A multi-path EDID, video security isolation and switching device and method of use thereof

Abstract

The application provides a multi-path EDID, video security isolation and switching device, which carries out one-way isolation on the EDID part, and data can only be read out from the display by the host, thereby ensuring the one-way nature of data transmission; and the device also considers the switching function of various display interfaces, and can realize the switching function between the multiple display interfaces in the case that the host has multiple display input. The device comprises: a first host display input end, which is integrated with a VGA interface and an HDMI interface, wherein the VGA interface is converted by a VGA conversion HDMI device; a second host display input end, which is integrated with an HDMI interface; a shared display output end, which comprises an HDMI interface and a VGA interface, wherein the VGA interface is converted by an HDMI conversion VGA device; a single-chip microcomputer A; a single-chip microcomputer B; and an FPGA; two interfaces of the display output end are respectively externally connected with corresponding displays, the EDID information of the display is connected to the single-chip microcomputer A after being selected by a shared display switching switch, and the single-chip microcomputer A simulates the host to detect and collect display basic information.

Description

Technical Field

[0001] This invention relates to the technical field of video transmission, specifically to a multi-channel EDID, video security isolation and switching device, and also provides a method for using the device. Background Technology

[0002] In current mainstream product applications, the display interface is directly connected to the monitor through a bridge chip and a display conversion chip. In addition to the displayed data signal, the monitor also has an EDID read signal. This signal uses the I2C protocol. I2C is a bidirectional data interface. The main controller first sends a command to the monitor. After the monitor responds, the main controller can read the EDID information from the monitor. If the information is correct, the display data can be output normally.

[0003] In applications involving switching between multiple host displays, existing technologies typically only allow switching between the same type of display interface, such as switching between two HDMI ports or two VGA ports.

[0004] Currently, the common protocol for EDID is the I2C bus, but this data bus is bidirectional, which poses a risk that the display can read the master control data, and the security of information cannot be guaranteed.

[0005] Current technology cannot meet the switching requirements of multiple display interfaces; it can only switch between the same display interface.

[0006] Therefore, there is an urgent need to develop a device that can guarantee unidirectional data transmission and enable switching between multiple display interfaces when the host has multiple display inputs. Summary of the Invention

[0007] To address the aforementioned issues, this invention provides a multi-channel EDID and video security isolation and switching device. It provides unidirectional isolation for the EDID portion, ensuring that data can only be read from the display by the main controller, thus guaranteeing the unidirectionality of data transmission. Furthermore, it also supports multiple display interface switching functions, enabling switching between multiple display interfaces when the host has multiple display inputs.

[0008] A multi-channel EDID and video security isolation and switching device, characterized in that it comprises:

[0009] The first host display input terminal integrates a VGA interface and an HDMI interface, wherein the VGA interface is converted through a VGA to HDMI converter.

[0010] The second host display input terminal integrates an HDMI interface;

[0011] The shared display output includes an HDMI interface and a VGA interface, wherein the VGA interface is converted through an HDMI to VGA converter.

[0012] Microcontroller A;

[0013] Microcontroller B;

[0014] And FPGA;

[0015] The two interfaces of the display output terminal are respectively connected to the corresponding displays. The EDID information of the displays is connected to the microcontroller A after the shared display switching switch selects the path. The microcontroller A simulates the host to perform DDC detection and collect basic display information. The microcontroller A converts the EDID information corresponding to the display output terminal into SPI packets, transmits them to the microcontroller B after unidirectional physical isolation through the FPGA, and the microcontroller B simulates the display peripheral and selects to provide the EDID information of the display corresponding to the first host display input terminal or the second host display input terminal through the host switching switch.

[0016] The first host display input terminal is connected to a display switch and then to a host switch. The second host display input terminal is connected to the host switch. The host switch is connected to a shared display switch. The shared display switch is connected to the HDMI interface and the HDMI to VGA converter of the shared display output terminal.

[0017] Its further features are:

[0018] The second host display input terminal includes a corresponding VGA interface and a VGA to HDMI converter. At this time, a display switching switch is set in the second host display input terminal.

[0019] The VGA interface and VGA to HDMI converter are transformed into the corresponding video interface and the corresponding data to HDMI converter according to the settings.

[0020] A one-way isolator is provided between the host switch and the shared display switch. The host switch transmits the HDMI video information input from the host display input terminal to the shared display switch through the one-way physical isolator, thereby enhancing the driving capability and allowing the signal transmission distance to be longer.

[0021] A method for using a multi-channel EDID and video security isolation and switching device, characterized in that it employs the following operation of the multi-channel EDID and video security isolation and switching device:

[0022] The EDID information of VGA or HDMI at the shared display output terminal is selected by the shared display switch to send one to microcontroller A. Microcontroller A simulates the host to complete DDC detection and collect the basic resolution information of the display.

[0023] Microcontroller A converts the EDID information into an SPI packet, uses the FPGA for unidirectional physical isolation, and provides it to microcontroller B.

[0024] The microcontroller B simulates a display peripheral and selects whether to provide the corresponding EDID information to the first or second host via a host switch.

[0025] The first host display input terminal selects to provide EDID information to either the VGA or HDMI interface via a display switch; the second host display input terminal only provides EDID information to the HDMI interface.

[0026] Its further features are:

[0027] The first host displays the video information of the input VGA or HDMI. By using the display switch, one output can be selected, and the VGA video is also converted to HDMI video format for output.

[0028] The HDMI input terminals of the first and second host displays can be switched to select one output via a host switch.

[0029] After passing through a unidirectional physical isolator, the HDMI output can be selected via a shared display switch. One output direction is to be converted by an HDMI to VGA converter and then connected to a VGA monitor via a VGA interface. The other output direction is to be directly connected to an HDMI monitor via an HDMI interface.

[0030] By adopting this invention, the EDID part is unidirectionally isolated through microcontroller A, FPGA, and microcontroller B. The data can only be read from the display by the main controller, ensuring the unidirectionality of data transmission. In addition, the device also supports multiple display interface switching functions, and can realize the switching function between multiple display interfaces when the host has multiple display inputs. Attached Figure Description

[0031] Figure 1 This is a schematic block diagram of a device according to a specific embodiment of the present invention;

[0032] Figure 2 This is a schematic diagram of EDID transmission according to the present invention;

[0033] Figure 3 This is a schematic diagram of video transmission according to the present invention;

[0034] Figure 4This is a schematic diagram illustrating the EDID process of the present invention;

[0035] Figure 5 This is a block diagram illustrating the unidirectional transmission principle of the I2C protocol of the present invention. Detailed Implementation

[0036] A secure isolation and switching device for multi-channel EDID and video, see Figure 1 It includes a first host display input terminal, a second host display input terminal, and a shared display output terminal;

[0037] In practice, the first host's display input terminal is the display input terminal for internal network hosts, and the second host's display input terminal is the display input terminal for external network hosts.

[0038] The display input terminals of the intranet host integrate VGA and HDMI interfaces. The VGA interface is converted through a VGA to HDMI converter, specifically model LT8522, which is equipped with an intranet display switch to select VGA or HDMI input.

[0039] The external network host display input terminal integrates an HDMI interface;

[0040] The shared display output includes an HDMI interface and a VGA interface. The VGA interface is converted through an HDMI to VGA converter, specifically model LT8511.

[0041] Microcontroller A is a GD32F407VGT6 MCU; Microcontroller B is a GD32F407VGT6 MCU; FPGA is a 7AL100.

[0042] Microcontroller A uses an embedded operating system to simulate a host computer, identifying and reading EDID information from display peripherals. It forwards the EDID data to microcontroller B via SPI packet forwarding, FPGA unidirectional isolation, and then stores the EDID information. Microcontroller B also uses an embedded operating system to simulate the display peripheral, establishing a display driver connection with the host computer. It then provides the stored EDID information to internal or external network hosts. For FPGA unidirectional isolation, refer to the attached document. Figure 5The FPGA has two SPI controllers. The first SPI controller receives SPI data from microcontroller A and writes it to the internal FIFO. The other SPI controller reads data from the FIFO and outputs it to microcontroller B. This device isolates the I2C bus, ensuring that only the host system can read the EDID information of the display, and the display cannot read information from the host system. It can meet the display switching function in the case of multiple hosts and is compatible with two display interfaces, making it more widely applicable.

[0043] In specific implementation, the two interfaces of the display output terminal are respectively connected to the corresponding displays. The EDID information of the displays is connected to the microcontroller A after the path is selected by the shared display switching switch (specifically, the CH482X model switching switch is selected). The microcontroller A simulates the host to perform DDC detection and collect basic display information. The microcontroller A converts the EDID information corresponding to the display output terminal into SPI packets, transmits them to the microcontroller B after unidirectional physical isolation through the FPGA, and the microcontroller B simulates the display peripheral and selects to provide the EDID information of the display corresponding to the display input terminal of the internal network host or the display input terminal of the external network host through the internal network switching switch (specifically, the CH482X model switching switch is selected, which is the host switching switch).

[0044] The intranet host display input terminal is connected to the display switch, and then to the host switch. The extranet host display input terminal is connected to the host switch. A one-way isolator is provided between the host switch and the shared display switch. The intranet and extranet switches transmit the HDMI video information input from the host display input terminal to the shared display switch through the one-way physical isolator, thereby enhancing the driving capability and allowing the signal transmission distance to be longer. The shared display switch is connected to the HDMI interface and VGA to HDMI converter of the shared display output terminal.

[0045] A method for using a multi-channel EDID and video security isolation and switching device is described in [link to documentation]. Figures 2-5 It employs a multi-channel EDID and video security isolation and switching device to perform the following operations:

[0046] The EDID information of VGA or HDMI at the shared display output terminal is selected to be sent to microcontroller A through the shared display switch. Microcontroller A simulates the host to complete DDC detection and collect the basic resolution information of the display.

[0047] Microcontroller A converts the EDID information into an SPI packet, uses the FPGA for unidirectional physical isolation, and provides it to microcontroller B.

[0048] The microcontroller B simulates a display peripheral, and the host selects whether to provide the corresponding EDID information to the internal host or the external host via a host switch;

[0049] The intranet host display input terminal selects to provide EDID information to either the VGA or HDMI interface via an intranet display switch; the external network host display input terminal only provides EDID information to the HDMI interface.

[0050] The specific operation method is as follows: the intranet host displays the video information of the VGA or HDMI input terminal, and selects one output through the intranet display switch. The VGA video is also converted to HDMI video format for output.

[0051] The HDMI input terminals of the intranet host and the HDMI input terminals of the external network host can be selected via an intranet / extranet switch;

[0052] After the HDMI output passes through the unidirectional physical isolator HDMI TSO TBD (specifically model ADN4654), a shared display switch selects an HDMI output path. One output direction is to be converted by an HDMI to VGA converter and then connected to a VGA monitor via a VGA interface. The other output direction is to be directly connected to an HDMI monitor via an HDMI interface.

[0053] Data signals and EDID signals are switched synchronously. Figure 2 The data paths 1→3→4→5→6→7→8 correspond to the appendix. Figure 3 The data path in the image is 1'→3'→4'→6'→7'→8'→9'; (See attached image) Figure 2 The data paths 2→3→4→5→6→7→9 correspond to the appendix. Figure 3 The data path in the image is 2'→3'→4'→6'→7'→8'→10'; (Attached) Figure 2 The data paths 2→3→4→5→6→7→10 correspond to the appendix. Figure 3 The data path in the middle is 5'→6'→7'→8'→10'.

[0054] This device isolates the I2C bus, ensuring that only the host system can read the monitor's EDID information, while the monitor cannot read information from the host system. It can also switch between multiple hosts and is compatible with two display interfaces, making it suitable for a wider range of applications.

[0055] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0056] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A multi-channel EDID and video security isolation and switching device, characterized in that, It includes: The first host display input terminal integrates a VGA interface and an HDMI interface, wherein the VGA interface is converted through a VGA to HDMI converter. The second host display input terminal integrates an HDMI interface; The shared display output includes an HDMI interface and a VGA interface, wherein the VGA interface is converted through an HDMI to VGA converter. Microcontroller A; Microcontroller B; And FPGA; The two interfaces of the display output terminal are respectively connected to the corresponding displays. The EDID information of the displays is connected to the microcontroller A after the shared display switching switch selects the path. The microcontroller A simulates the host to perform DDC detection and collect basic display information. The microcontroller A converts the EDID information corresponding to the display output terminal into SPI packets, transmits them to the microcontroller B after unidirectional physical isolation through the FPGA, and the microcontroller B simulates the display peripheral and selects to provide the EDID information of the display corresponding to the first host display input terminal or the second host display input terminal through the host switching switch. The first host display input terminal is connected to a display switch and then to a host switch. The second host display input terminal is connected to the host switch. The host switch is connected to a shared display switch. The shared display switch is connected to the HDMI interface and the HDMI to VGA converter of the shared display output terminal.

2. The multi-channel EDID and video security isolation and switching device as described in claim 1, characterized in that: The second host display input terminal includes a corresponding VGA interface and a VGA to HDMI converter. At this time, a display switching switch is set in the second host display input terminal.

3. The multi-channel EDID and video security isolation and switching device as described in claim 2, characterized in that: The VGA interface and VGA to HDMI converter are configured to become the corresponding video interface and the corresponding data to HDMI converter.

4. The multi-channel EDID and video security isolation and switching device as described in claim 1, characterized in that: A one-way isolator is provided between the host switch and the shared display switch. The host switch transmits the HDMI video information input from the host display input terminal to the shared display switch through the one-way physical isolator for HDMI one-way isolation.

5. A method for using a multi-channel EDID and video security isolation and switching device, characterized in that, It employs a multi-channel EDID and video security isolation and switching device, which operates as follows: The EDID information of VGA or HDMI at the shared display output terminal is selected by the shared display switch to send one to microcontroller A. Microcontroller A simulates the host to complete DDC detection and collect the basic resolution information of the display. Microcontroller A converts the EDID information into an SPI packet, uses the FPGA for unidirectional physical isolation, and provides it to microcontroller B. The microcontroller B simulates a display peripheral, and selects to provide the corresponding EDID information to the first host or the second host via a host switch; The first host display input terminal selects to provide EDID information to the VGA interface or HDMI interface via a display switch; The second host display input only provides EDID information to the HDMI interface.

6. The method of using a multi-channel EDID and video security isolation and switching device as described in claim 5, characterized in that: The first host displays the video information from the input VGA or HDMI. By using the display switch, one output can be selected, and the VGA video is also converted to HDMI video format for output.

7. The method of using a multi-channel EDID and video security isolation and switching device as described in claim 5, characterized in that: The HDMI input terminals of the first and second host displays can be switched via a host switch to select one output.

8. The method of using a multi-channel EDID and video security isolation and switching device as described in claim 5, characterized in that: After passing through a unidirectional physical isolator, the HDMI output can be selected via a shared display switch. One output direction is to be converted by an HDMI to VGA converter and then connected to a VGA monitor via a VGA interface. The other output direction is to be directly connected to an HDMI monitor via an HDMI interface.

Images