An 8-port HDMI ruggedized KVM switch

Abstract

This application belongs to the field of human-computer interaction technology, specifically disclosing an 8-port HDMI ruggedized KVM switch. This application utilizes cascaded multi-stage high-definition conversion chips to switch one of the eight HDMI inputs directly to the HDMI output, enabling full HD HDMI digital signal switching. Signal transmission is stable with minimal loss, balanced signal, and adjustable amplitude, meeting the needs of high-definition switching scenarios. Besides directly outputting HDMI signals, an HDMI-to-VGA chip can also be used to convert the digital video signal to a VGA video signal for output, increasing application flexibility and reducing costs while improving efficiency. Multi-stage USB hub chip drivers enhance the USB signal, improving its anti-interference capability and compatibility with operating systems such as Windows, Kylin, and others, eliminating the need for host USB driver optimization and resolving cross-platform USB peripheral recognition issues. Controlling cascaded analog switches enables multi-select switching of USB signals, ensuring the reliability of USB input signal switching.

Description

Technical Field

[0001] This application belongs to the field of human-computer interaction technology, and more specifically, relates to an 8-port HDMI ruggedized KVM switch. Background Technology

[0002] A ruggedized KVM switch is a KVM (Keyboard, Video, Mouse) switcher specifically designed for use in harsh environments or special application scenarios. Currently, ruggedized KVM switches include 8-channel VGA switches that support human-computer interaction. A VGA switcher is a device used for switching video signals, allowing users to switch from one or more VGA input sources (such as computers, game consoles, DVD players, etc.) to one or more VGA monitors. Because analog signals exhibit ghosting and ripple effects after switching and displaying, at high resolutions (… This leads to issues such as poor display quality. On the other hand, there are incompatibility issues between USB drivers on different host hardware architecture platforms and operating system platforms, resulting in the inability to recognize USB peripherals when switching USB input signals across hardware or software platforms. Summary of the Invention

[0003] In view of the shortcomings of the prior art, the purpose of this application is to provide an 8-port HDMI ruggedized KVM switch, which aims to solve the problems of poor display effect at high resolution and inability to recognize USB peripherals across platforms in existing ruggedized KVM switches.

[0004] This application relates to an 8-port HDMI ruggedized KVM switch, comprising: a main controller, four HDMI switcher chips, a VGA conversion chip, a USB signal enhancement driver module, two sets of two-channel single-pole four-throw analog switches, a high-speed double-pole double-throw analog switch, and a USB hub expansion chip; wherein...

[0005] The main controller is used to control the channel selection of the HDMI switcher chip through the I2C bus according to the display channel data information, so as to realize the multi-selection 1 switching of the display signal, and to control the channel selection of the two-channel single-pole four-throw analog switch through the IO interface, so as to realize the multi-selection 1 switching of the USB signal.

[0006] The four HDMI switcher chips are in a two-stage cascaded structure. The first stage consists of the first to third HDMI switcher chips, and the second stage is the fourth HDMI switcher chip, realizing 8 HDMI input signals and 1 HDMI output signal. The HDMI output signal is directly output to the monitor, or it is converted to a VGA signal by a VGA conversion chip before being output to the monitor.

[0007] The USB signal enhancement driver module, two sets of two-channel single-pole four-throw analog switches, high-speed bipolar double-throw analog switches, and USB HUB expansion chip are electrically connected in sequence. The USB signal enhancement driver module enhances the eight USB signals and sends them to the two sets of two-channel single-pole four-throw analog switches for a four-to-one output. The output signal is then sent to the high-speed bipolar double-throw analog switch for a two-to-one output, and finally sent to the uplink port of the USB HUB expansion chip for USB signal amplification and shaping before being output to the keyboard and mouse.

[0008] Preferably, the ruggedized KVM switch has an external I2C interface.

[0009] The I2C interface allows external controllers to program the HDMI switcher chip registers to achieve equalizer adjustment at the HDMI input and signal amplitude adjustment at the output, in order to meet the display signal adjustment needs in different application environments.

[0010] Preferably, the USB signal enhancement driver module consists of 8 USB HUB expansion chips, with each USB HUB expansion chip responsible for shaping one USB signal.

[0011] Preferably, the main controller acquires display channel data information through any of the following methods:

[0012] 1) Real-time detection of button switches; when a button is pressed, the key value is obtained through different I / O ports.

[0013] 2) Receive KVM switching commands sent from the external communication interface and parse the commands.

[0014] It should be noted that this application provides multiple control methods to adapt to different scenarios.

[0015] Preferably, the main controller adopts the GD32F103XX series or other main control chips with I2C, network controller, CAN port, and serial port, and has functions of key detection and processing, network control, LED indicator control, data communication and issuing control commands.

[0016] Preferably, the HDMI switcher chip is MS9601A and the VGA converter chip is MS9291.

[0017] Preferably, the main controller sets the RX register of the MS9601A to receive the EQ value and the TX output value, thereby achieving equalization adjustment of the input HDMI signal and amplitude adjustment of the output HDMI signal.

[0018] Preferably, the adjustment range of the input data signal amplitude is 150mV-1200mV, and the RX input signal adjustment includes: EQ frequency start point adjustment, EQ eye height adjustment, high frequency compensation point adjustment and low frequency gain adjustment, which are achieved by configuring the corresponding register values.

[0019] Preferably, the output adjustment adjusts the amplitude of the output signal by adjusting the current value of the register; the larger the current value, the larger the amplitude.

[0020] Preferably, the two-channel single-pole four-throw analog switch is CH444, the high-speed bipolar double-throw analog switch is RS2227XN, and the USB HUB expansion chip is FE1.1S (SL2.1S) chip.

[0021] Overall, the technical solutions conceived in this application have the following beneficial effects compared with the prior art:

[0022] (1) This application uses a cascaded multi-stage high-definition conversion chip to switch one of the eight HDMI channels in and directly output an HDMI signal, achieving full HD HDMI ( Digital signal switching ensures stable signal transmission with minimal loss, balanced signal, and adjustable signal amplitude, meeting the needs of high-definition switching scenarios. In addition to directly outputting HDMI signals, it can also convert digital video signals to VGA video signals via an HDMI-to-VGA converter chip, increasing application flexibility and reducing costs while improving efficiency.

[0023] (2) To improve the reliability of cross-platform USB switching, this application enhances the USB signal through a multi-level USB HUB chip driver, thereby improving the anti-interference capability of the USB signal. It can be adapted to operating systems such as WINDOWS, Kylin, and Dao, without the need to optimize the host USB driver, thus solving the problem of cross-platform inability to recognize USB peripherals. By controlling the cascaded analog switch to achieve multi-select switching of USB signals, the reliability of USB input signal switching is ensured. Attached Figure Description

[0024] Figure 1 This is a block diagram of an 8-port HDMI ruggedized KVM switch with HDMI display switching provided in this application embodiment.

[0025] Figure 2 This is a schematic diagram of an HDMI to VGA interface provided in an embodiment of this application.

[0026] Figure 3 This is a block diagram of an 8-port HDMI ruggedized KVM switch with USB switching provided in an embodiment of this application.

[0027] Figure 4This is a flowchart of the HDMI switching chip signal adjustment method provided in the embodiments of this application.

[0028] Figure 5 This is a schematic diagram of a hardware module structure for hardened KVM provided in an embodiment of this application. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0030] In this article, the term "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. The symbol " / " in this article indicates that the related objects are in an "or" relationship; for example, A / B means A or B.

[0031] The terms "first" and "second," etc., used in the specification and claims herein are used to distinguish different objects, not to describe a specific order of objects. For example, "first response message" and "second response message," etc., are used to distinguish different response messages, not to describe a specific order of response messages.

[0032] In the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design. Specifically, the use of the terms "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0033] In the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more, for example, multiple processing units means two or more processing units, multiple elements means two or more elements, etc.

[0034] For ease of understanding, the English abbreviations and related technical terms used in the embodiments of this application will be explained and described below.

[0035] The HDMI interface contains multiple channels, each responsible for a different function. The HDMI interface includes four TMDS differential pairs (one clock pair + three data pairs), one I2C pair, HPD, and CEC. The TMDS bus is used to transmit video and audio information; the I2C channel is used for communication between the source device and the display device to obtain basic display information (such as EDID information) and other control data; the CEC bus allows users to control the connection of multiple HDMI devices with a single remote control; the HPD channel is used to detect whether a device is connected to the HDMI port and trigger the corresponding initialization process.

[0036] The embodiments of this application are described below with reference to the accompanying drawings.

[0037] The main controller receives data and / or collects key input signals through various communication ports (RS232, RS485, CAN, network), parses the data messages to obtain display channel data information, controls the channel selection of the HDMI switcher chip through the I2C bus to achieve multi-select switching of display signals, and the output display interface supports both HDMI and VGA signals; the keyboard and mouse are combined into one USB signal, and the cascaded analog switch is controlled through the IO interface to achieve multi-select switching of USB signals.

[0038] The detailed technical solution is as follows:

[0039] The main controller receives and parses messages from the external communication interface to achieve KVM switching. Specifically, the main controller receives control commands from the external communication interface, parses and processes the control messages, and controls the selection of analog switch channels via the I / O interface to switch USB signals; it also sends commands via the I2C bus to control the HDMI display switching chip. Alternatively, the main controller can detect user key presses in real time, and when a key is pressed, it acquires the key value to achieve KVM switching.

[0040] Preferably, the domestically produced HDMI switcher chip can achieve high-resolution HDMI signal switching display with 3 inputs and 1 output. Through two-level cascading, it can achieve 8 HDMI signal inputs and 1 HDMI signal output to an external display device.

[0041] Preferably, in order to adapt to the VGA display device interface, the HDMI signal can be converted into a VGA signal and output to the external display device through a VGA conversion chip.

[0042] Preferably, the 8 external host input USB signals (the host USB mouse and keyboard are combined into 1 USB) are adjusted by the driver chip and then sent to a multi-channel analog two-pole four-throw analog switch. The USB signal is switched from four to one by the control encoding address. Then, the two USB signals are switched from two to one by the high-speed bipolar double-throw analog switch. Finally, the USB keyboard and mouse input is realized by the USBHUB expansion chip.

[0043] The main controller controls the input equalization and output signal amplitude of the domestic HDMI switcher chip by writing registers through the I2C bus. This interface can be configured by changing the register parameters as needed.

[0044] The main controller can read the currently configured display channel through messages and control the corresponding channel indicator light to light up through the I / O output interface, indicating the channel that is currently being displayed.

[0045] Example

[0046] like Figure 1 As shown, this embodiment uses a two-stage cascaded MS9601A architecture. The first stage uses three MS9601A chips, and the second stage uses one MS9601A chip, achieving eight HDMI signal inputs (HDMIIN1-HDMIIN8) and one HDMI signal output. The main controller writes to the MS9601A chip registers via I2C instructions. When a certain input signal is selected for output, the TMDS input of that channel is multiplexed to the TMDS channel of the output port through the internal 3-to-1 multiplexer of the MS9601A chip. The DDC interface of the selected input port is connected to the DDC interface of the output port. The HPD signal state of the selected input port is consistent with the HPD signal state of the output port. Unused ports are disconnected from TMDS input and output, the DDC channel is isolated, and the HPD signal remains low. The MS9601A chips can be cascaded by configuring different I2C addresses. The main control chip configures the address of the MS9601A chip by writing to the internal CHIPID register of the MS9601A chip through the I2C bus.

[0047] The MS9601A is a 3-input, 1-output HDMI signal switcher chip that supports signal rates up to 3Gbps. and HDMI input signal with resolution.

[0048] To accommodate cables of different lengths and qualities and ensure stable signal transmission, the equalizer at the HDMI input and the signal amplitude at the output can be adjusted via I2C interface chip programming when parameters need to be adjusted.

[0049] like Figure 2As shown, this embodiment uses the MS9291 chip to convert the HDMI signal into a VGA signal for output to an external display. Specifically, the three pairs of data signals and one pair of clock signals, as well as the HPD signal, of the HDMI signal output by the MS9601A chip are connected to the input terminal of the MS9291 chip. The MS9291 chip outputs RGBHV and EDID signals VGA_SCL and VGA_SDA to the external display interface.

[0050] The MS9291 is a low-cost, low-power semiconductor device that integrates an HDMI receiver and a 10-bit video digital-to-analog converter (DAC). It is primarily used to convert HDMI signals to VGA signals for output, supporting a maximum conversion speed of 300MHz and SPDIF output. The HDMI receiver supports 1080P@60Hz and is easy to use due to its integrated MCU and EDID.

[0051] like Figure 3 As shown, for 8 USB signals (1 USB signal for a composite USB mouse and USB keyboard), this embodiment uses 8 hub main chips FE1.1S to enhance the USB signal driving capability, then sends them to 2 sets of multiplexed analog switches CH444 for 4-to-1 output. The output signal is then sent to an RS2227XN 2-to-1 multiplexer for connection, and then sent to a single FE1.1S chip to expand the USB signal into two channels and reshape the USB signal before connecting it to the keyboard and mouse. The 8 hub main chips FE1.1S are used to implement 8 USB 2.0 signal inputs and outputs. The host USB signal passes through these chips to enhance electromagnetic interference and anti-static capabilities, thereby enhancing the USB driving capability.

[0052] The CH444 is a DPQT low-impedance broadband bidirectional analog switch chip, comprising two single-pole four-throw four-to-one switches. The CH444 is used to control the levels of encoded addresses IN1 and IN0 via a microcontroller's I / O port to achieve four-to-one switching of USB signals. The enable signal for both CH444 chips is active low.

[0053] The RS2227XN is a high-speed USB 2.0 (480-Mbps) 1:2 multiplexer / demultiplexer switch, a high-speed bipolar double-throw analog switch. The RS2227XN is used to control the switching between two USB signals. The output enable signal OE is grounded, and the output channel selection S is controlled by the microcontroller's I / O interface, enabling high-speed switching between the two USB signals.

[0054] The FE1.1S is a host control IC for USB 2.0 hubs, providing four USB ports and featuring high performance, low power consumption, and low cost. Due to these characteristics, it is widely used in USB device expansion and connectivity solutions. The FE1.1S chip is used to implement input expansion functions for USB keyboards and mice.

[0055] In this embodiment, the main controller uses the GD32F103XX series or other main control chips with I2C, network controller, CAN port, and serial port. It has functions such as key detection and processing, network control, LED indicator control, data communication, and issuing control commands. The GD32F103XX series is a 32-bit general-purpose microcontroller (MCU) based on the ARM Cortex-M4 processor.

[0056] The main controller is responsible for receiving switching control commands from external communication interfaces (RS485, RS232, CAN, Ethernet port), parsing and processing the received control commands, and controlling them through the I / O interface. Figure 3 Two-stage analog switch encoding addresses enable 8-to-1 channel connection, connecting USB keyboard and mouse signals to an external host for operation control. The main controller writes to the internal RX_PORT switching register of the secondary MS9601A chip via the I2C bus to achieve 8-to-1 HDMI signal output.

[0057] The KVM signal switching command message format is shown in Table 1. The KVM message header is 0xA5 or 0x5A, the switching command word is 0x80, the channel selection data bit is 0x00, the value range is 0-7, it identifies channels 1-8, it can support extended data, the validity is a fixed value of 0x01, and the check bit is 0x80 & the lower 8 bits of the data.

[0058] Table 1 KVM signal switching commands

[0059]

[0060] The main controller initializes the internal network controller, configures its IP address, receives control commands from the external network, parses and processes network packets, and sends commands to the I2C channel to achieve KVM switching.

[0061] Real-time detection of main controller Figure 1 The key1-key8 switching buttons, when triggered by a button, obtain key values ​​through different IO ports, control the corresponding analog switch to select the corresponding channel and control the corresponding display switching chip to work, switching between USB and HDMI signals.

[0062] The main controller can read the currently configured display channel via KVM channel read command messages. The message format is shown in Table 2. The KVM message header is 0xA5 or 0x5A, the read channel command word is 0x40, the data bits are 0x00, and the data validity is a fixed value of 0x01. The value of the data bits is obtained by parsing the return value to acquire the current display channel. This message is used to send the current display channel data to the external communication interface.

[0063] Table 2 KVM Channel Read Commands

[0064]

[0065] After initialization, the main control chip detects the frequency of the input CLK. By setting the RX receive EQ value and TX output value in the MS9601A register, it achieves equalization adjustment of the input HDMI signal and amplitude adjustment of the output HDMI signal, meeting the display signal adjustment needs in different application environments. RX input signal adjustment includes EQ frequency start point adjustment, EQ eye height adjustment, high-frequency compensation point adjustment, and low-frequency gain adjustment, all achieved by configuring the corresponding register values. Output adjustment modifies the amplitude of the output signal, which can be achieved by adjusting the current value of the register; the larger the current value, the larger the amplitude. The adjustment range for the input data signal amplitude is 150mV-1200mV. De-emphasis amplitude adjustment mainly reduces the amplitude of low-frequency signals; the larger the register value, the larger the drive current, and the greater the reduction in low-frequency signal amplitude. Two-stage de-emphasis processing can be implemented, adjusting all three data channels simultaneously. See specific implementation examples. Figure 4 .

[0066] like Figure 5 As shown, this application proposes a ruggedized KVM switch, which includes a main control unit, a power supply unit, and an interface unit.

[0067] The main control unit is a KVM switching control board, used to acquire commands sent from the push-button switch, network, serial port, and CAN port, parse the commands, and control the internal KVM switching circuit to achieve KVM switching. The KVM switching control board uses domestically produced chips and microcontrollers, supports 8 sets of HDMI and USB signal inputs, and 1 set of HDMI and USB signal outputs, realizing an 8-to-1 switching function.

[0068] The power supply unit consists of an AC filter and an AC-DC module power supply, providing DC power to the subsequent stages. The AC-DC module power supply provides 12V and 5V power to the subsequent stages, and the AC filter filters the AC input signal to enhance anti-interference capabilities.

[0069] The interface unit mainly consists of an aviation connector, switches, and indicator lights. The aviation connector is used for connecting the AC power supply interface and HDMI, USB, management network port, serial port, and CAN port for communication; the switch includes a power switch and a toggle button switch; the indicator lights include a power indicator light and a toggle button indicator light.

[0070] Based on the above, this application proposes a control method for an 8-port HDMI-enhanced KVM switch, comprising the following steps:

[0071] Step 1: Initialize the main controller's network port, serial port, CAN port, and I2C bus master mode; initialize the HDMI switching control chip's I2C, write the chip address, initialize the internal registers, disable the TX output, detect the input signal clk frequency, and set the RX receive EQ value and TX output drive value and write them to the registers.

[0072] Step 2: The main controller waits to receive control commands sent by external communication interfaces (network port, serial port, CAN port), parses and processes the control messages shown in Table 1, and obtains the display channel data information; the main controller detects user key presses in real time, and obtains the key value when a key is triggered, and obtains the display channel data information. The key values ​​key1-key8 correspond to the current display channels 1-8.

[0073] Step 3: The main controller acquires the display channel data and sends commands via the I2C bus to control the internal selection of the HDMI display switching chip. One HDMI switching chip has a high-resolution HDMI signal 3-input 1-output switching display function. Through a two-level cascade method, it can realize the output of 1 HDMI signal from the specified channel of 9 HDMI input signals. At the same time, the main controller I / O output interface controls the corresponding channel indicator light to light up, indicating the channel currently being displayed.

[0074] Step 4: The main controller writes to the register of the domestic HDMI switching chip via the I2C bus to control the input equalization and output signal amplitude of the HDMI display signal, and outputs default values. The parameters of this interface can be changed according to the specific application scenario.

[0075] Step 5: The VGA signal conversion chip converts the HDMI output signal from Step 3 into a VGA signal and outputs it to the external display device;

[0076] Step 6: The main controller obtains the current display channel data from Step 2 and controls the USB signal switching as follows: The four external host input USB composite signals (the host USB mouse and keyboard signals are combined into one USB peripheral) are adjusted by the USB HUB expansion chip and then connected to the multi-channel analog two-pole four-throw analog switch for selection. The main controller IO interface outputs the encoded address to control the multi-channel analog two-pole four-throw analog switch to select one of the four. One of the adjusted input USB composite signals is connected to the input terminal of the high-speed bipolar double-throw analog switch.

[0077] Step 7: The output signals of two sets of multi-channel single-pole four-throw analog switches are connected to the input terminals of high-speed double-pole double-throw analog switches. The main controller controls the high-speed double-pole double-throw analog switches through the IO port to achieve 2-to-1 selection of the input signal, and finally achieve 8-to-1 selection of the external host USB signal.

[0078] Step 8: Connect the USB keyboard and mouse signals to the downstream port of the USB HUB chip, and connect the upstream port of the USB HUB chip to the host USB interface of the current display channel.

[0079] The main controller controls the input equalization and output signal amplitude of the domestically produced HDMI switching chip by writing registers via the I2C bus. Default values ​​are written to the relevant registers during initialization based on the detected input CLK. When the display effect is poor, the register parameters can be configured by changing them according to the usage environment. The specific control method is as follows:

[0080] (1) Use an oscilloscope to collect the eye diagram of the HDMI signal output from each external host through a cable, and determine the eye height, eye width, jitter, clock frequency, rise and fall time;

[0081] (2) Based on the eye width and eye height of the eye diagram, adjust the EQ equalization value, determine the EQ frequency starting point F1 and the high-frequency compensation frequency point F2, set a small register current value and load value, and adjust the eye height. 4. Adjust the differential signal together to reduce signal jitter and increase high-frequency components;

[0082] (3) Adjust the low-frequency signal gain of the signal between F1 and F2, set a larger value to reduce the low-frequency gain, and make the rising and falling edges of the signal steeper;

[0083] (4) Perform gain compensation on frequencies after point F2, setting a larger value to enhance high-frequency gain compensation while preventing overcompensation;

[0084] (5) Limit the amplitude of the first-stage (near the external host) chip's TX output amplitude input terminal to between 0.8V and 1.1V, and set a register to prevent crosstalk and noise signal amplification; set a register for the second-stage (near the display) chip, and limit the amplitude of the output amplitude input terminal to between 1.0V and 1.2V;

[0085] (6) Adjust the three pairs of differential signals to reduce the amplitude of the low-frequency signal by no more than 20%.

[0086] Based on the methods in the above embodiments, this application provides a computer-readable storage medium storing a computer program that, when run on a processor, causes the processor to execute the methods in the above embodiments.

[0087] Based on the methods in the above embodiments, this application provides a computer program product that, when run on a processor, causes the processor to execute the methods in the above embodiments.

[0088] It is understood that the processor in the embodiments of this application can be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. A general-purpose processor can be a microprocessor or any conventional processor.

[0089] The method steps in this application embodiment can be implemented in hardware or by a processor executing software instructions. The software instructions can consist of corresponding software modules, which can be stored in random access memory (RAM), flash memory, read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), registers, hard disks, portable hard disks, CD-ROMs, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor, enabling the processor to read information from and write information to the storage medium. Of course, the storage medium can also be a component of the processor. The processor and the storage medium can reside in an ASIC.

[0090] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially as a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted through the computer-readable storage medium. The computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid-state disk (SSD)).

[0091] It is understood that the various numerical designations used in the embodiments of this application are merely for the convenience of description and are not intended to limit the scope of the embodiments of this application.

[0092] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. An 8-port HDMI ruggedized KVM switch, characterized in that, include: The main controller, four HDMI switcher chips, a VGA conversion chip, a USB signal enhancement driver module, two sets of two-channel single-pole four-throw analog switches, a high-speed double-pole double-throw analog switch, and a USB hub expansion chip; among them, The main controller is used to control the channel selection of the HDMI switcher chip through the I2C bus according to the display channel data information, so as to realize the multi-selection 1 switching of the display signal, and to control the channel selection of the two-channel single-pole four-throw analog switch through the IO interface, so as to realize the multi-selection 1 switching of the USB signal. The four HDMI switcher chips are in a two-stage cascaded structure. The first stage consists of the first to third HDMI switcher chips, and the second stage is the fourth HDMI switcher chip, realizing 8 HDMI input signals and 1 HDMI output signal. The HDMI output signal is directly output to the monitor, or it is converted to a VGA signal by a VGA conversion chip before being output to the monitor. The USB signal enhancement driver module, two sets of two-channel single-pole four-throw analog switches, high-speed double-pole double-throw analog switches, and USB HUB expansion chip are electrically connected in sequence. The USB signal enhancement driver module consists of 8 USB HUB expansion chips, each of which is an FE1.1S chip. The two-channel single-pole four-throw analog switch is CH444; The high-speed bipolar double-throw analog switch is RS2227XN; After enhancing the driving capability of 8 USB signals through 8 FE1.1S chips, the signals are sent to 2 sets of CH444 for 4-to-1 output. The output signals are sent to 1 RS2227XN for 2-to-1 connection and sent to the uplink port of 1 FE1.1S chip to expand the USB signal into two channels and shape the USB signal before connecting it to the keyboard and mouse.

2. The ruggedized KVM switch as described in claim 1, characterized in that, The hardened KVM switch has an external I2C interface. The I2C interface allows external controllers to program the HDMI switcher chip registers to achieve equalizer adjustment at the HDMI input and signal amplitude adjustment at the output, in order to meet the display signal adjustment needs in different application environments.

3. The ruggedized KVM switch as described in claim 1, characterized in that, The main controller acquires display channel data information through any of the following methods: 1) Real-time detection of button switches; when a button is pressed, the key value is obtained through different I / O ports. 2) Receive KVM switching commands sent from the external communication interface and parse the commands.

4. The ruggedized KVM switch as described in any one of claims 1 to 3, characterized in that, The main controller uses the GD32F103XX series or other main control chips with I2C, network controller, CAN port, and serial port, and has functions such as key detection and processing, network control, LED indicator control, data communication, and issuing control commands.

5. The ruggedized KVM switch as described in any one of claims 1 to 3, characterized in that, The HDMI switcher chip is MS9601A, and the VGA converter chip is MS9291.

6. The ruggedized KVM switch as described in claim 5, characterized in that, The main controller adjusts the input HDMI signal and the output HDMI signal amplitude by setting the RX register of the MS9601A to receive the EQ value and the TX output value.

7. The ruggedized KVM switch as described in claim 6, characterized in that, The equalization adjustment of the input HDMI signal includes: EQ frequency start point adjustment, EQ eye height adjustment, high frequency compensation point adjustment, and low frequency gain adjustment, which are achieved by configuring the corresponding register values.

8. The ruggedized KVM switch as described in claim 6, characterized in that, The amplitude of the output HMDI signal is adjusted by adjusting the current value of the register; the larger the current value, the larger the amplitude.

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