CN214429620U

CN214429620U - Circuit for carrying out line speed forwarding on low-speed signal of HDMI (high-definition multimedia interface) protocol

Info

Publication number: CN214429620U
Application number: CN202022640236.5U
Authority: CN
Inventors: 俞剑明; 王祚栋; 毛蔚; 白昀
Original assignee: Fei Ang Innovation Technology Nantong Co ltd
Current assignee: Fei Ang Innovation Technology Nantong Co ltd
Priority date: 2020-11-16
Filing date: 2020-11-16
Publication date: 2021-10-19
Anticipated expiration: 2030-11-16

Abstract

The utility model provides a circuit for transmitting line speed aiming at HDMI protocol low-speed signals, which comprises an HDMI transmitting terminal module and an HDMI receiving terminal module; the HDMI transmitting end module analyzes the interface signal of the source end in real time, transmits the signal to the HDMI receiving end after being compressed, receives a reverse communication signal from the HDMI receiving end module, decompresses the signal in real time and transmits the signal to the source end; the HDMI receiving end module analyzes the signal received from the HDMI transmitting end in real time, decompresses the signal and transmits the decompressed signal to the display equipment end, and compresses the signal of the display equipment end in real time and transmits the compressed signal to the HDMI receiving end module; the analysis module of the HDMI transmitting terminal module and the analysis module of the HDMI receiving terminal module can reasonably switch IO directions according to specific communication conditions, and low-delay bidirectional communication is achieved. The utility model discloses support EDID information to Read, support HDCP, SCDC, clock extension and Read Request function solve CEC bus arbitration problem, realize audio frequency passback and drive ARC port, correctly control the HPD signal when the cable is extracted to guarantee the low cost of scheme, low time delay, high reliability, high compatibility.

Description

Circuit for carrying out line speed forwarding on low-speed signal of HDMI (high-definition multimedia interface) protocol

Technical Field

The utility model relates to a microelectronics communication technology field, in particular to circuit that line speed was forwardded to HDMI agreement low-speed signal carries out.

Background

With the development of display technology, the resolution of the display is increasing. The transmission rate of audio and video data is from hundred megahertz to gigahertz to dozens of gigahertz, and the light-in copper degradation of a display transmission system becomes the necessity of the development of a display technology under the trend. In addition to the Definition of High-speed signals, display transmission protocols such as HDMI (High Definition Multimedia Interface), DVI (Digital Visual Interface), etc. specify five low-speed signals, namely SDA (Serial Data Line), SCL (Serial Clock Line), HPD (Hot Plug Detection), CEC (Consumer Electronics Control), ARC (Audio Return Channel ). These signals play an important role in display control, user manipulation, and audio return. Therefore, the low-cost, low-delay, high-reliability and high-compatibility optical fiber transmission of the low-speed signals plays an important role in the realization of the optical fiber HDMI and the optical DVI. However, half-duplex communication such as SDA, SCL is not well compatible with unidirectional communication such as fiber-optic communication. The single bus communication used in CEC has bus arbitration problem and conflicts with the topology of point-to-point communication of fiber optic communication. The ARC signal also has certain requirements on the bandwidth of the fiber transmission.

Some solutions are given in the prior art regarding HDMI protocol low speed signaling, such as:

(1) the DDC signal of the source terminal is connected to a local EEPROM (Electrically Erasable Programmable Read Only Memory), and EDID (Extended Display Identification Data) information of the general-purpose Display device is stored in the local EEPROM. The scheme has the defects that the EDID information of the actual display equipment cannot be read, and the scheme compatibility is poor.

(2) And electrifying to read the EDID information of the display equipment terminal, and then transmitting the EDID information to the source terminal in an optical fiber communication mode. The method can effectively copy EDID of the display equipment terminal at the source terminal, so that the EDID information of the display equipment can be correctly read when the far terminal initiates DDC (Direct Digital Control) communication. However, the drawback of this solution is that it cannot support HDCP (High-bandwidth Digital Content Protection), SCDC (Status and Control Data Channel, HDMI Status and Control Data Channel), clock extension, and Read request (Read request, function of the display device actively pulling down sda signal to request the source device to Read its flag bit).

(3) Using a store-and-forward approach, DDC information is first received, and when a device-side response is required, the SCL signal is actively pulled down to cause clock stretching at the remote end, thereby waiting for the slave to respond. And when the slave device responds, the clock is returned to the source device, and the clock extension is cancelled. The scheme can normally read EDID, supports HDCP and SCDC, and extends clock. However, the scheme has the disadvantages of long response delay, and the requirement of waiting for reading the response of the slave device and then feeding back the response to the source device. And this scheme does not work for the case where the source device does not support clock stretching. The compatibility of this scheme is poor.

In addition, in the prior art, no effective solution is provided for the bus arbitration problem of CEC communication.

Therefore, in order to solve the problems in the prior art and completely implement the SDA, SCL, HPD, CEC and ARC five low-speed signals for full duplex communication by using optical fiber transmission, a circuit for forwarding the low-speed signals according to the HDMI protocol at a line speed is needed.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a circuit that carries out line speed to HDMI agreement low-speed signal and forwardded, the circuit includes HDMI transmitting terminal module and HDMI receiving terminal module;

the HDMI transmitting terminal module analyzes a source terminal interface signal in real time, transmits the signal to an HDMI receiving terminal after being compressed, receives a reverse communication signal from the HDMI receiving terminal module, decompresses the signal in real time and transmits the signal to the source terminal;

the HDMI receiving end module analyzes the signal received from the HDMI transmitting end in real time, decompresses the signal and transmits the decompressed signal to the display equipment end, and compresses the signal of the display equipment end in real time and transmits the compressed signal to the HDMI receiving end module;

the analysis module of the HDMI transmitting terminal module and the analysis module of the HDMI receiving terminal module can reasonably switch IO directions according to specific communication conditions, and low-delay bidirectional communication is achieved.

Preferably, the HDMI transmitter module includes a DDC decoding and forwarding unit, a CEC arbitration unit, an ARC driving unit, a time division multiplexing unit, a channel coding unit, a synchronization unit, a time division multiplexing unit, a transmitting circuit, and a receiving circuit.

Preferably, the HDMI sink module includes a DDC decoding and forwarding unit, a CEC arbitration unit, an ARC signal amplification unit, a time division multiplexing unit, a channel coding unit, a synchronization unit, a time division multiplexing unit, a transmission circuit, and a reception circuit.

Preferably, in the HDMI origination module, the DDC decoding and forwarding unit is connected to an SDA signal pin and an SCL signal pin of the source, and is responsible for processing the source DDC communication;

in the HDMI originating module, the CEC decoding and forwarding unit and the CEC arbitration unit are respectively connected with a CEC signal of the source end and are responsible for processing CEC communication of the source end.

Preferably, in the HDMI origination module, the DDC decoding and forwarding unit and the CEC decoding and forwarding unit forward the SDA, SCL, and CEC signals of the source in real time with a local clock as an interval, and run the protocol in real time to analyze the actual communication direction of the state machine control signal.

Preferably, in the HDMI receiving end module, the DDC decoding and forwarding unit is connected to an SDA signal pin and an SCL signal pin of the display device end, and is responsible for processing source-end DDC communication;

in the HDMI receiving end module, the CEC decoding and forwarding unit and the CEC arbitration unit are respectively connected with a CEC pin of the display device end and are responsible for processing CEC communication of the display device end.

Preferably, in the HDMI receiving module, the CEC decoding and forwarding unit forwards the CEC signal at the display device end in real time with a local clock as an interval, and runs the protocol analysis state machine in real time to control the actual communication direction of the signal.

Preferably, the time division multiplexing unit, the time division demultiplexing unit, the channel coding unit, the synchronizing unit, the transmitting circuit and the receiving circuit in the HDMI transmitting-end module are configured to compress the low speed signals, i.e., the HPD signal, the SDA signal, the SCL signal, the CEC signal and the ARC signal, to two channels for bidirectional communication to communicate;

the HDMI receiving end module comprises a time division multiplexing unit, a time division demultiplexing unit, a channel coding unit, a synchronization unit, a sending circuit and a receiving circuit, wherein the time division multiplexing unit, the time division demultiplexing unit, the channel coding unit, the synchronization unit, the sending circuit and the receiving circuit are used for compressing five low-speed signals including an HPD signal, an SDA signal, an SCL signal, a CEC signal and an ARC signal to two bidirectional communication channels for communication.

Preferably, the time division multiplexing unit in the HDMI transmitting end module collects the SDA, SCL, CEC signals of the source end in a cyclic ring, and transmits the signals to the display device end through the HDMI receiving end module.

Preferably, the time division multiplexing unit in the HDMI receiving end module cyclically acquires SDA, SCL, CEC, HPD, and ARC signals of the display device end, and sends the signals to the source end through the HDMI sending end module.

The utility model provides a pair of circuit that line speed was forwardded to HDMI agreement low-speed signal can realize SDA completely, SCL, HPD, CEC, five low-speed signals of ARC use optical fiber transmission to carry out full duplex communication.

The utility model provides a pair of circuit that line speed was forwardded to HDMI agreement low-speed signal supports EDID information reading, supports HDCP, SCDC, and clock extension and Read Request function solve CEC bus arbitration problem, realize audio frequency passback and drive ARC port, correct control HPD signal when the cable is extracted to guarantee the low cost of scheme, low time delay, high reliability, high compatibility.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention, as claimed.

Drawings

Further objects, functions and advantages of the present invention will become apparent from the following description of embodiments of the present invention, with reference to the accompanying drawings, in which:

fig. 1 schematically shows an overall structure diagram of a circuit for performing line speed forwarding on a low-speed signal of an HDMI protocol according to the present invention.

Fig. 2 shows the structure diagram of the DDC decoding and forwarding unit of the HDMI transmitter module according to the present invention.

Fig. 3 shows a schematic structural diagram of the DDC decoding and forwarding unit of the HDMI receiving end module of the present invention.

Fig. 4 is a schematic diagram illustrating CEC arbitrated communication according to the present invention.

Fig. 5 shows a schematic diagram of the circuit forwarding I2C signal according to an embodiment of the present invention.

Fig. 6 shows a schematic diagram of the circuit of the present invention combined with high-speed signal forwarding in another embodiment of the present invention.

Fig. 7 shows a schematic diagram of a circuit according to another embodiment of the present invention, in which the circuit implements signal transmission of a plurality of different sources.

Detailed Description

The objects and functions of the present invention and methods for accomplishing the same will be apparent by reference to the exemplary embodiments. However, the present invention is not limited to the exemplary embodiments disclosed below; it can be implemented in different forms. The nature of the description is merely to assist those skilled in the relevant art in a comprehensive understanding of the specific details of the invention.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the drawings, the same reference numerals denote the same or similar parts, or the same or similar steps.

In order to solve the problem that active optical fiber low-speed signal full duplex communication exists in light transmission among the prior art, the utility model provides a circuit that line speed was forwardded is carried out to HDMI agreement low-speed signal. According to the utility model discloses an embodiment, as shown in fig. 1 the utility model relates to a carry out overall structure schematic diagram of circuit that line speed was forwardded to HDMI agreement low-speed signal, the utility model provides a circuit that line speed was forwardded to HDMI agreement low-speed signal includes HDMI transmitting terminal module and HDMI receiving terminal module, and the source links to each other with HDMI transmitting terminal module, and HDMI receiving terminal module links to each other with display device.

The HDMI transmitting end module analyzes the interface signal of the source end in real time, transmits the signal to the HDMI receiving end after being compressed, receives the reverse communication signal from the HDMI receiving end module, decompresses the signal in real time and transmits the signal to the source end.

The HDMI receiving end module analyzes the signal received from the HDMI transmitting end in real time, decompresses the signal and transmits the decompressed signal to the display equipment end, and the signal of the display equipment end is compressed in real time and then is transmitted to the HDMI receiving end module.

The analysis module of the HDMI transmitting end module and the analysis module of the HDMI receiving end module reasonably switch IO (Input/Output) directions according to specific communication conditions, and low-delay bidirectional communication is achieved.

In order to make the utility model discloses a circuit is more clear can explain HDMI sending end module and HDMI receiving terminal module respectively.

HDMI transmitting terminal module

According to the utility model discloses an embodiment, HDMI sending end module includes that DDC decodes and forwards the unit, and the CEC decodes and forwards the unit, CEC arbitration unit, ARC drive unit, time division multiplexing unit, channel coding unit, synchronization unit, time division multiplexing unit, transmitting circuit and receiving circuit.

In the HDMI transmitting-end module, a DDC decoding and forwarding unit is connected with an SDA signal pin and an SCL signal pin of a source end and is responsible for processing DDC communication of the source end; in the HDMI originating module, the CEC decoding and forwarding unit and the CEC arbitration unit are respectively connected with a CEC signal of the source end and are responsible for processing CEC communication of the source end.

In the HDMI originating module, the DDC decoding and forwarding unit and the CEC decoding and forwarding unit forward SDA, SCL and CEC signals of the source end in real time by taking a local clock as an interval, and run a protocol in real time to analyze the actual communication direction of the state machine control signals. The DDC decoding and forwarding unit analyzes SDA and SCL signals of the source end, and the CEC decoding and forwarding unit analyzes CEC signals of the source end.

The utility model discloses in adopt the mode that above-mentioned line speed was forwardded, postpone communication and reduce to within 50ns, strengthen the compatibility of transmission scheme to different equipment of ultimate demonstration greatly.

The HDMI transmitting terminal comprises a time division multiplexing unit, a time division demultiplexing unit, a channel coding unit, a synchronization unit, a transmitting circuit and a receiving circuit, wherein the time division multiplexing unit, the time division demultiplexing unit, the channel coding unit, the synchronization unit, the transmitting circuit and the receiving circuit are used for compressing five low-speed signals including an HPD signal, an SDA signal, an SCL signal, a CEC signal and an ARC signal to two channels for bidirectional communication to communicate.

And the time division multiplexing unit in the HDMI transmitting end module multiplexes the low-speed signal into one channel in a time division multiplexing mode and transmits the low-speed signal. In some embodiments, the ARC among the five low-speed signals at the HDMI initiator module, SDA, SCL, HPD, CEC and ARC requires the transmission bandwidth of the signals, so that 50% of the time slice is occupied in the time division multiplexing, and the rest of the bandwidth is divided equally among the four signals CEC, HPD, SDA and SCL.

And the time division demultiplexing unit in the HDMI transmitting end module is used for demultiplexing the received signal into a low-speed signal and outputting the low-speed signal to the source end interface.

The time division multiplexing unit in the HDMI transmitting end module circularly collects SDA, SCL and CEC signals of the source end and transmits the signals to the display equipment end through the HDMI receiving end module. The transmission sequence of the time division multiplexing unit to the five low-speed signals can be randomly arranged.

In the HDMI transmitting end module, a transmitting circuit modulates the encoded signal into a form suitable for transmission in a physical channel. Generally, a narrowband communication mode is adopted for wireless communication, signals are modulated onto a high-frequency carrier wave for transmission, and a PAM (pulse amplitude modulation) mode can be adopted for a copper wire or an optical fiber channel.

In the HDMI transmitting terminal module, a receiving circuit receives signals in a channel, and the HDMI transmitting terminal is provided with a local clock, so that after the signals are received, bit synchronization and frame synchronization are carried out on the received signals through a synchronization unit.

HDMI receiving terminal module

According to the utility model discloses an embodiment, HDMI receiving end module includes that DDC decodes and forwards the unit, and the CEC decodes and forwards the unit, CEC arbitration unit, ARC signal amplification unit, time division multiplex unit, channel coding unit, synchronization unit and time division multiplex unit, transmitting circuit and receiving circuit are dissolved to the CEC.

The transmitting circuit of the HDMI transmitting end module reaches the HDMI receiving end module through a physical medium (e.g., an optical fiber), and receives a signal through the receiving circuit of the HDMI receiving end module.

In the HDMI receiving end module, the DDC decoding and forwarding unit is connected with an SDA signal pin and an SCL signal pin of the display equipment end and is responsible for processing source end DDC communication.

In the HDMI receiving end module, the CEC decoding and forwarding unit and the CEC arbitration unit are respectively connected to a CEC pin of the display device end, and are responsible for processing CEC communication of the display device end.

In the HDMI receiving module, a CEC decoding and forwarding unit forwards CEC signals of a display device end in real time by taking a local clock as an interval, and a protocol is run in real time to analyze the actual communication direction of a state machine control signal. The CEC decoding and forwarding unit analyzes CEC signals at the display device side.

In the HDMI receiving module, the DDC decoding and forwarding unit monitors the levels of the SDA and SCL signal lines in real time, and when the clock extension and Read Request events of the equipment display end are monitored, the DDC decoding and forwarding unit forwards the Request to the HDMI transmitting end module so as to inform the source equipment of carrying out corresponding operation.

The DDC decoding and forwarding unit in the HDMI receiving end module can analyze SDA and SCL signals sent by the HMDI sending end module and feed back ACK and read data of the display equipment end to the source end in time.

And the time division multiplexing unit in the HDMI receiving end module multiplexes the low-speed signals into one channel in a time division multiplexing mode and transmits the low-speed signals. In some embodiments, the ARC among the five low-speed signals at the HDMI sink module, SDA, SCL, HPD, CEC and ARC requires the transmission bandwidth of the signals, so that 50% of the time slice is occupied in the time division multiplexing, and the rest of the bandwidth is divided equally among the four signals CEC, HPD, SDA and SCL.

And the time division demultiplexing unit in the HDMI receiving end module is used for demultiplexing the received signals into low-speed signals and outputting the low-speed signals to the display equipment end interface.

And the time division multiplexing unit in the HDMI receiving end module circularly acquires SDA, SCL, CEC, HPD and ARC signals of the display equipment end and sends the signals to the source end through the HDMI sending end module. The transmission sequence of the time division multiplexing unit to the five low-speed signals can be randomly arranged.

In the HDMI receiving module, a transmitting circuit modulates the encoded signal into a form suitable for transmission in a physical channel. Generally, a narrowband communication mode is adopted for wireless communication, signals are modulated onto a high-frequency carrier wave for transmission, and a PAM (pulse amplitude modulation) mode can be adopted for a copper wire or an optical fiber channel.

In the HDMI receiving end module, a receiving circuit receives signals in a channel, and the HDMI receiving end is provided with a local clock, so that after the signals are received, bit synchronization and frame synchronization are carried out on the received signals through a synchronization unit.

It is right in the foregoing the utility model discloses carried out detailed explanation to HDMI transmitting terminal module and HDMI receiving terminal module, the utility model discloses well HDMI transmitting terminal module and HDMI receiving terminal module's channel coding all adopts modified Manchester coding communication, need not to just can realize normal communication to the clock signal complete synchronization of transmitting terminal and receiving terminal.

According to the embodiment of the present invention, the line speed forwarding method used by the present invention is not limited to a specific I2C (Inter-Integrated Circuit) address, and is applicable to reading of EDID signals, communication of HDCP and communication of SCDC. Compatibility is achieved for all 128 addresses from 0x00 to 0x 7F.

As shown in fig. 2 the utility model discloses the structure schematic diagram that the DDC of HDMI sending end module decoded and forwarded the unit, fig. 3 is shown the utility model discloses the structure schematic diagram that the DDC of HDMI receiving end module decoded and forwarded the unit. The DDC decoding and forwarding unit of the HDMI transmitting end module and the DDC decoding and forwarding unit of the HDMI receiving end module support single read-write or continuous read-write operation on any I2C equipment address. When the HDMI receiving module sends a clock extension signal, the clock extension signal is pulled down, and the clock extension of the source device is informed by pulling down the SCL pin of the source device. When the HDMI receiving module sends a Read Request signal, the SDA pin of the source end is pulled down to inform the source end equipment of the Request, and the DDC communication to the A8 address is requested to be initiated.

The DDC decoding and forwarding unit of the HDMI transmitting end module and the DDC decoding and forwarding unit of the HDMI receiving end module use a DDC Slave state machine which runs in real time, the communication state is updated while the communication signal is forwarded in real time according to communication sent by the main I2C, the state machine can analyze whether the main I2C waits for an ACK signal (return signal) of the auxiliary I2C or waits for reading data in real time, accordingly, IO communication direction can be switched to forward the signal received from the I2C to the main I2C in time, and real-time I2C communication forwarding is achieved.

The DDC decoding and forwarding unit of the HDMI transmitting end module and the DDC decoding and forwarding unit of the HDMI receiving end module can also resolve the instructions of clock extension and Read Request according to the signal sent from I2C, and control the SDA and the SCL pins to forward the two requests.

According to the utility model discloses an embodiment, the electricity of HDMI sending end module is provided by the source end or then the external input power supply provides. The power of the HDMI receiving end block is provided by the display device end or an external input power supply. The utility model provides a circuit is supporting the HPD signal, can both correctly reflect the plug state of cable under the condition of HDMI receiving terminal module outer power supply or display device power supply.

According to the Utility model discloses an embodiment, take out the ARC signal from the Utility pin and HPD pin at HDMI receiving end module and amplify through ARC signal amplification unit. And the ARC driving unit adjusts the ARC signal to be output within a level range conforming to the HDMI protocol specification and provides certain driving capability. Specifically, the ARC driving unit in the HDMI transmitting terminal module converts the ARC signal transmitted from the display device terminal into an ARC signal meeting the HDMI level standard, and drives the peripheral circuit.

Fig. 4 shows a schematic diagram of CEC arbitrated communication according to the present invention, which includes the process of CEC signal arbitration. The CEC decoding and forwarding unit in the HDMI transmitting end module analyzes a CEC signal at the source end and forwards the CEC signal to the display device end, and the CEC arbitration unit judges the communication direction of CEC according to the signals at the source end and the display device end.

The CEC decoding and forwarding unit in the HDMI receiving end module analyzes a CEC signal at the display device end and forwards the CEC signal to the source end, and the CEC arbitration unit judges the communication direction of CEC according to the signals of the source end and the display device end.

The utility model discloses with the bus arbitration method among the CEC single bus communication, transplant to light transmission or these point-to-point communications of wireless transmission, use local arbitration and the method of arbitration result route, with the bus communication mapping of CEC for the route communication among the point-to-point communication.

Each block in fig. 4 represents a HDMI communication node, and the overall topology in fig. 4 is a topology of a network, and the communication mode is point-to-point communication. The utility model discloses in every node all have local CEC arbitration unit, every node carries out local arbitration. After the arbitration fails, the original communication direction is switched, so the CEC communication with the failed arbitration is not transmitted any more. For example, node 8 in fig. 4 fails to arbitrate, the communication sent by it will not be transmitted any more, and the CEC communication sent by node 4 will be broadcasted in the form of flooding throughout the network.

As shown in fig. 5 an embodiment of the utility model discloses use in an embodiment the utility model discloses the schematic diagram of I2C signal is forwardded to the circuit, can support to 400 Khz's I2C communication in the embodiment, can satisfy HDMI and DVI agreement completely to the highest requirement of I2C communication rate to the different chronogenesis realization homoenergetic that I2C leads to in this embodiment is normal communication, has stronger compatibility. The clock spread of the slave I2C in this embodiment is properly reflected to the master I2C.

Fig. 6 shows a schematic diagram of the circuit of the present invention combined with high-speed signal forwarding in another embodiment of the present invention, which uses the low-speed signal line speed forwarding circuit structure of the present invention, and combines the photoelectric conversion and the electro-optical conversion circuit of the HDMI high-speed signal. In the embodiment of an active cable, the cable distributes two splices of a sending end and a receiving end.

Fig. 7 shows in another embodiment of the present invention the utility model discloses the circuit realizes a plurality of different source end signal transmission's schematic diagram, uses above-mentioned active HDMI cable to be connected display device and video source equipment in the implementation example to with the audio output device of active HDMI cable connection display and support audio frequency passback function. Other control devices are also connected to the display through the upstream HDMI cable. Use through the test the utility model provides a low-speed forwarding circuit can support video source equipment to carry out HDMI1.4, HDMI2.0, the video signal transmission of HDMI2.1 agreement, can support the arbitrary switching from 480p to 4K60hz of resolution ratio, can support CEC control function, can support audio frequency passback function.

Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.

Claims

1. A circuit for forwarding a low-speed signal of an HDMI protocol at a line speed is characterized by comprising an HDMI transmitting terminal module and an HDMI receiving terminal module;

2. The circuit of claim 1, wherein the HDMI sender module comprises a DDC decoding and forwarding unit, a CEC arbitration unit, an ARC driving unit, a time division multiplexing unit, a channel coding unit, a synchronization unit, a time division multiplexing unit, a transmitting circuit, and a receiving circuit.

3. The circuit of claim 1, wherein the HDMI sink module comprises a DDC decoding and forwarding unit, a CEC arbitration unit, an ARC signal amplification unit, a time division multiplexing unit, a channel coding unit, a synchronization unit, a time division multiplexing unit, a transmission circuit, and a reception circuit.

4. The circuit according to claim 2, wherein in the HDMI sender module, the DDC decoding and forwarding unit is connected to an SDA signal pin and an SCL signal pin of the source, and is responsible for handling source DDC communication;

5. The circuit of claim 4, wherein in the HDMI origination module, the DDC decoding and forwarding unit and the CEC decoding and forwarding unit forward SDA, SCL and CEC signals at the source end in real time at intervals of a local clock, and run the protocol in real time to resolve the actual communication direction of the state machine control signals.

6. The circuit according to claim 3, wherein in the HDMI sink module, the DDC decoding and forwarding unit is connected to an SDA signal pin and an SCL signal pin of the display device side, and is responsible for handling source-side DDC communication;

7. The circuit of claim 6, wherein in the HDMI reception module, the CEC decoding and forwarding unit forwards the CEC signal on the display device side in real time at intervals of a local clock, and runs the protocol parsing state machine in real time to control the actual communication direction of the signal.

8. The circuit of claim 1, wherein the time division multiplexing unit, the time division demultiplexing unit, the channel coding unit, the synchronization unit, the transmission circuit and the reception circuit in the HDMI sender-side module are configured to compress five low-speed signals, i.e., an HPD signal, an SDA signal, an SCL signal, a CEC signal and an ARC signal, onto two bidirectional communication channels for communication;

9. The circuit of claim 8, wherein the time division multiplexing unit in the HDMI transmitter module cyclically acquires the SDA, SCL, and CEC signals of the source end, and sends the signals to the display device end through the HDMI receiver module.

10. The circuit of claim 8, wherein the time division multiplexing unit in the HDMI sink module cyclically collects SDA, SCL, CEC, HPD, and ARC signals of the display device, and sends the signals to the source end through the HDMI sender module.