Receiver, control method for receiver, and transmission / reception system

Abstract

The present invention enables a transmission device to read proper device information (EDID) from a reception device with less burden on a user.　The present invention includes: a memory unit for storing first device information and second device information; and a communication unit for communicating with an external device. A control unit determines, on the basis of the reception of a rewrite signal to the first device information from the external device, whether to cause the external device to read the second device information. The present invention enables the external device (transmission device) to read, from the reception device (receiver), the proper device information (EDID) with less burden on the user, thereby improving user convenience.

Description

[Technical field]

[0001] The present technology relates to a receiving device, a control method for a receiving device, and a transmission / reception system, and more particularly to a receiving device etc. that is designed to improve usability for users. [Background technology]

[0002] Currently, there are transmitting devices (source devices) on the market that cannot decode the HF-VSDB (HDMI Forum Vendor Specific Data Block) newly defined in the EDID (Extended Display Identification Data) of HDMI (High-Definition Multimedia Interface) 2.0. For this reason, the specifications of the receiving devices (sink devices) (television receivers) require the user to manually switch between the EDID for "HDMI 1.4 or earlier transmitting devices" and the EDID for "HDMI 2.0 compatible transmitting devices." Note that HDMI 2.0 here includes HDMI 2.0a and HDMI 2.0b. HDMI 1.4 also includes HDMI 1.4a.

[0003] For example, Patent Document 1 describes HDMI 2.1. HDMI 2.1 specifies transmission by FRL (Fixed Rate Link). In HDMI 2.1, image data is also packetized and transmitted, and before transmitting image data and audio data, an operation called FRL Link Training is performed to set a transmission rate (clock rate) according to the capability of the transmission path between a transmitting device and a receiving device, including the HDMI cable. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2017 / 151925 Summary of the Invention [Problem to be solved by the invention]

[0005] With the currently used 256-byte EDID, it is not possible to combine (merge) the EDID for "HDMI 2.0 compatible transmitters" and the EDID for "HDMI 2.1 compatible transmitters" into a single EDID data. Therefore, it is necessary to be able to switch between the EDID for "HDMI 1.4 or earlier transmitters", the EDID for "HDMI 2.0 compatible transmitters", and the EDID for "HDMI 2.1 compatible transmitters".

[0006] In this situation, both HDMI 2.0 compatible transmitters and HDMI 2.1 compatible transmitters use HDCP (High-bandwidth Digital Content Protection) 2.2 for content protection. Therefore, even if the operation performed by HDCP 2.2 is monitored, it cannot be used as a judgment criterion for selecting between the EDID for "HDMI 2.0 compatible transmitters" and the EDID for "HDMI 2.1 compatible transmitters."

[0007] As mentioned above, HDMI 2.1 performs an operation called FRL link training. When this FRL link training is performed, communication takes place between the transmitting device and the receiving device via the DDC (Display Data Channel) line. Therefore, by monitoring communication on the DDC line, it is possible to detect that HDMI transmission between the transmitting device and the receiving device is taking place via HDMI 2.1, and this can be used as a condition for selecting the EDID for "HDMI 2.1 compatible transmitting devices."

[0008] The purpose of this technology is to enable a transmitting device to read appropriate device information (EDID) from a receiving device with less burden on the user. [Means for solving the problem]

[0009] The concept of this technology is as follows: a memory unit for storing the first device information and the second device information; A communication unit that communicates with an external device; a control unit that determines to cause the external device to read the second device information based on reception of a rewrite signal to the first device information from the external device; in the receiving device.

[0010] The receiving device of the present technology may be, for example, a display device. The receiving device of the present technology includes a memory unit that stores the first device information and the second device information, and a communication unit that communicates with an external device. For example, the first device information may be information included in a Status and Control Data Channel Structure (SCDC). In this case, for example, the first device information may be FRL_Rate, which is information about a link rate selected by the external device. For example, the communication unit may communicate with the external device through a digital interface cable. In this case, for example, the digital interface cable may be a High-Definition Multimedia Interface (HDMI) cable.

[0011] The control unit determines to read the second device information into the external device based on reception of a rewrite signal for the first device information from the external device. For example, the rewrite signal may be determined in response to the second device information. In this case, for example, the rewrite signal may be Max_FRL_Rate, which is information about a link rate supported by the device and is described in the second device information.

[0012] In this way, in the present technology, it is determined to cause the external device to read the second device information based on reception of a rewrite signal to the first device information from the external device. Therefore, it is possible to cause the external device (transmitting device) to automatically read appropriate device information (EDID) from the receiving device (receiving device), thereby improving usability for the user.

[0013] The rewrite signal may be transmitted according to a value of FLT_ready, which is information indicating a preparation status of the link training process and is written in the first device information. In the present technology, for example, the memory unit may further store third device information, and the control unit may determine to cause the external device to read the third device information when the rewrite signal is not received. In this case, for example, the second device information may be information corresponding to version 2.1 of the High-Definition Multimedia Interface (HDMI), and the third device information may be information corresponding to version 2.0 of the HDMI.

[0014] In this case, the second device information and the third device information may each be Extended Display Identification Data (EDID) including an HDMI Forum Vendor Specific Data Block (HF-VSDB), which is information on functions supported by the device. In this case, the second device information may be a 512-byte EDID obtained by combining (merging) an EDID for 4K High frame rate (HFR) and an EDID for 8K.

[0015] Also, for example, the memory unit may further store fourth device information, and the control unit may determine to have the external device read the fourth device information when the external device does not support the second device information and the third device information. In this case, the control unit may determine that the external device does not support the second device information and the third device information when a predetermined signal is not received from the external device. In this case, the predetermined signal may be AKE_Init, which is a start signal of an authentication process between the external device and the external device. Also, for example, the fourth device information may be information corresponding to version 1.4 or earlier of the High-Definition Multimedia Interface (HDMI). In this case, the fourth device information may be Extended Display Identification Data (EDID) including a Vendor Specific Data Block (VSDB), which is information regarding functions supported by the device. [Brief description of the drawings]

[0016] [Figure 1] 1 is a block diagram showing an example of the configuration of a transmission / reception system according to an embodiment; [Diagram 2] FIG. 2 is a diagram for explaining EDID compatible with HDMI 1.4 and earlier, HDMI 2.0, and HDMI 2.1. [Diagram 3] 1 is a block diagram showing an example configuration of a data transmitting unit (HDMI transmitting unit) of a source device and a data receiving unit (HDMI receiving unit) of a sink device. FIG. [Figure 4] FIG. 2 is a diagram showing an example of a link rate and the number of lanes corresponding to each link in HDMI 2.1. [Diagram 5] 10 is a flowchart illustrating an example of a procedure of an EDID automatic switching control process in a control unit of a sink device. [Figure 6] FIG. 1 is a diagram illustrating an EDID for HDMI 2.1. [Figure 7] 13 is a diagram illustrating an outline of SCDC data stored in an SCDC register unit. FIG. [Figure 8]2 is a diagram illustrating HDCP data stored in an HDCP register unit. FIG. [Figure 9] 13 is a diagram showing an example of the structure of "AKE_Init" and the contents of main information in the example structure. FIG. [Figure 10] 13 is a flowchart illustrating another example of the procedure of the EDID automatic switching control process in the control unit of the sink device. [Figure 11] FIG. 13 is a diagram showing an example of a UI screen for selecting either an EDID for HDMI 2.1 (4K HFR) or an EDID for HDMI 2.1 (8K). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, modes for carrying out the invention (hereinafter, referred to as "embodiments") will be described. The description will be made in the following order. 1. Embodiment 2. Variations

[0018] <1. Preferred embodiment> [Example of transmission and reception system configuration] 1 shows a configuration example of a transmission / reception system 10 according to an embodiment. The transmission / reception system 10 is configured by connecting a source device (transmission device) 100 and a sink device (reception device) 200. The source device 100 is, for example, a game machine, a disc player, a set-top box, a digital camera, a mobile phone, a personal computer, etc. The sink device 200 is, for example, a display device (display device) such as a television receiver, a PC monitor, a projector, etc.

[0019] The source device 100 and the sink device 200 are connected via an HDMI cable 300, which is a digital interface cable. The source device 100 is provided with a receptacle 101 constituting a connector to which a data transmitting unit 102 is connected. The sink device 200 is provided with a receptacle 201 constituting a connector to which a data receiving unit 202 is connected. Furthermore, a plug 301 constituting a connector is provided at one end of the cable 300, and a plug 302 constituting a connector is provided at the other end. The plug 301 at one end of the cable 300 is connected to the receptacle 101 of the source device 100, and the plug 302 at the other end of this cable 300 is connected to the receptacle 201 of the sink device 200.

[0020] The source device 100 has a control unit 103. This control unit 103 controls the entire source device 100. The data transmission unit 102 supports HDMI 1.4 or earlier, HDMI 2.0, or HDMI 2.1. The sink device 200 has a control unit 203. This control unit 203 controls the entire sink device 200. This control unit 203 controls the data reception unit 202 so as to cause the source device 100 to read EDID corresponding to the HDMI version.

[0021] When the control unit 203 determines that the data transmission unit 102 supports HDMI 2.1, it determines to have the data transmission unit 102 read the EDID for HDMI 2.1. In this case, the EDID for HDMI 2.1 set in the EDID ROM in the data reception unit 202 is read into the data transmission unit 102.

[0022] Furthermore, when it is determined that the data transmission unit 102 supports HDMI 2.0, the control unit 203 determines to have the data transmission unit 102 read EDID for HDMI 2.0. In this case, the data transmission unit 102 reads the EDID for HDMI 2.0 set in the EDID ROM in the data reception unit 202.

[0023] Furthermore, when it is determined that the data transmission unit 102 supports HDMI 1.4 or earlier, the control unit 203 determines to have the data transmission unit 102 read EDID for HDMI 1.4 or earlier. In this case, the data transmission unit 102 reads EDID for HDMI 1.4 or earlier that is set in the EDID ROM in the data reception unit 202.

[0024] As shown in FIG. 2(a), in one embodiment, there is a 256-byte EDID "Standard" as an EDID for HDMI 1.4 or earlier, a 256-byte EDID "Enhanced" as an EDID for HDMI 2.0, and a 256-byte EDID "Enhanced (4K HFR)" and a 256-byte EDID "Enhanced (8K)" as EDIDs for HDMI 2.1. Here, for example, the EDID "Enhanced" includes device information corresponding to 4K resolution video with a frame rate of up to 60 Hz and High Dynamic Range (HDR) video, and the EDID "Enhanced (4K HFR)" and EDID "Enhanced (8K)" include device information corresponding to 4K (3840×2160) resolution video and 8K (7680×4320) resolution video with a frame rate of High Frame Rate (HFR) greater than 60 Hz, respectively. In addition, each of the above EDIDs is sometimes called Enhanced-EDID (E-EDID).

[0025] In another embodiment, as shown in Fig. 2(b), a 256-byte EDID "Standard" is handled as the EDID for HDMI 1.4 or earlier, a 256-byte EDID "Enhanced" is handled as the EDID for HDMI 2.0, and a 512-byte EDID "Enhanced (4K HFR / 8K)" is handled as the EDID for HDMI 2.1. This 512-byte EDID "Enhanced (4K HFR / 8K)" is a combination (merging) of the 256-byte EDID "Enhanced (4K HFR)" and the 256-byte EDID "Enhanced (8K)."

[0026] Here, EDID for HDMI 1.4 or earlier includes a Vendor Specific Data Block (VSDB), which is vendor-proprietary information that stores information about the features supported by the sink device, and EDID for HDMI 2.0 and HDMI 2.1 includes an extended VSDB, the HDMI Forum VSDB (HF-VSDB).

[0027] "Example of configuration of data transmission unit and data reception unit" FIG. 3 shows an example of the configuration of the data transmitting section (HDMI transmitting section) 102 of the source device 100 and the data receiving section (HDMI receiving section) 202 of the sink device 200 in the transmission and reception system 10 of FIG.

[0028] The data transmitting unit 102 unidirectionally transmits differential signals corresponding to pixel data of one screen's worth of uncompressed image to the data receiving unit 202 via multiple channels in an effective image interval (hereinafter also referred to as an active video interval, as appropriate), which is the interval from one vertical synchronizing signal to the next vertical synchronizing signal, excluding the horizontal and vertical blanking intervals, and also unidirectionally transmits differential signals corresponding to at least audio data, control data, other auxiliary data, etc. associated with the image to the data receiving unit 202 via multiple channels in the horizontal blanking interval or vertical blanking interval.

[0029] That is, the data transmitting unit 102 has an HDMI transmitter 121. The HDMI transmitter 121 converts, for example, pixel data of an uncompressed image into a corresponding differential signal, and transmits the signal serially in one direction to the data receiving unit 202 connected via an HDMI cable 300 over three TMDS channels #0, #1, and #2, which are multiple channels.

[0030] In addition, the HDMI transmitter 121 converts audio data accompanying the uncompressed images, as well as necessary control data and other auxiliary data, into corresponding differential signals and transmits them serially in one direction to the data receiving unit 202 connected via the HDMI cable 300 over three TMDS channels #0, #1, and #2.

[0031] Furthermore, the HDMI transmitter 121 transmits, on the TMDS clock channel, a pixel clock synchronized with the pixel data transmitted on the three TMDS channels #0, #1, and #2 to the data receiving unit 202 connected via the HDMI cable 300. Here, on one TMDS channel #i (i=0, 1, 2), 10 bits of pixel data are transmitted during one clock of the pixel clock.

[0032] Here, TMDS coding is an 8-bit / 10-bit conversion coding that converts 8-bit data to 10-bit data, and is a coding that maintains DC balance while suppressing adverse effects such as unwanted radiation by reducing the number of transition points compared to the previous data. Therefore, since the run length of the coding cannot be theoretically guaranteed, DC coupling and separate clock transmission are essential.

[0033] The data receiving unit 202 receives differential signals corresponding to pixel data transmitted unidirectionally from the data transmitting unit 102 over multiple channels during the active video interval, and also receives differential signals corresponding to audio data or control data transmitted unidirectionally from the data transmitting unit 102 over multiple channels during the horizontal or vertical blanking interval.

[0034] That is, the data receiving unit 202 has an HDMI receiver 221. The HDMI receiver 221 receives differential signals corresponding to pixel data and differential signals corresponding to audio data and control data transmitted in one direction from the data transmitting unit 102 connected via the HDMI cable 300 on TMDS channels #0, #1, and #2, in synchronization with a pixel clock transmitted on the TMDS clock channel from the data transmitting unit 102.

[0035] In the above, an example was shown in which image data, audio data, and control data are transmitted over TMDS channels #0, #1, and #2, and the pixel clock is transmitted over the TMDS clock channel, but this is compatible with HDMI 1.4 and earlier and HDMI 2.0. In the case of HDMI 2.1, transmission is performed using FRL lanes #0, #1, #2, and #3. In this case, the TMDS clock channel in Figure 3 becomes FRL lane #3.

[0036] In this case, data transmission is performed by a fixed rate link (FRL) packet using three lanes #0 to #2 or four lanes #0 to #3. Here, FRL character coding is 16-bit / 18-bit conversion coding that converts 16-bit data into 18-bit data, and is coding that maintains DC balance and allows clock extraction.

[0037] FIG. 4 shows an example of the link rate and the number of lanes corresponding to each link. For link rates identified by "1" (binary 0001) and "2" (binary 0010), three lanes #0 to #2 out of four lanes #0 to #3 are used. In this case, lane #3 is an inactive lane. An active lane means a lane that transmits data. For link rates identified by "3" (binary 0011), "4" (binary 0100), "5" (binary 0101), and "6" (binary 0110), all four lanes #0 to #3 are used.

[0038] In the illustrated example, the link rate identified by "1" (binary 0001) has a bit rate of 3 Gbps per lane. The link rates identified by "2" (binary 0010) and "3" (binary 0011) have a bit rate of 6 Gbps per lane. The link rate identified by "4" (binary 0100) has a bit rate of 8 Gbps per lane. The link rate identified by "5" (binary 0101) has a bit rate of 10 Gbps per lane. The link rate identified by "6" (binary 0110) has a bit rate of 12 Gbps per lane.

[0039] 3, the HDMI system including the data transmitting unit 102 and the data receiving unit 202 also includes a transmission channel called a Display Data Channel (DDC). This DDC is made up of two signal lines (not shown) included in the HDMI cable 300, and performs IIC (Inter-Integrated Circuit) communication between the data transmitting unit 102 and the data receiving unit 202.

[0040] That is, the data transmitting unit 102 has an IIC master block 122. Also, the data receiving unit 202 has a memory unit 222. The memory unit 222 includes an EDID ROM (Extended Display Identification Data ROM) 231, a SCDC (Status and Control Data Channel) register unit 232, and an HDCP (High-bandwidth Digital Content Protection) register unit 233.

[0041] EDID, which is information regarding the configuration and available functions of the sink device 200, is set in the EDID ROM 231, and is read to the source device 100 side by the IIC master block 122 via DDC. This allows the source device 100 to recognize the configuration and available functions of the sink device 200. The EDID ROM 231 is realized by a rewritable memory such as an EEPROM (Electrically Erasable Programmable Read-Only Memory) or a flash memory, but may also be a RAM (Random access memory), or any other storage medium.

[0042] In this embodiment, when it is determined that the data transmission unit 102 is compatible with HDMI 2.1, HDMI 2.0, and HDMI 1.4 or earlier, an EDID for HDMI 2.1, an EDID for HDMI 2.0, and an EDID for HDMI 1.4 or earlier are set in the EDID ROM 231, and the set EDID is read into the source device 100.

[0043] SCDC (Status and Control Data Channel) corresponds to a point-to-point communication protocol for exchanging data between the source device 100 and the sink device 200. Note that this SCDC is defined in HDMI 2.0 and later. The SCDC register unit 232 is made up of a group of registers that store SCDCS (SCDC Structure).

[0044] The source device 100 (data transmission unit 102) can read and write the SCDCS data stored in the SCDC register unit 232 by the IIC master block 122 through the DDC. The SCDCS data includes data on the current link state, data for controlling the operation of the source device, and the like.

[0045] HDCP (High-bandwidth Digital Content Protection) is an encryption technology that prevents copyrighted video content from being illegally copied while being transmitted to a display device. The HDCP register unit 233 is made up of a group of registers that store data related to HDCP. The data related to HDCP includes an encryption key for encrypting image data.

[0046] The source device 100 (data transmission unit 102) can read and write data related to HDCP stored in the HDCP register unit 233 by the IIC master block 122 via the DDC.

[0047] Although not shown, the HDMI cable 300 includes a CEC (Consumer Electronics Control) line, an HPD (Hot Plug Detect) line, a reserve line, a power line, etc. The CEC line is used for bidirectional communication of control data between the source device 100 and the sink device 200. The HPD line is used for the source device 100 to detect the connection of the sink device 200, etc.

[0048] "EDID automatic switching control processing" An example of the procedure of the EDID automatic switching control process in the control unit 203 of the sink device 200 will be described with reference to the flowchart of FIG.

[0049] In step ST1, the control unit 203 sets an EDID for HDMI 2.1 (Enhanced (4K HFR / 8K)) in the EDID ROM 231, and causes the source device 100 to read this EDID. In this case, the control unit 203 sets an HPD (Hot Plug Detect) line (not shown) to a high level, thereby causing the source device 100 to read the EDID for HDMI 2.1 set in the EDID ROM 231.

[0050] 6 shows an outline of an EDID for HDMI 2.1. This EDID for HDMI 2.1 includes "Max_FRL_Rate" data. The EDID includes an HF-VSDB (HDMI Forum Vendor Specific Data Block). The "Max_FRL_Rate" data is data in the HF-VSDB. This "Max_FRL_Rate" data is a data item that specifies the maximum link rate that can be supported by the sink device 200. This "Max_FRL_Rate" data is 4-bit field data that specifies the link rate identifier (see FIG. 4) of the maximum link rate that can be supported by the sink device 200.

[0051] For example, when the “Max_FRL_Rate” data has a value of “5”, this indicates that sink device 200 supports link rates associated with link rate identifiers “1”, “2”, “3”, “4”, and “5”, but does not support the link rate associated with link rate identifier “6”.

[0052] The value of "Max_FRL_Rate" may also indicate whether sink device 200 supports link training. For example, if the multimedia link is HDMI, the value of "Max_FRL_Rate" may be "0". In that case, it indicates that sink device 200 supports HDMI operation according to HDMI 1.4 or earlier or HDMI 2.0. In other words, if the value of "Max_FRL_Rate" is "0", it indicates that sink device 200 does not support any of the link rates shown in FIG. 4.

[0053] Link training is not performed in HDMI 1.4 or earlier or HDMI 2.0. Therefore, a value of "0" for "Max_FRL_Rate" indicates that sink device 200 does not support link training, and a value of "1" to "6" for "Max_FRL_Rate" indicates that sink device 200 supports link training.

[0054] Returning to FIG. 5, in step ST2, the control unit 203 sets "FLT_ready" included in the SCDC data present in the SCDC register unit 232 to "1."

[0055] 7 shows an outline of the SCDC data stored in the SCDC register unit 232. The SCDC data includes three categories of data items: update flags, configuration parameters, and status flags. The status flags are values ​​that indicate the current status of the sink device 200.

[0056] The update flags are values ​​(such as 1-bit binary values) associated with commands of the source device 100. If the source device 100 supports HDMI 2.1, a source link training circuit (not shown) periodically polls the update flags, for example, every 2 milliseconds.

[0057] If one of the update flags has a value of, for example, “1” when polled by the source link training circuitry, the source link training circuitry executes the instructions associated with that update flag. In this manner, the update flags provide a method for controlling the link training circuitry of source device 100.

[0058] The status flag includes “FLT_ready.” A link training control circuit (not shown) of the sink device 200 indicates to the source device 100 that the sink device 200 is ready to start link training processing by writing “1” to “FLT_ready” as described above.

[0059] The configuration parameters are the current data transmission parameters of the HDMI link. The configuration parameters include "FRL_Rate". "FRL_Rate" is a link rate identifier of the current link rate. For example, when using the example of the link rate and link rate identifier shown in FIG. 4, "FRL_Rate" is a 4-bit field data, and stores the link rate identifier (Link Rate Identifier (Binary)) of the link rate at which the HDMI link is currently operating.

[0060] In the source device 100 compatible with HDMI 2.1, the source link training circuit reads the EDID for HDMI 2.1 (see FIG. 6) set in the EDID ROM via the DDC as described above. In particular, the source link training circuit reads "Max_FRL_Rate" to determine whether the sink device 200 supports link training.

[0061] If the sink device 200 is compatible with HDMI 1.4 or earlier or HDMI 2.0, the sink device 200 does not support link training. In that case, the value of "Max_FRL_Rate" is "0." In this embodiment, the sink device 200 is compatible with HDMI 2.1, and the source link training circuit reads EDID for HDMI 2.1 (see FIG. 6), so the value of "Max_FRL_Rate" is a value other than "0."

[0062] When the value of "Max_FRL_Rate" is other than "0", the source link training circuit of source device 100 and the link training control circuit of sink device 200 perform several actions to prepare the HDMI link for link training processing. The link training control circuit writes a value of 1 to "FLT_ready" to indicate that sink device 200 is ready to start link training processing.

[0063] The source link training circuit reads "FLT_ready" periodically, for example every 2 milliseconds. If the source link training circuit reads "FLT_ready" as a value of "1", the source link training circuit selects a link rate and writes an identifier of the selected link rate to the "FRL_Rate" register. The source link training circuit selects a link rate that is equal to or less than the maximum link rate value specified by "Max_FRL_Rate" and is fast enough to support the transmission of content.

[0064] 5, in step ST3, the control unit 203 determines whether the "FRL_Rate" register has been rewritten, that is, whether an identifier of the link rate has been written to the "FRL_Rate" register. When determining that an identifier of the link rate has been written to the "FRL_Rate" register, this writing is performed when the source device 100 supports link training as described above. Therefore, the control unit 203 determines to have the source device 100 read the EDID for HDMI 2.1, and in step ST4, the EDID for HDMI 2.1 is kept held in the EDID ROM 231.

[0065] In this case, the EDID for HDMI 2.1 has already been read into the source device 100 (see the description of step ST1). Therefore, at this point, it is not necessary to cause the source device 100 to read the EDID for HDMI 2.1 stored in the EDID ROM 231, but it may be read again.

[0066] Also, when it is determined in step ST3 that the link rate identifier has not been written to the "FRL_Rate" register, the control unit 203 proceeds to the process of step ST5. As described above, since "FLT_ready" is read periodically, for example, every 2 milliseconds, this determination is made, for example, after a time period equal to or longer than the time interval for reading "FLT_ready" has elapsed since the value of 1 was written to "FLT_ready".

[0067] In step ST5, the control unit 203 determines whether "AKE_Init" has been written. Image data transmitted from the source device 100 to the sink device 200 via the HDMI cable 300 is encrypted by HDCP (High-bandwidth Digital Content Protection). HDMI 2.0 and HDMI 2.1 adopt HDCP 2.2.

[0068] The source device 100 performs authentication processing between the sink device 200 and the source device 100 via the DDC to determine whether the sink device 200 has a normal HDCP processing function. In HDCP2.2, an AKE (Authentication and Key Exchange) process is performed to exchange encryption keys as the first step of the authentication protocol. "AKE_Init" is an authentication start message transmitted from the source device (HDCP transmitter) 100 to the sink device (HDCP receiver) 200 at the beginning of this AKE process.

[0069] The sink device 200 receives "AKE_Init" sent from the source device 100, and writes it to a corresponding address in the HDCP register unit 233. Fig. 8 shows an outline of the HDCP data stored in the HDCP register unit 233. The HDCP data includes the data of "AKE_Init".

[0070] Figure 9(a) shows an example of the structure (Syntax) of "AKE_Init", and Figure 9(a) shows the main information contents (Semantics) in the example structure. The 1-byte field "msg_id (=2)" is a message identifier indicating that it is "AKE_Init". The 8-byte field "rTX [63.,0]" is a pseudo-random value. The 3-byte field "TxCaps" is a fixed value (0x02 0x00 0x00) that includes version information.

[0071] 5, when it is determined in step ST5 that "AKE_Init" has been written, "AKE_Init" is written only when the source device 100 employs HDCP2.2 as described above, and since HDCP2.2 is employed in HDMI2.0, the control unit 203 decides to have the source device 100 read the EDID for HDMI2.0, and in step ST6 rewrites the EDID held in the EDID ROM 231 to the EDID (Enhanced) for HDMI2.0. Then, after this rewrite, the control unit 203 sets the HPD line to a high level, thereby causing the source device 100 to read the EDID for HDMI2.0 set in the EDID ROM 231.

[0072] Furthermore, when it is determined in step ST5 that "AKE_Init" has not been written, the control unit 203 decides to have the source device 100 read an EDID (Standard) for HDMI 1.4 or earlier, and in step ST7 rewrites the EDID held in the EDID ROM 231 to an EDID for HDMI 1.4 or earlier. After this rewriting, the control unit 203 sets the HPD line to a high level, thereby causing the source device 100 to read the EDID for HDMI 1.4 or earlier set in the EDID ROM 231. This determination is made after a predetermined time or more, for example, several hundred milliseconds or more, has elapsed since the value of 1 was written to "FLT_ready."

[0073] 1, the sink device 200 determines whether the source device 100 supports HDMI 2.1, HDMI 2.0, or HDMI 1.4 or earlier, sets the EDID of the version corresponding to the determination result in the EDID ROM 231, and causes the source device 100 to read it. This eliminates the need for the user to set the EDID of the version corresponding to the source device 100 in the EDID ROM 231 in the sink device 200, thereby improving usability for the user.

[0074] <2. Modifications> In the above embodiment, an example has been shown in which the sink device 200 handles a 256-byte EDID “Standard” as an EDID for HDMI 1.4 or earlier, a 256-byte EDID “Enhanced” as an EDID for HDMI 2.0, and a 512-byte EDID “Enhanced (4K HFR / 8K)” as an EDID for HDMI 2.1, as shown in FIG. 2(b).

[0075] However, a similar example is also conceivable in which the sink device 200 handles a 256-byte EDID “Standard” as an EDID for HDMI 1.4 or earlier, a 256-byte EDID “Enhanced” as an EDID for HDMI 2.0, a 256-byte EDID “Enhanced (4K HFR)” as an EDID for HDMI 2.1, and a 256-byte EDID “Enhanced (8K)” as an EDID for HDMI 2.1, as shown in FIG. 2(a).

[0076] The flowchart in FIG. 10 shows an example of the procedure of the EDID automatic switching control process in the control unit 203 of the sink device 200 in this case.

[0077] In step ST11, the control unit 203 sets an EDID for HDMI 2.1 (4K HFR) in the EDID ROM 231, and causes the source device 100 to read this EDID. In this case, the control unit 203 sets an HPD (Hot Plug Detect) line (not shown) to a high level, thereby causing the source device 100 to read the EDID for HDMI 2.1 (4K HFR) set in the EDID ROM 231. This EDID for HDMI 2.1 (4K HFR) also includes data of "Max_FRL_Rate" (see FIG. 6).

[0078] Next, in step ST12, the control unit 203 sets "FLT_ready" included in the SCDC data present in the SCDC register unit 232 to "1." The source link training circuit of the source device 100 reads "FLT_ready" periodically, for example, every 2 milliseconds. When the source link training circuit reads "1" as the value of "FLT_ready," the source link training circuit selects a link rate and writes an identifier of the selected link rate to the "FRL_Rate" register.

[0079] Next, in step ST13, the control section 203 determines whether or not the "FRL_Rate" register has been rewritten, that is, whether or not an identifier of the link rate has been written to the "FRL_Rate" register.

[0080] When it is determined that the link rate identifier is written to the "FRL_Rate" register, this writing is performed in the case of HDMI2.1 in which the source device 100 supports link training, so in step ST14, the control unit 203 displays a UI (User Interface) screen on a display unit (not shown) for allowing the user to select either an EDID for HDMI2.1 (4K HFR) or an EDID for HDMI2.1 (8K). FIG. 11 shows an example of the UI screen. The user refers to this UI screen to select, for example, either "4K HFR" or "8K". The example shown in the figure shows a state in which an EDID for HDMI2.1 (4K HFR) is selected.

[0081] Next, in step ST15, the control unit 203 determines whether "4K HFR" or "8K" has been selected. When determining that "4K HFR" has been selected, the control unit 203 determines to cause the source device 100 to read the EDID for HDMI2.1 (4K HFR), and in step ST16, the control unit 203 keeps the EDID for HDMI2.1 (4K HFR) held in the EDID ROM 231.

[0082] In this case, the EDID for HDMI 2.1 (4K HFR) has already been read into the source device 100 (see the description of step ST11). Therefore, at this point, it is not necessary to cause the source device 100 to read the EDID for HDMI 2.1 (4K HFR) held in the EDID ROM 231, but it may be read again.

[0083] Furthermore, when it is determined in step ST15 that "8K" has been selected, the control unit 203 decides to have the source device 100 read the EDID for HDMI 2.1 (8K), and in step ST17 rewrites the EDID held in the EDID ROM 231 to the EDID for HDMI 2.1 (8K). After this rewriting, the control unit 203 sets the HPD line to a high level, thereby causing the source device 100 to read the EDID for HDMI 2.1 (8K) set in the EDID ROM 231.

[0084] Also, when it is determined in step ST13 that the link rate identifier has not been written to the "FRL_Rate" register, the control unit 203 proceeds to the process of step ST18. As described above, "FLT_ready" is read periodically, for example, every 2 milliseconds, so this determination is made, for example, after a time period at least equal to or longer than the time interval for reading "FLT_ready" has elapsed since the value of 1 was written to "FLT_ready".

[0085] In step ST18, the control unit 203 determines whether "AKE_Init" has been written. Image data transmitted from the source device 100 to the sink device 200 via the HDMI cable 300 is encrypted by HDCP (High-bandwidth Digital Content Protection). HDMI 2.0 and HDMI 2.1 adopt HDCP 2.2.

[0086] The source device 100 performs authentication processing between the sink device 200 and the source device 100 via the DDC to determine whether the sink device 200 has a normal HDCP processing function. In HDCP2.2, an AKE (Authentication and Key Exchange) process is performed to exchange encryption keys as the first step of the authentication protocol. "AKE_Init" is an authentication start message transmitted from the source device (HDCP transmitter) 100 to the sink device (HDCP receiver) 200 at the beginning of this AKE process.

[0087] When it is determined in step ST18 that "AKE_Init" has been written, "AKE_Init" is written only when the source device 100 employs HDCP2.2 as described above. Since HDMI2.0 employs HDCP2.2, the control unit 203 determines to have the source device 100 read the EDID for HDMI2.0.

[0088] Then, in step ST19, the control unit 203 rewrites the EDID held in the EDID ROM 231 to the EDID for HDMI 2.0. After this rewriting, the control unit 203 sets the HPD line to a high level, thereby causing the source device 100 to read the EDID for HDMI 2.0 set in the EDID ROM 231.

[0089] Furthermore, when it is determined in step ST18 that "AKE_Init" has not been written, the control unit 203 decides to have the source device 100 read an EDID for HDMI 1.4 or earlier. This determination is made after a predetermined time or more, for example, several hundred milliseconds or more, has elapsed since the value of 1 was written to "FLT_ready."

[0090] Then, in step ST20, the control unit 203 rewrites the EDID held in the EDID ROM 231 to an EDID for HDMI 1.4 or earlier. After this rewriting, the control unit 203 sets the HPD line to a high level, thereby causing the source device 100 to read the EDID for HDMI 1.4 or earlier set in the EDID ROM 231.

[0091] In the EDID automatic switching control process shown in the flowchart of FIG. 10, an EDID for HDMI 2.1 (4K HFR) is set in the EDID ROM 231 in step ST11, and this EDID is read by the source device 100. However, it is also possible to configure the EDID for HDMI 2.1 (8K) to be set in the EDID ROM 231 in step ST11, and this EDID to be read by the source device 100.

[0092] In the above embodiment, an example is shown in which the interface (multimedia link) is HDMI. The present technology can be similarly applied to other interfaces that handle similar EDID. Examples of other interfaces include a DP (Display Port) interface and an MHL (Mobile High-definition Link). In the above embodiment, examples of HDMI2.1, HDMI2.0, and HDMI1.4 or earlier are shown, but the present technology is not limited to such examples and may be applied to future versions of HDMI. Similarly, in the above embodiment, the description is given using HDCP2.2, but the present technology may be implemented using a version of HDCP earlier than HDCP2.2 or a version of HDCP later than HDCP2.2.

[0093] In addition, in the above embodiment, the EDID for HDMI 2.1 is stored first in steps ST1 and ST11, but it is also possible to store the EDID for HDMI 1.4 or earlier or the EDID for HDMI 2.0 first, and then switch to the EDID for HDMI 2.1 in response to writing of "FRL_Rate".

[0094] In addition, although the preferred embodiment of the present disclosure has been described in detail with reference to the attached drawings, the technical scope of the present disclosure is not limited to such examples. It is clear that a person having ordinary knowledge in the technical field of the present disclosure can conceive of various modified or amended examples within the scope of the technical ideas described in the claims, and it is understood that these also naturally belong to the technical scope of the present disclosure.

[0095] In addition, the effects described in this specification are merely descriptive or exemplary and are not limiting. In other words, the technology according to the present disclosure may achieve other effects that are apparent to a person skilled in the art from the description of this specification, in addition to or in place of the above effects.

[0096] The present technology can also be configured as follows. (1) a memory unit for storing first device information and second device information; A communication unit that communicates with an external device; a control unit that determines to cause the external device to read the second device information based on reception of a rewrite signal to the first device information from the external device; Receiving device. (2) the memory unit further stores third device information; When the control unit does not receive the rewrite signal, the control unit determines to cause the external device to read the third device information. The receiving device according to (1) above. (3) the second device information is information corresponding to version 2.1 of the High-Definition Multimedia Interface (HDMI), and the third device information is information corresponding to version 2.0 of the HDMI; The receiving device according to (2) above. (4) The second device information and the third device information are each Extended Display Identification Data (EDID) including an HDMI Forum Vendor Specific Data Block (HF-VSDB), which is information regarding functions supported by the device. The receiving device according to (3) above. (5) The second device information is a 512-byte EDID that combines an EDID for 4K High frame rate (HFR) and an EDID for 8K. The receiving device according to (3) above. (6) the memory unit further stores fourth device information; The control unit determines to cause the external device to read the fourth device information when the external device does not support the second device information and the third device information. A receiving device according to any one of (2) to (5). (7) When the control unit does not receive a predetermined signal from the external device, the control unit determines that the external device does not correspond to the second device information and the third device information. The receiving device according to (6) above. (8) The predetermined signal is an AKE_Init signal which is a start signal of an authentication process with the external device. The receiving device according to (7) above. (9) The fourth device information is information compatible with High-Definition Multimedia Interface (HDMI) version 1.4 or earlier. A receiving device according to any one of (6) to (8). (10) The fourth device information is Extended Display Identification Data (EDID) including a Vendor Specific Data Block (VSDB), which is information about functions supported by the device. The receiving device according to (9) above. (11) The rewrite signal is determined in response to the second device information. A receiving device according to any one of (1) to (10). (12) The rewrite signal is information corresponding to Max_FRL_Rate, which is information regarding a link rate supported by the device and is written in the second device information. The receiving device according to (11) above. (13) The rewrite signal is transmitted in response to a value of FLT_ready, which is information indicating a preparation status for link training processing and is written in the first device information. A receiving device according to any one of (1) to (12). (14) The first device information is information included in a Status and Control Data Channel Structure (SCDCS). A receiving device according to any one of (1) to (13). (15) The first device information is FRL_Rate, which is information about a link rate selected by the external device. The receiving device according to (14) above. (16) The communication unit communicates with the external device through a digital interface cable. A receiving device according to any one of (1) to (15). (17) The digital interface cable is a High-Definition Multimedia Interface (HDMI) cable. The receiving device according to (16) above. (18) The receiving device is a display device. A receiving device according to any one of (1) to (17). (19) A memory unit that stores the first device information and the second device information; A method for controlling a receiving device having a communication unit that communicates with an external device, comprising: determining to cause the external device to read the second device information based on reception of a rewrite signal for the first device information from the external device; A method for controlling a receiving device. (20) A transmitter and a receiver, The receiving device includes: a memory unit for storing the first device information and the second device information; A communication unit that communicates with the transmitting device; a control unit that determines to cause the transmitting device to read the second device information based on reception of a rewrite signal for the first device information from the transmitting device. Transmitting and receiving system. [Explanation of symbols]

[0097] 10. Transmitting and receiving system 100 Source device (transmitter) 101···Receptacle 102 Data transmission unit (HDMI transmission unit) 103 Control section 121···HDMI Transmitter 122 IIC Master Block 200 Sink device (receiving device) 201···Receptacle 202 Data receiving unit (HDMI receiving unit) 203 Control section 221···HDMI Receiver 222 Memory section 231··EDID ROM 232 SCDC register section 233 HDCP register section 300···HDMI cable 301, 302...Plug

Claims

1. a memory unit for storing the first device information, the second device information, and the third device information; A communication unit that communicates with an external device; a control unit that determines to cause the external device to read the second device information based on reception of a rewrite signal for the first device information from the external device, and determines to cause the external device to read the third device information when the rewrite signal is not received; The second device information corresponds to High-Definition Multimedia Interface (HDMI) version 2.1, and the third device information corresponds to HDMI version 2.

0. Receiving device.

2. The second device information and the third device information are each Extended Display Identification Data (EDID) including an HDMI Forum Vendor Specific Data Block (HF-VSDB), which is information regarding functions supported by the device.

2. The receiving device according to claim 1.

3. The second device information is a 512-byte EDID that combines an EDID for 4K High frame rate (HFR) and an EDID for 8K.

2. The receiving device according to claim 1.

4. a memory unit that stores the first device information, the second device information, the third device information, and the fourth device information; A communication unit that communicates with an external device; a control unit that determines, based on reception of a rewrite signal for the first device information from the external device, to cause the external device to read the second device information, and determines, when the rewrite signal is not received, to cause the external device to read the third device information, and determines, when the external device does not support the second device information and the third device information, to cause the external device to read the fourth device information; When the control unit does not receive an AKE_Init signal, which is a start signal of an authentication process between the external device and the control unit, from the external device, the control unit determines that the external device does not correspond to the second device information and the third device information. Receiving device.

5. The fourth device information is information corresponding to High-Definition Multimedia Interface (HDMI) version 1.4 or earlier.

5. The receiving device according to claim 4.

6. The fourth device information is Extended Display Identification Data (EDID) including Vendor Specific Data Block (VSDB), which is information regarding functions supported by the device.

6. The receiving device according to claim 5.

7. a memory unit for storing the first device information and the second device information; A communication unit that communicates with an external device; a control unit that determines to cause the external device to read the second device information based on reception of a rewrite signal for the first device information from the external device; The rewrite signal is determined in accordance with the second device information. Receiving device.

8. The rewrite signal is information corresponding to Max_FRL_Rate, which is information about a link rate supported by the device and is written in the second device information.

8. The receiving device according to claim 7.

9. a memory unit for storing the first device information and the second device information; A communication unit that communicates with an external device; a control unit that determines to cause the external device to read the second device information based on reception of a rewrite signal for the first device information from the external device; The rewrite signal is transmitted in response to a value of FLT_ready, which is information indicating a preparation status for link training processing and is written in the first device information. Receiving device.

10. a memory unit for storing the first device information and the second device information; A communication unit that communicates with an external device; a control unit that determines to cause the external device to read the second device information based on reception of a rewrite signal for the first device information from the external device; The first device information is FRL_Rate, which is information about the link rate selected by the external device and is included in the Status and Control Data Channel Structure (SCDCS). Receiving device.

11. The communication unit communicates with the external device through a digital interface cable.

11. A receiving device according to claim 1, 4, 7, 9 or 10.

12. The digital interface cable is a High-Definition Multimedia Interface (HDMI) cable.

12. The receiving device according to claim 11.

13. The receiving device is a display device.

11. A receiving device according to claim 1, 4, 7, 9 or 10.

14. a memory unit for storing the first device information, the second device information, and the third device information; A method for controlling a receiving device having a communication unit that communicates with an external device, comprising: determining to cause the external device to read the second device information based on reception of a rewrite signal for the first device information from the external device, and determining to cause the external device to read the third device information when the rewrite signal is not received; The second device information corresponds to High-Definition Multimedia Interface (HDMI) version 2.1, and the third device information corresponds to HDMI version 2.

0. A method for controlling a receiving device.

15. a memory unit that stores the first device information, the second device information, the third device information, and the fourth device information; A method for controlling a receiving device having a communication unit that communicates with an external device, comprising: determining to have the external device load the second device information based on reception of a rewrite signal for the first device information from the external device, determining to have the external device load the third device information when the rewrite signal is not received, and determining to have the external device load the fourth device information when the external device does not support the second device information and the third device information; When an AKE_Init signal, which is a start signal of an authentication process between the external device and the external device, is not received from the external device, the external device is determined not to correspond to the second device information and the third device information. A method for controlling a receiving device.

16. a memory unit for storing the first device information and the second device information; A method for controlling a receiving device having a communication unit that communicates with an external device, comprising: determining to cause the external device to read the second device information based on reception of a rewrite signal for the first device information from the external device; The rewrite signal is determined in accordance with the second device information. A method for controlling a receiving device.

17. a memory unit for storing the first device information and the second device information; A method for controlling a receiving device having a communication unit that communicates with an external device, comprising: determining to cause the external device to read the second device information based on reception of a rewrite signal for the first device information from the external device; The rewrite signal is transmitted in response to a value of FLT_ready, which is information indicating a preparation status for link training processing and is written in the first device information. A method for controlling a receiving device.

18. a memory unit for storing the first device information and the second device information; A method for controlling a receiving device having a communication unit that communicates with an external device, comprising: determining to cause the external device to read the second device information based on reception of a rewrite signal for the first device information from the external device; The first device information is FRL_Rate, which is information about the link rate selected by the external device and is included in the Status and Control Data Channel Structure (SCDCS). A method for controlling a receiving device.

19. The system comprises a transmitting device and a receiving device, The receiving device includes: a memory unit for storing the first device information, the second device information, and the third device information; A communication unit that communicates with the transmitting device; a control unit that determines to cause the second device information to be read into the transmitting device based on reception of a rewrite signal for the first device information from the transmitting device, and determines to cause the third device information to be read into the transmitting device when the rewrite signal is not received; The second device information corresponds to High-Definition Multimedia Interface (HDMI) version 2.1, and the third device information corresponds to HDMI version 2.

0. Transmitting and receiving system.

20. The system comprises a transmitting device and a receiving device, The receiving device includes: a memory unit that stores the first device information, the second device information, the third device information, and the fourth device information; A communication unit that communicates with the transmitting device; a control unit that determines to have the second device information read into the transmitting device based on reception of a rewrite signal for the first device information from the transmitting device, determines to have the third device information read into the transmitting device when the rewrite signal is not received, and determines to have the fourth device information read into the transmitting device when the transmitting device does not support the second device information and the third device information; When the control unit does not receive an AKE_Init signal, which is a start signal of an authentication process between the control unit and the transmitting device, from the transmitting device, the control unit determines that the transmitting device does not support the second device information and the third device information. Transmitting and receiving system.

21. The system comprises a transmitting device and a receiving device, The receiving device includes: a memory unit for storing the first device information and the second device information; A communication unit that communicates with the transmitting device; a control unit that determines to cause the transmitting device to read the second device information based on reception of a rewrite signal for the first device information from the transmitting device; The rewrite signal is determined in accordance with the second device information. Transmitting and receiving system.

22. The system comprises a transmitting device and a receiving device, The receiving device includes: a memory unit for storing the first device information and the second device information; A communication unit that communicates with the transmitting device; a control unit that determines to cause the transmitting device to read the second device information based on reception of a rewrite signal for the first device information from the transmitting device; The rewrite signal is transmitted in response to a value of FLT_ready, which is information indicating a preparation status for link training processing and is written in the first device information. Transmitting and receiving system.

23. The system comprises a transmitting device and a receiving device, The receiving device includes: a memory unit for storing the first device information and the second device information; A communication unit that communicates with the transmitting device; a control unit that determines to cause the transmitting device to read the second device information based on reception of a rewrite signal for the first device information from the transmitting device; The first device information is FRL_Rate, which is information about the link rate selected by the transmitting device and is included in the Status and Control Data Channel Structure (SCDCS). Transmitting and receiving system.

Images