|||||||||||||||||||||||||l|||||||||||||||||l||||||l|||||l||||||||||||||||||
`
`U800794570832
`
`(12; United States Patent
`US 7,945,708 32
`(10) Patent 010.:
`Ohkita
`
`(45) Date of Patent: May 1?, 2011
`
`(54) APPARATUS AND METHOD OF RECEIVING
`DATA FROM AUDIOJ'VIDEO EQUIPMENT
`
`(75}
`
`inventor:
`
`IlidekiOhkita. KunitaehiUl’)
`
`(73) Assignee: Kabushiki Kaisha Toshiba. Tokyo (JP)
`
`( * } Notice:
`
`Subject to an}r disclaimer. the term oftltis
`patent is extended or adjusted under 35
`use. 1540)) by 21 a days.
`
`(21)
`
`.-tpp1.Nn.: 121351.475
`
`(22)
`
`Filed:
`
`Jan. 9, 2009
`
`(65)
`
`Prior Publication Data
`
`US 2009t0138935 Al
`
`May 23. 2009
`
`Related US. Application Data
`
`(63} Continuation ofapplieation No. l’Cf'l‘tJP2008t061599.
`tiled on Jun. 19. 2008.
`
`(30}
`
`Foreign Application Priority Data
`
`Jun. 25, 2007
`
`(JP) ................................. 2007—166635
`
`(51}
`
`lnt.(.‘l.
`(IMF 3/00
`(EMF t3/t2
`0061’ 7/04
`(52} U.S.CI.
`
`(2006.01 )
`(2006.01)
`(2006.01)
`710.04:710t3;710t36:?10162:
`726.32
`
`[58)
`
`(56}
`
`Field ofClassifieation Search
`See application file for complete search history.
`
`None
`
`References Cited
`
`U .S. PA'I'I'ENT DOCU Ml ENTS
`200430239310 .-’\1*
`1232004 Ando ............................ 348-705
`200030000|TI'TIr Al
`1-"2006 Salzanoetal.
`2007-‘0036l58 Al
`2-‘200?
`l'lun-Kwonetal.
`2001-0055316 A1
`3.3200? C'hoi
`2007-0051931 .-\1
`3-200? Takarnori
`
`El’
`JP
`J1’
`JP
`JP
`JP
`W0
`
`FOREIGN PATENT DOCUMENTS
`”61052 AZ
`3200?
`2004-357029
`[252004
`2006-2 03'335
`852006
`2006-3 509 i 9
`[232006
`BOUT-073980
`3200?
`20075134955
`55200?
`HIDE-049556 Al
`5-“2007
`
`OTHER PUBLICATIONS
`
`International Search Report and Written Opinion for PCT application
`No. PCI'I'JP2008:001599 dated Sep. 9. 2008.
`High-Definition Multimedia Interface. Specification Version [.33:
`l-IDMI Licensing. I.I.(‘; Nov. 10. 2006.
`State
`Intellectual Proper!)r Office of P.R.C. application No.
`2008800004810. Notifieat ion ol'the First OllieeAclion. ntai led Apr.
`29. 2010 (English translation).
`"Extended European Search Report Dated Oct. '5’. 2001". European
`Patent Application No. USTTTG l LS.
`“High-Definition Multimedia Specification. specification version
`1.3". Jun. 22. 2006. X0030001519.
`
`"‘ cited by examiner
`
`Primary Et'antt'ner — Alan Chen
`(74) Attorngt'. Agent. or firm Blakely. Sokt)loiI.'l‘aylor&
`Zal'man LIP
`
`(57]
`
`A BS'I'RAC'I~
`
`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 outp utting a eotmection detection signal. a data input
`terminal receiving a data signal. and an address terminal
`trmtsntitting a physical address. A nonvolatile memory is
`comiected to the address terminal. A cotutection detection
`
`signal output from the detection terminal is set to a detection—
`slate voltage irrespective onlietlier the data input terminal is
`selected.
`
`9 Claims. 4 Drawing Sheets
`
`*39-
`mi:1.
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`
`
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`was
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`“Tit:
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`”cm H;"
`
`Halo—WU},
`
`53
`
`Connie :
`
`Roku EX1039
`
`US. Patent No. 9,716,853
`
`Roku EX1039
`U.S. Patent No. 9,716,853
`
`

`

`US. Patent
`
`May 17, 2011
`
`Sheet] ofd
`
`US 7,945,708 B2
`
`
`
`

`

`US. Patent
`
`May 17, 2011
`
`Sheet 2 OH
`
`US 7,945,708 B2
`
`.
`Input dewce
`
`+5V power-supply
`output device
`
`.
`
`#27
`
`5°”th .
`
`HPD~signaJ receiver
`
`Video data
`
`220
`
`'
`
`J28
`
`, EDlD-receiver/
`HDCP-authenticator
`
`(EEC-transmitter
`/receiver
`
`:.
`
`FIG.2
`
`

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`US. Patent
`
`May 17, 2011
`
`Sheet 4 OH
`
`US 7,945,708 B2
`
`
`
`Terminals of
`
`the sink apparatus
`
`Standby
`
`HDMl not selected
`
`HDMI selected
`
` State of the sink
`apparatus
`
`
`
`EDIDreading _—OK
`
`
`
`
`_---
`
`
`-nn-
`
`
`
`HPD potential
`
`High
`
`High
`
`Switching device 36
`
`Port
`
`1
`
`Port 3
`
`F I G. 5A
`
`HPD terminal of
`HDMI port
`1
`
`FIG.SB
`
`HPD terminal of
`HDMI port 2
`
`FlG.5C
`
`High
`
`l
`
`l
`
`High
`
`
`
`HPD terminal of
`HDMI port 3
`
`ngh
`
`FIG. SD
`
`M
`
`

`

`US T,945.T08 E32
`
`1
`APPARATUS AND METHOD OF RECEIVING
`DATA FROM AUDIONIDEO EQUIPMENT
`
`C ROSS-REFERENCE. TO RELATED
`APPLICATIONS
`
`This is a ContinuationApplication of PCT Application No.
`PCTllP2008l061599. filed Jun. 19. 2008. which was pub-
`lished under PCTArticle 21(2) in English.
`This application is based upon and claims the benefit of
`priority frotn Japanese Patent Application No. 2007-166635.
`tiled Jun. 25. 2007. the entire contents of which are incorpo—
`rated herein by reference.
`
`BACKGROUND
`
`1. Field
`One embodiment of the invention relates to an apparatus
`and method for receiving video data via a digital interface.
`2. Description ofthe Related Art
`An example of a multimedia interface between a video—
`data tnutsmission 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
`with the high definition multimedia interface (I-IDMl) stan-
`dard (High-Definition Multimedia interface Specification
`Version 1.3a). Any apparatus that has an HDMl output ter~
`mina] is called a source apparatus, and any apparatus that has
`an III )MI input terminal is 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 rut HDMI
`output tenninal and perfomts both the function of a source
`apparatus and the function of a sink apparatus is known as a
`repeater apparatus.
`When the source apparatus is connected to the sink appa—
`ratus. the source apparatus transmits a +5\" 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.
`Upon receiving the +SV power-supply signal. the sink
`apparatus starts making itselfpmpared 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 (I-IPD) signal is also a signal showing
`that the sink apparatus is now ready to receive video data.
`The sink apparatus has an EDID memory that stores
`extended display identification data (EDID). i.e.. the videow
`format data that the sink apparatus can display. The video—
`format data includes video specification items such as video
`format. resolution and sync frequency. and audio specifica-
`tion items such as audio-data format. sampling frequency F5
`and bit length.
`Upon receiving the l-ll’D signal at a high level. the source
`apparatus reads the PEDID from the ED] D memory of the sink
`apparatus through a display-data channel (1)le) line. reading
`the video-liirtnat data. which is written in the i.il)ll) and in
`which the sink apparatus can display video data.
`The source apparatus transmits and receives data required
`to achieve the authentication of high-bandwidth digital coit-
`tent protection (l-lDCP).
`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 content protection
`
`ll]
`
`21']
`
`I.) 1):
`
`3t]
`
`35
`
`.
`
`51]
`
`55
`
`54]
`
`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 with the secret-key data shared with the sink apparatus,
`and then transmits the video data. thus decrypted. to the sink
`apparatus.
`After reading and authenticating the EDID. the source
`apparatus transmits video data. audio data and AUX data. all
`complying to the sink-apparatus format. to the sink apparatus
`by means of transmission minimized differential signaling
`(TMDS).
`The I-IDMJ standards describe optional standards concern-
`ing the mutual control of apparatuses. known as consumer
`electronic control [(il'iC‘). I-IDMI devices are tree-connected
`by repeaters. The CliC utilizes a single-line. low-speed serial
`bus. One of the 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 tnode (that is. when the playback button on the
`apparatus is pushed). the source apparatus controls the sink
`apparatus (e.g._. a TV receiver) and to automatically turns on
`the sink apparatus ifnecessary and automatically connect the
`signal path to it [i.e.. DVD player). Thus. the source apparatus
`enables the sink apparatus to display the image played back.
`lit order to designate one ofapparatuses so that a switching
`device may be controlled to set a signal path, all apparatuses
`ntttst have a physical address each. The physical address of
`the source apparatus is Written in the 151)] I) ol‘the sink appa-
`ratus or the lilJll) of the repeater apparatus. When the appa-
`ratuses are nnttttally 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. If the tree connection is composed
`of five stages at most. the address of each apparatus is a
`four—digit data item. represented as “n.n.n.n." Any sink appa-
`ratus or repeater apparatus that serves as a route. generates its
`physical address “0.0.0.0." The sink apparatus or repeater
`apparatus reads its physical address frotn the EDI!) memory
`of the sink apparatus comtected to it.
`The timing the sottrce apparatus or repeater apparatus
`reads its own physical address is the time when it receives the
`high-level llPI) signal that the sink apparatus or repeater
`apparatus transmits in response to the +5\/‘ power-supply
`signal it receives from the source apparatus. The sink appa-
`ratus has a plurality of HDM] ports. but only one EDlD
`tnetnory. 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 or not the switching device
`has set a signal path for any apparatus designated.
`Assume that a sourceapparatus til is connected to a port ill
`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 signal rises to a high level. The source appa-
`ratus it! holds this physical address even a liar the [-il’l) signal
`falls back to a low level. If the source apparatus is pulled out
`of the port #1. the sink apparatus cannot detect this event
`because tlte l-lPD signal is now at a low level. The HPD signal
`remains low even if the source apparatus all is connected to a
`port #2. because the port #2 is not selected. Consequently. the
`source apparatus #1 keeps holding the physical address ofthe
`port
`til. 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 7.945308 BZ
`
`4
`
`(DDC) and consumer electronics control (CBC). The DDC
`line is almost identical in specification to an inter-integrated
`circuit {12C} bus.
`The HDMI output port 24 has a TMDS transmitter 25. a
`+SV power-supply output device 26. an I-lPD-signal receiver
`27. an ii])lD-receiverflIIXTP-authenticator 28. and a CEC-
`lransmittert'reccivcr 29. The TMDS transmitter 25 transmits
`
`5
`
`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 may fail to
`read the physical address of the data receiver apparatus.
`depending on what state the apparatuses assume and which
`apparatus the switching device selects.
`
`BRIEF DESCRIPTION OF THE SEVERAL
`VIEWS OF THE DRAWINGS
`
`A general architecture that implements the various feature
`of the invention will now be described with reference to the
`
`drawings. The drawings and the associated descriptions are
`provided to illustrate embodiments of the invention and not to
`limit the scope of the invention.
`FIG. 1 is an exemplary view showing an entire video sys-
`tem according to a first embodiment of the invention:
`FIG. 2 is an exemplary view showing a circuit diagram of
`a source apparatus according to the first embodiment of the
`invention:
`
`1”
`
`21']
`
`FIG. 3 is an exemplary view showing a circuit diagram of
`a sink apparatus according to the first embodiment of the
`invention:
`FIG. 4 is an exemplary view showing levels oftenninals of
`the sink apparatus depending on the state of the sink apparatus
`according to the Iirst embodiment of the invention: and
`FIGS. 5A. 5B. 5C. and 5]) are an exemplary view showing
`levels of l-IPD terminals of HDMI p011 according to the first 3“
`embodiment of the invention.
`
`25
`
`DETAILED DESCRIPTION
`
`video data. audio data and auxiliary data. The +5V power-
`supply output device 26 outputs a +5V power-supply signal
`(source-ready signal ) when the video-data transmission appa-
`ratus 12.9 is connected to the sink apparatus 10 or repeater
`apparatus. In other words,
`the +5V" power-supply sigial
`informs the sink apparatus II] or repeater apparatus that the
`source apparatus 12:: has been connected (or that the sink
`apparatus 10 is ready). The EDID-receiveri‘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 CI'iC-transmitterir
`receiver 29 can transmit and receive an apparatus control
`signal and a CEC . i.e.. control protocol.
`1’ 1G. 3 shows a circuit configuration of the video-data
`receiver apparatus 10. As shown in FIG. 3. the video-data
`receiver apparatus 10 ltas a plurality of HDMI input ports. or
`more precisely three HDMI input ports 32a. 32b and 32c. 1n
`the video~data receiver apparatus It]. a switching device 36
`selects one of the HDMI input pons 32a, 32b and 326.
`The IIDMI input ports 32a. 32b and 32e have the same pin
`arrangement as the HDMI output port 24.
`The CEC lines of the HDMI input ports 320. 32b and 32(-
`are connected. in common. to a C EC-transmittertreceiver 34.
`The TMDS line and DDC line ofeach HDMI input port are
`connected to each ofthe three input term inals of the switching
`device 36. which has one output terminal. The DDC lines of
`the HDMI input ports 320. 325 and 32:.” are respectively
`connected to EDID memories 38a. 38!) and 38:.“ which are
`formed of nonvolatile memories. They are not limited to flash
`memories. Rather. they may be hard disks or RAMs with a
`backup power supply. The EDI D memories 38a. 3815 said 38c
`store the physical addresses allocated to the source appara-
`tuses 126.. 12th and 11.(‘ that are connected to the HDMI input
`ports 32a. 32b and 326, respectively. If the sink apparatus 10
`has physical addreSs “1.0.0.0.“ the EDID memory 38a stores
`. “1.1.0.0." the DID memory 38b stores “1.2.0.0." and the
`EDID memory 38c stores “1.3.0.0.“
`The +5V litres of the HDMI ports 32a. 32b and 320 are
`connected to the EDID memories 38a. 38b and 386. respec-
`tively. The HPD lines ofthe HDMI ports 32a. 32b and 32c are
`connected to the +SV litres via switches 42a. 42b and 42c.
`respectively. The cotutection points of the switches 42a. 42b
`and 42:- and EDID memories 380. 386 and 38: are connected
`to the ground potential via pull-down resistors 40a. 40b and
`40c. The switches 42a. 42b and 42.? are normally on. They are
`turned ed" for a short constant time when the switching device
`36 switches over or when the sink apparatus 10 changes in
`operating state.
`The 'l‘Ml)S line of any HDMI input port that the switching
`device 36 selects is connected to a TMDS receiver 46.
`whereas the DDC line ofthe HDMI input port is connected to
`air EDID-transtnittert'l-lDCP-authenticator 58.
`
`do
`
`5th
`
`Various embodiments according to the invention will be 35
`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.
`The video system has a video-data receiver apparatus (i.e._.
`sink apparatus) 10 and video—data transmission apparatuses
`(for example. three apparatuses) (i.e.. source apparatuses)
`120. 126 and 12e. HDMI cables Me. 141) and 14c cotutect the
`video-data transmission apparatuses 12a. 12!) and 12c:
`respectively. to the video-data receiver apparatus 10. The
`video-data transmission apparatuses 12u. 12b and 12:" are. tor
`example. digital versatile disc (DVD) players. streaming
`video—data transmission apparatuses. tuners. set—top boxes. or
`game apparatuses. The videOAdata receiver apparatus 10 is.
`for example. a television receiver. or a monitor for a personal
`computer (PC). or the like.
`FIG. 2 is a diagram showing a configuration of the video-
`data transmission apparatus l2n. As shown in FIG. 2. the
`video-data transmission apparatus 12a comprises a display
`device 2|]. an input device 21. a storage device 22. a controller
`23. and an HDMI output port 24. The display device 21}
`displays a playback time ot‘video. The input device 21 may be
`operated to make the apparatus 12a perform various opera-
`tions. The sloragedevice 22 stores video data 220 and the like.
`The controller 23 controls the display device 20. input device
`21 and storage device 22. The HDMI output port 24 is con—
`nected to the HDMI cables 14a. 14!; or Me. The HDMI output
`port 24 has pins that are responsible. respectively. for trans—
`mission minimized dilTerential signaling (TMDS}, +5V
`power supply. hot-plug detect (l-IPIJ). digital data channel
`
`55
`
`64]
`
`A video signal output from the TMDS receiver 46 is sup-
`plied via a video processor 52 to a display panel 54. while an
`audio signal is supplied via a DEA converter 48 to a speaker
`50.
`The controller 66 controls the other components o fthe sink
`apparatus 10.
`
`

`

`US 7,945,?08 BZ
`
`5
`FIG. 4 shows the various states of the sink apparatus 10 in
`accordance with the potentials at the various terminals of the
`sink apparatus.
`“Standby" shown in FIG. 4 is the state in which the display
`does not display an image even il‘the power is supplied to the
`sink apparatus It]. In this state. the IIPI) signal is high. irre-
`spective ofwhetherthe switching device 36 selects the I-IDMI
`port 320. 32b or 32c. Therefore. the EDID metnory 38a. 38!)
`or 38c can be read (OK). the I-lDCIJ authentication cannot be
`performed (NG), and the ‘I‘MDS potential is low.
`As indicated above. the +5V line is connected to the HPD
`line in the sink apparatus 10 and the HPD line is connected to
`the ground potential via the pulI~down resistor 40a. 40!) or
`400. The [ IPI) line therefore remains at +5V (high) as long as
`the source apparatus 12a. 12!) or 12c is connected to the
`HDMI input port 32a. 3211 or 32c. Hence. the source appara-
`tus 12o. 12b or 12c can read data from the EDID memories
`38a, 38b and 39:.
`llowever, the [-lDCP authentication cannot be perfonued
`(NG). This is because the source apparatus 12:}. 12b 01' er.’
`needs not perform the HDCP authentication while the sink
`apparatus It] remains in the standby state. Further. while the
`sink apparatus 19 remains in the standby state, the source
`apparatus 12a. 12b or 12c transmits no video data to the sink
`apparatus 10. Therefore. the TMDS potential is low.
`While the sink apparatus 10 is on (that is, the display device
`is on in the on se where the sink apparatus 10 is a TV receiver},
`some terminals each assume one state or the other. in accor-
`dance with whether the switching device 36 selects which
`port 32a. 32b or 32::
`the
`As described above. the +5V line extending front
`source apparatus 12m 12!) or 120 is connected to the I-IPD line
`provided in the sink apparatus 10 and the IIPD line is cott-
`uccted to the ground potential via the pull-down resistor 40a.
`40!; or 40c. The HPD line therefore remains at +5V (high) as
`long as the source apparatus 12a, 12b or 12c is connected to
`the HDMT input port 32a. 32!; or 321". Since the HPD line
`remains at +5 V", the source apparatus 12a, 12!) or 12c can read
`data from the EDID memories 38a. 38b or 39c.
`Nonetheless. the HDCP authentication for any port not
`selected by the switching device 36 is disabled (NG), whereas
`the IIDCP authentication for any port selected is enabled
`(OK). This is because it so [flees to perform I'IDCP authenti-
`cation utilizing the DIX? line for only the source apparatus
`120. 12th or 12c comtected to the HDMT input port selected by
`the switching device 36. Similarly, the TMDS potential is
`high for only the port 326'. 32b or 32c selected. and is low liar
`any port not selected. because video data is transmitted to the
`sink apparatus 10 from only the source apparatus 12a, 12th or
`12c selected by the switching device 36. It shouid be noted.
`however, that the TMDS potential at any port not selected
`may be set to a high level. not limited to a low level.
`When the source apparatus 12a, 12!) or 12r- is connected to
`any one of the HDMI ports of the sink apparatus 10, the
`source apparatus 12a. 12b or 12c transmits a +5V’ power-
`supply signal to the sink apparatus II). In the sink apparatus
`II]. the +5V' mover-supply signal is folded back. providing an
`I-lPI) signal. The HPD signal is transmitted to the source
`apparatus 120. 12b or er'. As seen from FIG. 4. the HPD
`signal is at a high level (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 high level. the source
`apparatus 125:. 125 or 12c reads the EDID via the DDC line
`from the IEDII) memory 38a. 38.6 or 38c ofthe sink apparatus
`10. The source apparatus 12a. 12b or 12c thus acquires, from
`
`It]
`
`21']
`
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`\
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`
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`
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`
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`
`6
`the I'EDII) memory 380, 38!) or 38:? of the sink apparatus 10,
`the physical address attd the video-format data representing
`the fortnat in which the sink apparatus 10 can display images.
`When the HPD signal rises from a lowr level to a high level, the
`source apparatus 12a. 121) or 12c exchanges the [IDCP key
`data items indispensable for the IIIXTP authentication, with
`the sink apparatus 10 through the DDC line. The Ill'JCP key
`data is stored in the EDID memory 38a. 38!: or 3&- ofthe sink
`apparatus 10. too. lfthe HDCP authentication succeeds, the
`source apparatus l2u. 12!) or 12: encrypts the video data 229
`with the secret key shared with the sink apparatus l0. gener-
`ating video data of the TMDS format complying with the sink
`apparatus 10. This video data is transmitted to the sink appa-
`ratus 10.
`Once the EDID memories 38a. 38!) or 38¢. each ofwhich
`stores a physical address. and a source apparatuses have been
`connected to l-lDMl ports 32a. 32b or 32c. the sink apparatus
`10 transmits an HPD signal at a high level
`to the source
`apparatuses 120. 12!) and 12c in response to the +SV power-
`supply signal even if the HDMI port 32a. 32!; or 32c is not
`selected by the switching device 36. The source apparatus
`12o. 12!) or 12:: can therefore read its own physical address
`even if it is not selected. Moreover. even if the sink apparatus
`ID is in a standby states the source apparatus 12:1. 1232 or 12(-
`can read the physical address. The source apparatus 12a, III)
`or 12: can thus reliably acquire the physical addresses nec~
`essary for achieving the CEC control.
`Only the HUM] input port 329. 32b or 32(- sclected by the
`switching device 36 is connected to the [IDCP-authcnticator
`58. Since the HDCP-authenticator 58 cannot perform the
`HDCP authentication while the sink apparatus 10 remains in
`the standby state, wasteful authentication can be prevented.
`The source apparatuses 12a. 12b and 12c: may be designed
`to display an alert such as an authentication error if the IIIXIP
`authentication caruiot be performed [NG]. In this case, each
`source apparatus 12u. 12b or 12:? checks the 'I‘MDS potential
`at each port, detennining whether the potential is high or low.
`If HPD=high and TMDS =low, the source apparatus 12a, 12b
`or l2e does not display an alert even if the HDCP authenti-
`cation is NO.
`
`As seen from FIG. 4. the Ill-’1) tcmtinal is always high. As
`the I-l])M] standard describes, however, the sink apparatus
`starts the HDCP authentication when the HPD signal rises
`fro m a low level to a high level. Hence. the sink apparatus may
`not perform the HDCP authentication when the I-IDMI port is
`switched over and its state changes ( from the standby state to
`the on~state) under the stems shown in FIG. 4.
`Thus. the HPD line connected to any port that the switching
`device 36 selects (i.e.. any port not selected a moment before)
`is set to a low level for a moment. [c.g.. 500 milliseconds} and
`then back to a high level. This can be accomplished by
`momentarily turning off the switch 42a, 42!; or 245 provided
`on the HM) line.
`in this regard. it should be noted that the
`switches 42a, 42b and 24c are normally on. but are olT for a
`moment when the ports on which the switching device 36
`stops selecting them. Also note that any switch 42a, 42}; or
`42.:- that is connected to the HDMI port selected under the
`control of the controller 66 is momentarily turned off when
`the state of the sink apparatus changes front the standby state
`to the tin-state.
`The I-ll’D terminal is therefore high at all times. Nonethe—
`less, the HDC‘P 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 of the
`correct encryption-decryption key.
`
`

`

`US 7,945,?08 E32
`
`7
`As has been explained, appropriate physical addresses can
`be given to all source apparatuses connected to the DHMI
`input ports in the first embodiment of the preseitt 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 front the detection tenniital of each
`input port is asserted on the voltage detected. The data trans-
`mission apparatuses can read their physical addresses from
`tlte data receiver apparatus. irrespective ofthe 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 can be
`modified in various mamters in reduciitg the invention to
`practice. without departing from tlte sprit or scope of the
`invention. The method oftransmitting an HPD signal at a high
`level. for example. is not limited to the method explained with
`reference to FIG. 3. attd can be modified in various ways. For
`instance, a +5V HPD signal may be generated tion: the power
`supply of the sink apparatus. In this case. the sink apparatus
`transmits the +5\" HPD signal to the source apparatuses when
`it becomes operative. irrespective of whether it has received a
`+5V HPD signal from any source apparatus. or when it cott-
`fin'ns that it has received a +5V HPD signal 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. sonte of the compo-
`nents of the embodiment may not be used. Moreover. the
`components of the different embodiments may be combined
`in any desired fashion.
`Still
`litrther. the present invention may be applied to a
`computer~readable recording medium holding a progra at that
`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 systents 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 item 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 and spirit of the inventions.
`What is claimed is:
`
`1. A data receiver apparatus comprising:
`input ports which comply with a prescribed digital inter-
`face standard: and
`
`a switching device which is 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
`front tlte data transmission apparatus. and alt address
`terminal configured to transmit a physical address to the
`data transmission apparatus. and
`the switching device which is configured to select data
`signals supplied front the data input terminals of the
`input ports, and the data receiverapparatus further com-
`prising:
`
`5
`
`1t]
`
`8
`nonvolatile storage devices each of which is connected
`between the address terminal arid 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 inpttt ports to a detectio n-stalc voltage irrespective of
`whether the switching device selects the data input ter-
`ntinal of the input ports.
`2. 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,
`and is configured to set the connection detection signal otttput
`from the detectioit tennith of the one of tlte input ports to a
`non-detection-state voltage for a prescribed period and then
`set the corutection detection signal back to the detection-state
`voltage when the switching device selects the one ot‘the 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,
`I.) .1:
`\ attd is configured to set the connection detection signal output
`from the detection terminal of any input port selected by the
`switching device to a nott-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 from a standby state to an on state.
`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 to the detec-
`tion terminal. and a connection point of the voltage signal
`tenninal and the detection terminal is connected to :1 refer-
`
`it]
`
`3t]
`
`35
`
`do
`
`ence potential via a resistor.
`6. The apparatus according claim 1 . wherein the prescribed
`digital interface standard is high definition multimedia iltte -
`face (I [DMD standard.
`7. A data receiving method for use in a system which
`. comprises a data transmission apparatus including an output
`port complying with a prescribed digital interface standard,
`and a data receiver apparatus including input ports cotnplying
`with tltedigital interface standard, physical address memories
`connected to the input ports. and a switching device config—
`ured to select any one of input signals 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 oncofthe physical address memories colt-
`nected to one of the input ports to which the data trans-
`ntission ap