Control signal transmission circuit and control signal receiving circuit of audio/video interface

Control signal transmission circuit and control signal receiving circuit of audio-visual interface

Control signal transmission circuit and control signal receiving circuit of audio/video interface

The present invention relates to a digital audio-visual interface, in particular to a control signal transmission circuit and a control signal receiving circuit of the digital audio-visual interface.

Figure 1 shows a conventional display (eg a television). The display 100 includes a display control chip 110 , a panel 120 , and a panel control circuit 125 . The panel control circuit 125 is used to control the display of the panel 120, including display content (ie, image data) and backlight. The display control chip 110 is electrically connected to the panel control circuit 125 through the cable C1 and the cable C2. The cable C1 is used for transmitting image signals (ie, image data), and the cable C2 is used for transmitting control signals (ie, control data). The control signal is, for example, a backlight control signal. Generally speaking, the length of the cable C2 for transmitting the control signal is limited, so that the distance between the display control chip 110 and the panel control circuit 125 cannot be too large, thus limiting the design flexibility of the multimedia device.

In view of the deficiencies of the prior art, one objective of the present invention is to provide a control signal transmission circuit for an audio-visual interface and a control signal receiving circuit for an audio-visual interface, so as to increase the design flexibility of a multimedia device.

The invention discloses a control signal transmission circuit of an audio-visual interface, comprising an audio-visual interface encoder and a signal packaging circuit. The audio-visual interface encoder is used for receiving a video packet and an audio packet, and supports a user-defined packet format. The signal encapsulation circuit is coupled to the audio-visual interface encoder for receiving a control signal, and encapsulates the control signal into a control data packet according to the user-defined packet format. The AV interface encoder encapsulates the control data packet, the video packet, and the audio packet according to an AV transmission protocol to generate an AV and control data.

The present invention further discloses a control signal receiving circuit of an audio-visual interface, comprising an audio-visual interface decoder and a signal decapsulation circuit. The AV interface decoder supports a user-defined packet format for receiving an AV and control data, and decapsulates the AV and control data according to an AV transmission protocol to generate a control data packet, a video packet, and an audio packet. The signal decapsulation circuit is coupled to the audio-visual interface decoder for receiving the control data packet, and decapsulates the control data packet according to the user-defined packet format to generate a control signal.

The present invention further discloses a control signal transmission circuit of an audio-visual interface, comprising an audio-visual interface encoder and a data distributor. The video interface encoder is used to receive an audio packet. The data distributor is coupled to the audio-visual interface encoder for receiving a video data and a control signal, and for mixing the control signal and the video data to generate a mixed data packet. The AV interface encoder encapsulates the mixed data packet and the audio packet according to an AV transmission protocol to generate an AV and control data.

The present invention further discloses a control signal receiving circuit of an audio-visual interface, comprising an audio-visual interface decoder and a data de-distributor. The AV interface decoder is used for receiving an AV and control data, and decapsulating the AV and control data according to an AV transmission protocol to generate a mixed data packet and an audio packet. The data de-distributor is coupled to the audio-visual interface decoder for receiving the mixed data packet and decoding the mixed data packet to generate a video data and a control signal.

The present invention further discloses a control signal transmission circuit for an audio-visual interface, comprising an audio-visual interface encoder, a signal packaging circuit, and a data distributor. The video interface encoder is used for receiving an audio packet and supports a user-defined packet format. The signal encapsulation circuit is coupled to the audio-visual interface encoder for receiving a first control signal, and encapsulates the first control signal into a control data packet according to the user-defined packet format. The data distributor is coupled to the AV interface encoder for receiving a video data and a second control signal, and for mixing the second control signal and the video data to generate a mixed data packet. The audiovisual interface encoder encapsulates the control data packet, the mixed data packet, and the audio packet according to an audiovisual transmission protocol to generate an audiovisual and control data.

The present invention further discloses a control signal receiving circuit of an audio-visual interface, comprising an audio-visual interface decoder, a signal decapsulation circuit, and a data de-distributor. The AV interface decoder supports a user-defined packet format for receiving an AV and control data, and decapsulates the AV and control data according to an AV transmission protocol to generate a mixed data packet, a control data packet, and an audio packet . The signal decapsulation circuit is coupled to the audio-visual interface decoder for receiving the control data packet, and decapsulates the control data packet according to the user-defined packet format to generate a first control signal. The data de-distributor is coupled to the audio-visual interface decoder for receiving the mixed data packet and decoding the mixed data packet to generate a video data and a second control signal.

The control signal transmission circuit of the audio-visual interface and the control signal receiving circuit of the audio-visual interface of the present invention can transmit or receive the control signal through the connection line or cable of the audio-visual interface (such as a high-definition multimedia interface cable or a DisplayPort cable). Compared with the conventional technology, using the multimedia device of the present invention can increase the distance between the display control chip and the panel control circuit, thereby improving the design flexibility of the multimedia device. In this way, the display control chip and the panel control circuit can be arranged in two Different devices (such as the host and the screen respectively) transmit control signals through the connection line or cable of the audio-visual interface.

With regard to the features, implementations and effects of the present invention, embodiments are described in detail as follows in conjunction with the drawings.

<p>100: Monitor</p><p>110: Display control chip</p><p>120: Panel</p><p>125: Panel control circuit</p><p>C1, C2: Cable</p><p>200,300,400: Control signal transmission circuit</p><p>210: Signal packaging circuit</p><p>220: Video interface encoder</p><p>250, 350, 450: Control signal receiving circuit</p><p>260: Signal Decapsulation Circuit</p><p>270: Video interface decoder</p><p>310: Data Distributor</p><p>312: Multiplexer</p><p>314,364: Counter</p><p>316: Data Regeneration and Encoding Circuits</p><p>SC: select signal</p><p>CLK: system clock</p><p>360: Data De-allocator</p><p>362: Demultiplexer</p><p>366: Data decoding and distribution circuit</p><p>SM: Mixed Signal</p><p>Ctrl1, Ctrl2: Control signal</p>

1 shows a conventional display; FIG. 2 shows a functional block diagram of an embodiment of a control signal transmission circuit of an audio-visual interface of the present invention; FIG. 3 shows a functional block diagram of an embodiment of a control signal receiving circuit of an audio-visual interface of the present invention; Fig. 4 shows a functional block diagram of another embodiment of the control signal transmission circuit of the audio-visual interface of the present invention; Fig. 5 is a functional block diagram of an embodiment of the data distributor 310; Fig. 6 shows the control signal receiving circuit of the audio-visual interface of the present invention A functional block diagram of an embodiment; FIG. 7 is a functional block diagram of an embodiment of the data de-distributor 360; FIG. 8 shows a functional block diagram of another embodiment of the control signal transmission circuit of the audio-visual interface of the present invention; 9 shows a functional block diagram of another embodiment of the control signal receiving circuit of the audio-visual interface of the present invention.

The technical terms used in the following description refer to the common terms in the technical field. If some terms are described or defined in this specification, the interpretation of these terms is subject to the descriptions or definitions in this specification.

The disclosure of the present invention includes a control signal transmission circuit and a control signal of an audio-visual interface number receiving circuit. Since some components included in the control signal transmission circuit and the control signal receiving circuit of the audio-visual interface of the present invention may be known components individually, without affecting the full disclosure and practicability of the invention of the device, the following description Details of known components will be omitted.

FIG. 2 shows a functional block diagram of an embodiment of a control signal transmission circuit for an audio-visual interface of the present invention. The control signal transmission circuit 200 includes a signal packaging circuit 210 and an audio-visual interface encoder 220 . In some embodiments, the audio-visual interface encoder 220 is a high-definition multimedia interface (High Definition Multimedia Interface, HDMI) or DisplayPort (may be abbreviated as DP) encoder. According to the specifications of the High Definition Multimedia Interface and DisplayPort, the High Definition Multimedia Interface and DisplayPort allow circuit designers to define their own packet formats. In this way, circuit designers can transmit user-defined packets through the High Definition Multimedia Interface or DisplayPort. The packet in the packet format.

The signal packaging circuit 210 receives control signals (such as panel-related control signals, including but not limited to backlight control signals, panel calibration signals, and timing control ( timing control, Tcon) signal), and encapsulates the control signal according to a user-defined packet format to generate a control data packet. Control signals can be serial or parallel data. The panel calibration signal is used to correct the traces caused by the uneven brightness of the display. In some embodiments, the signal packaging circuit 210 further includes a register, a memory or a storage circuit for storing the control data packets to be transmitted. In other words, in some embodiments, the signal packaging circuit 210 has the function of temporarily storing the control data packets. The operation of encapsulating the control signal according to the user-defined packet format is to add a self-defined header to the control signal. The headers of packets (including but not limited to video packets, audio packets, and auxiliary data packets) are different.

In addition to receiving packets in various predetermined formats, the audio-visual interface encoder 220 also receives A packet of a user-defined format (ie, a control data packet generated by the signal encapsulation circuit 210). The video packet is generated by the video processing chip (not shown) or the multimedia processing chip (not shown) packaging video data (eg, image data) according to the specifications of the video interface encoder 220 . The audio packet is generated by the audio-visual processing chip or the multimedia processing chip packaging audio data (eg, audio data) according to the specifications of the audio-visual interface encoder 220 . The auxiliary data package is generated by the video processing chip or the multimedia processing chip packaging auxiliary data according to the specifications of the video interface encoder 220. For example, the auxiliary data can be the specifications of the video data and the information required by the receiver to reconstruct the sound clock. . The audio-visual interface encoder 220 schedules and arbitrates (eg, encodes and/or arranges the sequence of the packets) for video packets, audio packets, auxiliary data packets, and control data packets according to the specifications, so as to generate audio-visual and control data. Scheduling and arbitration according to the specifications of the multimedia interface are well known to those skilled in the art, and thus will not be repeated here.

FIG. 3 shows a functional block diagram of an embodiment of a control signal receiving circuit of an audio-visual interface of the present invention. The control signal receiving circuit 250 includes a signal decapsulating circuit 260 and an audio-visual interface decoder 270 . The audio-visual interface decoder 270 is connected to the audio-visual interface encoder 220 through a corresponding connection line or cable (eg, a high-definition multimedia interface cable or a DisplayPort cable), and receives audio-video and control data through the connection line or cable. In some embodiments, the AV interface decoder 270 is a high-definition multimedia interface decoder or a DisplayPort interface decoder. The AV interface decoder 270 processes (eg, decodes and/or decapsulates) the AV and control data according to the specifications to extract the video packets, audio packets, auxiliary data packets, and control data packets therein. The audio-visual interface decoder 270 may also be referred to as a data recovery circuit. The video packets, the audio packets, and the auxiliary data packets are processed (eg, decapsulated) by the video circuit, the audio circuit, and the auxiliary data processing circuit, respectively, to obtain the video data, the audio data, and the auxiliary data, respectively. The control data packets are processed by the signal decapsulation circuit 260 .

The signal decapsulation circuit 260 is coupled or electrically connected to the audio-visual interface decoder 270 for decapsulating the control data packets according to a user-defined packet format to generate control signals. In other words, as long as the control signal transmission circuit 200 (ie, the transmitting end of the multimedia data) and the control signal receiving circuit 250 (ie, the receiving end of the multimedia data) determine the packet format defined by the user in advance, the control signal receiving circuit 250 can decapsulate smoothly Control data packets and obtain control signals. In this way, the panel control circuit (not shown in FIG. 3 , such as the panel control circuit 125 in the prior art in FIG. 1 ) of the receiving end (including the display or the panel) can control the backlight and/or calibrate the panel according to the control signal. Control signals can be serial or parallel data.

FIG. 4 shows a functional block diagram of another embodiment of the control signal transmission circuit of the audio-visual interface of the present invention. The control signal transmission circuit 300 includes a data allocator 310 and an audio-visual interface encoder 220 . The data distributor 310 receives video data and control signals, and mixes the video data and control signals to generate mixed data packets. More specifically, the video data includes a plurality of frames, and each frame includes a plurality of line data, and the data distributor 310 places or inserts control signals between the line data and the line data. blank area (including horizontal front porch, HFP) and/or horizontal back porch (HBP)), or the blank area placed or inserted between picture frames (including vertical leading edge ( vertical front porch (VFP) and/or vertical back porch (VBP). Therefore, the mixed data packet contains video data and control signals. The mixed data packets are transmitted in the form of video packets, in other words, the AV interface encoder 220 regards the mixed data packets as video packets. The audio-visual interface encoder 220 schedules and arbitrates the audio packets, auxiliary data packets, and mixed data packets according to the specifications, so as to generate audio-visual and control data. Control signals can be serial or parallel data.

In some embodiments, the data distributor 310 assigns the next sheet (the n+1th sheet, where n is Positive integer) The control signal of the picture frame is placed in the blank area (including HFP, HBP and/or VBP) of this (nth) picture.

FIG. 5 is a functional block diagram of one embodiment of the data distributor 310 . Data distributor 310 includes multiplexer 312 , counter 314 , and data regeneration and encoding circuit 316 . The multiplexer 312 receives the control signal and the video data, and outputs the control signal or the video data according to the selection signal SC generated by the counter 314 . In some embodiments, the counter 314 includes a pixel counter (not shown) and a line counter (not shown), and the pixel counter and the line counter count according to the system clock CLK. The counter 314 knows the start and end of a line data according to the count value of the pixel counter, and knows the start and end of a picture frame according to the count value of the line counter. The counter 314 controls the multiplexer 312 to output control signals between line data and line data or between picture frames and picture frames. For example, if the control signal is to be placed or inserted into the blank space between the line data, the counter 314 controls the multiplexer 312 to output the control signal between the end of one line of data and the beginning of the next line of data, At other times, the multiplexer 312 is controlled to output video data. For another example, if the control signal is to be placed or inserted in the blank area between frames, the counter 314 controls the output of the multiplexer 312 between the end of one frame and the beginning of the next frame control signal, and control the multiplexer 312 to output video data at other times.

The data regeneration and encoding circuit 316 combines the control signal and the video data according to the received order, and encapsulates and/or encodes the control signal and the video data into a mixed data packet. A mixed data packet has the same format as a video packet containing only video data, but with a different amount of data. More specifically, when a control signal is placed or inserted in the blank space between the row data and the row data, the mixed data will be redefined with the amount of row data, so that the redefined mixed data packet has a larger amount of row data than only video The amount of line data in the video packet of the data. When the control signal is placed or inserted into the blank area between the frames, the mixed data will be redefined as the frame data volume, so that the frame data volume of the redefined mixed data packet will be redefined. Larger than the amount of frame data for a video packet containing only video data.

FIG. 6 shows a functional block diagram of an embodiment of a control signal receiving circuit of an audio-visual interface of the present invention. The control signal receiving circuit 350 includes a data deallocator 360 and an audio-visual interface decoder 270 . The audio-visual interface decoder 270 is connected to the audio-visual interface encoder 220 through a corresponding connection line or cable (eg, a high-definition multimedia interface cable or a Display Port cable), and receives audio-video and control data through the connection line or cable. The AV interface decoder 270 processes (eg, decodes and/or decapsulates) the AV and control data according to the specifications to extract the audio packets, auxiliary data packets, and mixed data packets therein. The mixed data packets are processed by the data de-distributor 360 to extract the control signals and video data therein. In this way, the panel control circuit (not shown in FIG. 6 , such as the panel control circuit 125 in the prior art in FIG. 1 ) of the receiving end (including the display or the panel) can control the backlight and/or calibrate the panel according to the control signal. Control signals can be serial or parallel data.

FIG. 7 is a functional block diagram of one embodiment of data de-allocator 360 . Data demultiplexer 360 includes demultiplexer 362 , counter 364 , and data decoding and distribution circuitry 366 . The data decoding and distribution circuit 366 decodes the mixed data packet and outputs a mixed signal SM, where the mixed signal SM includes control signals and video data. In some embodiments, the counter 364 includes a pixel counter (not shown) and a line counter (not shown), and the pixel counter and the line counter are counted according to the system clock CLK. The counter 364 knows the start and end of a line data according to the count value of the pixel counter, and knows the start and end of a picture frame according to the count value of the line counter. The demultiplexer 362 outputs the control signal or video data in the mixed signal SM according to the selection signal SC generated by the counter 364 . The operation of the demultiplexer 362 is the inverse operation of the multiplexer 312 in FIG. 5 , and the details are well known to those skilled in the art, and thus will not be repeated here.

In some embodiments, the control signal receiving circuit 350 uses timing recovery (timing recovery) technology to synchronize the system clock CLK of the receiving end with the system clock CLK of the transmitting end.

FIG. 8 shows a functional block diagram of another embodiment of the control signal transmission circuit of the audio-visual interface of the present invention. The control signal transmission circuit 400 includes a signal packaging circuit 210 , a data distributor 310 , and an audio-visual interface encoder 220 . The control signal transmission circuit 400 is a combination of the control signal transmission circuit 200 and the control signal transmission circuit 300 . In the embodiment of FIG. 8 , the signal packaging circuit 210 and the data distributor 310 receive and process different control signals. For example, the control signal Ctrl1 is one of the backlight control signal and the panel calibration signal, and the control signal Ctrl2 is the other. In other words, the control data packet includes one of the backlight control signal and the panel calibration signal, and the mixed data packet includes the other.

FIG. 9 is a control signal receiving circuit corresponding to FIG. 8 . The control signal receiving circuit 450 includes a signal decapsulation circuit 260 , a data de-distributor 360 , and an audio-visual interface decoder 270 . The signal decapsulation circuit 260 outputs one of the backlight control signal and the panel calibration signal, and the data de-distributor 360 outputs the other.

As shown in FIG. 8 and FIG. 9 , in the embodiments of FIG. 8 and FIG. 9 , different control signals are placed in different positions in the video and control data, that is, different control signals are transmitted and received by using different signal formats. The control signal receiving circuit 250 of FIG. 3 and the control signal receiving circuit 350 of FIG. 6 can distinguish the control signal Ctrl1 and the control signal Ctrl2 according to the signal content (eg, header, but not limited thereto). In the embodiments of FIG. 8 and FIG. 9 , the control signal receiving circuit 450 can determine whether the control signal is carried by the mixed data packet or the control data packet according to the format of the control signal (ie, whether the control signal is carried by the mixed data packet or the control data packet) or the source (ie, the source of the signal The decapsulation circuit 260 outputs or is output by the data de-distributor 360) to distinguish the control signal Ctrl1 and the control signal Ctrl2.

Although the foregoing embodiments take the backlight control signal and the panel calibration signal as examples, this is not a limitation of the present invention, and those skilled in the art can appropriately apply the present invention to other devices according to the disclosure of the present invention. type of control signal. Although the above-described embodiments take the high-definition multimedia interface and DisplayPort as examples, this is not a limitation of the present invention, and those skilled in the art can appropriately apply the present invention to other types of multimedia audio-visual interfaces according to the disclosure of the present invention.

Please note that the shapes, sizes, and proportions of the components in the preceding figures are only schematic representations, which are for those skilled in the art to understand the present invention, and are not intended to limit the present invention.

Although the embodiments of the present invention are described above, these embodiments are not intended to limit the present invention. Those skilled in the art can change the technical features of the present invention according to the explicit or implicit contents of the present invention. All such changes may belong to the scope of patent protection sought by the present invention. In other words, the scope of patent protection of the present invention shall be determined by the scope of the patent application in this specification.