI cable 150 detected by the connection state detection circuit 114. Means are shown.

Reference numeral 113e denotes a first switching means register for controlling the first switching means 114a. Since the first switching means register 113e is provided in the register group 113, it can be read and written from the external control device 130 via the I ² C bus 160.

  When the “H” level information is set in the first switching means register 113e by the external control device 130, the first switching means 114a switches so as to permit direct control of the power control register 113b by the connection state detection circuit 114. It is done. The level information is written to the connection status register 113a regardless of the setting of the first switching means register 113e. Since the subsequent operations are the same as the contents of the first embodiment, description thereof is omitted here.

  When “L” level information is set in the first switching means register 113e by the external control device 130, the first switching means 114a is switched so as to prohibit direct control of the power control register 113b by the connection state detection circuit 114. . The level information is written into the connection state register 113a regardless of the setting of the first switching means register 113e. In this case, since the power control of the transmitting device 100 is not automatically performed, the power control is performed by writing a desired set value in the power control register 113b by the external control device 130 as usual.

  As described above, according to the second embodiment, the power control by the connection state detection circuit 114 can be switched to either automatic control or manual control, thereby selecting a control method according to the specification (situation). This makes it possible to improve usability.

  Note that the definition of the information level and the stop control specification of each part in the power suppression state are not limited to those of the second embodiment.

(Embodiment 3)
The third embodiment of the present invention will be described below with reference to the drawings.

  FIG. 3 is a block diagram showing a configuration of transmitting device 100C according to the third embodiment of the present invention. The transmission device 100C is used in place of the transmission device 100 of FIG. 1, and the other configuration is the same as that of the first embodiment shown in FIG.

  In this transmission device 100C, the communication state detection circuit 123 is separated from the video / audio processing unit 120, the power supply is independent from the video transmission processing unit 120, and even if the power of the video transmission processing unit is shut off, Power supply to the communication state detection circuit 123 is configured to continue. The communication state detection circuit 123 writes data to the communication state register 113c and also writes data directly to the power control register 113b. That is, the control unit 110C is used instead of the control unit 110A.

  Even when the receiving device 140 is turned off while the transmitting device 100 and the receiving device 140 are connected by the HDMI cable 150, or when the communication becomes impossible, the HDMI cable 150 is still connected. Therefore, there is no change in level information by the connection state detection circuit 114, and the connection state register 113a and the power control register 113b hold “H” level information. However, the communication state detection circuit 123 writes “L” level information indicating the communication disabled state to the communication state register 113c when the power of the receiving device 140 is turned off or when the communication is disabled, and at the same time, the power control register Since “L” level information is also written to 113b, “L” level information is written to the power control register 113b as a result. By this “L” level information writing, the video / audio processing unit 120 is stopped and the state is shifted to the power suppression state. The external control device 130 is notified by the interrupt notification unit 111 that the content of the communication status register 113c has changed.

  When the power of the receiving device 140 is turned off → on or communication is disabled → communication enabled when the transmission device 100 and the receiving device 140 are connected by the HDMI cable 150, the level of the connection status detection circuit 114 There is no change in information, and the connection state register 113a holds “H” level information, and the power control register 113b holds “L” level information. However, the communication state detection circuit 123 writes “H” level information indicating the communicable state in the communication state register 113c and simultaneously writes “H” level information in the power control register 113b. As a result, the communication state detection circuit 123 writes in the power control register 113b. "H" level information is written. This “H” level information writing cancels the suspension of the video / audio processing unit 120 and simultaneously cancels the power suppression state. The external control device 130 is notified by the interrupt notification unit 111 that the content of the communication status register 113c has changed.

  In this way, the suspension of the video / audio processing unit 120 can be released because the communication state detection circuit 123 is separated from the video / audio processing unit 120, the power supply to the communication state detection circuit 123 is continued, and the communication state detection circuit 123 This is because it continues to operate.

  As described above, according to the third embodiment, the power control of the transmission device 100C can be performed automatically and in a short time by directly controlling the power control register 113b for power control by the communication state detection circuit 123. Can do.

  Furthermore, the external control device can allocate processing time related to power control to other processing, and the use efficiency of the external control device can be improved. Further, the power control state can be notified to the external control device at any time.

  Furthermore, since only the communication state detection circuit 123 is separated, an increase in device price can be suppressed.

  Note that the definition of the information level and the stop control specifications of each part in the power suppression state are not limited to those of the third embodiment.

  In the third embodiment, the same implementation contents are provided even when the same first switching means as in the second embodiment is provided.

(Embodiment 4)
Embodiment 4 of the present invention will be described below with reference to the drawings.

  FIG. 4 is a block diagram showing the configuration of the control unit 110D and the communication state detection circuit 123D in the transmission device of the present invention. Since other configurations are the same as those of the first embodiment, illustration and description are omitted.

  Reference numeral 123a denotes second switching means for switching whether to directly control the power control register 113b using level information ("H" or "L") indicating the communication state detected by the communication state detection circuit 123.

Reference numeral 113d denotes a second switching means register for controlling the second switching means 123a. Since the second switching means register 113d is provided in the register group 113, it can be read and written from the external control device 130 via the I ² C bus 160.

  As in FIG. 3, the communication state detection circuit 123 is separated from the audio / video processing unit 120 and has an independent power source.

  When “H” level information is set in the second switching means register 113d by the external control device 130, the second switching means 123a switches so as to permit direct control of the power control register 113b by the communication state detection circuit 123. It is done. The level information is written into the communication status register 113c regardless of the setting of the second switching means register 113d. Since the subsequent operation is the same as that of the third embodiment, the description thereof is omitted here.

  When “L” level information is set in the second switching means register 113d by the external control device 130, the second switching means 123a switches so as to prohibit direct control of the power control register 113b by the communication state detection circuit 123D. It is done. The level information is written into the communication status register 113c regardless of the setting of the second switching means register 113d.

  In this case, since power control is not automatically performed, the external control device 130 performs power control by writing a desired set value in the power control register 113b as usual.

  As described above, according to the fourth embodiment, the power control by the communication state detection circuit 123D can be switched to either automatic control or manual control, thereby selecting a control method according to the specification (situation). It is possible to improve the usability.

  In the fourth embodiment, the same implementation contents are provided even when the same first switching means as in the second embodiment is provided.

  Note that the definition of the information level and the stop control specifications of each part in the power suppression state are not limited to those of the fourth embodiment.

  The transmission device of the present invention is useful for power control of high speed interfaces used to transmit video and audio information.

It is a block diagram which shows the structure of the transmission device of Embodiment 1 of this invention. It is a block diagram which shows the structure of the transmission device which provided the switching means of Embodiment 2 of this invention. It is a block diagram which shows the structure of the transmission device of Embodiment 3 of this invention. It is a block diagram which shows the structure of the transmission device which provided the switching means of Embodiment 4 of this invention. It is a block diagram which shows the structure of the conventional transmission device.

Explanation of symbols

100 ... transmitting device 110 ... controller 111 ... interrupt notification unit 112 ... ^{I 2} C bus interface unit 113 ... register group 113a ... connection status register 113b ... power control register 113c ... communication status register 114 ... connection status detection circuit 120 ... audiovisual Processing unit 121 ... Communication processing unit 122 ... Digital processing unit 123 ... Communication state detection circuit 130 ... External control device 140 ... Receiving device 150 ... HDMI cable 150a ... Signal line constituting HDMI cable 150b ... Signal line constituting HDMI cable 160 ... I ² C bus

Claims (6)

Digital processing means for digitally processing video / audio data, communication processing means for transmitting data from the digital processing means to an arbitrary external device, and whether the communication processing means and the external device are in a connected state A connection state determination means, a control means for controlling the digital processing means and the communication processing means including power control, a notification means for notifying the state of the control means to an arbitrary external control device, An interface means for performing communication between the control device and the control means,
The connection state determination unit causes the control unit to perform power control of the digital processing unit and the communication processing unit by directly controlling the control unit based on a result of determining a connection state with the external device. Transmitting device characterized.   The transmission according to claim 1, further comprising a first power control switching unit that switches between enabling and disabling power control of the digital processing unit and the communication processing unit by directly controlling the control unit by the connection state determination unit. device. The transmission device according to claim 2, wherein the first power control switching unit is controlled to be switched by the control unit. Comprising a communication state determining means for determining whether or not communication between the external device and the communication processing means is possible,
The communication state determination means is provided with a power source separated from the digital processing means and the communication processing means,
The communication state determination unit causes the control unit to perform power control of the digital processing unit and the communication processing unit by directly controlling the control unit based on a result of determining a communication state with the external device. The transmission device according to claim 1.   5. The transmission according to claim 4, further comprising: a second power control switching unit that switches between enabling and disabling power control of the digital processing unit and the communication processing unit by directly controlling the control unit by the communication state determination unit. device. The transmission device according to claim 5, wherein the second power control switching unit is controlled to be switched by the control unit.

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