JP5171345B2 - Receiving apparatus and program - Google Patents

Description

The present invention relates to a receiving apparatus and a program.

  In the High-Definition Multimedia Interface (HDMI) that is a digital signal transmission standard, a standard relating to CEC (Consumer Electronics Control) for device control is defined. By using this CEC function, it is possible to remotely operate devices connected by an HDMI cable. For example, when a playback button of a recording device connected to a television with an HDMI cable is pressed, the television is turned on, and the input of the television can be switched to the input to which the recording device is connected. .

  In order to realize this input switching, an address called a physical address indicating a physical connection relationship of devices is used. FIG. 10 shows the correspondence between this connection relationship and each physical address.

  The television 1001 located at the top of the connection tree has a physical address “0.0.0.0”. A device connected to the television 1001 acquires a different physical address depending on the connected input terminal. The physical address is stored in EDID (Extended Display Identification Data) -ROM (1008, 1009 in FIG. 11) that the television 1001 has.

  As shown in FIG. 11, the physical address “1.0.0.0” is stored in the EDID-ROM 1008 of the input terminal 1 of the television, and the physical address “2.0.0.0” is stored in the EDID-ROM 1009 of the input terminal 2. "Is stored. Therefore, the devices connected to the input terminal 1 and the input terminal 2 read the contents of the respective EDID-ROMs by DDC (Display Data Channel) communication, and recognize the read physical address as the physical address of the device. For example, the DVD recorder 1002 connected to the input terminal 1 of the television acquires the physical address “1.0.0.0”. Further, the AV amplifier 1003 connected to the input terminal 2 acquires the physical address “2.0.0.0”.

  In addition, the Blu-ray disc recorder (BD) 1004 connected to the input terminal 1 of the AV amplifier 1003 reads the EDID-ROM of the connected terminal and acquires the physical address “2.1.0.0”. Similarly, the HD-DVD 1005 acquires the physical address “2.2.0.0”, and the set top box (STB) 1006 acquires the physical address “2.3.0.0”. Hereinafter, when the hierarchy is deeper, the connection relationship is expressed by using the third digit and the fourth digit of the physical address. In FIG. 10, the PVR 1007 acquires the physical address “2.3.1.0” using up to the third digit of the physical address.

Each connected device can grasp the physical connection relationship with each device by knowing the physical address of each other. Each source device connected to the television 1001 (directly or via another device) transmits the acquired physical address to the television 1001 using a CEC command. Accordingly, the television 1001 can determine from which input terminal the video source is supplied based on the physical address, and thus can select an appropriate input. For example, Patent Document 1 discloses a method of using EDID.
JP 2005-528853 A

  By the way, among the devices compatible with the CEC of the HDMI standard, there are devices that have specifications that cannot read their own EDID-ROM when the power supply is in a standby (or off) state. A device connected to such a device cannot read the EDID-ROM and cannot acquire an appropriate physical address. As a result, the device may recognize an inappropriate address as its own physical address. If the device is controlled using CEC in this state, an input switching error may occur due to an inappropriate physical address.

For example, in FIG. 10, it is assumed that the AV amplifier 1003 is not turned on and access to the EDID-ROM of the AV amplifier 1003 is impossible. At this time, the device connected to the AV amplifier 1003 operates as follows, for example, depending on the design.
-Recognize the initial physical address (for example, “1.0.0.0”) as its own physical address.
-Retain the previously acquired physical address and recognize it as the current physical address.
・ The CEC function is disabled and operations using the CEC command become impossible.

  The correct physical address of the BD 1004 in FIG. 10 is “2.1.0.0”, but it is assumed that the EDID-ROM of the AV amplifier 1003 cannot be read. At this time, it is assumed that the BD 1004 recognizes “1.0.0.0” that was previously obtained as its physical address. Here, the user presses the playback button of the BD 1004 to perform one-touch play (a series of operations in which the sink device is turned on and switched to an appropriate input by pressing the playback button of the source device connected via HDMI). In this case, the BD 1004 transmits to the television 1001 a physical address “1.0.0.0” that is different from the actual value. Receiving it, the television 1001 switches the input terminal of the external device to “input terminal 1”. As a result, the video of the DVD recorder 1002 that is not the video of the BD 1004 that the user intends to view is output from the television 1001. Such an operation is not the operation desired by the user.

  Thus, if an inappropriate device cooperation operation is performed, the CEC function, which should be a great merit for the user, cannot be fully utilized.

An object of the present invention is to prevent a device corresponding to the HDMI standard from recognizing an erroneous physical address.

According to the High-Definition Multimedia Interface (HDMI) standard, the receiving device according to the present invention detects a communication unit that communicates with an external device, a first physical address corresponding to the first external device, and a second physical address. Detecting means for detecting a second physical address corresponding to the external device and detecting a third physical address corresponding to the third external device, and the first physical address and the second physical address. Control means for turning off the power of the first external device if they match, and if the first physical address and the second physical address match, the third physical address When the physical address and the first physical address do not match and the third physical address and the second physical address do not match, the control means Controlling the power supply of the third external device to cause the second external device to perform processing for acquiring a physical address, and the detecting means controls the power supply of the third external device. The first physical address and the second physical address are detected from the first physical address and the second physical address does not match the first physical address and the second physical address. If the address does not match , the control means turns on the power of the first external device, and the second external device communicates with the communication means via the third external device. It is characterized by performing communication .

The program according to the present invention is a program for controlling a receiving device that communicates with an external device in accordance with the HDMI (High-Definition Multimedia Interface) standard, and is a first program corresponding to the first external device. Detecting a physical address of the second external device, detecting a second physical address corresponding to a second external device that communicates with the receiving device via a third external device, and a third external device. detecting a corresponding third physical address, and a step to make the case of the first physical address and the second physical address matches, not turn on the power of the first external device, When the first physical address and the second physical address match, the third physical address and the first object If the third physical address does not match the second physical address without matching the address, the third external address is processed to cause the second external device to perform processing for obtaining the physical address. A step of controlling the power supply of the external device; a step of detecting the first physical address and the second physical address after the power supply of the third external device is controlled; and the first physical address and the in the case where a second physical address does not match, if the first physical address and the said third physical address does not match, and a step of the to turn on the power source of the first external device A program for causing a computer to execute.

  Other features of the present invention will become more apparent from the accompanying drawings and the following description of the best mode for carrying out the invention.

According to the present invention, Ru can and child so as not to recognize the Physical address incorrect device compatible with the HDMI standard.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. The individual embodiments described below will help to understand various concepts from the superordinate concept to the subordinate concept of the present invention.

  The technical scope of the present invention is determined by the scope of the claims, and is not limited by the following individual embodiments. In addition, all combinations of features described in the embodiments are not necessarily essential to the present invention.

  FIG. 1 is a block diagram illustrating a configuration of a broadcast receiving apparatus 100 according to Embodiment 1 of the present invention. The broadcast receiving apparatus 100 has a control unit 101 that controls the whole. Also, it has two HDMI receiving units, an HDMI receiving unit-A102 and an HDMI receiving unit-B103.

  The HDMI receiving unit-A102 has an EDID-ROM-A104, and the HDMI receiving unit-B103 has an EDID-ROM-B105.

  The broadcast receiving apparatus 100 includes a CEC transmission / reception unit 106 that transmits and receives CEC commands, a TMDS switching unit 107 that is controlled by the control unit 101, and a video switching unit 108. In addition, it includes a video display unit 109 that displays a video selected according to switching by the TMDS switching unit 107 and the video switching unit 108, and a tuner unit 110 that receives broadcast waves.

  In this embodiment, the broadcast receiving apparatus 100 has two HDMI input terminals, and accordingly has two HDMI receiving units and two EDID-ROMs. However, the number of HDMI input terminals is limited to two. Absent. Further, the tuner unit 110 is the same as that described in Chapters 4 to 6 of “ARIB STD-B21”, for example, and thus description thereof is omitted.

  The broadcast receiving apparatus 100 can communicate with other devices via an input terminal. Here, the broadcast receiving apparatus 100 can communicate not only with a device directly connected to the input terminal, but also with a device connected indirectly through another device.

  When the broadcast receiving apparatus 100 is connected to another device via the HDMI line A, the HDMI receiving unit-A102 receives a signal from the device. Among the received signals, the CEC signal is input to the CEC transmission / reception unit 106. The CEC transmission / reception unit 106 analyzes a command included in the CEC signal and transmits the analysis result to the control unit 101. The control unit 101 controls the TMDS switching unit 107 and the video switching unit 108 according to the contents of the CEC command, and switches the TMDS switching unit 107 and the video switching unit 108 as necessary. As a result, the video displayed on the video display unit 109 changes. These processes are the same when the broadcast receiving apparatus 100 is connected to other devices via the HDMI line B.

  For example, when the video switching unit 108 selects the HDMI input and the TMDS switching unit 107 selects the HDMI receiving unit-A102, the video input from the HDMI receiving unit-A102 is displayed on the video display unit 109. When the broadcast receiving apparatus 100 transmits a CEC command, the control unit 101 controls the CEC transmission / reception unit 106 and transmits the CEC command to an external device via the CEC line.

  The basic concept of the present embodiment will be described with reference to FIG. The basic concept of this embodiment is to turn on the power in order from a device close to the broadcast receiving apparatus 100. As a result, since power is turned on from a device located higher in the device connection tree, the lower device can read the EDID-ROM of the higher device and recognize an appropriate physical address when the power is turned on.

  In step S <b> 201, the control unit 101 controls the CEC transmission / reception unit 106 to transmit a CEC command asking for a physical address to all connected devices. Each device that has received the CEC command transmits a CEC command that informs its physical address to the broadcast receiving apparatus 100, so that the CEC transmission / reception unit 106 analyzes the received CEC command to identify the connected device. The physical address can be grasped.

  In step S <b> 202, the control unit 101 powers on a device whose second address of the physical address is “0”, that is, a device that is considered to be located in the next layer of the broadcast receiving apparatus 100. Thereafter, similarly in S203 and S204, the power of the lower devices is turned on one by one in order.

  The above is the basic concept of the present embodiment, but in reality, when there is a device that recognizes an incorrect physical address, the broadcast receiving apparatus 100 cannot know the correct hierarchy of the device. For example, as shown in FIG. 3, an AV amplifier 303 is connected to a television 301, the power state of the AV amplifier 303 is in a standby state, and the EDID-ROM of the AV amplifier 303 cannot be accessed in the standby state. Consider the case. (In FIG. 3, the television 301 corresponds to the broadcast receiving apparatus 100 of this embodiment. The same applies to the television 501 in FIG. 5 and the television 801 in FIG. 8.) In this case, a device connected to the AV amplifier 303 (FIG. 3 is STB 304. Actually, any CEC-compliant device may not be able to acquire an appropriate physical address. Therefore, it is assumed that the STB 304 recognizes “1.0.0.0” set as an initial value as its own physical address.

  As a result, since there are two devices having the physical address “1.0.0.0”, the broadcast receiving apparatus 100 cannot determine which device is the real “1.0.0.0”. If the broadcast receiving apparatus 100 turns on the power of the STB 304 before the AV amplifier 303, the STB 304 cannot access the EDID-ROM of the AV amplifier 303 and cannot correct an incorrect physical address.

  Therefore, in this embodiment, when a plurality of devices have the same physical address, the broadcast receiving apparatus 100 postpones the power-on of such devices.

  In this embodiment, a logical address is used to determine the order in which the power is turned on. The Logical address is an ID for device identification used in the CEC command, and there are 16 types from 0x00 to 0x0f. The numbers in parentheses beside each device name in FIG. 3 indicate the logical address.

  In this embodiment, when the broadcast receiving apparatus 100 turns on another device, if there is a device having the same physical address, the device is not turned on, and yet another device is turned on. Turn on the power first. In addition, every time the power of one device is turned on, a physical address updated by turning on the power is grasped by transmitting a CEC command for inquiring the physical address again to all the devices.

  FIG. 4 is a flowchart illustrating a procedure in which the broadcast receiving apparatus 100 turns on the power of other connected HDMI compatible devices. Unless otherwise specified, the processing of each step in this flowchart is performed by the control unit 101 executing a control program (the same applies hereinafter).

  In the processing of FIG. 4, power-on determination is performed in the order of Logical addresses. Here, N represents a logical address, and M represents a digit of the physical address.

  In step S401, the control unit 101 substitutes 0x01 for N. That is, in this embodiment, power on is attempted from a device having a logical address of 1.

  In step S402, the control unit 101 substitutes 0x02 for M. This is because, as described with reference to FIG. 2, devices in a hierarchy close to the broadcast receiving apparatus 100 have “0” Physical address in the second digit.

  In step S403, the control unit 101 controls the CEC transmission / reception unit 106 to transmit a CEC command asking for a physical address to all connected devices. Each device that has received the CEC command transmits a CEC command that informs its physical address to the broadcast receiving apparatus 100, so that the CEC transmission / reception unit 106 analyzes the received CEC command to identify the connected device. The physical address can be grasped.

  In step S404, the control unit 101 determines whether the device with Logical address = N is in a standby state. In the case of the standby state, the process proceeds to S405.

  In step S405, the control unit 101 determines whether the M-th digit of the physical address of the device with logical address = N is zero. If 0, the process proceeds to S406.

  In step S406, the control unit 101 determines whether there is another device having the same physical address as the device having Logical address = N. If not, the process proceeds to S407.

  In step S407, the control unit 101 turns on the power of the device having Logical address = N.

  In step S <b> 408, the control unit 101 waits while a device connected to the HDMI input terminal of the logical address = N device reads the EDID-ROM of the logical address = N device. When reading of the EDID-ROM is completed, the physical address of the device connected to the HDMI input terminal of the device with Logical address = N is updated.

  In step S409, the control unit 101 acquires the physical addresses of all devices as in step S403.

  In S410 and S411, the control unit 101 initializes N = 0x01 and M = 0x02, and returns to S404 to repeat the same processing.

  If the device of Logical address = N is not in the standby state in S404, it is not necessary to turn on the device, and the process proceeds to S412. Similarly, if the Mth digit of the physical address of the device with Logical address = N is not 0 in S405, the device is not located in the hierarchy to be powered on, and the process proceeds to S412. Further, if there is another device having the same physical address as the device with Logical address = N in S406, the process proceeds to S412 to postpone the power-on of the device.

  In step S412, the control unit 101 determines whether N is less than 0x0f. If it is less than 0x0f, 1 is added to N in S413, and the process returns to S404 and the same processing is repeated. If it is not less than 0x0f, the process proceeds to S414.

  In S414, the control unit 101 determines whether M is less than 4. If it is less than 4, 1 is added to M in S415, N is initialized to 0x01 in S416, and the process returns to S404 to perform the same processing for the next layer. If it is not less than 4, it means that the processing has been completed for all the hierarchical levels and all the logical addresses (that is, that all the devices have been powered on), so the processing of this flowchart is terminated.

  What is important in S404 to S406 is the physical address property of the device to be powered on. There is only one physical address in the physical address acquired in S403. Also, in this physical address, there is no physical address in the physical address of the device in the standby state in which 0 appears first in the higher digit than the digit where 0 appears first. Of course, the device to be powered on is in a standby state.

  The above processing will be described with reference to the example of FIG. 3. Since the DVD recorder 302 is in a standby state in S404, the process proceeds to S405, and the physical address of the DVD recorder 302 is “1.0.0.0”. Since it is “0”, the process proceeds to S406. However, since there is another device (STB 304) having “1.0.0.0”, the DVD recorder 302 is not turned on, and the process proceeds to the investigation of the device having the next logical address via S412 and S413. .

  When investigating the STB 304 at N = 0x03, as in the case of the DVD recorder 302, since there are two identical physical addresses, the process branches to Y in S406 and the power is not turned on.

  When investigating the AV amplifier 303 with N = 0x05, since there is no other device having the same physical address “2.0.0.0” as the AV amplifier 303, the control unit 101 determines that the AV amplifier 303 has Turn on the power. When the power of the AV amplifier 303 is turned on, access to the EDID-ROM of the AV amplifier 303 becomes possible and an HPD (Hot Plug Detect) line is asserted. Therefore, using this as a trigger, the STB 304 reads the EDID-ROM of the AV amplifier 303 and acquires the correct physical address “2.1.0.0”. In step S409, the control unit 101 acquires the updated physical address.

  When returning to S404 and investigating the device (DVD recorder 302) with the logical address “0x01” again, there is only one device with the physical address “1.0.0.0”. Power is turned on. Similarly, when N = 0x05, the STB 304 is powered on in S407.

  As described above, according to the present embodiment, the broadcast receiving apparatus 100 turns on the power in order from the device in the higher hierarchy while deferring a device having a plurality of devices having the same physical address.

  As a result, it is possible to suppress a device compatible with the HDMI standard from recognizing an incorrect physical address.

  In the first embodiment, the physical address is updated using the assertion of the HPD line as a trigger. However, if there is a device that is turned on before the processing shown in FIG. 4 starts, the state of the HPD line does not change, so that the device connected to the lower level of the device cannot update the physical address. there is a possibility.

  For example, as shown in FIG. 5, consider a case where the AV amplifier 502 directly connected to the TV 501 is in a standby state, and the STB 503 connected to the AV amplifier 502 and the DVD recorder 504 connected to the STB 503 are turned on. In this case, when the power is sequentially turned on from the side closer to the television 501 using the method of the first embodiment, when the power of the AV amplifier 502 is turned on, the HPD signal becomes a trigger, and the STB 503 has the correct physical address “2. 1.1.0 "is acquired. However, since the DVD recorder 504 always detects the HPD signal, the state change is not detected and the EDID-ROM is not read again. Therefore, there is a high possibility that a physical address updated to a correct value cannot be acquired.

  Therefore, in the present embodiment, before starting the processing illustrated in FIG. 4, the broadcast receiving apparatus 100 sets the power supplies of all devices to the standby state using the CEC command.

  FIG. 6 is a flowchart illustrating a procedure in which the broadcast receiving apparatus 100 turns on the power of other connected HDMI compatible devices. In FIG. 6, steps in which processing similar to that in FIG. 4 is performed are denoted by the same reference numerals and description thereof is omitted.

  In step S601, the control unit 101 uses the CEC command to check the operation state of all devices.

  In step S <b> 602, the control unit 101 uses the CEC command to set the power supplies of all devices other than the operating device to the standby state. In the case where priority is given to the accuracy of the physical address over the prevention of the interruption of the operation of the device, the control unit 101 may put the power supplies of all the devices including the operating device in a standby state.

  The subsequent processing is the same as in the first embodiment. However, if M is not less than 4 in S414, in S603, the control unit 101 may use the CEC command to set the power supplies of all the devices except for the operating device to the standby state.

  Even after the broadcast receiving apparatus 100 acquires the correct physical address of the device using the method of the first or second embodiment, the device may be inserted or removed by the user, and as a result, a change may appear in the connection tree structure. Therefore, in this embodiment, the broadcast receiving apparatus 100 performs processing so that a newly connected device can recognize a correct physical address.

  FIG. 7 is a flowchart illustrating a procedure in which the broadcast receiving apparatus 100 turns on the power of other connected HDMI compatible devices. In FIG. 7, steps in which processing similar to that in FIGS. 4 and 6 is performed are denoted by the same reference numerals and description thereof is omitted.

  In step S701, the control unit 101 periodically transmits a CEC ping message to another device (for example, once every 10 seconds) and observes the response.

  In step S702, the control unit 101 determines whether a new device is connected. If the new device is connected, the process proceeds to step S601.

  The subsequent processing is the same as in the second embodiment. As a result, the newly connected device can recognize the correct physical address.

  As described above, when there is no access to the EDID-ROM, there is a device in which the CEC function is disabled and the operation using the CEC command is impossible. When such a device exists, as described in the third embodiment, if the device is set in the standby state after acquiring the physical address, the broadcast receiving apparatus 100 cannot operate the device using the CEC command. Such a case will be described with reference to FIG.

  It is assumed that an AV amplifier 802 is connected to the television 801, an STB 803 is connected to the AV amplifier 802, and a DVD recorder 804 is connected to the STB 803. Actually, each device may be any CEC-compatible device. Here, it is assumed that the DVD recorder 804 is a device having a specification in which CEC is invalid when the EDID-ROM cannot be accessed.

  In this case, when the STB 803 is not turned on and the DVD recorder 804 cannot access the EDID-ROM of the STB 803, the CEC of the DVD recorder 804 becomes invalid. For this reason, the television 801 cannot control the DVD recorder 804 and cannot grasp the presence of the ping message.

  In this embodiment, a method for enabling the TV 801 (broadcast receiving apparatus 100) to operate the DVD recorder 804 in such a case will be described. As a premise of the present embodiment, the broadcast receiving apparatus 100 grasps the physical address of the DVD recorder 804 by the method of the first, second, or third embodiment, but since the STB 803 is in the standby state, the DVD recorder 804 It shall not accept commands.

  When the broadcast receiving apparatus 100 tries to operate the DVD recorder 804 according to a user instruction or the like and the CEC command is not accepted, the broadcast receiving apparatus 100 executes the process shown in FIG.

  In step S901, the control unit 101 turns on the AV amplifier 802 using a CEC command. Next, in step S902, the control unit 101 turns on the STB 803. In this state, since the DVD recorder 804 can access the EDID-ROM of the STB 803, the CEC function is also enabled at the same time. Therefore, in step S903, the control unit 101 operates the DVD recorder 804 by transmitting a CEC command to the DVD recorder 804.

  Note that the DVD recorder 804 may not accept the CEC function, and the DVD recorder 804 may be disconnected from the STB 803. In this case, even if the STB 803 is powered on in S902, the broadcast receiving apparatus 100 cannot find the DVD recorder 804, and the control unit 101 does nothing in S903.

[Other Examples]
In order to realize the functions of the above-described embodiments, a recording medium in which a program code of software embodying each function is recorded may be provided to the system or apparatus. Then, the function of each embodiment described above is realized by the computer (or CPU or MPU) of the system or apparatus reading and executing the program code stored in the recording medium. In this case, the program code itself read from the recording medium realizes the functions of the above-described embodiments, and the recording medium on which the program code is recorded constitutes the present invention. As a recording medium for supplying such a program code, for example, a floppy (registered trademark) disk, a hard disk, an optical disk, a magneto-optical disk, or the like can be used. Alternatively, a CD-ROM, CD-R, magnetic tape, nonvolatile memory card, ROM, or the like can be used.

  The configuration for realizing the functions of the above-described embodiments is not limited to executing the program code read by the computer. Including the case where the OS (operating system) running on the computer performs part or all of the actual processing based on the instruction of the program code, and the functions of the above-described embodiments are realized by the processing. It is.

  Further, the program code read from the recording medium may be written in a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer. Thereafter, the CPU of the function expansion board or function expansion unit performs part or all of the actual processing based on the instruction of the program code, and the functions of the above-described embodiments may be realized by the processing. Is included.

1 is a block diagram illustrating a configuration of a broadcast receiving apparatus according to Embodiment 1. FIG. 3 is a flowchart for explaining a basic concept of the first embodiment. It is a figure which shows the case where a some apparatus has the same Physical address. 7 is a flowchart illustrating a procedure in which the broadcast receiving apparatus according to the first embodiment turns on the power of another connected HDMI-compatible device. FIG. 5 is a diagram illustrating a case where there is a device that is turned on before the processing illustrated in FIG. 4 is started. 12 is a flowchart illustrating a procedure in which the broadcast receiving apparatus according to the second embodiment powers on another connected HDMI compatible device. 12 is a flowchart illustrating a procedure in which the broadcast receiving apparatus according to the third embodiment turns on the power of another connected HDMI compatible device. It is a figure explaining the case where there exists an apparatus in which a CEC function becomes invalid when EDID-ROM cannot be accessed. 14 is a flowchart illustrating a procedure in which a broadcast receiving apparatus according to a fourth embodiment operates a device in which a CEC function is disabled. It is a figure which shows the example of the connection tree of an HDMI corresponding | compatible apparatus. It is a figure explaining EDID-ROM of an HDMI corresponding | compatible apparatus.

Claims (5)

In accordance with the HDMI (High-Definition Multimedia Interface) standard, communication means for communicating with an external device;
A first physical address corresponding to the first external device is detected, a second physical address corresponding to the second external device is detected, and a third physical address corresponding to the third external device is detected. Detection means;
Control means for preventing the first external device from being turned on when the first physical address matches the second physical address;
When the first physical address matches the second physical address, the third physical address does not match the first physical address, and the second physical address matches the second physical address. If the physical address does not match, the control means controls the power supply of the third external device to cause the second external device to perform processing for acquiring the physical address,
The detection means detects the first physical address and the second physical address after the power supply of the third external device is controlled,
When the first physical address and the second physical address do not match, and the first physical address and the third physical address do not match, the control unit is configured to control the first external device. To turn on
The second external device communicates with the communication means via the third external device.   2. The reception according to claim 1, wherein, when the first physical address and the third physical address coincide with each other, the control unit does not control a power supply of the first external device. apparatus. If a second physical address and the first physical address matches, the control means, to claim 1 or 2, characterized in that to avoid controlling the power of the second external device The receiving device described.   When the first physical address matches the second physical address, the third physical address does not match the first physical address, and the second physical address matches the second physical address. 4. The receiving apparatus according to claim 1, wherein when the physical address does not match, the control unit controls the third external apparatus to be turned on. 5. A program for controlling a receiving device that communicates with an external device in accordance with the HDMI (High-Definition Multimedia Interface) standard,
Detecting a first physical address corresponding to the first external device;
Detecting a second physical address corresponding to a second external device communicating with the receiving device via a third external device;
Detecting a third physical address corresponding to the third external device;
Preventing the first external device from being turned on if the first physical address matches the second physical address;
When the first physical address matches the second physical address, the third physical address does not match the first physical address, and the second physical address matches the second physical address. If the physical address does not match, controlling the power supply of the third external device to cause the second external device to perform processing for obtaining the physical address;
Detecting the first physical address and the second physical address after the power supply of the third external device is controlled;
When the first physical address and the second physical address do not match, and the first physical address and the third physical address do not match, the first external device is turned on. A program for causing a computer to execute the steps to be performed.

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