INAA
`
`a2) United States Patent
`US 7,945,708 B2
`(10) Patent No.:
`May17, 2011
`(45) Date of Patent:
`Ohkita
`
`(54) APPARATUS AND METHOD OF RECEIVING
`DATA FROM AUDIO/VIDEO EQUIPMENT
`
`(75)
`
`Inventor: Hideki Ohkita, Kunitachi (JP)
`
`(73) Assignee: Kabushiki Kaisha Toshiba, Tokyo(JP)
`
`(*) Notice:
`
`Subject to any disclaimer, the term ofthis
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 218 days.
`
`(21) Appl. No.: 12/351,475
`
`(22)
`
`Filed:
`
`Jan. 9, 2009
`
`(65)
`
`Prior Publication Data
`
`US 2009/0138935 Al
`
`May28, 2009
`
`Related U.S. Application Data
`
`(63) Continuation of application No. PCT/JP2008/061599,
`filed on Jun. 19, 2008.
`
`EP
`JP
`JP
`JP
`JP
`JP
`Wo
`
`FOREIGN PATENT DOCUMENTS
`1761052 A?
`3/2007
`2004-357029
`12/2004
`2006-203725
`8/2006
`2006-350919
`12/2006
`2007-078980
`3/2007
`2007-134956
`5/2007
`2007/049556 Al
`§/2007
`
`OTHER PUBLICATIONS
`
`International Search Report and Written Opinion for PCTapplication
`No. PCT/JP2008/061599 dated Sep. 9, 2008.
`High-Definition Multimedia Interface, Specification Version |.3a;
`HDMI Licensing, LLC; Nov. 10, 2006.
`State
`Intellectual Property Office of PR.C. application No.
`20088000048 1.9, Notification of the First Office Action, mailed Apr.
`29, 2010 (English translation).
`“Extended European Search Report Dated Oct. 7, 2010", European
`Patent Application No. 08777611.8.
`“High-Definition Multimedia Specification, specification version
`1.3”, Jun, 22, 2006, XPO30001519.
`
`* cited by examiner
`
`Primary Examiner — Alan Chen
`(74) Attorney, Agent, or Firm—Blakely, Sokoloff, Taylor &
`FURS 200F:
` 1CIP) bessassenasssrinesiorsisacvorsase 2007-166635
`Zafman LLP
`
`(30)
`
`Foreign Application Priority Data
`
`(51)
`
`Int. Cl.
`(2006.01)
`G06F3/00
`(2006.01)
`G06F 13/12
`(2006.01)
`G06F 7/04
`(52) U.S. Ch occ TLO/14; 710/8; 710/36; 710/62;
`726/2
`None
`
`(58)
`
`Field of Classification Search ........................
`See applicationfile for complete search history.
`
`(56)
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`2004/0239816 AL* 12/2004 Ando ...ccccsseseeereneees 348/705
`2006/0000177 Al
`1/2006 Salzanoet al.
`2007/0036158 Al
`2/2007 Hun-Kwonet al.
`2007/0055876 Al
`3/2007 Choi
`2007/0057931 Al
`3/2007 Takamori
`
`(57)
`
`ABSTRACT
`
`According to one embodiment, a data receiver apparatus
`comprises input ports complying with a digital interface stan-
`dard, wherein each input port comprises a voltage signal
`terminal receiving a prescribed voltage signal, a detection
`terminal outputting a connectiondetection signal, a data input
`terminal receiving a data signal, and an address terminal
`transmitting a physical address. A nonvolatile memory is
`connected to the address terminal. A connection detection
`
`signal output fromthe detection terminalis set to a detection-
`state voltage irrespective ofwhetherthe data input terminalis
`selected.
`
`9 Claims, 4 Drawing Sheets
`
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`va
`Twos
`8
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`
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`TMOS
`ie
`DDC
`Conor|t
`
`ee 58— ay:
`
`Roku EX1039
`U.S. Patent No. 9,716,853
`
`Roku EX1039
`U.S. Patent No. 9,716,853
`
`

`

`US 7,945,708 B2
`
`May 17,2011
`
`Sheet 1 of 4
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`
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`0¢
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`U.S. Patent
`
`

`

`U.S. Patent
`
`May17, 2011
`
`Sheet 2 of 4
`
`US 7,945,708 B2
`
`device
`
`Controller
`
`220
`Video data
`
`
`
` Display
`
`
`
`
`
`
`
`+5V power-supply
`
`
`
`
`CEC-transmitter
`[receiver
`
`‘|
`
`

`

`U.S. Patent
`
`“May 17
`
`, 2011
`
`Sheet 3 of 4
`
`US 7,945,708 B2
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`U.S. Patent
`
`May 17,2011
`
`Sheet 4 of 4
`
`US 7,945,708 B2
`
`apparatus
`
`
`Terminals of
`the sink apparatus
`
`
`Standby
`
`HDMI not selected}
`
`HDMIselected
`
`
` State of the sink
`
`
`
`EDIDreading ep
`
`
`
`
`HDCP authentication pow|ow fm
`
`
`Pe[=[=|=
`
`HPD potential
`
`High
`
`FIG.4
`
`Port
`
`1
`
`High
`
`Port 3
`
`High
`
`
`
`High
`
`Low
`
`Switching device 36
`FIG.5A
`
`HPD terminal of
`HDMI port
`1
`FIG. 9B
`
`HPD terminal of
`HDMI port 2
`
`FIG. SC
`
`HPD terminal of
`HOMI port 3
`FIG. 5D
`
`

`

`US 7,945,708 B2
`
`1
`APPARATUS AND METHODOF RECEIVING
`DATA FROM AUDIO/VIDEO EQUIPMENT
`
`CROSS-REFERENCE TO RELATED
`APPLICATIONS
`
`This is a Continuation Application of PCT Application No.
`PCT/JP2008/061599,filed Jun. 19, 2008, which was pub-
`lished under PCT Article 21(2) in English.
`This application is based upon and claims the benefit of
`priority from Japanese Patent Application No. 2007-166635,
`filed Jun. 25, 2007, the entire contents of which are incorpo-
`rated herein by reference.
`
`BACKGROUND
`
`1. Field
`One embodimentof the invention relates to an apparatus
`and method for receiving video data via a digital interface.
`2. Description of the Related Art
`An example of a multimedia interface between a video-
`data transmission apparatus, such as a DVD player,a digital
`tuner and a set-top box, and a video data-data receiver appa-
`ratus, such as a TV receiver and a monitor, is one complying
`withthe high definition multimedia interface (HDMI) stan-
`dard (High-Definition Multimedia Interface Specification
`Version 1.3a). Any apparatus that has an HDMI outputter-
`minalis called a source apparatus, and any apparatusthat has
`an HDMIinputterminalis called a sink apparatus. The video-
`data transmission apparatus is a source apparatus, while the
`video data-data receiver apparatus is a sink apparatus. Any
`apparatus that has an HDMI input terminal and an HDMI
`output terminal and performs both the function of a source
`apparatus and the function ofa sink apparatus is knownas a
`repeater apparatus.
`When the source apparatusis connected to the sink appa-
`ratus, the source apparatus transmits a +5V power-supply
`signal to the sink apparatus, informing the sink apparatus that
`the source apparatus has been connected to the sink appara-
`tus. The +5V power-supply signal is also a signal showing
`that the source apparatus is ready to operate.
`Uponreceiving the +5V power-supply signal, the sink
`apparatus starts makingitself prepared to receive video data.
`When so prepared, the sink apparatus transmits a hot-plug
`detection (HPD)signal (High signal) to the source apparatus.
`The hot-plug detection (HPD)signal is also a signal showing
`that the sink apparatus is now ready to receive videodata.
`The sink apparatus has an EDID memory that stores
`extended display identification data (EDID),i.e., the video-
`format data that the sink apparatus can display. The video-
`format data includes video specification items such as video
`format, resolution and syne frequency, and audio specifica-
`tion items suchas audio-data format, sampling frequency Fs
`andbit length.
`Uponreceiving the HPD signal at a high level, the source
`apparatus reads the EDIDfrom the EDID memory of the sink
`apparatus through a display-data channel (DDC) line, reading
`the video-format data, which is written in the EDID and in
`whichthe sink apparatus can display video data.
`The source apparatus transmits and receives data required
`to achieve the authentication of high-bandwidth digital con-
`tent protection (HDCP),
`to and from the sink apparatus
`through the DDC line. The data required to achieve the
`authentication is,
`for example, HDCP key data.
`In this
`instance, the HDCP key data is assumed to be stored in a
`storage area the sink apparatus has. For the source apparatus,
`to authenticate the high-bandwidth digital contentprotection
`
`20
`
`30
`
`35
`
`5
`
`50
`
`55
`
`60
`
`2
`is to confirm that the sink apparatus is authorized to receive
`video signals. Upon authenticating the high-bandwidth digi-
`tal content protection, the source apparatus decrypts the video
`data withthe secret-key data shared with the sink apparatus,
`and then transmits the videodata, thus decrypted,to the sink
`apparatus.
`After reading and authenticating the EDID, the source
`apparatus transmits video data, audio data and AUX data, all
`complyingto the sink-apparatus format, to the sink apparatus
`by means oftransmission minimized differential signaling
`(TMDS).
`The HDMI standardsdescribe optional standards concern-
`ing the mutual control of apparatuses, known as consumer
`electronic control (CEC). HDMIdevices are tree-connected
`by repeaters. The CECutilizes a single-line, low-speed serial
`bus. One ofthe functions the CEC achieves is a one-touch
`display in which the source apparatus controls the sink appa-
`ratus. When the source apparatus (e.g., a DVD player) is set to
`the playback mode(that is, when the playback button on the
`apparatus is pushed), the source apparatus controls the sink
`apparatus (e.g., a TVreceiver) and to automatically turns on
`the sink apparatus if necessary and automatically connect the
`signal path to it (i.e.,DVD player). Thus, the source apparatus
`enables the sink apparatusto display the image played back.
`In orderto designate one ofapparatuses so that a switching
`device maybe controlled to set a signal path, all apparatuses
`must have a physical address each. The physical address of
`the source apparatusis written in the EDID ofthe sink appa-
`ratus or the EDIDofthe repeater apparatus. When the appa-
`ratuses are mutually tree-connected anew or disconnected
`from the tree connection, changing the tree connection,
`physical addresses are detected. Thus, the physical addresses
`of all sink apparatuses and all repeater apparatuses are
`detected and propagated.Ifthe tree connection is composed
`of five stages at most, the address of each apparatusis a
`four-digit data item, represented as “n.n.n.n.” Any sink appa-
`ratus or repeater apparatus that serves as a route, generatesits
`physical address “0.0.0.0." The sink apparatus or repeater
`apparatus reads its physical address from the EDID memory
`of the sink apparatus connectedto it.
`The timing the source apparatus or repeater apparatus
`reads its own physical addressis the time whenit receives the
`high-level HPD signal that the sink apparatus or repeater
`apparatus transmits in response to the +5V power-supply
`signal it receives from the source apparatus. The sink appa-
`ratus has a plurality of HDMI ports, but only one EDID
`memory. Hence, the source apparatus or repeater apparatus
`may fail
`to read its own physical address, depending on
`whether or not power is supplied to the source, sink and
`repeater apparatuses and whether ornot the switching device
`has set a signal path for any apparatus designated.
`Assumethat a source apparatus#1 is connectedto a port #1
`of a sink apparatus(thus, the port #1 is selected). In this case,
`the source apparatus #1 acquires physical address “1.0.0.0”
`when the HPD signalrises to a high level. The source appa-
`ratus #1 holds this physical address evenafter the HPDsignal
`falls back to a low level. If the source apparatusis pulled out
`of the port #1, the sink apparatus cannot detect this event
`because the HPDsignalis now at a lowlevel. The HPD signal
`remains lowevenif the source apparatus #1 is connectedto a
`port #2, because the port #2 is not selected. Consequently, the
`source apparatus #1 keeps holding the physical address of the
`port #1, and cannot acquire the correct physical address
`“2.0.0.0.” Therefore, correct CEC control may not be per-
`formed,
`Thus, any apparatus that receives video data from a data
`transmission apparatus through a conventional digital inter-
`
`

`

`US 7,945,708 B2
`
`3
`face, e.g.,HDMI, must exchange physical addresses with the
`data transmission apparatus so that the data receiver appara-
`tus and the data transmission apparatus may control each
`other. However, the data transmission apparatus mayfail to
`read the physical address of the data receiver apparatus,
`depending on whatstate the apparatuses assume and which
`apparatus the switching device selects.
`
`BRIEF DESCRIPTION OF THE SEVERAL
`VIEWS OF THE DRAWINGS
`
`A generalarchitecture that implements the various feature
`ofthe invention will now be described with reference to the
`
`drawings. The drawings and the associated descriptions are
`provided toillustrate embodimentsofthe invention andnot to
`limit the scope of the invention.
`FIG, 1 is an exemplary view showing an entire video sys-
`tem according to a first embodimentofthe invention:
`FIG. 2 is an exemplary view showing a circuit diagram of
`a source apparatus according to the first embodimentof the
`invention;
`
`FIG. 3 is an exemplary view showing a circuit diagram of
`a sink apparatus according to the first embodiment ofthe
`invention;
`FIG. 4 is an exemplary view showinglevels ofterminals of
`the sink apparatus depending onthestate of the sink apparatus
`according to the first embodimentof the invention; and
`FIGS. 5A, 5B, 5C, and 5Dare an exemplary view showing
`levels of HPD terminals of HDMI port according tothefirst
`embodimentofthe invention.
`
`DETAILED DESCRIPTION
`
`Various embodiments according to the invention will be
`described hereinafter with reference to the accompanying
`drawings.
`According to an embodiment, FIG. 1 is a schematic dia-
`gram showing a video system according to an embodiment of
`the present invention.
`Thevideo system has a video-data receiver apparatus (i.e.,
`sink apparatus) 10 and video-data transmission apparatuses
`(ior example, three apparatuses) (i.e., source apparatuses)
`12a, 126 and 12c. HDMIcables 14a, 146 and 14c connectthe
`video-data transmission apparatuses 12a, 12b and 12e,
`respectively, to the video-data receiver apparatus 10. The
`video-data transmissionapparatuses 12a, 125 and 12care, for
`example, digital versatile disc (DVD) players, streaming
`video-data transmission apparatuses,tuners, set-top boxes, or
`game apparatuses. The video-data receiver apparatus 10 is,
`for example,a television receiver, or a monitor for a personal
`computer(PC), orthe like.
`FIG. 2 is a diagram showing a configuration of the video-
`data transmission apparatus 12a. As shown in FIG. 2, the
`video-data transmission apparatus 12a comprises a display
`device 20, an input device 21, a storage device 22, a controller
`23, and an HDMI output port 24. The display device 20
`displays a playback timeofvideo. The input device 21 may be
`operated to make the apparatus 12a perform various opera-
`tions. The storage device 22 stores videodata 220 andthelike.
`The controller 23 controls the display device 20, input device
`21 and storage device 22. The HDMIoutput port 24 is con-
`nected to the HDMI cables 14a, 144 or 14c. The HDMI output
`port 24 has pins that are responsible, respectively, for trans-
`mission minimized differential signaling (TMDS), +5V
`power supply, hot-plug detect (HPD), digital data channel
`
`ta0
`
`rm a
`5
`
`wa
`
`4
`(DDC) and consumerelectronics control (CEC). The DDC
`line is almost identical in specification to an inter-integrated
`circuit (PC) bus.
`The HDMI output port 24 has a TMDStransmitter 25, a
`+5Vpower-supply output device 26, an HPD-signal receiver
`27, an EDID-receiver/HDCP-authenticator 28, and a CEC-
`transmitter/receiver 29. ‘The TMDStransmitter 25 transmits
`video data, audio data and auxiliary data. The +5V power-
`supply output device 26 outputs a +5V power-supply signal
`(source-readysignal) whenthe video-data transmissionappa-
`ratus 12a is connected to the sink apparatus 10 or repeater
`apparatus. In other words,
`the +5V power-supply signal
`informsthe sink apparatus 10 or repeater apparatus that the
`source apparatus 12a has been connected (or that the sink
`apparatus 10 is ready), The EDID-receiver/HDPC-authenti-
`cator 28 receives EDID,i.e., data representing the product
`information of the sink apparatus connected and the video
`format compatible to the sink apparatus, and also authenti-
`cates the sink apparatus connected. The CEC-transmitter/
`receiver 29 can transmit and receive an apparatus control
`signal and a CEC, i.e., control protocol.
`FIG. 3 shows a circuit configuration of the video-data
`receiver apparatus 10. As shown in FIG. 3, the video-data
`receiver apparatus 10 has a plurality ofHDMI input ports, or
`more precisely three HDMIinputports 32a, 324 and 32c. In
`the video-data receiver apparatus 10, a switching device 36
`selects one of the HDMI inputports 32a, 326 and 32c.
`The HDMI input ports 32a, 326 and 32c have the samepin
`) arrangement as the HDMIoutputport 24.
`The CEC linesofthe HDMIinput ports 32a, 326 and 32¢
`are connected, in common, to a CEC-transmitter/receiver 34,
`The TMDSline and DDCline ofeach HDMI input portare
`connectedto each ofthe three input terminals of the switching
`device 36, which has one output terminal. The DDC lines of
`the HDMI input ports 32a, 326 and 32care respectively
`connected to EDID memories 38a, 385 and 38¢ whichare
`formed of nonvolatile memories. They are notlimited to flash
`memories. Rather, they may be hard disks or RAMs with a
`backup powersupply. The EDID memories 38a, 385 and 38c
`store the physical addresses allocated to the source appara-
`tuses 12a, 124 and 12cthat are connected to the HDMI input
`ports 32a, 326 and 32c, respectively. If the sink apparatus 10
`has physical address “1.0.0.0,” the EDID memory 38a stores
`5 “1.1.0.0.” the DID memory 384 stores “1.2.0.0,” and the
`EDID memory 38cstores “1.3.0.0.”
`The +5Vlines of the HDMI ports 32a, 324 and 32c¢ are
`connected to the EDID memories 38a, 386 and 38c, respec-
`tively. The HPDlines ofthe HDMI ports 32a, 324 and 32care
`» connected to the +5Vlines via switches 42a, 426 and 42c,
`respectively. The connectionpoints ofthe switches 42a, 42h
`and 42¢ and EDID memories 38a, 385 and 38c are connected
`to the groundpotential via pull-downresistors 40a, 40and
`40c. The switches 42a, 425 and 42¢are normally on. They are
`turned off for a short constant time whenthe switching device
`36 switches over or when the sink apparatus 10 changes in
`operatingstate.
`The TMDSline of any HDMI inputport that the switching
`device 36 selects is connected to a TMDSreceiver 46,
`whereas the DDC line of theHDMI inputport is connected to
`an EDID-transmitter/HDCP-authenticator 58.
`A videosignal output from the TMDSreceiver 46 is sup-
`plied via a video processor 52 to a display panel 54, while an
`audio signal is supplied via a D/A converter 48 to a speaker
`50.
`The controller 66 controls the other componentsof the sink
`apparatus 10.
`
`

`

`US 7,945,708 B2
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`10
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`Fi
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`20
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`4on
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`5
`FIG. 4 shows the variousstates of the sink apparatus 10 in
`accordancewith the potentials at the various terminals ofthe
`sink apparatus.
`“Standby” shown in FIG. 4 is the state in whichthe display
`does notdisplay an image even ifthe poweris supplied to the
`sink apparatus 10. In this state, the HPDsignal is high, irre-
`spective ofwhetherthe switching device 36 selects the HDMI
`port 32a, 326 or 32c. Therefore, the EDID memory 38a, 385
`or 38¢ canbe read (OK), theHDCP authentication cannot be
`performed (NG), and the TMDSpotential is low.
`Asindicated above, the +5Vline is connected to the HPD
`line in the sink apparatus 10 and the HPDline is connected to
`the ground potential via the pull-downresistor 40a, 405 or
`40c. The HPDline therefore remainsat +5V(high) as long as
`the source apparatus 12a, 124 or 12¢ is connected to the
`HDMIinputport 32a, 326 or 32c. Hence, the source appara-
`tus 12a, 126 or 12c can read data from the EDID memories
`38a, 38) and 39¢.
`However, the HDCP authentication cannot be performed
`(NG). This is because the source apparatus 12a, 12 or 12¢
`needs not perform the HDCP authentication while the sink
`apparatus 10 remains in the standby state. Further, while the
`sink apparatus 10 remains in the standby state, the source
`apparatus 12a, 124 or 12ctransmits novideo datato the sink
`apparatus 10. Therefore, the TMDSpotential is low.
`While the sink apparatus 10 is on (thatis, the display device
`is on in the case where the sink apparatus 10 is a T'Vreceiver),
`some terminals each assumeonestate orthe other, in accor-
`dance with whether the switching device 36 selects which
`port 32a, 326 or 32c.
`As described above, the +5Vline extending from the
`source apparatus12a, 12 or 12¢ is connected to the HPD line
`provided in the sink apparatus 10 and the HPD line is con-
`nected to the ground potential via the pull-downresistor 40a,
`405 or 40c. The HPD line therefore remainsat +5V(high) as
`long as the source apparatus 12a@, 124 or 12cis connected to
`the HDMI input port 32a, 326 or 32c. Since the HPD line
`remainsat +5V, the source apparatus 12a, 12or 12¢ can read
`data from the EDID memories 38a, 384 or 39¢.
`Nonetheless, the HDCP authentication for any port not
`selected by the switching device 36 is disabled (NG), whereas
`the HDCP authentication for any port selected is enabled
`(OK). This is because it suffices to perform HDCPauthenti-
`cation utilizing the DDC line for only the source apparatus
`12a, 124 or 12c connected to the HDMI input port selected by
`the switching device 36. Similarly, the TMDSpotential is
`highfor only the port 32a, 326 or 32¢ selected, and is lowfor
`any port not selected, because video datais transmitted to the
`sink apparatus 10 from only the source apparatus 124, 126 or
`12c selected by the switching device 36. It should be noted,
`however, that the TMDSpotential at any port not selected
`may beset to a highlevel, not limited to a lowlevel.
`When the source apparatus 12a, 125 or 12cis connected to
`any one of the HDMIports of the sink apparatus 10, the
`source apparatus 12a, 124 or 12¢transmits a +5V power-
`supply signal to the sink apparatus 10. In the sink apparatus
`10, the +5Vpower-supply signal is folded back, providing an
`HPDsignal. The HPD signal is transmitted to the source
`apparatus 12a, 12 or 12c. As seen from FIG. 4, the HPD
`signal is at a highlevel (indicating the connection-detected
`state) at all times,
`irrespective of which HDMI port
`the
`switching device 36 selects or in which state the sink appa-
`ratus 10 is operating.
`Upon receiving the HPD signal at a highlevel, the source
`apparatus 12a, 126 or 12creads the EDID via the DDC line
`from the EDID memory 38a, 385or 38¢ ofthe sink apparatus
`10. The source apparatus 12a, 126 or 12 thus acquires, from
`
`6
`the EDID memory 38a, 38or 38c ofthe sink apparatus 10,
`the physical address and the video-format data representing
`the format in whichthe sink apparatus 10 candisplay images.
`Whenthe HPD signalrises from a low levelto a high level, the
`source apparatus 12a, 12) or 12c exchanges the HDCP key
`data items indispensable for the HDCP authentication, with
`the sink apparatus 10 through the DDCline. The HDCP key
`data is stored in the EDID memory 38a, 386 or 38cofthe sink
`apparatus 10, too. Ifthe HDCP authentication succeeds, the
`source apparatus 12a, 125 or 12c encrypts the video data 220
`with the secret key shared with the sink apparatus 10, gener-
`ating videodata of the TMDSformat complying with the sink
`apparatus 10. This video data is transmitted to the sink appa-
`ratus 10.
`Once the EDID memories 38a, 385 or 38c, each of which
`stores a physical address, and a source apparatuses have been
`connected to HDMI ports 32a, 32 or 32c, the sink apparatus
`10 transmits an HPDsignal at a highlevel to the source
`apparatuses 12a, 12 and 12c in response to the +5V power-
`supplysignal even if the HDMIport 32a, 326 or 32cis not
`selected by the switching device 36. The source apparatus
`12a, 126 or 12c can therefore read its own physical address
`even if it is not selected. Moreover, evenif the sink apparatus
`10 is in a standby states the source apparatus 12a, 12or 12¢
`can read the physical address. The source apparatus 12a, 125
`or 12c can thus reliably acquire the physical addresses nec-
`essary for achieving the CEC control.
`Only the HDMI input port 32a, 32h or 32c selected by the
`switching device 36 is connected to the HDCP-authenticator
`58. Since the HDCP-authenticator 58 cannot perform the
`HDCP authentication while the sink apparatus 10 remainsin
`the standby state, wasteful authentication can be prevented.
`The source apparatuses 12a, 125 and 12¢ may be designed
`to display analert such as an authenticationerror ifthe HDCP
`authentication cannot be performed (NG). In this case, each
`source apparatus 12a, 126 or 12c checks the TMDSpotential
`at each port, determining whether the potential is high or low.
`If HPD=high and TMDS=low,the source apparatus 12a, 126
`or 12c does not display an alert even if the HDCP authenti-
`cation is NG.
`
`As seen from FIG. 4, the HPD terminalis always high. As
`the HDMI standard describes, however, the sink apparatus
`starts the HDCP authentication when the HPD signal rises
`froma lowleveltoa highlevel. Hence,the sink apparatus may
`not perform the HDCP authentication when the HDMIport is
`switched overandits state changes (from the standbystate to
`the on-state) under the status shownin FIG. 4.
`Thus, the HPDline connected to any port that the switching
`device 36 selects(i.e., any port not selected a momentbefore)
`is set to a low level fora moment, (e.g., 500 milliseconds) and
`then back to a high level. This can be accomplished by
`momentarily turning off the switch 42a, 425 or 24c provided
`on the HPD line.
`Inthis regard, it should be noted that the
`switches 42a, 425 and 24¢ are normally on, but are off for a
`moment when the ports on which the switching device 36
`stops selecting them. Also note that any switch 42a, 426 or
`42ethat is connected to the HDMIport selected under the
`control of the controller 66 is momentarily turned off when
`the state of the sink apparatus changes fromthe standbystate
`to the on-state.
`The HPDterminalis therefore highat all times. Nonethe-
`less, the HDCP authentication can be performed when the
`HDMI port is switched from one to another or when the sink
`apparatus changes in state. This prevents illegal use ofthe
`correct encryption-decryption key.
`
`

`

`US 7,945,708 B2
`
`7
`As has been explained, appropriate physical addresses can
`be given to all source apparatuses connected to the DHMI
`inputports in the first embodimentof the present invention.
`According to the present invention, as described above,
`nonvolatile storages for storing physical addresses are con-
`nected between the address terminals and switching devices
`of the data receiver apparatus, and a connection detection
`signal which is output from the detection terminal of each
`inputport is asserted onthe voltage detected. The data trans-
`mission apparatuses can read their physical addresses from
`the data receiver apparatus,irrespective of the power-supply
`state of the data receiver apparatus or whether the switching
`devices are selected or not.
`The present invention is not limited to the embodiment
`described above. The components of any embodiment canbe
`modified in various manners in reducing the invention to
`practice, without departing from the sprit or scope of the
`invention. The method oftransmitting an HPD signalata high
`level, for example,is not limited to the method explained with
`reference to FIG. 3, and can be modified in various ways. For
`instance, a +5V HPD signal may be generated from the power
`supply of the sink apparatus. In this case, the sink apparatus
`transmits the +5V HPDsignalto the source apparatuses when
`it becomesoperative, irrespective of whether it has received a
`+5V HPDsignal from any source apparatus, or whenit con-
`firmsthat it has received a +5V HPDsignal from any source
`apparatus.
`the components of the embodiment described
`Further,
`above may be combined, if necessary, in various ways to
`make different inventions. For example, some ofthe compo-
`nents of the embodiment may not be used. Moreover, the
`components ofthe different embodiments may be combined
`in any desired fashion.
`Still further, the present invention may be applied to a
`computer-readable recording medium holding a programthat
`causes computers to execute prescribed means or to operate
`as specific means or to perform specific functions.
`While certain embodiments of the inventions have been
`described, these embodiments have been presented by way of
`example only, and are not intended to limit the scope of the
`inventions. Indeed, the novel methods and systems described
`herein may be embodied in a variety of other forms; further-
`more, various omissions, substitutions and changes in the
`form of the methods and systems described herein may be
`made without departing from the spirit of the inventions. The
`accompanying claims and their equivalents are intended to
`cover such forms or modifications as would fall within the
`scope andspirit ofthe inventions.
`What is claimedis:
`
`1. A data receiver apparatus comprising:
`input ports which comply with a prescribed digital inter-
`face standard; and
`
`aswitching device whichis configured to select any one of
`the input ports, wherein
`each of the input ports comprises a voltage signal terminal
`configured to receive a prescribed voltage signal trans-
`mitted from a data transmission apparatus, a detection
`terminal configured to output a connection detection
`signal to the data transmission apparatus, a data input
`terminal configured to receive a data signal transmitted
`from the data transmission apparatus, and an address
`terminal configured to transmit a physical addressto the
`data transmission apparatus, and
`the switching device which is configured to select data
`signals supplied from the data input terminals of the
`input ports, and the data receiver apparatus further com-
`prising:
`
`5
`
`10
`
`wa
`
`20
`
`8
`nonvolatile storage devices each of which is connected
`betweenthe address terminal and the switching device
`and which are configured to store physical addresses
`associated with the input ports; and
`a setting unit which is configured to set the connection
`detection signal output from the detection terminal of
`the inputports to a detection-state voltageirrespective of
`whetherthe switching device selects the data inputter-
`minal ofthe input ports.
`2. The data receiver apparatus according to claim 1,
`wherein the setting unit is configured to set the connection
`detection signalto the detection-state voltage when the data
`transmission apparatus is connected to one of the inputports,
`and is configuredto set the connection detection signal output
`from the detection terminal of the one ofthe input ports to a
`non-detection-state voltage for a prescribed period and then
`set the connection detection signal back to the detection-state
`voltage when the switching deviceselects the one ofthe input
`ports.
`3. The data receiver apparatus according to claim 1,
`wherein the setting unit is configured to set the connection
`detection signal to the detection-state voltage when the data
`transmission apparatus is connected to one of the input ports,
`rm a
`5 and is configuredtoset the connection detectionsignal output
`from the detection terminal of any input port selected by the
`switching device to a non-detection-state voltage for a pre-
`scribed period and then set the connection detection signal
`back to the detection-state voltage when the data receiver
`apparatus is switched froma standby state to an onstate.
`4. The data receiver apparatus according to claim 1,
`wherein the detection-state voltage of the connection detec-
`tion signal, which the setting unit sets,
`is a voltage of the
`prescribed voltage signal.
`5. The data receiver apparatus according to claim 4,
`wherein the voltage signal terminal is connected tothe detec-
`tion terminal, and a connection point of the voltage signal
`terminal and the detection terminal is connected to a refer-
`
`a0)
`
`had 5
`
`40
`
`ence potential via a resistor.
`6. The apparatus according claim 1, wherein the prescribed
`digital interface standard is high definition multimedia inter-
`face (HDMI) standard.
`7. A data receiving method for use in a system which
`5 comprises a data transmission apparatus including an output
`port complying with a prescribed digital interface standard,
`and a data receiver apparatus including input ports complying
`withthe digital interface standard, physical addressmemories
`connected to the inputports, and a switching device config-
`ured to select any oneofinputsignals supplied from the input
`ports, the data receiving method comprising:
`transmitting a prescribed voltage signal from the data
`transmission apparatus to the data receiver apparatus:
`transmitting a connection detection signal from the data
`receiver apparatus to the data transmission apparatus:
`reading, by the data transmission apparatus, a physical
`address from one of the physical address memories con-
`nected to oneof the input ports to which the data trans-
`mission apparatus is connected when the connection
`detectionsignal is at a connection detection potential;
`detecting, by the data transmission apparatus, a connection
`of a data input terminal when the connection detection
`signal changes from a non-connection detection poten-
`tial to a connection detection potential:
`performing, by the data transmission apparatus, an authen-
`tication when the connection of the data input terminalis
`detected:
`
`50
`
`60
`
`

`

`US 7,945,708 B2
`
`9
`encrypting data in a prescribed encryption method by the
`data transmission apparatus when the authentication
`succeeds; and
`transmitting the encrypted data to the data receiving appa-
`ratus from the data transmission apparatus, and wherein;
`the connection detection signal is set to the connection
`detection potential when the data