CN218159009U - Signal switching device based on 6U-CPEX standard - Google Patents

Abstract

The utility model discloses a signal switching device based on 6U-CPEX standard, which comprises a power supply conversion module, a host communication and selection module, a FPGA switching control module, a DVI switching module, a USB switching module, a RS232 interface module, a RS422 interface module and a PS2 interface module; the power supply conversion module is used for supplying power to the device, and the host communication and selection module and the FPGA switching control module are matched with each other to complete the switching of each signal and each interface. The utility model discloses a signal switching device can accomplish the switching of single device completion multiple signal and interface, and work efficiency and security are high, and the device accords with 6U-CPEX standard, satisfies the switching control application demand of each control field, demonstration and the multiple interface of controlgear, has certain spreading value.

Description

Signal switching device based on 6U-CPEX standard

Technical Field

The utility model relates to a signal switching control technical field, especially a signal switching device based on 6U-CPEX standard.

Background

The complete computer system comprises a mainboard unit, an operation control and display unit, wherein the display unit is common in DVI and VGA interfaces, and the DVI interface can adapt to higher 1080P resolution; the operation control interface is commonly used by a USB interface and a PS2 interface, and the serial port becomes a low-speed communication interface commonly used by a mainboard externally.

In industrial and military environments, the application scenarios of dual-computer backup, multi-computer backup and multi-computer alternate work are common, and at this time, applications involving a plurality of computers sharing an operation control and display unit require switching processing for the operation control and display unit.

In the field of industrial control, the CPEX interface can adapt to more high-bandwidth application requirements compared with the CPCI interface, and in addition, in the last two years, as the trade and war between countries are intensified, the autonomous controllable security of the circuit design receives more and more attention of enterprises.

Therefore, it is urgently needed to design a domestic switching device meeting the 6U-CPEX standard to meet the application requirements of switching control of various interfaces of display and control equipment in the military and industrial control fields.

Disclosure of Invention

The utility model provides a technical problem provide a signal auto-change over device based on 6U-CPEX standard.

Realize the utility model discloses the technical solution of purpose does:

a signal switching device based on 6U-CPEX standard comprises a power supply conversion module, a host communication and selection module, an FPGA switching control module, a DVI switching module, a USB switching module, an RS232 interface module, an RS422 interface module and a PS2 interface module;

the FPGA switching control module is respectively connected with the host communication and selection module, the DVI switching module, the USB switching module, the RS232 interface module, the RS422 interface module and the PS2 interface module;

the power supply conversion module is used for converting an accessed power supply into a power supply required by the operation of the switching device and supplying power to each module of the switching device;

the host communication and selection module is used for receiving switching instructions sent by an external host and IO switching selection signal input;

the FPGA switching control module is used for receiving a switching instruction of the host communication and selection module and sending the switching instruction to the DVI switching module, the USB switching module, the RS232 interface module, the RS422 interface module and the PS2 interface module;

the DVI switching module and the USB switching module are used for realizing DVI and USB signal switching; the RS232 interface module and the RS422 interface module are used for realizing the conversion of the signal level of the RS232 and RS422 serial ports; the PS2 interface module is used for realizing the conversion of PS2 signal level.

Furthermore, 12V voltage is connected to one end of the power conversion module, and the 12V power supply is switched to 5V and 3.3V voltage through two power conversion chips, respectively, and the output ends of the 5V and 3.3V voltage are respectively connected in series with a resistor and a light emitting diode for power supply indication;

the 5V direct-current voltage and the 3.3V direct-current voltage of the two power conversion chips are respectively connected with a 5V power supply network and a 3.3V power supply network of the switching device through magnetic beads and are used for debugging and isolating a power supply and filtering a working direct-current power supply;

the power supply conversion chip adopts a BL8033 power supply chip.

Further, the host communication and selection module comprises two serial interfaces and four IO selection signal inputs;

the two serial interfaces are used for connecting an external host and the FPGA switching control module, and one transceiving chip is adopted for the two serial interfaces to complete data transceiving level conversion;

the four IO selection signal inputs are suspended or connected with a signal ground;

the serial interface of the host communication and selection module adopts RS232 level standard, the conversion from RS232 to LVTTL level adopts ER3232SS chip, and a single chip completes the data transceiving level conversion of two RS232 serial communication interfaces.

Furthermore, the USB switching module includes a plurality of USB2.0 signal switching channels, and each USB2.0 signal switching channel selects one path of the input multiple paths of USB signals to be switched and output by using a bidirectional multiple-path switch selection chip;

the USB switching module is connected with the FPGA switching control module through an IO pin;

the bidirectional multi-way switch selection chip adopts a WAS4735Q chip.

Furthermore, the RS232 interface module includes a plurality of transceiver chips, each transceiver chip completes the conversion from two RS232 levels to the LVTTL level standard of the FPGA, and realizes an external RS232 signal path;

the RS422 interface module comprises a plurality of transceiver chips, and each transceiver chip completes conversion from one path of RS422 level to LVTTL level standard of the FPGA to realize an external RS422 signal path;

the transceiver chip of the RS232 interface module adopts an ER3232SS chip;

and the transceiver chip of the RS422 interface module adopts an ER3491SS chip.

Further, the PS2 interface module adopts a plurality of discrete components to realize conversion from the PS2 level to the LVTTL level standard of the FPGA.

Further, the DVI switching module comprises a DVI switching chip and an ESD protection chip;

the DVI switching chip is connected with the FPGA switching control module through an IO pin and is used for completing switching output selection control of a DVI input video channel of the FPGA switching control module;

the ESD protection chips are respectively connected with the DVI input video channel of the FPGA switching control module and the DVI video output by the DVI switching chip for ESD protection;

the DVI switching chip adopts an LT8642UX chip, and the ESD protection chip adopts an ESD5344D chip.

Furthermore, the DVI switches the module and includes a plurality of EEPROM chips, and the EEPROM chip switches control module with FPGA respectively and is connected, receives the DVI digital video data that FPGA switches control module output, and the DVI digital video signal of the corresponding resolution ratio of EDID information output according to the chip is predetermine.

Furthermore, the FPGA switching control module adopts a GW1N-9 type domestic FPGA chip.

Compared with the prior art, the utility model, it is showing the advantage and is:

(1) The interfaces in the utility model all adopt standard CPEX interfaces and CPCI interfaces, and the switching device has better signal integrity, thereby enabling the signal switching to have stronger stability;

(2) The interface switching control of the utility model is flexible and configurable, and the switching control interface supports a plurality of mixed control modes of serial ports and common IO;

(3) The signal switching device of the utility model can realize DVI, USB, RS232, RS422 and PS2 signal switching by a single device, and the number of signal interface circuits can be expanded;

(4) The utility model discloses a DVI interface among the signal switching device switches the module and sets up ESD protection circuit, and it has certain safety protection ability to pull out the condition to the mistake plug.

The present invention will be described in further detail with reference to the accompanying drawings and examples.

Drawings

Fig. 1 is a schematic structural diagram of the signal switching device based on the 6U-CPEX specification of the present invention.

Fig. 2 is a schematic diagram of a circuit structure in an embodiment of the present invention.

Fig. 3 is a schematic circuit diagram of a DVI switching module according to an embodiment of the present invention.

Fig. 4 is a functional schematic diagram of the FPGA switching control module in an embodiment of the present invention.

Fig. 5 is a circuit schematic diagram of the PS2 interface module according to an embodiment of the present invention.

Fig. 6 is a schematic diagram of an appearance of an embodiment of the present invention.

Detailed Description

Examples

With reference to fig. 1 and 2, a signal switching apparatus based on 6U-CPEX specification includes a power conversion module, a host communication and selection module, an FPGA switching control module, a DVI switching module, a USB switching module, an RS232 interface module, an RS422 interface module, and a PS2 interface module;

the FPGA switching control module is respectively connected with the host communication and selection module, the DVI switching module, the USB switching module, the RS232 interface module, the RS422 interface module and the PS2 interface module;

the FPGA switching control module receives a switching control command of the host communication and selection circuit, outputs a switching control signal to the DVI switching circuit and the USB switching circuit, switches signals subjected to level conversion by the RS232 interface circuit and the RS422 interface circuit, and performs PS2 protocol matching identification and switching on the signals subjected to the PS2 interface circuit;

the DVI switching module and the USB switching module adopt special integrated circuits, receive signals output by the FPGA switching control module and realize the switching of DVI and USB signals;

the RS232 interface module and the RS422 interface module are respectively responsible for the conversion of the levels of the RS232 and RS422 serial port signals, and the switching of the serial port signals is realized by an FPGA switching control circuit;

the PS2 interface module is responsible for the conversion of PS2 signal level, and the protocol matching identification and switching processing of the PS2 signal are realized by an FPGA switching control circuit;

and the DC-DC power supply conversion module is used for converting the voltage accessed by the CPEX interface into the voltage required by the operation of the switching device and supplying power to each module of the switching device.

Furthermore, 12V voltage is connected to one end of the DC-DC power conversion module, the 12V power supply is switched to 5V voltage and 3.3V voltage through two power conversion chips respectively, and the output ends of the 5V voltage and the 3.3V voltage are respectively connected with a resistor and a surface-mounted light emitting diode in series to signal ground for power supply indication;

the power conversion chip adopts a BL8033 domestic power chip of Shanghai Berlin Limited;

the 5V direct-current voltage and the 3.3V direct-current voltage of the two power conversion chips are respectively connected with 5V and 3.3V power networks of the switching device through JPB3216-800/4A type magnetic beads and are used for primary debugging isolation of a power supply and filtering of a normal working direct-current power supply.

Furthermore, the host communication and selection module comprises a serial interface for communicating with an external host, is used for receiving a switching control command sent by a host serial port, and simultaneously comprises an input of an IO selection signal, so that the switching device is in different working modes by configuring the high and low level states of the IO selection signal, thereby realizing the switching control of the switching device;

the host communication and selection module comprises two paths of serial interfaces and four paths of IO selection signal inputs;

the two serial interfaces are used for connecting an external host and the FPGA switching control module, and one transceiving chip is adopted for completing data transceiving level conversion; the communication serial port of the host adopts RS232 level standard, the conversion from RS232 to LVTTL level adopts ER3232SS domestic chip of a celestial light semiconductor, a single chip completes the data transceiving level conversion of two RS232 serial communication interfaces, and the converted LVTTL level serial port signal is connected to the FPGA switching control circuit;

the four paths of IO selection signals are input in a suspension state or connected with a signal ground, when the input is in the suspension state, an IO pull-up circuit arranged in the switching device forms a high level to be output to the FPGA switching control circuit, and when the input is connected with the signal ground, a low level is output to the FPGA switching control circuit.

Aiming at a special application scene, the host communication and selection circuit can be adaptively changed, when the host communication interface is required to have anti-electromagnetic interference capability or the host only has an RS422/RS485 interface, the level standard adopted by the host communication serial port can be changed from RS232 level to RS422/RS485 level, and at the moment, an ER3491SS domestic chip of a skylight semiconductor can be selected; when the input 4 paths of IO selection signals have LVTTL high level states compatible with the IO level of the FPGA chip, the switching device can cancel the built-in IO pull-up circuit.

Furthermore, the USB switching module includes a plurality of USB2.0 signal switching channels, and each USB2.0 signal switching channel selects one path of the input multiple paths of USB signals to be switched and output by using a bidirectional multiple-path switch selection chip;

the USB switching module is connected with the FPGA switching control module through an IO pin;

in this embodiment, the USB switching module uses a WAS4735Q chip made by a weil semiconductor, and includes four sets of USB2.0 signal switching channels with the same function, each USB signal switching channel uses a WAS4735Q chip, so that one input four channels of USB signals are switched and output, the switching control of the WAS4735Q chip is controlled by two common IO pins of the FPGA, and the switching control is realized by controlling different high and low level combinations of the two common IO pins.

Furthermore, the RS232 interface module includes a plurality of transceiver chips, each transceiver chip completes the conversion from two RS232 levels to the LVTTL level standard of the FPGA, and realizes an external RS232 signal path;

in the embodiment, the transceiver chip is an ER3232SS chip made of a celestial semiconductor; the RS232 interface module adopts 6 ER3232SS chips to realize 12 external RS232 signal paths;

the RS422 interface module comprises a plurality of transceiver chips, and each transceiver chip completes the conversion from one path of RS422 level to the LVTTL level standard of the FPGA to realize an external RS422 signal path;

in this embodiment, the transceiver chip is an ER3491SS chip made by a celestial semiconductor, and the RS422 interface module is implemented by 12 ER3491SS chips to implement external 12-channel RS422 signal paths;

each RS232 and RS422 signal channel can be customized as the serial port signal input of a host or as the serial port signal switching output, and the signal switching control is realized by an FPGA switching control chip;

in this embodiment, in the 12 paths of RS232 signal paths externally connected by the RS232 interface module, the four paths of signals are used to connect the four paths of RS232 serial ports of the host a, the four paths of signals are used to connect the four paths of RS232 serial ports of the host B, and the four paths of signals are used to switch and output the four paths of RS232 serial ports of the host a or the four paths of RS232 serial ports of the host B;

in 12 paths of RS422 signals externally connected by the RS422 interface module, four paths of signals are used for connecting four paths of RS422 serial ports of the host A, four paths of signals are used for connecting four paths of RS422 serial ports of the host B, and four paths of signals are used for switching and outputting the four paths of RS422 serial ports of the host A or the four paths of RS422 serial ports of the host B;

and the switching control of the RS232 and RS422 serial port signals is completed by an FPGA switching control chip.

Further, the PS2 interface module adopts a plurality of discrete components to realize conversion from the PS2 level to the LVTTL level standard of the FPGA;

in this embodiment, the PS2 interface module provides 10 PS2 interface paths, and the 10 PS2 interface paths have the same circuit connection mode, as shown in fig. 5:

the PS2 interface path of the signal switching device comprises a clock signal PS2_ CLK and a data signal PS2_ DAT, the PS2_ CLK and PS2_ DAT signals are respectively connected with FPGA _ CLK and FPGA _ DAT signals of a common IO pin of the FPGA chip through a first resistor R1 and a second resistor R2, the PS2_ CLK and PS2_ DAT signals are respectively connected with a 5V power supply network output by the power supply conversion module through a third resistor R3 and a fourth resistor R4, the FPGA _ CLK and FPGA _ DAT signals are respectively connected with a signal ground and a 3.3V power supply network output by the power supply conversion module through a first bidirectional diode V1 and a second bidirectional diode V2, and the voltage of the FPGA _ CLK and FPGA _ DAT signals is clamped between 0V and 3.3V.

In this embodiment, the resistances of the first resistor R1 and the second resistor R2 are 120 ohms, the resistances of the third resistor R3 and the fourth resistor R4 are 2K ohms, and the first bidirectional diode V1 and the second bidirectional diode V2 are BAT 54S-type domestic bidirectional diodes of yowa permat light;

in the 10 paths of PS2 interface channels, four paths of PS2 interfaces are used for connecting mouse interfaces of 4 paths of hosts, one path is used for connecting mouse equipment, and the mouse interfaces of the 4 paths of hosts are switched and connected to one path of mouse equipment; and the other four paths of PS2 interfaces are used for connecting keyboard interfaces of the 4 paths of hosts, one path of PS2 interfaces is used for connecting keyboard equipment, and the keyboard interfaces of the 4 paths of hosts are switched and connected to the path of keyboard equipment.

Further, with reference to fig. 3, the DVI switching module includes a DVI switching chip and an ESD protection chip;

the DVI switching chip is connected with the FPGA switching control module through an IO pin and is used for completing switching output selection control of a DVI input video channel of the PGA switching control module;

in this embodiment, the DVI switching chip selects the LT8642UX domestic chip of the dragon-news semiconductor, a single chip realizes the switching output of two selective paths in the four-path input DVI-D single-channel digital video to two DVI video output ports, the four-path input DVI-D digital video is used for receiving DVI video signals output by an external host, the two output DVI video signals are used for connecting display equipment, the FPGA chip outputs RS232 protocol serial signals of LVTTL level standard through two common IO pins, and is used for connecting the control port of the LT8642UX switching chip, and the switching output selection control of the input video channel is completed.

The switching from the input to the output DVI video channel of the LT8642UX chip not only comprises the switching of three pairs of differential data signals and one pair of differential clock signals related to DVI digital video data, but also comprises the synchronous switching of DDC communication signals of a DVI channel, and the LT8642UX chip reads EDID information of display equipment connected with the two paths of output DVI video channels and switches and outputs the EDID information to the selected two paths of input DVI video interfaces.

The ESD protection chips are respectively connected with the DVI input video channel of the FPGA switching control module and the DVI video output by the DVI switching chip for ESD protection;

in this embodiment, the ESD protection chip is an ESD5344D type domestic ESD protection chip manufactured by welr semiconductor, and performs ESD protection on four input DVI-D digital videos and two output DVI videos, three pairs of differential DATA signal lines DATA0+/-, DATA1+/-, DATA2 +/-and one pair of differential DATA clock signal lines DATA _ CLK +/-in each DVI-D digital video signal need to perform ESD protection, and a single ESD5344D chip can complete ESD protection on two pairs of differential signals, so that two ESD5344D chips are needed for each DVI-D digital video signal.

In addition, DDC communication signals of the four-input DVI-D digital video interface can be connected with the four-input DVI interface of the LT8642UX chip, and can also be directly connected with EEPROM chips of the four I2C interfaces in a mode of winding wire jumpers or adjusting the welding positions of series resistors, preset EDID information is stored in the EEPROM chips and is used for controlling a four-host computer to forcibly output DVI digital video signals with corresponding resolution according to the preset EDID information, the EEPROM chips are BL24C02 type I2C interface domestic EEPROM chips of Shanghai Beiling Bingshang corporation, DDC _ CLK signals of the DDC communication signals are connected with clock signals of the BL24C02 chips, and DDC _ DAT signals are connected with bidirectional data signals of the BL24C02 chips.

The DVI signal is a DVI-D single-channel digital video signal, each path of DVI-D digital video signal comprises three pairs of differential DATA signal lines DATA0+/-, DATA1+/-, DATA2+/-, and a pair of differential DATA clock signal lines DATA _ CLK +/-, and is used for transmitting DVI digital video DATA; a hot plug detection signal HPD for hot plug identification of DVI connector; a DDC communication data signal DDC _ DAT, and a DDC communication clock signal DDC _ CLK, DDC _ CLK signal and DDC _ DAT signal constitute a set of DDC communication signals, and the host recognizes information such as resolution of the display apparatus through the DDC communication signals of the DVI interface.

Further, with reference to fig. 4, the FPGA switching control module adopts a GW1N-9 type domestic FPGA chip of the guangdong high cloud semiconductor, the FPGA switching control chip receives a switching control command of the host communication and selection circuit, outputs a switching control signal to the DVI switching circuit and the USB switching circuit, switches signals after level conversion by the RS232 interface circuit and the RS422 interface circuit, and performs PS2 protocol matching identification and switching on signals passing through the PS2 interface circuit;

a GW1N-9 type domestic FPGA chip is internally provided with a FLASH unit, a serial interface part logic communicated with an external host is driven by an external 9.8304MHz crystal oscillator, all switching control logics and a protocol matching identification part logic of PS2 signals are driven by an external 25MHz crystal oscillator, and logic units driven by different crystal oscillators are communicated in an asynchronous mode.

The FPGA chip is internally provided with a signal debouncing module which is used for carrying out signal debouncing processing on an input IO selection signal of the host communication and selection circuit and filtering out signal dithering of the IO selection signal when the level jumps;

an RS232 protocol analysis module is arranged in the FPGA chip, and is used for carrying out protocol analysis on the host serial port signal after level conversion according to the RS232 communication protocol standard and outputting a received serial data bit stream;

the FPGA chip is internally provided with a communication instruction protocol analysis module which is used for analyzing a data format of a plurality of bytes formed by a serial data bit stream output by the RS232 protocol analysis module and identifying the instruction requirement of the byte data stream;

the FPGA chip is internally provided with a switching control module which is used for receiving the instruction requirement information output by the communication instruction protocol analysis module, receiving the selection signal output by the signal debouncing module and executing corresponding switching control action according to the requirement of a pre-designed working mode;

a DVI switching instruction data module is arranged in the FPGA chip, and the switching control requirement output by the switching control module is converted into a byte instruction data stream which can be identified by the DVI switching control chip;

an RS232 protocol generation module is arranged in the FPGA chip, a byte instruction data stream output by the DVI switching instruction data module is converted into a serial bit data stream according to an RS232 communication protocol standard, the process and the processing flow of the RS232 protocol analysis module are mutually inverse, and finally the serial bit data stream is output to the DVI switching chip through an IO pin of the FPGA;

a USB switching control signal module is arranged in the FPGA chip, switching requirements of the switching control module are converted into control signal IO levels which can be identified by the USB switching chip according to a control signal truth table of the USB switching chip, and the control signal IO levels are connected to the USB switching chip through an IO pin of the FPGA chip;

an RS232 signal switching module and an RS422 signal switching module are arranged in the FPGA chip, and corresponding input serial port signals and output serial port signal paths are connected according to the switching action requirements of the switching control module;

a PS2 switching control signal module is arranged in the FPGA chip, and switching output of the PS2 signal is executed according to the switching action requirement of the switching control module;

the FPGA chip is internally provided with a PS2 protocol generation module for protocol matching identification of the PS2 signal, executing power-on initial identification of the PS2 signal and solving the problem that the PS2 signal does not support the influence of hot plug on signal switching.

Fig. 6 is a schematic view of the appearance and interface of the switching device according to the embodiment of the present invention;

the external dimension of the circuit printed board is 233.35mm (length) × 160mm (width), the arrangement of the external connectors XP1 to XP8 conforms to the CPEX specification, the circuit power supply is taken from the XP 1-bit CPEX connector, and the 3.3V power supply is taken from the pins B1 to B4 of the XP1 connector; the 5V power supply is taken from pins C1 to C4 of the XP1 connector; the 12V power supply is taken from pins E1 to E4 and F1 to F4 of the XP1 connector; RS232, RS422 serial port signals and PS2 signals can be distributed in XP2 to XP8 connectors, and DVI and USB high-speed signals can be distributed in XP2, XP3 and XP5 to XP8 connectors.

In some embodiments, only the 12V power supply of the XP1 connector is used for DC-DC power conversion, the input and output signals of the RS232 interface circuit are located in the XP2 connector, the input and output signals of the RS422 interface circuit are located in the XP3 connector, the input and output signals of the PS2 interface circuit are located in the XP4 connector, the input and output signals of the USB switching circuit are located in the XP5 connector, and the input and output signals of the DVI switching circuit are located in XP 6-XP 8 connectors.

The signal switching device of the utility model can realize DVI, USB, RS232, RS422 and PS2 signal switching by a single device, and the number of signal interface paths can be expanded, and the switching function has stronger flexibility; and all chips adopt home-made chips, realize independently controllable, make auto-change over device possess stronger guarantee nature, when having improved auto-change over device localization rate, satisfy military use and industrial control field, show and control the switching control application demand of multiple interface of control device.

Claims (9)

1. A signal switching device based on 6U-CPEX standard is characterized by comprising a power supply conversion module, a host communication and selection module, an FPGA switching control module, a DVI switching module, a USB switching module, an RS232 interface module, an RS422 interface module and a PS2 interface module;

the FPGA switching control module is respectively connected with the host communication and selection module, the DVI switching module, the USB switching module, the RS232 interface module, the RS422 interface module and the PS2 interface module;

the power supply conversion module is used for converting an accessed power supply into a power supply required by the operation of the switching device and supplying power to each module of the switching device;

the host communication and selection module is used for receiving a switching instruction and an IO switching selection signal sent by an external host;

the FPGA switching control module is used for receiving a switching instruction of the host communication and selection module and sending the switching instruction to the DVI switching module, the USB switching module, the RS232 interface module, the RS422 interface module and the PS2 interface module;

the DVI switching module and the USB switching module are used for realizing DVI and USB signal switching; the RS232 interface module and the RS422 interface module are used for realizing the conversion of the signal level of the RS232 and RS422 serial ports; the PS2 interface module is used for realizing the conversion of PS2 signal level.

2. The signal switching device based on the 6U-CPEX specification according to claim 1, wherein one end of the power conversion module is connected to 12V voltage, and the 12V power is switched to 5V and 3.3V voltage through two power conversion chips, respectively, and the output ends of the 5V and 3.3V voltage are respectively connected in series with a resistor and a light emitting diode for power supply indication;

the 5V direct-current voltage and the 3.3V direct-current voltage of the two power conversion chips are respectively connected with a 5V power supply network and a 3.3V power supply network of the switching device through magnetic beads and are used for debugging and isolating a power supply and filtering a working direct-current power supply;

the power conversion chip adopts a BL8033 power chip.

3. The 6U-CPEX specification-based signal switching device of claim 1, wherein the host communication and selection module comprises two serial interfaces and four IO selection signal inputs;

the two serial interfaces are used for connecting an external host and the FPGA switching control module, and one transceiving chip is adopted for the two serial interfaces to complete data transceiving level conversion;

the four paths of IO selection signal inputs are suspended or connected with a signal ground;

the serial interface of the host communication and selection module adopts RS232 level standard, the conversion from RS232 to LVTTL level adopts ER3232SS chip, and a single chip completes the data transceiving level conversion of two RS232 serial communication interfaces.

4. The signal switching apparatus according to claim 1, wherein the USB switching module includes a plurality of USB2.0 signal switching channels, each USB2.0 signal switching channel selects one channel of the input multiple USB signals to be switched and output by using a bidirectional multi-channel switch selection chip;

the USB switching module is connected with the FPGA switching control module through an IO pin;

the bidirectional multi-way switch selection chip adopts a WAS4735Q chip.

5. The signal switching apparatus according to claim 1, wherein the RS232 interface module comprises a plurality of transceiver chips, each transceiver chip performs conversion from two RS232 levels to LVTTL level standards of an FPGA to implement an external RS232 signal path;

the RS422 interface module comprises a plurality of transceiver chips, and each transceiver chip completes the conversion from one path of RS422 level to the LVTTL level standard of the FPGA to realize an external RS422 signal path;

the transceiver chip of the RS232 interface module adopts an ER3232SS chip;

and the transceiver chip of the RS422 interface module adopts an ER3491SS chip.

6. The 6U-CPEX specification-based signal switching device according to claim 1, wherein the PS2 interface module adopts a plurality of discrete components to realize conversion from a PS2 level to an LVTTL level standard of an FPGA.

7. The 6U-CPEX specification-based signal switching apparatus of claim 1, wherein the DVI switching module comprises a DVI switching chip, an ESD protection chip;

the DVI switching chip is connected with the FPGA switching control module through an IO pin and is used for completing the switching output selection control of the DVI input video channel of the FPGA switching control module,

the ESD protection chips are respectively connected with the DVI input video channel of the FPGA switching control module and the DVI video output by the DVI switching chip for ESD protection;

the DVI switching chip adopts an LT8642UX chip, and the ESD protection chip adopts an ESD5344D chip.

8. The 6U-CPEX specification-based signal switching device of claim 7, wherein the DVI switching module comprises a plurality of EEPROM chips, the EEPROM chips are respectively connected with the FPGA switching control module, receive DVI digital video data output by the FPGA switching control module, and output DVI digital video signals with corresponding resolution according to EDID information preset by the chips.

9. The 6U-CPEX specification-based signal switching device of claim 1, wherein the FPGA switching control module adopts a GW1N-9 type FPGA chip.

Images