JP2009043177A - Data processor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a malfunction from occurring by leakage current in a hotplug processing part with a simple configuration. <P>SOLUTION: A diode D20 supplies voltage of TMDS (Transition Minimized Differential Signaling) supplied to a 3. 3V power supply line to a 5V power supply line when the power is turned off. Although leakage current is caused to flow from the 3. 3V power supply line to a hotplug processing part through a parasite diode, voltage is supplied to the 5V power supply line to thereby be able to make a cathode potential of the parasite diode high and prevent the leakage current from flowing through the parasite diode. Then, In the hotplug processing part with a simple configuration, operation can be prevented from being unstable by the leakage current, and the malfunction of each part can be prevented. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a data processing apparatus that is connected to a first power supply line and a second power supply line and processes a first signal and a second signal that are input and output.

In recent years, an AV system including a source device that supplies content data such as video data and audio data and a receiving device such as a sink device and a repeater device that receives the content data has become widespread. The source device is, for example, a DVD (Digital Versatile Disk) player, a BD (Blue-ray Disc) player, an HDDVD (High
Definition DVD) player. The sink device is, for example, an LCD (Liquid Crystal Display), a PDP (Plasma Display Panel), a projector, or the like. The repeater device is, for example, an AV amplifier or an AV receiver. These devices comply with the HDMI standard and are connected to each other via an HDMI cable.

  FIG. 3 is a schematic block diagram illustrating a main part of a general AV amplifier 30. The AV amplifier 30 includes an HDMI processing unit 11, a control unit 12, and connectors 13 and 14. For example, a DVD player is connected to the connector 13 via an HDMI cable. For example, a display device is connected to the connector 14 via an HDMI cable.

  The HDMI line mainly includes three types of lines (hot plug line, DDC line, and TMDS line). TMDS transmits content data conforming to the HDMI standard from a DVD player to an AV amplifier. Hot plug notifies the DVD player of changes in AV amplifier settings (eg, selector switching, HDMI link disconnection, etc.) from the AV amplifier. The hot plug signal is always at a high level when connected. The DDC is used for the DVD player to acquire and authenticate information (EDID) about the AV amplifier.

  The AV amplifier 30 has two power supply lines (a 5V power supply line and a 3.3V power supply line). A 5V power supply line is connected to the hot plug and the DDC, and a 3.3V power supply line is connected to the TMDS.

  The AV amplifier 30 has the following problems. When the power of the AV amplifier 30 is in an off state (both the 5V power line and the 3.3V power line are 0V) and the connected DVD player is on, the hot plug line, DDC line, A voltage is supplied to the AV amplifier 30 via the TMDS line or other lines (for example, + 5V power supply line). Based on this voltage, there is a problem in that a leakage current flows inside the HDMI processing unit 11, the operation of the HDMI processing unit 11 becomes unstable, and malfunction occurs. Hereinafter, this will be described in detail with reference to FIG.

  FIG. 4 is a schematic circuit diagram showing a part of the internal configuration of the HDMI processing unit 11. The HDMI processing unit 11 includes a TMDS processing unit 21 connected to the connector 13 via a TMDS line, a hot plug processing unit 22 connected to the connector 13 via a hot plug line, and a connector 13 via a DDC line. And a DDC processing unit 23 to be connected. A 3.3 V power supply line is connected to the TMDS processing unit 21, and a 5 V power supply line is connected to the hot plug processing unit 22 and the DDC processing unit 23. Further, since the HDMI processing unit 11 is configured by an IC, the N-type semiconductor and the N-type semiconductor between the stacked P-type semiconductor and the N-type semiconductor, or a P-type semiconductor that forms a switch element (for example, a transistor or FET) in the IC Parasitic diodes (for example, D51, D52, etc.) are generated between the type semiconductors and the like.

  When the AV amplifier 30 is in the power-off state, both the 3.3V power line and the 5V power line are 0V. At this time, the voltage supplied from the DVD player via the TMDS line is supplied to the 3.3V power supply line via the diode D1 or a parasitic diode (not shown), and a voltage is generated on the 3.3V power supply line. A leakage current due to a voltage generated in the 3.3V power supply line flows into the hot plug processing unit 22 (for example, the source of the MOSFET Q1) via the parasitic diode D51, and the operation of the hot plug processing unit 22 is unstable due to the leakage current. become.

  Similarly, leakage current due to voltage supplied from the DVD player via the DDC line flows into the hot plug processing unit 22 (for example, the source of the MOSFET Q1) via the parasitic diode D52, and the hot plug processing unit 22 is caused by the leakage current. Operation becomes unstable.

  That is, the hot plug processing unit 22 outputs a high level hot plug signal to a DVD player or a display device by outputting a voltage due to a leakage current. The DVD player detects a high level hot plug and erroneously recognizes that the AV amplifier is in a power-on state. As a result, the DVD player transmits a signal for acquiring EDID to the AV amplifier 30 via the DDC line. However, since the AV amplifier 30 is in a power-off state, the EDID cannot be acquired indefinitely. The signal for earning EDID is continuously transmitted. As a result, problems such as generation of noise from the AV amplifier 30 occur.

  Note that the above problem occurs not only in the hot plug processing unit 22 but also in the DDC processing unit 23.

  Furthermore, since the 5V power supply line is in an off state, a sufficient operating voltage is not supplied to the MOSFET Q1 in the hot plug processing unit 22. Therefore, there is a problem that leakage current flows to the output side (display device side) via the MOSFET Q1 due to the voltage supplied from the DVD player via the hot plug line, causing malfunction on the output side.

  Similarly, since the 5V power supply line is in an off state, an operable voltage is not supplied to the MOSFET Q2 in the DDC processing unit 23. Therefore, there is a problem that leakage current flows to the output side (display device side) via the MOSFET Q2 due to the voltage supplied from the DVD player via the DDC line, causing malfunction on the output side.

  In the TMDS processing unit 21 as well, a leakage current flows to the output side due to the voltage supplied from the DVD player through the TMDS line. (MOSFET or the like) is provided, so that it is blocked by the switch element and is not supplied to the display device.

  In order to solve such a problem, an AV amplifier 50 shown in FIGS. 5 and 6 has been proposed. As shown in FIG. 5, the AV amplifier 50 is provided with a switch unit 51 in a hot plug line and a DDC line between the HDMI processing unit 11 and the connector 13. When the power of the AV amplifier 50 is off, the switch unit 51 is turned off to prevent the voltage from being supplied from the DVD player via the hot plug line or the DDC line. This prevents the level hot plug signal from being erroneously detected by the DVD player via the hot plug line. Specifically, as shown in FIG. 6, a MOSFET Q51 is connected between the hot plug processing unit 22 and the connector 13, a MOSFET Q52 is connected between the DDC processing unit 23 and the connector 13, and the AV amplifier 50 is powered. In the off state, MOSFETs Q51 and Q52 are turned off by a control signal from the microcomputer.

  However, in the AV amplifier 50, it is necessary to provide MOSFETs Q51 and Q52 (in the actual circuit, six MOSFETs are required), and it is necessary to provide a port for controlling on / off of a plurality of MOSFETs in the microcomputer. There is a problem that the number of points increases and the cost increases.

Patent No. 3952077

  The present invention has been made to solve the above-described conventional problems, and its purpose is to prevent malfunctions due to leakage currents in the HDMI processing unit with a simple configuration without increasing the number of components. A data processing apparatus is provided.

  A data processing apparatus according to a preferred embodiment of the present invention includes a first processing unit to which a first power supply line is connected and a first signal is input or output, and a second power supply line to which a second signal is input or output. A second processing unit, and when the power supply of the first power supply line and the second power supply line is off, the voltage of the first signal is supplied to the first power supply line. A leakage current flows from the line to the second processing unit via a parasitic diode, and the voltage supplied to the first power supply line is supplied to the second power supply line, whereby the first power supply line is supplied. Voltage supply means for preventing leakage current from flowing into the second processing section through a parasitic diode.

  When the power supply of the first power supply line and the second power supply line is off (that is, when the voltage is 0), the voltage of the first signal is supplied to the first power supply line. The voltage supply means supplies the voltage supplied to the first power supply line to the second power supply line. A leakage current flows from the first power supply line to the second processing unit via the parasitic diode. However, by supplying a voltage to the second power supply line, the cathode potential of the parasitic diode can be increased, and the parasitic diode is passed through the parasitic diode. This prevents leakage current from flowing. Therefore, it is possible to prevent the operation of the second processing unit from becoming unstable due to a leakage current and to prevent malfunction of each unit with a simple configuration without providing a MOSFET or microcomputer port.

  A data processing apparatus according to another preferred embodiment of the present invention includes a first processing unit to which a first power line is connected and a first signal is input or output, and a second power line to which a second signal is input. Or an output second processing unit, and the second processing unit performs an on / off operation by supplying a control signal to the control electrode in a state where the operating voltage is supplied from the second power supply line. And a switching element (for example, FET) that does not perform an on / off operation and a leakage current flows to an input side or an output side in a state where an operating voltage is not supplied from the second power supply line, The voltage of the first signal is supplied to the first power supply line when the power of the line and the second power supply line is off, and the voltage supplied to the first power supply line is supplied to the second power supply line. thing More, further comprising a voltage supplying means for supplying an operating voltage to the switch element (e.g., FET) from the second power supply line.

  When the power supply of the first power supply line and the second power supply line is off (that is, when the voltage is 0), the voltage of the first signal is supplied to the first power supply line. The voltage supply means supplies the voltage supplied to the first power supply line to the second power supply line. If there is no voltage on the second power supply line, the FET in the second processing section will leak and the operation will become unstable, causing malfunctions in each part, but by supplying voltage to the second power supply line, the FET is normal It is possible to prevent the leakage current from flowing through the FET. Therefore, it is possible to prevent the operation of the second processing unit from becoming unstable due to a leakage current and to prevent malfunction of each unit with a simple configuration without providing a MOSFET or microcomputer port.

  In a preferred embodiment, the voltage supply means is a Schottky barrier diode having an anode connected to the first power supply line and a cathode connected to the second power supply line.

  A Schottky barrier diode has a lower forward voltage effect than a PN junction diode. Therefore, a large voltage can be supplied from the first power supply line to the second power supply line, and as a result, a voltage close to a normal operating voltage can be supplied to the FET. Furthermore, since the parasitic diode generated inside the transistor or IC is a PN junction diode, by supplying a voltage obtained by subtracting the forward voltage drop of the Schottky barrier diode from the voltage of the first power supply line to the cathode of the parasitic diode, The parasitic diode can be reliably turned off, and leakage current can be prevented from flowing to the second processing unit.

  In a preferred embodiment, the voltage of the first signal is supplied to the first power supply line via a parasitic diode.

  In this case, the leakage current supplied to the first power supply line via the parasitic diode can be used to prevent leakage current from flowing in the second processing unit.

  In a preferred embodiment, the data processing device conforms to the HDMI standard, and the second signal is a hot plug.

  When the second signal is a hot plug, if a leakage current flows in the second processing unit, an external device connected in accordance with the HDMI standard erroneously detects the hot plug and erroneously determines that the connected device is in a power-on state. However, the authentication process is repeatedly executed, which causes problems such as noise. Therefore, by applying the above configuration to the data processing apparatus in which the second signal is hot plug, an extremely excellent effect of preventing erroneous detection of hot plug can be obtained.

  Without providing a MOSFET or a microcomputer port, the second processing unit can be prevented from becoming unstable due to leakage current with a simple configuration, and malfunction of each unit can be prevented.

  Hereinafter, although preferable embodiment of this invention is described, this invention is not limited to these embodiment.

  FIG. 1 is a schematic block diagram illustrating a main part of an AV amplifier 10 according to a preferred embodiment of the present invention. The AV amplifier 10 is a device compliant with the HDMI (High-Definition Multimedia Interface) standard and is called a repeater device. The AV amplifier 10 includes an HDMI processing unit 11, a control unit 12, connectors 13 and 14, and voltage supply means (D20). For example, a DVD player as a source device is connected to the connector 13 via an HDMI cable. For example, a display device that is a sink device is connected to the connector 14 via an HDMI cable.

  The HDMI line mainly includes three types of lines (hot plug line, DDC line, and TMDS line). A TMDS (Transition Minimized Differential Signaling) line is a line for transmitting content (video and audio) data (hereinafter referred to as HDMI data) compliant with the HDMI standard from the DVD player to the AV amplifier 10. The hot plug line is a line for notifying the AV player 10 of a change in setting of the AV amplifier 10 (for example, selector switching, HDMI link disconnection, etc.) from the AV amplifier 10 to the DVD player. The hot plug signal is always at a high level when connected. The DDC (Display Data Channel) line is a line for the DVD player to acquire information (EDID: Extended Display Identification Data) related to the AV amplifier 10.

  The AV amplifier 10 is provided with two power supply lines (5V power supply line and 3.3V power supply line). A 5V power supply line is connected to the hot plug and the DDC, and a 3.3V power supply line is connected to the TMDS.

  The control unit 12 controls each unit of the AV amplifier 10, and specifically controls the HDMI processing unit 11.

  The HDMI processing unit 11 performs predetermined processing on each signal transmitted from the DVD player and outputs it to the subsequent stage. Alternatively, the HDMI processing unit 11 outputs each signal transmitted from the DVD player to the subsequent stage as it is. For example, when the HDMI processing unit 11 is provided with a plurality of connectors 13 and a plurality of DVD players are connected to the AV amplifier 10, the HDMI processing unit 11 selects each signal transmitted from one DVD player and outputs it to the subsequent stage. Processing as a (switcher) is executed. Alternatively, the HDMI processing unit 11 converts the HDMI data transmitted from the DVD player into the original audio data and video data, supplies the audio data to an amplifier unit (not shown), converts the video data into HDMI data again, and Output to a display device connected to the connector 14.

  FIG. 2 is a schematic circuit diagram showing a part of the internal configuration of the HDMI processing unit 11 and voltage supply means. The HDMI processing unit 11 includes a TMDS processing unit 21, a hot plug processing unit 22, and a DDC processing unit 23.

  The TMDS processing unit 21 inputs and outputs TMDS signals with the outside. That is, the TMDS processing unit 21 is connected to a 3.3V power supply line, supplied with a TMDS signal (HDMI data) from the DVD player via the TMDS line, executes predetermined processing on the TMDS signal, Output to the output unit). The TMDS processing unit 21 includes, for example, diodes D1 to D4.

  The hot plug processing unit 22 inputs and outputs a hot plug signal with the outside. That is, the hot plug processing unit 22 is connected to a 5V power supply line, and outputs a high level or low level hot plug signal to the DVD player. The hot plug processing unit 22 includes, for example, diodes D5 to D8 and a switching element FET (MOSFET) Q1. The hot plug processing unit 22 is supplied with an operating voltage from the 5V power line, a control signal is supplied from the control unit 12 to the gate of the MOSFET Q1, and the MOSFET Q1 is turned on and off to output a high level or low level hot plug signal. To do.

  The DDC processing unit 23 inputs and outputs DDC signals with the outside. That is, the DDC processing unit 23 is connected to a 5V power line and outputs EDID to the DVD player. The DDC processing unit 23 has two processing units, DDC data and DDC clock, but only one is shown here for simplicity. The DDC processing unit 23 includes, for example, diodes D9 to D12 and an FET (MOSFET) Q2 that is a switch element.

  Since the HDMI processing unit 11 is typically configured by an IC (integrated circuit), the HDMI processing unit 11 is formed between a stacked P-type semiconductor and an N-type semiconductor, or a P-type semiconductor that forms a transistor inside the IC and an N-type semiconductor. A parasitic diode is generated between the semiconductor and the type semiconductor. Therefore, the parasitic diode is a PN junction diode. For example, a parasitic diode D51 (two diodes) exists between the 3.3V power supply line and the source of the MOSFET Q1 in the hot plug processing unit 22, and the input terminal of the DDC processing unit 23 and the hot plug processing unit 22 A parasitic diode D52 exists between the source of the MOSFET Q1. In addition, parasitic diodes are generated in other places, but they are omitted for simplicity.

  When the power of the AV amplifier 10 is off, the power of the 3.3V power line and the 5V power line is off, and the power supply voltage is 0V. However, the TMDS voltage supplied from the DVD player 10 via the TMDS line is supplied to the 3.3V power supply line via the diode D1 or a parasitic diode (not shown), and a voltage of 2V, for example, is applied to the 3.3V power supply line. appear.

  The voltage supply means supplies the voltage supplied to the 3.3V power supply line via the TMDS line also to the 5V power supply line. By supplying a voltage to the 5V power supply line, an operating voltage is supplied to the drain and source of the MOSFETs Q1 and Q2, and leakage current is prevented from flowing through the source and drain of the MOSFETs Q1 and Q2. Focusing on the hot plug processing unit 22, the leakage current here is, for example, leakage current due to voltage supplied from the DVD player via the hot plug line, or supplied from the DVD player via the DDC line. For example, a leakage current supplied to the hot plug processing unit 22 via the diode D52.

  Further, the voltage supply means increases the cathode potential of the parasitic diode D51 by supplying a voltage to the 5V power supply line, so that the hot plug processing unit 22 and the DDC processing are performed from the 3.3V power supply line via the parasitic diode D51. The leakage current is prevented from flowing through the portion 23.

  The voltage supply means includes a diode D20. The anode of the diode D20 is connected to the 3.3V power supply line, and the cathode is connected to the 5V power supply line. By providing the diode D20, a voltage obtained by subtracting the forward voltage drop of the diode 20 from the voltage generated in the 3.3V power supply line is supplied to the 5V power supply line.

  The diode D20 is preferably a Schottky barrier diode. The Schottky barrier diode has a lower forward voltage drop than the PN junction diode, and the forward voltage drop of the PN junction diode is about 0.6 V, whereas the forward voltage drop of the Schottky barrier diode is about 0. 3V. Therefore, by using a Schottky barrier diode, a higher voltage can be supplied from the 3.3V power supply line to the 5V power supply line, so that a voltage closer to the normal operating voltage can be supplied to the drain and source of the MOSFETQ1.

  Further, the source of the MOSFET Q1 to which the cathode of the parasitic diode D51 is connected is substantially the same potential as the 5V power supply line (actually, a value obtained by subtracting the voltage of the diode D6), and the parasitic diode D51 has no forward voltage drop. .6V (for example, 1.2V when two are connected) By using a Schottky barrier diode for the diode D20, the cathode potential of the parasitic diode D51 is made higher than the potential at which the parasitic diode D51 can be turned on. The parasitic diode D51 can be turned off. Therefore, it is possible to prevent leakage current from flowing through the MOSFET Q1 via the parasitic diode D51.

The operation and effect of the AV amplifier 10 having the above configuration will be described.
[When 5V power line and 3.3V power line are on]
Since the 3.3V power supply line is in the on state, the TMDS voltage supplied from the DVD player side via the TMDS line in the TMDS processing unit 21 is higher than the voltage of the 3.3V power supply line. It is not supplied to the 3V power line. In addition, since the 5V power supply line is in the on state, the normal operation voltage is supplied to the MOSFET Q1 in the hot plug processing unit 22, the on / off operation is executed by the control signal, and the hot plug signal is normally set to the high level or the low level. Perform the correct operation. Therefore, no leakage current flows from the MOSFET Q1. The same applies to the DDC processing unit 23.

[When 5V power line and 3.3V power line are off]
Since the 5V power supply line and the 3.3V power supply line are 0V, the TMDS voltage supplied from the DVD player side via the TMDS line in the TMDS processing unit 21 is lower than the voltage of the 3.3V power supply line. 3.3V is supplied to the power supply line via a diode D1 or a parasitic diode. The voltage of the 3.3V power supply line is 2V, for example. The voltage supplied to the 3.3V power supply line is also supplied to the 5V power supply line via the Schottky barrier diode D20. Since the forward voltage drop of the Schottky barrier diode D20 is 0.3V, the voltage of the 5V power supply line is 1.7V.

  In the hot plug processing unit 22, since the anode voltage of the parasitic diode D51 is 2V and the cathode voltage is 1.1V (the source voltage of the MOSFET Q1, 5V power supply line 1.7V−the voltage of the diode D6 is 0.6V), The cathode voltage does not fall below 0.8V at which the parasitic diode D51 is turned on, and the parasitic diode D51 is turned off, preventing leakage current from flowing from the 3.3V power supply line to the source of the MOSFET Q1. Accordingly, it is possible to prevent the hot plug processing unit 22 from becoming unstable due to a leakage current and malfunctioning.

  When a voltage of 1.7 V is supplied to the 5 V power supply line, a voltage obtained by subtracting the voltages of the diodes D5 and D6 is supplied to the drain and source of the MOSFET Q1. This voltage is a voltage close to the operating voltage of the MOSFET Q1. Since the control signal is not supplied to the gate of the MOSFET Q1, the MOSFET Q1 maintains the off state. By turning off the MOSFET Q1, even if a voltage is supplied from the DVD player side via the hot plug line, a leakage current due to the voltage is not output to the output side, causing a malfunction on the output side. Can be prevented.

  Furthermore, leakage current due to the voltage supplied from the DVD player side via the DDC line and supplied to the MOSFET Q1 via the parasitic diode D52 can be prevented from being output to the DVD player side via the hot plug line. . In particular, if the DVD player erroneously recognizes that the hot plug has become high level, the DVD player continues to execute the authentication process and noise is generated in the AV amplifier 10, but such a problem can be solved.

  Similarly, in the DDC processing unit 23, since the anode voltage of the parasitic diode (not shown) is 2V and the cathode voltage is 1.1V, the parasitic diode is turned off and leaks from the 3.3V power supply line to the MOSFET Q2. Current is prevented from flowing. Therefore, the operation of the DDC processing unit 23 becomes unstable due to the leakage current, and it is possible to prevent malfunction.

  When a voltage of 1.7 V is supplied to the 5 V power supply line, a voltage obtained by subtracting the voltages of the diodes D9 and D10 is supplied to the drain and source of the MOSFET Q2. This voltage is close to the operating voltage of MOSFETQ2. Since the control signal is not supplied to the gate of the MOSFET Q2, the MOSFET Q2 maintains the off state. By turning off the MOSFET Q2, it is possible to prevent leakage current due to the voltage from being output to the output side even when a voltage is supplied from the DVD player side via the DDC line. Further, leakage current due to the voltage supplied from the DVD player side via the hot plug line and supplied to the MOSFET Q2 via the parasitic diode (not shown) is transferred to the DVD player side or the output side via the DDC line. It is output and it can prevent causing malfunction.

  As described above, according to the present embodiment, the voltage supplied to the 3.3V power supply line is also supplied to the 5V power line via the Schottky barrier diode D20 which is a voltage supply means, so that the HDMI processing unit 11, for example, an unstable operation due to leakage current is prevented in the hot plug processing unit 22 and the DDC processing unit 23.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to these embodiment. The internal structure of the HDMI processing unit 11 is merely an example, and any appropriate structure may be adopted as long as there are conditions that two power supply lines are provided and leakage current is generated inside the HDMI processing unit 11. In contrast to the above embodiment, a 3.3V power supply line may be connected to the hot plug and the DDC, and a 5V power supply line may be connected to the TMDS. Further, the present invention can be similarly applied to a leakage current due to a voltage supplied from the DVD player side through another line. Further, the HDMI processing unit in the AV amplifier has been described as an example, but the present invention can also be applied to a source device such as a DVD player and an HDMI processing unit in a sink device such as an LCD. Further, the present invention is not limited to the HDMI standard device, and can be applied to any device such as the DVI standard that is compatible with the HDMI standard.

  The present invention can be suitably used for a source device such as a DVD player, a repeater device such as an AV amplifier, or a sink device such as an LCD or PDP that conforms to the HDMI standard.

1 is a block diagram showing an AV amplifier 10 according to a preferred embodiment of the present invention. 2 is a circuit diagram illustrating an internal structure of an HDMI processing unit 11 of the AV amplifier 10. FIG. 1 is a block diagram showing a conventional AV amplifier 30. FIG. 7 is a circuit diagram illustrating an internal structure of an HDMI processing unit 11 of a conventional AV amplifier 30. FIG. FIG. 10 is a block diagram showing a conventional AV amplifier 50. FIG. 6 is a circuit diagram illustrating an internal structure of an HDMI processing unit 11 of a conventional AV amplifier 50.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 AV amplifier 11 HDMI processing part 12 Control part 13,14 Connector 21 TDMS processing part 22 Hot plug processing part 23 DDC processing part D20 Voltage supply means Q1, Q2 MOSFET

Claims (5)

A first processing unit to which a first power supply line is connected and a first signal is input or output;
A second processing unit to which a second power supply line is connected and a second signal is input or output,
When the power supply of the first power supply line and the second power supply line is in an off state, the voltage of the first signal is supplied to the first power supply line, and the second power supply line is further supplied from the first power supply line via a parasitic diode. Leakage current flows through the processing part,
Voltage supply that prevents leakage current from flowing from the first power supply line to the second processing unit via a parasitic diode by supplying the voltage supplied to the first power supply line to the second power supply line. A data processing apparatus further comprising means. A first processing unit to which a first power supply line is connected and a first signal is input or output;
A second processing unit to which a second power supply line is connected and a second signal is input or output,
In a state where the operating voltage is supplied from the second power supply line, the second processing unit performs an on / off operation by supplying a control signal to the control electrode, and the operating voltage is supplied from the second power supply line. Including a switch element that does not perform an on / off operation and in which leakage current flows to the input side or the output side,
When the power of the first power line and the second power line is in an off state, the voltage of the first signal is supplied to the first power line,
A data processing apparatus further comprising voltage supply means for supplying an operating voltage from the second power supply line to the switch element by supplying a voltage supplied to the first power supply line to the second power supply line.   The data processing apparatus according to claim 1 or 2, wherein the voltage supply means is a Schottky barrier diode having an anode connected to the first power supply line and a cathode connected to the second power supply line.   The data processing apparatus according to claim 1, wherein the voltage of the first signal is supplied to the first power supply line via a parasitic diode. Conforms to the HDMI standard,
The data processing apparatus according to claim 1, wherein the second signal is a hot plug.

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