CN117615086A - HDMI interface multiplexing circuit and control method thereof - Google Patents

HDMI interface multiplexing circuit and control method thereof Download PDF

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Publication number
CN117615086A
CN117615086A CN202311368334.XA CN202311368334A CN117615086A CN 117615086 A CN117615086 A CN 117615086A CN 202311368334 A CN202311368334 A CN 202311368334A CN 117615086 A CN117615086 A CN 117615086A
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China
Prior art keywords
hdmi
soc chip
circuit
signal
multiplexing circuit
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孙波
吴建国
付长昭
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Suzhou Metabrain Intelligent Technology Co Ltd
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Suzhou Metabrain Intelligent Technology Co Ltd
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Priority to CN202311368334.XA priority Critical patent/CN117615086A/en
Publication of CN117615086A publication Critical patent/CN117615086A/en
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N5/00—Details of television systems
    • H04N5/76—Television signal recording
    • H04N5/765—Interface circuits between an apparatus for recording and another apparatus
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F13/00—Interconnection of, or transfer of information or other signals between, memories, input/output devices or central processing units
    • G06F13/38—Information transfer, e.g. on bus
    • G06F13/40—Bus structure
    • G06F13/4004—Coupling between buses
    • G06F13/4022—Coupling between buses using switching circuits, e.g. switching matrix, connection or expansion network
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F13/00—Interconnection of, or transfer of information or other signals between, memories, input/output devices or central processing units
    • G06F13/38—Information transfer, e.g. on bus
    • G06F13/40—Bus structure
    • G06F13/4063—Device-to-bus coupling
    • G06F13/4068—Electrical coupling
    • G06F13/4081—Live connection to bus, e.g. hot-plugging
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N5/00—Details of television systems
    • H04N5/222—Studio circuitry; Studio devices; Studio equipment
    • H04N5/262—Studio circuits, e.g. for mixing, switching-over, change of character of image, other special effects ; Cameras specially adapted for the electronic generation of special effects
    • H04N5/268—Signal distribution or switching
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N7/00—Television systems
    • H04N7/015—High-definition television systems

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Theoretical Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Physics & Mathematics (AREA)
  • Computer Hardware Design (AREA)
  • General Physics & Mathematics (AREA)
  • Mathematical Physics (AREA)
  • Two-Way Televisions, Distribution Of Moving Picture Or The Like (AREA)

Abstract

The invention provides an HDMI multiplexing circuit and a control method thereof, wherein the circuit comprises an SOC chip and a switching circuit arranged on each HDMI transmission channel, and the switching circuit comprises: the first HDMI transmission channel signal branch line is electrically connected with the SOC chip; the MIPI signal branch line is electrically connected with the SOC chip; the first gating switch, the stiff end is connected with HDMI socket electricity, and first contact end sets up the one end that the SOC chip was kept away from at first HDMI transmission channel signal branch line, and the second contact end sets up the one end that the SOC chip was kept away from at MIPI signal branch line, and gating switch is used for realizing HDMI signal transmission through connecting stiff end and first contact end or realizing MIPI signal transmission through connecting stiff end and second contact end under the control of SOC chip. On the basis of not changing the original HDMI interface circuit, the MIPI signal transmission circuit is newly added, the requirements of video data transmission delay, long-distance transmission and expansibility are met, and the purposes of reducing the data transmission delay, long-distance data transmission and high expansibility are achieved.

Description

HDMI interface multiplexing circuit and control method thereof
Technical Field
The invention relates to the technical field of interfaces, in particular to an HDMI multiplexing circuit and a control method thereof.
Background
In the current network cameras on the market, the sampled video files are usually compressed and then transmitted to box type equipment (edge processor) through a network, and in the scene, the transmission delay of the network cameras is longer. For some application scenes with high real-time requirements, the compatibility coverage is difficult. Taking entrance guard of face recognition as an example, a camera is used for monitoring the face, and if the face is authorized, the door is opened. The image transmission delay of such cameras directly affects the user experience. For example, if a face is brushed, the door is opened only after 3 seconds, which makes the experience of the customer poor.
Currently, in this scenario, which similarly requires short delays, the solution for the box-type device is as follows:
a soft flat cable is adopted to connect the camera and the box type equipment, communication is carried out through an MIPI interface, if the box type equipment adopts the mode, the plug life of a socket is short, the socket is easy to damage, MIPI signals are transmitted on the cable, the signal transmission distance is short, and if the box type equipment adopts the connecting mode, the physical distance between the camera and the box type equipment is required to be kept close enough (the distance is generally not more than 300 mm). In general application scenes in the field, cameras are required to be arranged at specific positions in high positions, and box-type equipment is also required to be connected with a plurality of cameras.
Another possible solution is to leave an interface on the box-like device (typically a FAKRA interface) for application on board the vehicle, accessing such cameras. The disadvantage of this solution is that: the panel space of the box type equipment is limited, the requirement for connecting the MIPI camera is not general, most users cannot use the interface, only a small part of users can use the interface with high requirement on the real-time performance of the image data, the interface occupies the positions of other functions, and the function realization of most users is influenced.
In summary, it is difficult for the box-type device in the existing scheme to simultaneously satisfy the delay requirement, the transmission distance and the expansibility requirement of video data transmission.
Disclosure of Invention
In view of this, the present invention provides an HDMI interface multiplexing circuit and a control method thereof, so as to solve the problems of high video data transmission delay, incapability of performing long distance and low expansibility in the prior art.
In a first aspect, the present invention provides an HDMI interface multiplexing circuit, including an SOC chip and a switching circuit provided in each HDMI transmission channel, the switching circuit including: the first HDMI transmission channel signal branch line is electrically connected with the SOC chip; the MIPI signal branch line is electrically connected with the SOC chip; the first gating switch, the stiff end is connected with HDMI socket electricity, and first contact end sets up first HDMI transmission channel signal branch is kept away from the one end of SOC chip, the second contact end sets up MIPI signal branch is kept away from the one end of SOC chip, gating switch is used for under the control of SOC chip, through connecting the stiff end with HDMI signal transmission is realized to first contact end or through connecting the stiff end with MIPI signal transmission is realized to second contact end.
Optionally, the MIPI signal leg includes: a voltage source circuit connected to the second contact terminal for providing a voltage of 12V; and one end of the signal processing module is electrically connected with the voltage source circuit and is connected to the second contact end, and the other end of the signal processing module is connected with the SOC chip.
Optionally, the voltage source circuit includes: a voltage source; the control end of the electric control switch is electrically connected with the SOC chip and is used for controlling the on-off of the voltage source; and one end of the inductance filter circuit is connected to the voltage source through the electric control switch, and the other end of the inductance filter circuit is connected to the second contact end, wherein the electric control switch and the inductance filter circuit are grounded through a first capacitor.
Optionally, the inductance filter circuit includes: the first inductor is connected to the electric control switch, and the third inductor is connected to the second contact end; and the first resistor is connected with the second inductor in parallel.
Optionally, the first inductance is greater than the second inductance, and the second inductance is greater than the third inductance.
Optionally, the signal processing module adopts a MAX9296 chip for converting GMSL signals into MIPI signals, wherein the SOC chip is further electrically connected with the signal processing module through an I2C signal line.
Optionally, a second capacitor is connected between the MAX9296 chip and the second contact terminal.
Optionally, the switching circuit further includes: the second HDMI transmission channel signal branch line is electrically connected with the SOC chip; and the fixed end of the second gating switch is electrically connected with the HDMI socket, the first contact end is arranged at one end of the second HDMI transmission channel signal branch line far away from the SOC chip, and the second contact end is grounded.
Optionally, the fixed end of the first gating switch is grounded through a first grounding branch; the fixed end of the second gating switch is grounded through a second grounding branch; and the control ends of the first grounding branch and the second grounding branch are electrically connected with the SOC chip.
Optionally, the first ground branch is the same as the second ground branch, and includes: the second resistor and the switching tube; the second resistor is connected with the switching tube in series, and the control end of the switching tube is electrically connected with the SOC chip.
Optionally, the shielding signal of the HDMI socket is grounded, and the hot plug pin of the HDMI socket is connected with the SOC chip.
Alternatively, the switching circuit structures of different HDMI transmission channels are the same.
In a second aspect, the present invention provides a control method for an HDMI interface multiplexing circuit, which is adapted to the HDMI interface multiplexing circuit, and the control method includes: detecting whether a hot plug pin of the HDMI socket is effective; if the hot plug pin is invalid, controlling the first gating switch to be connected to the second contact end so as to realize MIPI signal transmission; and if the hot plug pin is effective, controlling the first gating switch to be connected to the first contact end so as to realize HDMI signal transmission.
Optionally, the method further comprises: and if the hot plug pin is invalid, controlling the GPIO signal to output a low level, controlling the electric control switch to be closed, and connecting the second gating switch to the second contact terminal.
Optionally, the method further comprises: and if the hot plug pin is effective, controlling the GPIO signal to output a high level, controlling the electric control switch to be disconnected, and connecting the second gating switch to the first contact terminal.
The technical scheme provided by the embodiment of the invention can achieve the following technical effects:
through setting up the switching circuit on every transmission channel on HDMI interface socket in box-type equipment, select the signal line through first gating switch, select control by the SOC chip to real HDMI signal transmission or MIPI signal transmission, on the basis of not changing the interface circuit of original HDMI, newly increased MIPI signal transmission circuit, satisfy the video data transmission time delay and the requirement in the aspect of long-range transmission and expansibility, reach the purpose that reduces data transmission time delay, and long-range data transmission and high expansibility.
By adopting the interface multiplexing circuit described in the above embodiment, whether the hot plug pin is effective is detected, the type of the accessed interface is determined based on the effectiveness of the hot plug pin, and then the data transmission is performed by switching to the corresponding interface circuit, so that the interface self-adaptive identification can be realized without manual control.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are needed in the description of the embodiments or the prior art will be briefly described, and it is obvious that the drawings in the description below are some embodiments of the present invention, and other drawings can be obtained according to the drawings without inventive effort for a person skilled in the art.
Fig. 1 is a circuit diagram of a switching circuit according to an embodiment of the invention;
FIG. 2 is a circuit diagram of a switching circuit according to another embodiment of the present invention;
FIG. 3 is a schematic diagram of a line-end interface according to an embodiment of the invention;
fig. 4 is a block diagram of an HDMI interface multiplexing circuit according to an embodiment of the invention;
FIG. 5 is a schematic diagram of HDMI interface pins according to an embodiment of the present invention;
fig. 6 is a flowchart of a control method of an embodiment of the present invention.
Detailed Description
For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments of the present invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
Before describing the embodiments of the present invention, the technical terms used in the embodiments of the present invention will be explained:
HDMI: the high definition multimedia interface (High Definition Multimedia Interface, HDMI) is a fully digital video and audio transmission interface that can transmit uncompressed audio and video signals.
FD-LINK: flat panel display link, the high-speed interface proposed by TI company has the same application scenario and function as GMSL.
GMSL: gigabit Multimedia Serial Links the Chinese name is gigabit multimedia serial link, which is a high-speed serial interface proposed by Maxim company and is suitable for transmission of audio, video and control signals.
GPIO: general-purpose input/output, general-purpose input/output for short, functions like P0-P3 of 8051, and its pins can be used freely by program control.
MIPI: mobile industry processor interface (Mobile Industry Processor Interface abbreviated MIPI).
According to the embodiment of the invention, the original HDMI interface is adjusted and improved, and the switching circuit is designed so that MIPI signal transmission can be realized while HDMI signal transmission is realized.
Currently, HDMI is mainly used for display debugging and testing in practical applications, and display data is generally transmitted from a network in practical applications of camera. According to the technical scheme provided by the embodiment of the invention, the following functions are realized through multiplexing the HDMI interface: and multiplexing the HDMI, and automatically outputting an HDMI signal by the HDMI after the HDMI is inserted into the HDMI equipment for connecting a display. After the GSMEL or FD-LINK camera signal line is inserted, the non-compressed real-time data of the camera can be transmitted by using the GMSL or the FD-LINK through software setting, so as to be used for the application with high real-time requirement.
Specifically, the embodiment of the invention provides an HDMI multiplexing circuit, which comprises an SOC chip and a switching circuit arranged on each HDMI transmission channel.
In the embodiment of the invention, since the HDMI interface generally includes 3 TMDS transmission channels for transmitting data, there are also 1 independent TMDS clock channels. In the embodiment of the invention, each transmission channel and each TMDS clock channel are provided with a switching circuit so as to realize switching between HDMI signal transmission and MIPI signal transmission. The switching circuits on each channel may have the same structure or different structures. In the embodiment of the invention, the same circuit structure is preferentially adopted, so that the consistency of all channels is ensured.
It should be noted that in the embodiment of the present invention, the HDMI interface multiplexing circuit is an improved circuit between the original HDMI interface socket and the SOC chip, that is, a cable capable of customizing the FAKRA port to HDMI is plugged by a unified HDMI socket, so as to realize two different signal transmissions. The customized cable has 1 HDMI interface, and the other end of the cable is 4 FAKRA interfaces, specifically FAKRA coaxial cable, and the differential pin of the TMDS of connecting HDMI or clock, wherein the signal pin is connected with the positive pole of differential pin, and the shielding layer of coaxial cable links into the shielding signal pin of TMDS of negative pole and HDMI socket or clock.
The switching circuit of the embodiment of the invention comprises: the first HDMI transmission channel signal branch line is electrically connected with the SOC chip; the MIPI signal branch line is electrically connected with the SOC chip; the first gating switch, the stiff end is connected with HDMI socket electricity, and first contact end sets up first HDMI transmission channel signal branch is kept away from the one end of SOC chip, the second contact end sets up MIPI signal branch is kept away from the one end of SOC chip, gating switch is used for under the control of SOC chip, through connecting the stiff end with HDMI signal transmission is realized to first contact end or through connecting the stiff end with MIPI signal transmission is realized to second contact end.
In the embodiment of the present invention, the first HDMI transmission channel signal branch may refer to a positive signal line of a transmission channel, such as a tmds0+ signal line shown in fig. 1, and the MIPI signal branch may refer to a line for converting to a MIPI signal, which is connected through tmds0+ of an HDMI socket. When the contact of the first gating switch K1 is connected to the first contact end, the MIPI signal transmission is needed; when the contact of the first gating switch K1 is connected to the second contact terminal, HDMI signal transmission is performed, and the electrical control connection line between the SOC chip and the switch K1 is not shown in fig. 1.
According to the embodiment of the invention, the switching circuit is arranged on each transmission channel on the HDMI interface socket in the box type equipment, the signal line is selected through the first gating switch, and the selection control is performed by the SOC chip, so that the HDMI signal transmission or MIPI signal transmission is realized, the MIPI signal transmission circuit is newly added on the basis of not changing the original HDMI interface circuit, the requirements of video data transmission delay, long-distance transmission and expansibility are met, and the purposes of reducing the data transmission delay, long-distance data transmission and high expansibility are achieved.
Further, in this embodiment, because the HDMI type transmission is different from the circuit for MIPI signal transmission, and the HDMI has a hot plug pin, the validity of the hot plug pin identified by the SOC chip can be used to automatically determine which cable is connected, and that signal transmission is needed. When the HDMI cable connected with the HDMI equipment is inserted, the HDMI has the hot-deflection identification pin, the switching control circuit can identify that the HDMI equipment is inserted, and signals are automatically switched to the HDMI circuit through the switching circuit, so that the function related to HDMI is realized.
As an alternative implementation manner, as shown in fig. 1, in an embodiment of the present invention, the MIPI signal leg includes: a voltage source circuit 10 connected to the second contact terminal for providing a voltage of 12V; and one end of the signal processing module 20 is electrically connected with the voltage source circuit and is connected to the second contact end, and the other end of the signal processing module is connected with the SOC chip.
In the embodiment of the invention, when the cable of the GMSL is connected, the power supply and the signal transmission of the cable are transmitted through the cable according to the specification of the GMSL, and the power supply is 12V voltage, if a cable detection circuit is arranged, the cable detection circuit outputs 12V voltage to the HDMI equipment if the cable detection circuit is used for false detection, and the HDMI equipment is damaged. The voltage source circuit 10 is used to generate a 12V voltage as the voltage required for MIPI signaling to the GMSL cable. Meanwhile, in order to avoid the influence on the HDMI equipment, the voltage is only used when MIPI signal transmission is used, and the HDMI signal transmission is not needed.
The signal processing module adopts a MAX9296 chip for converting GMSL signals into MIPI signals, wherein the SOC chip is also electrically connected with the signal processing module through an I2C signal line. A second capacitor C1 is connected between the MAX9296 chip and the second contact terminal.
Further, as shown in fig. 2, the voltage source circuit includes: a voltage source Vdd; the control end of the electric control switch K2 is electrically connected with the SOC chip (not shown in the figure) and is used for controlling the on-off of the voltage source Vdd; and one end of the inductance filter circuit 101 is connected to the voltage source Vdd through the electric control switch K2, and the other end of the inductance filter circuit 101 is connected to the second contact terminal, wherein the electric control switch K2 and the inductance filter circuit 101 are grounded through a first capacitor C4.
Considering the actual application scenario, the situation of switching to GMSL is generally a known fixed application scenario, and corresponding processing software is deployed on the SOC chip, so that the application of switching to GMSL needs to be confirmed by software control, and the GMSL function is switched to only when the GMSL camera is used. Therefore, the hardware loss can be avoided, and the condition that the HDMI equipment is burnt out by inputting 12V when the HDMI equipment is accessed is prevented.
As an alternative implementation manner, the inductance filtering circuit of the embodiment of the present invention includes: the first inductor L1, the second inductor L2 and the third inductor L3 are sequentially connected in series, the first inductor is connected to the electric control switch, and the third inductor is connected to the second contact end; and the first resistor R3 is connected with the second inductor in parallel. The first inductance is larger than the second inductance, and the second inductance is larger than the third inductance. The inductance of the first inductor is 100uH, the inductance of the second inductor is 22uH, and the inductance of the third inductor is 560nH.
The switching circuit of the embodiment of the invention further comprises: the second HDMI transmission channel signal branch line TMDS 0-is electrically connected with the SOC chip; and the fixed end of the second gating switch K3 is electrically connected with the HDMI socket, the first contact end is arranged at one end of the second HDMI transmission channel signal branch line far away from the SOC chip, and the second contact end is grounded to the Vss.
In the embodiment of the invention, the first gating switch K1, the electric control switch K2 and the second gating switch K3 are all controlled by an SOC chip (connection relationship is not shown in the figure) to select a corresponding circuit, wherein the SOC chip may be a JETSON NX SOC, specifically, the switching device may be an analog switch, for example, a transistor or a MOS transistor, and the switching device may also be a small relay.
As an optional implementation manner, in the HDMI interface multiplexing circuit of the embodiment of the present invention, the fixed end of the first gating switch is grounded through the first grounding branch; the fixed end of the second gating switch is grounded through a second grounding branch; the control ends of the first grounding branch and the second grounding branch are electrically connected with the SOC chip. Specifically, the first grounding branch is the same as the second grounding branch, and includes: second resistors (R1 and R2) and switching tubes (V1 and V2); the second resistor is connected with the switching tube in series, and the control end of the switching tube is electrically connected with the SOC chip.
In the embodiment of the invention, the SOC chip controls the positive and negative pins of the transmission channel to be grounded through GPIO signals. The on and off of the switching tube is controlled according to the control requirement of a specific interface, for example, under the requirement of HDMI signal transmission or MIPI signal transmission, the SOC chip is controlled according to the specific transmission requirement.
The shielding signal of the HDMI socket is grounded, and the hot plug pin of the HDMI socket is connected with the SOC chip. And detecting the validity of the hot plug pin by detecting the SOC chip to judge whether the current transmission requirement is HDMI signal transmission or MIPI signal transmission.
The technical scheme of the present application is described in detail with reference to fig. 2:
when the GMSL device is selected to be accessed, K2 is closed, VDD 12V is filtered through inductance, the power supply is supplied to a pin of a K1 switch, K1 is gated to a TMDS+ pin, and the power supply is connected to a camera through a cable. While K3 connects TMDS 0-to ground, along with TMDS0 shield pins, to the ground (shield) of the coaxial cable. For signals, the data signal of the front-end camera is connected to a TMDS0+ pin through a cable, and is connected to the left side of a pin at the end of a capacitor C1 through K1, and because the signal frequency is GHz, the signal is connected to a MAX9296 through a blocking capacitor, the MAX9296 chip converts the GMSL signal into the MIPI signal, and the MIPI signal is connected to an MIPI interface of an SOC chip for data processing.
When the default or connected HDMI equipment is HDMI equipment, K2 is disconnected, K1 and K3 are connected with lower end points, V1 and V2 are conducted through GPIO, bias level is provided, HDMI signal specifications are met, HDMI signals are obtained, and an HDMI controller of JETSON NX SOC is connected with an HDMI cable through capacitors C2 and C3 and an HDMI socket to drive a display to work.
In the interface circuit block diagram provided by the embodiment of the invention, as shown in fig. 3, the line end is a cable from the FAKRA port to the HDMI, and the FAKRA port is correspondingly connected with each transmission channel of the HDMI plug. The HDMI plug is inserted into the HDMI socket, the circuit connection structure in the socket is shown in fig. 4, the HDMI socket realizes switching between the GMSL interface function and the HDMI interface function through the switching circuit, so that MIPI signal transmission or HDMI signal transmission is realized, and then data are transmitted to the SOC chip. The pin schematic diagram of the HDMI plug is shown in fig. 5.
The embodiment of the invention also provides a control method of the HDMI multiplexing circuit, which is applicable to the HDMI multiplexing circuit according to the above embodiment of the invention, as shown in FIG. 6, and comprises the following steps:
in step S601, it is detected whether the hot plug pin of the HDMI socket is valid. In the using process, when HDMI signal transmission is adopted, the hot plug pin can receive effective electric signals; when the MIPI signal transmission is adopted, a hot plug pin is not required, so that no electric signal is arranged on the hot plug pin. Therefore, whether the FAKRA interface or the HDMI interface is accessed can be rapidly confirmed by judging the validity of the hot plug pin.
In step S602, if the hot plug pin is invalid, the first gating switch is controlled to be connected to the second contact terminal, so as to realize MIPI signal transmission.
In step S603, if the hot plug pin is valid, the first gating switch is controlled to be connected to the first contact terminal, so as to realize HDMI signal transmission.
When the hot plug pin is invalid, the FAKRA interface is indicated to be accessed, and the first gating switch K1 is controlled to be connected to the second contact end, so that MIPI signal transmission is realized; when the hot plug pin is effective, the HDMI interface is indicated to be connected, and the first gating switch K1 is controlled to be connected to the first contact end, so that HDMI signal transmission is realized.
According to the embodiment of the invention, the interface multiplexing circuit is adopted to detect whether the hot plug pin is effective or not, the type of the accessed interface is determined based on the effectiveness of the hot plug pin, and then the interface is switched to the corresponding interface circuit to perform data transmission, so that the interface self-adaptive identification can be realized without manual control.
Further alternatively, in the embodiment of the present invention, if the hot plug pin is invalid, the GPIO signal is controlled to output a low level, and the electronic control switch K3 is controlled to be closed, and the second gating switch K3 is connected to the second contact terminal. Thereby turning on all circuits for MIPI signaling. If the hot plug pin is effective, the GPIO signal is controlled to output a high level, so that the switching tubes (V1 and V2) are connected, the electric control switch K2 is controlled to be disconnected, and the second gating switch K3 is connected to the first contact end, so that all HDMI signal transmission circuits are started.
Although embodiments of the present invention have been described in connection with the accompanying drawings, various modifications and variations may be made by those skilled in the art without departing from the spirit and scope of the invention, and such modifications and variations fall within the scope of the invention as defined by the appended claims.

Claims (15)

1. An HDMI interface multiplexing circuit, comprising an SOC chip and a switching circuit provided in each HDMI transmission channel, the switching circuit comprising:
the first HDMI transmission channel signal branch line is electrically connected with the SOC chip;
the MIPI signal branch line is electrically connected with the SOC chip;
the first gating switch, the stiff end is connected with HDMI socket electricity, and first contact end sets up first HDMI transmission channel signal branch is kept away from the one end of SOC chip, the second contact end sets up MIPI signal branch is kept away from the one end of SOC chip, gating switch is used for under the control of SOC chip, through connecting the stiff end with HDMI signal transmission is realized to first contact end or through connecting the stiff end with MIPI signal transmission is realized to second contact end.
2. The HDMI interface multiplexing circuit of claim 1, wherein said MIPI signal leg comprises:
a voltage source circuit connected to the second contact terminal for providing a voltage of 12V;
and one end of the signal processing module is electrically connected with the voltage source circuit and is connected to the second contact end, and the other end of the signal processing module is connected with the SOC chip.
3. The HDMI interface multiplexing circuit of claim 2, wherein said voltage source circuit comprises:
a voltage source;
the control end of the electric control switch is electrically connected with the SOC chip and is used for controlling the on-off of the voltage source;
and one end of the inductance filter circuit is connected to the voltage source through the electric control switch, and the other end of the inductance filter circuit is connected to the second contact end, wherein the electric control switch and the inductance filter circuit are grounded through a first capacitor.
4. The HDMI interface multiplexing circuit of claim 3, wherein said inductive filter circuit comprises:
the first inductor is connected to the electric control switch, and the third inductor is connected to the second contact end;
and the first resistor is connected with the second inductor in parallel.
5. The HDMI interface multiplexing circuit of claim 4, wherein the first inductance is greater than the second inductance, and wherein the second inductance is greater than the third inductance.
6. The HDMI interface multiplexing circuit of claim 2, wherein the signal processing module employs a MAX9296 chip for converting GMSL signals to MIPI signals, and wherein the SOC chip is further electrically connected to the signal processing module via an I2C signal line.
7. The HDMI multiplexing circuit of claim 6, wherein a second capacitor is connected between said MAX9296 chip and said second contact terminal.
8. The HDMI interface multiplexing circuit of claim 1, wherein said switching circuit further comprises:
the second HDMI transmission channel signal branch line is electrically connected with the SOC chip;
and the fixed end of the second gating switch is electrically connected with the HDMI socket, the first contact end is arranged at one end of the second HDMI transmission channel signal branch line far away from the SOC chip, and the second contact end is grounded.
9. The HDMI interface multiplexing circuit of claim 1, wherein,
the fixed end of the first gating switch is grounded through a first grounding branch;
the fixed end of the second gating switch is grounded through a second grounding branch;
and the control ends of the first grounding branch and the second grounding branch are electrically connected with the SOC chip.
10. The HDMI interface multiplexing circuit of claim 9, wherein said first ground leg is identical to said second ground leg, and comprises: the second resistor and the switching tube;
the second resistor is connected with the switching tube in series, and the control end of the switching tube is electrically connected with the SOC chip.
11. The HDMI interface multiplexing circuit of claim 9, wherein the HDMI socket is grounded at a shield signal, and wherein the hot plug pin of the HDMI socket is connected to the SOC chip.
12. The HDMI interface multiplexing circuit of claim 9, wherein the switching circuit structures of different HDMI transmission channels are identical.
13. A control method of an HDMI interface multiplexing circuit, which is applicable to the HDMI interface multiplexing circuit of any one of claims 1 to 12, comprising:
detecting whether a hot plug pin of the HDMI socket is effective;
if the hot plug pin is invalid, controlling the first gating switch to be connected to the second contact end so as to realize MIPI signal transmission;
and if the hot plug pin is effective, controlling the first gating switch to be connected to the first contact end so as to realize HDMI signal transmission.
14. The control method according to claim 13, characterized by further comprising:
and if the hot plug pin is invalid, controlling the GPIO signal to output a low level, controlling the electric control switch to be closed, and connecting the second gating switch to the second contact terminal.
15. The control method according to claim 13, characterized by further comprising:
and if the hot plug pin is effective, controlling the GPIO signal to output a high level, controlling the electric control switch to be disconnected, and connecting the second gating switch to the first contact terminal.
CN202311368334.XA 2023-10-20 2023-10-20 HDMI interface multiplexing circuit and control method thereof Pending CN117615086A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202311368334.XA CN117615086A (en) 2023-10-20 2023-10-20 HDMI interface multiplexing circuit and control method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202311368334.XA CN117615086A (en) 2023-10-20 2023-10-20 HDMI interface multiplexing circuit and control method thereof

Publications (1)

Publication Number Publication Date
CN117615086A true CN117615086A (en) 2024-02-27

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Family Applications (1)

Application Number Title Priority Date Filing Date
CN202311368334.XA Pending CN117615086A (en) 2023-10-20 2023-10-20 HDMI interface multiplexing circuit and control method thereof

Country Status (1)

Country Link
CN (1) CN117615086A (en)

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