Multiplexing device and switching system

Abstract

The invention discloses a multiplexing device and a switching system, relates to the field of circuits, and aims to solve the problem that when a device selection signal is in a preset state, a configuration capacitor starts to be charged and the configuration capacitor is charged, communication channels corresponding to all sub-devices are disconnected and cannot transmit information with a main device. The main device detects disconnection of the sub-device through the state; and after the voltage of the configuration capacitor reaches the preset voltage, the multiplexing module controls the communication channel corresponding to the required target sub-equipment to be switched on according to the equipment selection signal, and switching of the sub-equipment is completed. The switching time of the sub-device is adjusted to be in an external adjustable setting mode through the configuration capacitor, and the main device is helped to complete judgment of disconnection and connection recovery of the sub-device through the charging process of the configuration capacitor, so that the main device can adjust an output signal of the main device according to the currently connected sub-device. Compatibility between the output signal and the sub-device is realized, and accurate information transmission between the main device and the corresponding sub-device is ensured.

Description

Technical Field

[0001] The present invention relates to the field of circuits, and particularly to a multiplexing device and a switching system. Background Art

[0002] With the continuous progress of technology, various video source devices and display devices are increasing day by day. Users hope to flexibly view the content of different video sources on a limited display device. Therefore, the video switching multiplexer has emerged. It can realize the sharing of a display device by multiple video sources or the distribution of a single video source to multiple display devices for simultaneous display by switching video signals, avoiding the frequent plugging and unplugging of the connection lines between the video source and the display device. Taking the sharing of a display device by multiple video sources as an example, when switching the display device, the communication connection between the currently used display device and the video source device will be disconnected first, and then after waiting for a certain switching time, another display device to be switched will be controlled to establish a communication connection with the video source device, thus completing the switching between the two display devices. At the same time, a power supply module is also set in the peripheral circuit of the video switching multiplexer. When the video source device detects that there is a connection with the display device, it will control the power supply module to supply power to the display device so that the display device can normally send signals to the video source device, and generate a high-level hot plug detection signal based on this power supply to inform the video source device that there is currently a display device connected to it, so that the video source device can obtain information such as the performance parameters and hot plug detection signal of the display device when the display device is not powered on.

[0003] In the prior art, a fixed switching time is built into the video switching multiplexer. The size of the switching time is usually about a dozen microseconds. When actually switching the display device, because this switching time is very short, the video source device will re-obtain the hot plug detection signal of another display device in a short time, resulting in the hot plug detection signal received by the video source device always being high level, unable to accurately judge the disconnection of the display device and whether there is a new device connected, thus resulting in a situation where the output signal is incompatible with the actually connected display device, causing phenomena such as screen flickering or flashing of the display device. Summary of the Invention

[0004] The purpose of the present invention is to provide a multiplexing device and a switching system, which use the charging process of a configured capacitor to help the master device complete the judgment of the disconnection and reconnection of the slave device, so that the master device can adjust its own output signal according to the currently connected slave device, realize the compatibility between the output signal and the slave device, and ensure accurate information transmission between the master device and the corresponding slave device.

[0005] To solve the above technical problems, the present invention provides a multiplexing device, including:

[0006] A multiplexing module, with a first data terminal connected to a main device and a second data terminal respectively connected to a plurality of sub-devices;

[0007] A configuration capacitor, with a first end connected to a configuration pin of the multiplexing module and a second end grounded;

[0008] The multiplexing module is used to start charging the configuration capacitor when a preset state of a device selection signal is detected, stop charging when the voltage of the configuration capacitor has not reached a preset voltage and the preset state of the device selection signal is detected again or when the voltage of the configuration capacitor reaches the preset voltage; and control the disconnection of the communication channel between itself and all the sub-devices when the configuration capacitor is in a charging state and the voltage of the configuration capacitor has not reached the preset voltage; when the voltage of the configuration capacitor reaches the preset voltage, select a corresponding communication channel to conduct from a plurality of the sub-devices according to the received device selection signal, so as to switch the sub-device for information transmission with the main device.

[0009] Optionally, the multiplexing module includes:

[0010] An enable signal generation module, with an input terminal receiving the device selection signal and signal output terminals respectively connected to the enable terminals of the communication channels corresponding to each of the sub-devices;

[0011] A delay module, with an input terminal connected to the logic output terminal of the enable signal generation module, a first output terminal connected to the control terminal of the enable signal generation module, and a second output terminal connected to the first end of the configuration capacitor, used to start charging the configuration capacitor when a preset state of the device selection signal is detected, and output a flip signal to the enable signal generation module when the voltage of the configuration capacitor reaches the preset voltage; discharge the configuration capacitor when the voltage of the configuration capacitor has not reached the preset voltage and the preset state of the device selection signal is detected again or when the device selection signal is not detected;

[0012] The enable signal generation module is used to control the disconnection of the initially-conducted communication channel when a preset state of the device selection signal is detected, and control the conduction of the target communication channel according to the device selection signal when receiving the flip signal; when not receiving the flip signal and detecting the preset state of the device selection signal again, control the conduction of the initially-conducted communication channel.

[0013] Optionally, the delay module includes:

[0014] A charging switch, whose control terminal is connected to the logic output terminal of the enable signal generation module, and whose first terminal is connected to a first preset power supply, is used to conduct based on the control of the enable signal generation module when the enable signal generation module detects a preset state of the device selection signal, and to turn off when the enable signal generation module receives a flip signal or when the enable signal generation module does not receive the flip signal and detects the preset state of the device selection signal again;

[0015] A discharging switch, whose first terminal is grounded and whose control terminal is connected to the logic output terminal of the enable signal generation module, is used to turn off based on the control of the enable signal generation module when the enable signal generation module detects a preset state of the device selection signal, and to conduct when the enable signal generation module receives a flip signal or when the enable signal generation module does not receive the flip signal and detects the preset state of the device selection signal again;

[0016] A comparison module, whose first input terminal is respectively connected to the second terminal of the charging switch and the second terminal of the discharging switch, and whose second input terminal is connected to a preset voltage, is used to output a first level signal as a flip signal when the voltage of the configuration capacitor reaches the preset voltage, and to output a second level signal when the voltage of the configuration capacitor does not reach the preset voltage; the first level signal and the second level signal are opposite.

[0017] Optionally, the delay module further includes:

[0018] A constant current source, whose input terminal is connected to the first preset power supply and whose output terminal is connected to the first terminal of the charging switch, is used to output a preset current to charge the configuration capacitor when the charging switch conducts.

[0019] Optionally, it further includes:

[0020] A power supply module, whose input terminal is connected to the power supply pin of the main device, whose first output terminal is connected to the power supply pin of the multiplexing module, and whose second output terminal is respectively connected to the power supply pins of each sub-device, is used to supply power to the multiplexing module and each sub-device when the main device is powered on;

[0021] Both the sub-device and the main device include hot-swap detection pins;

[0022] The hot-swap detection pin of the sub-device is used to generate a detection signal based on the power supply of the power supply module;

[0023] The hot-swap detection pin of the main device is used to obtain the detection signal based on the communication channel between itself and the multiplexing module and the communication channels that are in a conducting state between the multiplexing module and each sub-device, so as to obtain the connection state of the sub-device.

[0024] Optionally, it further includes:

[0025] A selection signal generation module, whose output terminal is connected to the device selection pin of the multiplexing module, and is used to generate a device selection signal.

[0026] Optionally, the selection signal generation module includes:

[0027] A self - recovery button, which is used to conduct when pressed;

[0028] A first controllable switch, whose first terminal is connected to the device selection pin of the multiplexing module;

[0029] A first capacitor, whose first terminal is connected to a second preset power supply, and is respectively connected to the first terminal of the self - recovery button and the second terminal of the first controllable switch, and is used to charge based on the second preset power supply when the first controllable switch is turned off, and discharge when the self - recovery button conducts;

[0030] A second controllable switch, whose first terminal is connected to the control terminal of the first controllable switch, and is used to conduct when the first controllable switch is turned off and the self - recovery button conducts, so as to control the first controllable switch to conduct; and turn off when the first controllable switch conducts and the self - recovery button conducts, so as to control the first controllable switch to turn off;

[0031] A first resistor, whose first terminal is connected to the first terminal of the first controllable switch;

[0032] A second resistor, whose first terminal is respectively connected to the second terminal of the self - recovery button, the second terminal of the first resistor, and the control terminal of the second controllable switch;

[0033] A third resistor, whose first terminal is respectively connected to the second terminal of the first capacitor, the second terminal of the second resistor, and the second terminal of the second controllable switch, and the second terminal is grounded.

[0034] Optionally, the selection signal generation module further includes:

[0035] A pull - down resistor, whose first terminal is respectively connected to the first terminal of the first resistor, the first terminal of the first controllable switch, and the device selection pin of the multiplexing module, and the second terminal is grounded;

[0036] And / or,

[0037] A bias resistor, whose first terminal is connected to the second terminal of the first controllable switch, and the second terminal is connected to the control terminal of the first controllable switch.

[0038] Optionally, the selection signal generation module further includes:

[0039] A voltage dividing circuit, with its first input terminal connected to a second preset power supply and also connected to the second terminal of the first controllable switch, its second input terminal grounded, and its output terminal connected to the first terminal of the self - recovery button and the first terminal of the first capacitor;

[0040] and / or,

[0041] A second capacitor, with its first terminal connected to the second terminal of the self - recovery button, the second terminal of the first resistor, the first terminal of the second resistor, and the control terminal of the second controllable switch respectively, and its second terminal connected to the second terminal of the first capacitor, the second terminal of the second resistor, the first terminal of the third resistor, and the second terminal of the second controllable switch respectively.

[0042] To solve the above - mentioned technical problems, the present invention also provides a switching system, which includes a main device, a multiplexing device as described above, and several sub - devices. The main device is connected to the several sub - devices through the multiplexing device.

[0043] The present invention provides a multiplexing device, which includes a multiplexing module and a configuration capacitor connected to the multiplexing module. The multiplexing module switches the sub - device for information transmission with the main device by detecting a device selection signal. When the multiplexing module detects a preset state of the device selection signal, the configuration capacitor starts to charge, and then determines the moment of sub - device switching by detecting the voltage of the configuration capacitor. At the same time, during the entire charging process of the configuration capacitor, the communication channels corresponding to all sub - devices are in a disconnected state and cannot perform information transmission with the main device, so that the main device can detect the disconnection of the sub - device through this signal interruption situation; after the voltage of the configuration capacitor reaches the preset voltage, the multiplexing module then controls the communication channel corresponding to the target sub - device to be switched on according to the device selection signal, thereby completing the switching of the sub - device, and the main device can also detect the connection of the new device according to the restored transmission signal. By adjusting the switching time of the sub - device to an externally adjustable setting method through the configuration capacitor, and using the charging process of the configuration capacitor to help the main device complete the judgment of the disconnection and re - connection of the sub - device, the main device can adjust its own output signal according to the currently connected sub - device, realize the compatibility between the output signal and the sub - device, and ensure accurate information transmission between the main device and the corresponding sub - device.

[0044] The present invention also provides a switching system, which has the same beneficial effects as the above - mentioned multiplexing device. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] To more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required in the prior art and the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0046] Figure 1 Structural schematic diagram of a multiplexing device provided by the present invention;

[0047] Figure 2 Structural schematic diagram of an HDMI switch provided by the present invention;

[0048] Figure 3 Channel switching timing diagram in the first HDMI switch provided by the present invention;

[0049] Figure 4 Channel switching timing diagram in the second HDMI switch provided by the present invention;

[0050] Figure 5 Channel switching timing diagram in the third HDMI switch provided by the present invention;

[0051] Figure 6 Schematic diagram of the linear relationship between the switching time and the capacitance value of the configuration capacitor provided by the present invention;

[0052] Figure 7 Structural schematic diagram of a multiplexing module provided by the present invention;

[0053] Figure 8 Structural schematic diagram of a delay module provided by the present invention;

[0054] Figure 9 Structural schematic diagram of a selection signal generation module provided by the present invention. Detailed implementation manners

[0055] The core of the present invention is to provide a multiplexing device and a switching system. By configuring a capacitor, the switching time of the sub-device is adjusted to an externally adjustable setting method. At the same time, the charging process of the configured capacitor is used to help the main device complete the judgment of disconnecting and reconnecting the sub-device, so that the main device can adjust its output signal according to the currently connected sub-device, realize the compatibility between the output signal and the sub-device, and ensure accurate information transmission between the main device and the corresponding sub-device.

[0056] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0057] Please refer to Figure 1 , Figure 1 which is a schematic structural diagram of a multiplexing device provided by the present invention; please refer to Figure 2 , Figure 2 which is a schematic structural diagram of an HDMI switch provided by the present invention; To solve the above technical problems, the present invention provides a multiplexing device, including:

[0058] A multiplexing module SW, with its first data terminal connected to the master device M and its second data terminal respectively connected to a plurality of slave devices S;

[0059] A configuration capacitor C0, with its first end connected to the configuration pin CTBBM of the multiplexing module SW and its second end grounded;

[0060] The multiplexing module SW is used to start charging the configuration capacitor C0 when detecting a preset state of the device selection signal, stop charging when the voltage of the configuration capacitor C0 has not reached the preset voltage and the preset state of the device selection signal is detected again or when the voltage of the configuration capacitor C0 reaches the preset voltage; and control the disconnection of the communication channel between itself and all slave devices S when the configuration capacitor C0 is in the charging state and the voltage of the configuration capacitor C0 has not reached the preset voltage; when the voltage of the configuration capacitor C0 reaches the preset voltage, select the corresponding communication channel to conduct from a plurality of slave devices S according to the received device selection signal to switch the slave device S for information transmission with the master device M.

[0061] It is not difficult to understand that the multiplexing device provided by the present invention is applied in a one-to-many circuit architecture. Here, "one" refers to a main device M, and "many" refers to several sub-devices S. The main device M can be respectively connected to each sub-device S to achieve different operations. The multiplexing module SW is arranged between the main device M and the sub-devices S. The first data terminal is connected to the main device M, and a communication connection is established with the main device M through a communication channel. The second data terminal is respectively connected to each sub-device S, and an independent communication connection is established with each sub-device S through a communication channel. In actual application, the multiplexing module SW switches the sub-device S connected to the main device M according to requirements by controlling the conduction or disconnection of the communication connections corresponding to each sub-device S. To help the main device M accurately identify the connection switching of the sub-device S, the present invention adds a configuration pin CTBBM to the multiplexing module SW, and a grounded configuration capacitor C0 is connected to the configuration pin CTBBM. If the device selection signal appears in a preset state, it indicates that the switching of the sub-device S needs to be performed at this time, that is, disconnect the sub-device S currently connected to the main device M, and select the target sub-device S required currently to establish a connection with the main device M. When the multiplexing module SW detects the preset state of the device selection signal, it will first start charging the configuration capacitor C0, and at the same time control the communication channels between the multiplexing module SW itself and all sub-devices S to be disconnected, so as to disconnect the currently connected sub-device S. At this time, the main device M cannot transmit information with any sub-device S, and can effectively detect the disconnection of the sub-device S. Then the multiplexing module SW continuously detects the voltage across the configuration capacitor C0. Once the voltage of the configuration capacitor C0 reaches the preset voltage, it will determine the required target sub-device S according to the current state of the device selection signal, and control the conduction of the communication channel corresponding to the target sub-device S to establish a connection between the target sub-device S and the main device M, thus completing the entire process of sub-device S switching.

[0062] It can be understood that through the setting of the configuration capacitor C0, the switching time t during the switching of the sub-device S is achieved by the time required for the configuration capacitor C0 to be charged. BBM(also known as the break-before-make time), and uses the charging time of the capacitor to control the disconnection of the communication channels corresponding to all sub-devices S, helping the master device M to identify the disconnection of the sub-devices S. If after the multiplexing module SW configures the capacitor C0 to start charging, and before the voltage of the capacitor C0 reaches the preset voltage, the preset state of the device selection signal is detected again, it means that the preset state of the device selection signal is caused by factors such as abnormal jitter. For example, when the device selection signal is controlled by a self-locking button or a self-recovery button J11, the jitter of the button causes the device selection signal to briefly stay at a low level and then return to a high level state. This is not a normal signal that needs to control the switching. At this time, there is no need to configure the capacitor C0 to continue charging to control the switching of the sub-devices S. Therefore, it is necessary to discharge the capacitor C0 to release the energy stored during the charging of the capacitor C0, and restore the connection between the previously disconnected sub-devices S and the master device M, that is, restore the conduction of the communication channels corresponding to the sub-devices S connected to the master device M before the capacitor starts charging. At the same time, in order to facilitate the adjustment of the switching time, the capacitor C0 is set outside the multiplexing module SW and can be connected to the multiplexing module SW through the configuration pin CTBBM.

[0063] It should be noted that the device selection signal is used to represent the connection status of each sub-device S for the current application requirements, and the preset state of the device selection signal represents a change in the connection status of the sub-device S; the sub-device S connected to the master device M refers to the sub-device S whose communication connection with the master device M is turned on and can perform information transmission. The specific types and implementation methods of the multiplexing module SW, the master device M, and the sub-device S are not particularly limited in this application. The multiplexing module SW can be specifically implemented by means of a multiplexer, a multiplexing chip, or a demultiplexer chip, etc., such as the ASW3642 chip. The master device M and the sub-device S can be selected according to the actual application scenario and application requirements. When the multiplexing device is applied in a computer, functions such as switching multiple video sources to the same display terminal or switching multiple display terminals to a single computer can be realized through the multiplexing device. For example, an HDMI (High-Definition Multimedia Interface) two-in-one or one-in-two bidirectional switch can be realized based on the multiplexing device. The specific implementation method of the communication channel is not particularly limited in this application and can be realized by means of communication cables, etc. When the multiplexing device is realized as an HDMI switch, the communication channel is preferably realized in a way that supports bidirectional transmission of HDMI2.0 4K@120Hz signals. The specific setting method of the first data terminal and the second data terminal of the multiplexing module SW needs to be set and selected according to the specific type of the corresponding master device M or sub-device S. The specific number of sub-devices S set can also be designed according to the actual application.

[0064] Further, when the device selection signal does not appear in a preset state, the multiplexing module SW will maintain the conduction or disconnection of the communication channels corresponding to each sub-device S according to the device selection signal. The specific types and implementation manners of the device selection signal and the preset state are not particularly limited in this application. It can be implemented by using a level signal and the corresponding rising edge or falling edge. When the configuration capacitor C0 is not charged, the multiplexing module SW directly maintains the connection or disconnection of the two sub-devices S according to the detected level state of the device selection signal.

[0065] It can be understood that the specific implementation manner of the conduction or disconnection of the communication channel is not particularly limited in this application. Specifically, the communication channel can be disconnected by controlling the communication channel to maintain a high-impedance state. As a specific embodiment, please refer to Figure 3 , Figure 3 which is the channel switching timing diagram in the first HDMI switch provided by the present invention; please refer to Figure 4 , Figure 4 which is the channel switching timing diagram in the second HDMI switch provided by the present invention; please refer to Figure 5 , Figure 5 which is the channel switching timing diagram in the third HDMI switch provided by the present invention; taking the number of sub-devices S as 2, the low level of the device selection signal indicating the connection between the first sub-device S and the main device M, and the high level of the device selection signal indicating the connection between the second sub-device S and the main device M as an example, the preset voltage is defined as 1V, all communication channels corresponding to the first sub-device S are defined as Channel A, and all communication channels corresponding to the second sub-device S are defined as Channel B. When the channel selection pin SEL2 of the multiplexing module SW receives the device selection signal, when the multiplexing module SW detects the level change of the channel selection pin SEL2 (from low level to high level or from high level to low level), the multiplexing module SW will charge the configuration capacitor C0 connected to the configuration pin CTBBM (CTBBM pin) with a current of 10 μA, and at the same time adjust both Channel A and Channel B to a high-impedance state (Hi-Z). When the voltage on the CTBBM pin reaches 1V, Channel A will change from the high-impedance state to the conduction state (ON). As shown in Figure 3 , during the period when the voltage on the CTBBM pin does not reach 1V, all Channel A and Channel B will be in a high-impedance state, as shown in Figure 4 and Figure 5 . The high-impedance state can also effectively filter out the glitch signals on the selection pin SEL2.

[0066] It should be noted that, in the present invention, by adding an external pin CTBBM and a corresponding connected configuration capacitor C0, the break-before-make time of the multiplexer or demultiplexer chip for video switching is changed from being internally fixed to being externally adjustable, and the break-before-make time is directly determined by the external capacitance value. The specific type and capacitance value of the configuration capacitor C0 are not particularly limited in this application. The value of the preset voltage also needs to be set according to the specific implementation manner of the configuration capacitor C0 and the charging implementation manner of the multiplexing module SW, which is not particularly limited in this application. Please refer to Figure 6 , Figure 6 is a schematic diagram of the linear relationship between the switching time and the capacitance value of the configuration capacitor C0 provided by the present invention; the abscissa represents capacitance values of different magnitudes, and the ordinate is the break-before-make time of the communication channel. When the CTBBM pin is floating, the break-before-make time is the default value, approximately several microseconds to dozens of microseconds; when a 1uF capacitor is externally connected to the CTBBM pin, the break-before-make time is approximately 100 milliseconds. When a 2.2uF capacitor is externally connected to the CTBBM pin, the break-before-make time is approximately 220 milliseconds.

[0067] As a specific embodiment, the circuit architecture when implementing a two-in-one-out or one-in-two-out bidirectional HDMI switch using the multiplexing device provided in this application is as Figure 2As shown, the computer Connector 0 serves as the master device M, and the display device Connector 1 and the display device Connector 2 serve as two slave devices S. Both the master device M and the slave devices S are connected to the multiplexing module SW via HDMI. When the SEL2 pin is at a low level, the display device Connector 1 is connected to the master device M. When the SEL2 pin is at a high level, the display device Connector 2 is connected to the master device M. The first data terminal of the multiplexing module SW includes 12 data pins: D0+, D0-, D1+, D1-, D2+, D2-, D3+, D3-, SCL, SDA, HPD, CEC. The second data terminal includes 12 data pins connected to the display device Connector 1: D0+A, D0-A, D1+A, D1-A, D2+A, D2-A, D3+A, D3-A, SCL_A, SDA_A, HPD_A, CEC_A, and 12 data pins connected to the display device Connector 2: D0+B, D0-B, D1+B, D1-B, D2+B, D2-B, D3+B, D3-B, SCL_B, SDA_B, HPD_B, CEC_B. All communication channels corresponding to the display device Connector 1 are defined as Channel A, and all communication channels corresponding to the display device Connector 2 are defined as Channel B. The configuration capacitor C0 is set to 1 uF, and the break-before-make time is correspondingly set to 100 milliseconds. When the SEL2 pin changes from a low level to a high level, all Channel A and Channel B will be in a high-impedance state, that is, all Channel A and Channel B are in a completely disconnected state and last for 100 milliseconds. During this period, although the computer shares the same +5V power supply (V5V_COM) with the display device Connector 1 and the display device Connector 2, and the HPD_A and HPD_B corresponding to the display device Connector 1 and the display device Connector 2 are both at a high level under the action of the power supply, since all Channel A and Channel B are in a completely disconnected state, the HPD signal on the computer side is still at a low level. Therefore, the computer determines that the HDMI connection between the display device Connector 1 and the computer has been disconnected, and the TMDS signal transmission circuit (a digital video signal transmission circuit) in the computer graphics card stops working and lasts for 100 milliseconds.After 100 milliseconds, all A channels are in a high-impedance state, and all B channels are in a conducting state. The computer detects that HPD_B is at a high level, determines that the display device Connector 2 is connected to the computer via HDMI, and reads the EDID data (Extended Display Identification Data) in the display device through the DDC channels (Display Data Channel) corresponding to pins 15 and 16 of the HDMI interface, and enables the TMDS signal transmission circuit in the computer graphics card to start working.

[0068] When the SEL2 pin changes from a high level to a low level, all A channels and B channels will be in a high-impedance state and last for 100 milliseconds. During this period, although the computer shares the same +5V power supply (V5V_COM) with the display device Connector 1 and the display device Connector 2, and HPD_A and HPD_B of the display device Connector 1 and the display device Connector 2 are both at a high level, since all A channels and B channels are in a completely disconnected state, the HPD signal on the computer side is still at a low level. The computer determines that the HDMI connection between the display device and the computer has been disconnected, and the TMDS signal transmission circuit in the computer graphics card stops working and lasts for 100 milliseconds. After 100 milliseconds, all B channels are in a high-impedance state, and all A channels are in a conducting state. When the computer (graphics card controller) detects that HPD_A is at a high level, it determines that the display device Connector 1 is connected to the computer via HDMI, reads the EDID data in the display device through the DDC channels (connected to the I2C bus) corresponding to pins 15 and 16 of the HDMI interface, and enables the TMDS signal transmission circuit in the computer graphics card to start working.

[0069] The present invention provides a multiplexing device. By setting the configuration pin CTBBM and the corresponding configuration capacitor C0 connected thereto to configure the CTBBM function for the multiplexing module SW, adjustable control of the switching time during device switching of the multiplexing module SW is realized. It is possible to adjust and control the device switching time without an external processor or the like, saving costs, improving the flexibility of the entire multiplexing device, and expanding the applicable range of the multiplexing device. Using the charging of the configuration capacitor C0 corresponding to the switching time to control the disconnection of the communication channels corresponding to all sub-devices S, thereby helping the main device M to accurately identify the connection state of the sub-devices S and ensuring the accuracy and reliability of the operation of the main device M.

[0070] Based on the above embodiments:

[0071] Please refer to Figure 7 ,Figure 7 Schematic diagram of a multiplexing module provided by the present invention; As an alternative embodiment, the multiplexing module SW includes:

[0072] An enable signal generation module 11, with its input terminal connected to the device selection signal, and its signal output terminals respectively connected to the enable terminals of the communication channels corresponding to each sub-device S;

[0073] A delay module 12, with its input terminal connected to the logical output terminal of the enable signal generation module 11, its first output terminal connected to the control terminal of the enable signal generation module 11, and its second output terminal connected to the first terminal of the configuration capacitor C0, for starting to charge the configuration capacitor C0 when a preset state of the device selection signal is detected, and outputting a flip signal to the enable signal generation module 11 when the voltage of the configuration capacitor C0 reaches the preset voltage; Discharging the configuration capacitor C0 when the voltage of the configuration capacitor C0 does not reach the preset voltage and the preset state of the device selection signal is detected again or the preset state of the device selection signal is not detected;

[0074] The enable signal generation module 11 is used to control the disconnection of the initially conducting communication channel when a preset state of the device selection signal is detected, and control the conduction of the target communication channel according to the device selection signal when receiving the flip signal; When the flip signal is not received and the preset state of the device selection signal is detected again, control the conduction of the initial communication channel.

[0075] It is not difficult to understand that the multiplexing module SW specifically includes an enable signal generation module 11 and a delay module 12. The enable signal generation module 11 is used to identify the device selection signal and generate enable signals for outputting the communication channels corresponding to each sub-device S through the preset control logic corresponding to the device selection signal. Generally speaking, when the enable signal output by the enable signal generation module 11 to the communication channel is at a high level, it means enabling the communication channel, that is, controlling the communication channel to conduct. When the enable signal output by the enable signal generation module 11 to the communication channel is at a low level, it means disabling the communication channel, that is, controlling the communication channel to disconnect. The delay module 12 is used to implement the charging and discharging of the configuration capacitor C0 and the detection of the voltage of the configuration capacitor C0, and then determine whether to output a flip signal to the enable signal generation module 11 according to the voltage of the configuration capacitor C0; under normal circumstances, the enable signal generation module 11 controls the enabling or disabling of the communication channels corresponding to each sub-device S through the received device selection signal. When it is necessary to switch the sub-device S, that is, to switch the communication channel to be conducted, the enable signal corresponding to the communication channel to be disconnected first will respond immediately and immediately control the communication channel corresponding to the sub-device S currently connected to the main device M to disconnect. However, the enable signal corresponding to the next communication channel to be conducted, that is, the target communication channel to be conducted according to the current application requirement, will respond after receiving the flip signal, and there will be a certain delay in the conduction of the communication channel. Taking the high level as an example to represent the enable of the communication channel, if the device selection signal indicates that a certain communication channel needs to be switched from the conducting state to the disconnecting state, the corresponding enable signal output by the enable signal generation module 11 will immediately change from the high level to the low level; if the device selection signal indicates that a certain communication channel needs to be switched from the disconnecting state to the conducting state, the corresponding enable signal output by the enable signal generation module 11 needs to change from the low level to the high level after receiving the flip signal, so as to realize the conduction delay of the target communication channel to be conducted when the sub-device S is normally switched.

[0076] Further, if the delay module 12 has started working, that is, the configuration capacitor C0 has started charging, but before the voltage of the configuration capacitor C0 reaches the preset voltage, the preset state of the device selection signal is detected again, the delay module 12 will control the configuration capacitor C0 to discharge and stop the delay timing. At this time, the enable signal generation module 11 will not receive the flip signal, and the preset state of the device selection signal is detected again, then the communication channel is controlled to restore the previous state, that is, the communication channel disconnected when the preset state of the device selection signal was first detected is restored to the conducting state again. This is not a normal switchover and no delay timing is required. The specific type and implementation manner of the delay module 12 are not particularly limited in this application. The specific type and implementation manner of the enable signal generation module 11 and the enable signal are not limited to the implementation manner of this embodiment, and are not particularly limited in this application. In the enable signal generation module 11, the delay control of the enable signal can be specifically implemented by setting an AND gate or the like. The flip signal output by the delay module 12 and the transition of the device selection signal are used as the two inputs of the AND gate, and the switching signal is output through the AND gate to indicate the conduction of the target communication channel, achieving a delay effect.

[0077] As a specific embodiment, such as Figure 7As shown in the figure, taking the case where the low level of the device selection signal of the device selection signal represents the connection between the first sub-device S and the master device M, and the high level of the device selection signal represents the connection between the second sub-device S and the master device M as an example, all communication channels corresponding to the first sub-device S are defined as Channel A, and all communication channels corresponding to the second sub-device S are defined as Channel B. The enable signal generation module 11 outputs an enable signal for Channel A to control the conduction or disconnection of Channel A, and outputs an enable signal for Channel B to control the conduction or disconnection of Channel B. The rising edge or falling edge of the device selection signal, that is, the transition of the device selection signal, is used as the trigger signal for starting the switching of the sub-device S. After the device selection signal (SEL2) is triggered, if the device selection signal changes from low level to high level, the enable signal for Channel A immediately changes from high level to low level, and the enable signal for Channel B remains low level unchanged. The delay module 12 starts to perform delay timing. If the continuous transition time of the device selection signal is not less than the set break-then-make time, the configuration capacitor C0 can be normally charged to the preset voltage, and the delay module 12 normally outputs a flip signal to the enable signal generation module 11. After receiving the flip signal, the enable signal generation module 11 controls the enable signal for Channel B to change from low level to high level, that is, the enable signal for Channel B changes after a period of delay under the action of the delay module 12; if during the delay process, the continuous transition time of the device selection signal is less than the set break-then-make time, the enable signal generation module 11 will control the enable signal for Channel A to immediately jump to high level when detecting the second transition of the device selection signal, and the enable signal for Channel B remains low level unchanged. If the device selection signal changes from high level to low level, the enable signal for Channel B immediately changes from high level to low level, and the enable signal for Channel A changes from low level to high level after a period of delay under the action of the delay module 12; if during the delay process, the continuous transition time of the device selection signal is less than the set break-then-make time, the enable signal generation module 11 will control the enable signal for Channel B to immediately jump to high level when detecting the second transition of the device selection signal, and the enable signal for Channel A remains low level unchanged. The continuous transition time of the device selection signal refers to the duration between two consecutive transitions of the device selection signal, and the delay time of the delay module 12 is determined by the size of the configuration capacitor C0 externally connected to the multiplexing module SW.

[0078] Specifically, by setting the enable signal generation module 11 to detect the state of the device selection signal in real time, and then using the delay module 12 to control the delay of the enable signal corresponding to the communication channel to be conducted, a certain time reaction is provided for the master device M to detect the disconnection of the sub-device S, and the effective control of the communication channel is realized through the output of the enable signal. The circuit topology is simple and easy to implement.

[0079] Please refer to Figure 8 ,Figure 8 Schematic structural diagram of a delay module provided by the present invention; As an alternative embodiment, the delay module 12 includes:

[0080] A charging switch S1, whose control terminal is connected to the logic output terminal of the enable signal generation module 11, and the first terminal is connected to the first preset power supply V DD connected, for controlling based on the enable signal generation module 11, and conducting when the enable signal generation module 11 detects a preset state of the device selection signal, and turning off when the enable signal generation module 11 receives a flip signal or the enable signal generation module 11 does not receive a flip signal and detects the preset state of the device selection signal again;

[0081] A discharging switch S2, whose first terminal is grounded and the control terminal is connected to the logic output terminal of the enable signal generation module 11, for controlling based on the enable signal generation module 11, and turning off when the enable signal generation module 11 detects a preset state of the device selection signal, and conducting when the enable signal generation module 11 receives a flip signal or the enable signal generation module 11 does not receive a flip signal and detects the preset state of the device selection signal again;

[0082] A comparison module, whose first input terminal is respectively connected to the second terminal of the charging switch S1 and the second terminal of the discharging switch S2, and the second input terminal is connected to a preset voltage Vref, for outputting a first level signal as a flip signal when the voltage of the configuration capacitor C0 reaches the preset voltage Vref, and outputting a second level signal when the voltage of the configuration capacitor C0 does not reach the preset voltage Vref; The first level signal and the second level signal are opposite.

[0083] It can be understood that considering that the delay module 12 needs to achieve delay timing through the charging and discharging of the configuration capacitor C0, a charging switch S1 and a discharging switch S2 connected to the configuration capacitor C0 are provided in the delay module 12 to respectively control the charging and discharging of the configuration capacitor C0. When the charging switch S1 conducts, the first preset power supply V DDIt is possible to charge the configuration capacitor C0 through the conducting charging switch S1. The larger the capacitor, the longer the charging time required. When the discharging switch S2 conducts, the voltage across the configuration capacitor C0 can release energy through the grounded discharging switch S2. At the same time, the delay module 12 also needs to detect the voltage of the configuration capacitor C0 to generate a flip signal. Therefore, a comparison module is also set in the delay module 12. The comparison module directly compares the voltage of the configuration capacitor C0 with the preset voltage Vref and outputs a corresponding level signal, and directly uses the level signal output by the comparison module as the flip signal. The specific types and implementation methods of the charging switch S1, the discharging switch S2, and the comparison module are not particularly limited in this application. The charging switch S1 and the discharging switch S2 can be implemented using various types of switching devices, and the comparison module can be implemented using a comparator U0 and other methods. For the first preset power supply V DD The specific types and implementation methods, etc. are not particularly limited in this application.

[0084] As a specific embodiment, as Figure 8 shown, when the device selection signal (SEL2) remains unchanged, the charging switch S1 is turned off, the discharging switch S2 is turned on, the voltage at the positive input terminal of the comparator U0 is 0, and the flip signal is 0; when the device selection signal (SEL2) undergoes a transition, the discharging switch S2 is turned off, the charging switch S1 is turned on, and the configuration capacitor C0 is charged with a constant current source I0. The voltage at the positive input terminal of the comparator U0 increases. When it reaches the preset voltage Vref connected to the negative input terminal of the comparator U0, the output signal of the comparator U0 flips, and the flip signal becomes 1. At this time, the delay module 12 outputs the flip signal to the enable signal generation module 11. After receiving the flip signal, the enable signal generation module 11 sends a control signal to control the charging switch S1 to turn off and the discharging switch S2 to turn on, so that the voltage of the configuration capacitor C0 discharges to 0, and the flip signal resumes to 0; when there are consecutive transitions of the device selection signal (SEL2) and the interval time of the consecutive transitions is less than the set break-then-make time, the enable signal generation module 11 will control the discharging switch S2 to turn off and the charging switch S1 to turn on when detecting the first transition. The voltage of the configuration capacitor C0 rises. When the charging switch S1 is turned on and the voltage of the configuration capacitor C0 has not reached the flip value and SEL2 undergoes another transition, that is, when the enable signal generation module 11 detects the second transition, it will control the charging switch S1 to turn off and the discharging switch S2 to turn on, and the voltage of the configuration capacitor C0 is discharged to 0 again, and the flip signal is always 0.

[0085] Specifically, by setting the charging switch S1 and the discharging switch S2, the delay module 12 controls the charging and discharging of the configuration capacitor C0. At the same time, a comparison module is set to effectively detect the voltage of the configuration capacitor C0. The circuit structure of the entire delay module 12 is simple and easy to implement, which is conducive to the simple implementation of the entire multiplexing module SW.

[0086] As an alternative embodiment, the delay module 12 further includes:

[0087] A constant current source I0, with its input terminal connected to a first preset power supply and its output terminal connected to the first terminal of the charging switch S1, is configured to output a preset current to charge the configuration capacitor C0 when the charging switch S1 is turned on.

[0088] It is not difficult to understand that, in order to precisely control the charging rate of the configuration capacitor C0 and ensure that the duration for the configuration capacitor C0 to be charged to a preset voltage can be stably maintained within the set break-before-make time, a constant current source I0 is additionally provided in the charging circuit of the configuration capacitor C0 in the delay module 12. The constant current source I0 can provide a stable charging current. Cooperating with the charging switch S1, it can achieve a charging process for the configuration capacitor C0 where the charging current always remains constant. By setting the preset current and the preset voltage, the break-before-make time of the multiplexing module SW can be precisely configured, thereby realizing the automatic control of the switching of the sub-device S. The specific type and implementation method of the constant current source I0 are not particularly limited in this application. There are also multiple choices for the specific value of the preset current, which are not particularly limited in this application. For example, a current source of 10uA can be used to implement it.

[0089] Specifically, by setting the constant current source I0, the charging rate and charging time of the configuration capacitor C0 can be precisely controlled, thereby accurately configuring the break-before-make time of the multiplexing module SW. At the same time, the stable charging current can avoid current mutations caused by factors such as input voltage fluctuations, protect the circuit, and ensure the safety and reliability of the configuration capacitor C0.

[0090] As an alternative embodiment, it further includes:

[0091] A power supply module, with its input terminal connected to the power supply pin of the main device M, its first output terminal connected to the power supply pin of the multiplexing module SW, and its second output terminal respectively connected to the power supply pins of each sub-device S, is configured to supply power to the multiplexing module SW and each sub-device S when the main device M is powered on;

[0092] Both the sub-device S and the main device M include hot-swap detection pins;

[0093] The hot-swap detection pin of the sub-device S is configured to generate a detection signal based on the power supply of the power supply module;

[0094] The hot-swap detection pin of the main device M is configured to obtain a detection signal based on the communication channel between itself and the multiplexing module SW and the communication channels in the conducting state between the multiplexing module SW and each sub-device S, so as to obtain the connection state of the sub-device S.

[0095] It can be understood that, for the convenience of the master device M to obtain performance parameters such as the hardware configuration of the slave device S and detect the connection status of the slave device S even when the slave device S is not powered on, a power supply module is also provided in the multiplexing device. The input end of the power supply module is connected to the master device M, obtains the power supply from the power supply pin of the master device M, and then uses the power supply of the master device M to supply power to the multiplexing module SW and each slave device S. For any slave device S, after receiving the power supply output by the power supply module, it uses this power supply to generate a detection signal on its own hot-swap detection pin. The detection signal can be transmitted to the hot-swap detection pin of the master device M through the communication channel conducting between the slave device S and the multiplexing module SW and the communication channel conducting between the multiplexing module SW and the master device M. When the master device M detects the detection signal from the hot-swap detection pin, it indicates that there is a communication connection between the current slave device S and the master device M, thereby realizing the detection of the connection status of the slave device S. At the same time, the master device M can also identify the currently connected slave device S according to different detection signals, determine which slave device S is currently connected, so as to determine the specific form of the output signal output to the slave device S or the specific manner of receiving signals from the slave device S, ensuring the compatibility and accuracy of communication between the master device M and the connected slave device S. The specific type and implementation method of the power supply module and the detection signal are not particularly limited in this application. Voltage conversion circuits such as boost circuits, buck circuits, and LDO (Low-Dropout Regulator) chips can be selected in the power supply module according to requirements. As shown in Figure 2 It can also be increased to set a grounding capacitor C11 for filtering and voltage stabilization. If the power supply voltage range supported by the multiplexing module SW is relatively wide, such as the ASW3742 chip, the power supply module can also directly output the voltage of the power supply pin of the master device M to the multiplexing module SW without setting conversion circuits such as LDO chips, saving circuit costs.

[0096] As a specific embodiment, such as Figure 2As shown, if the master device M is a computer and the slave device S is a display device, and both the master device M and the slave device S are connected to the multiplexing module SW through an HDMI interface or a DVI interface, the hot plug detection pin can directly use the HPD pin of the HDMI interface to implement HPD (Hot Plug Detect) between the master device M and the slave device S, thereby helping the master device M determine the connection status of the slave device S. At the same time, the corresponding detection signal (HPD signal) will be used as the basis for whether the computer sends TMDS signals to the display device. The HPD signal is a detection signal output from the display device to the computer. The function of hot plug detection is that when a digital display such as a display device is connected or disconnected from the computer through an HDMI interface or a DVI interface, the computer can detect this event through the HPD pin of the HDMI interface or DVI interface and make a response.

[0097] When the computer is connected to the display device through the HDMI interface, the computer applies its +5V voltage to the DDC memory (i.e., the EDID data memory) of the display device through the PWR_CON_PIN18 pin of the HDMI interface to supply power to the DDC memory, ensuring that the computer can read the EDID data of the display device through the HDMI interface even if the display device is not powered on. After the computer is powered on, it generates a 5V power supply and supplies power to the display device. At this time, after receiving the +5V voltage, the display device makes the HPD pin of the HDMI interface turn to a high level through the internal circuit. When the computer (graphics card controller) detects that the HPD pin is at a high level, it determines that there is a display device connected to the computer through the HDMI, and reads the EDID data in the display device through the DDC channel (using the I2C bus) of the HDMI interface, and makes the TMDS signal sending circuit in the computer graphics card start to work. When the HDMI connection between the display device and the computer is disconnected, the HPD signal on the computer side is at a low level, and the TMDS signal sending circuit in the computer graphics card stops working. A preferred embodiment is that when the graphics card in the computer detects that the voltage of the HPD pin in the HDMI interface is greater than 2V, it is determined that the display device is connected to the computer through the HDMI interface; when it detects that the voltage of the HPD pin is less than 0.8V, it is determined that the HDMI connection between the display device and the computer has been disconnected.

[0098] Specifically, in order to implement the detection of the connection status of the slave device S by the master device M, both the master device M and the slave device S need to set corresponding hot plug detection pins, or directly reuse the pins of the interface during connection to implement hot plug detection, so that the master device M can detect the connection status of the slave device S by obtaining the corresponding detection signal, thereby accurately outputting or receiving signals and ensuring the effectiveness and compatibility during the communication between the master device M and the slave device S.

[0099] Please refer to Figure 9 , Figure 9 , which is a schematic structural diagram of a selection signal generation module provided by the present invention. As an alternative embodiment, it further includes:

[0100] A selection signal generation module, whose output terminal is connected to the device selection pin of the multiplexing module SW, and is used to generate a device selection signal.

[0101] It is not difficult to understand that the multiplexing module SW needs to receive the device selection signal sent by the user according to the demand to accurately switch the sub-device S according to the user's demand. Therefore, a selection signal generation module also needs to be set in the multiplexing device to generate the corresponding device selection signal according to the user's demand to instruct the multiplexing module SW to complete the corresponding device switching function. The specific type and implementation manner of the selection signal generation module are not particularly limited in this application. It can be implemented by a self-locking button or other button devices, or can be implemented by other types of human-computer interaction devices.

[0102] It should be noted that the device selection pins of the multiplexing module SW include a pull-up pin SEL1 and a channel selection pin SEL2. The pull-up pin SEL1 is connected to the second preset power supply through a pull-up resistor R0 to ensure that the device selection pin maintains a stable logic level without external drive, and to avoid signal instability or false triggering caused by the floating state of the device selection pin. The channel selection pin SEL2 is used to receive user instructions to instruct the multiplexing module SW to switch the sub-device S.

[0103] Specifically, by setting the selection signal generation module to effectively receive user instructions, the information interaction between the multiplexing device and the user is realized, ensuring that the multiplexing device can accurately respond to the user's demand and improving the user experience.

[0104] As an alternative embodiment, the selection signal generation module includes:

[0105] A self-recovery button J11, which is conductive when pressed;

[0106] A first controllable switch Q1, whose first end is connected to the device selection pin of the multiplexing module SW;

[0107] A first capacitor C1, whose first end is connected to the second preset power supply, and is respectively connected to the first end of the self-recovery button J11 and the second end of the first controllable switch Q1, and is used to charge based on the second preset power supply when the first controllable switch Q1 is turned off, and discharge when the self-recovery button J11 is conductive;

[0108] The second controllable switch Q2 has its first end connected to the control end of the first controllable switch Q1, and is used to conduct when the first controllable switch Q1 is turned off and the self - restoring button J11 is turned on, so as to control the first controllable switch Q1 to conduct; and turn off when the first controllable switch Q1 is turned on and the self - restoring button J11 is turned on, so as to control the first controllable switch Q1 to turn off.

[0109] The first resistor R1 has its first end connected to the first end of the first controllable switch Q1;

[0110] The second resistor R2 has its first end connected to the second end of the self - restoring button J11, the second end of the first resistor R1, and the control end of the second controllable switch Q2 respectively;

[0111] The third resistor R3 has its first end connected to the second end of the first capacitor C1, the second end of the second resistor R2, and the second end of the second controllable switch Q2 respectively, and its second end is grounded.

[0112] It can be understood that the self - restoring button J11 can be specifically used to obtain user instructions. The user will press the self - restoring button J11 according to the need to switch the device. When the user presses the self - restoring button J11, the self - restoring button J11 remains on. When the user stops pressing, the self - restoring button J11 will return to the off state. In order to ensure the latching of user instructions, a peripheral circuit including the first controllable switch Q1, the second controllable switch Q2, the first capacitor C1, the first resistor R1, the second resistor R2, and the third resistor R3 is additionally provided in the signal generation module. The specific types and implementation methods of the first controllable switch Q1, the second controllable switch Q2, the first capacitor C1, the first resistor R1, the second resistor R2, and the third resistor R3 are not particularly limited in this application. The first controllable switch Q1 and the second controllable switch Q2 can be specifically implemented by controllable switches such as triodes or MOS transistors (Metal - Oxide - Semiconductor Field - Effect Transistors). The specific value and implementation method of the second preset power supply are not particularly limited in this application, and the power supply of the main device M can be directly reused, such as Figure 9As shown, a 5V voltage is used to realize the second preset power supply. Taking the initial state of the first controllable switch Q1 as off as an example, after the multiplexing device is connected to the main device M and the sub-device S, if the main device M is turned on, the main device M can provide the second preset power supply for the selection signal generation module. Since the first controllable switch Q1 is turned off, and the user basically has no switching demand at the beginning, the second preset power supply will continue to charge the first capacitor C1 at this time; if the user has a switching demand, press the self-recovery button J11, and the self-recovery button J11 is turned on. At this time, the first capacitor C1 will pass through the loop formed by the turned-on self-recovery button J11 and the second resistor R2. During discharge, the voltage at the control end of the second controllable switch Q2 rises, so that the second controllable switch Q2 is turned on. The turned-on second controllable switch Q2 will pull down the control end of the first controllable switch Q1, thereby controlling the first controllable switch Q1 to be turned on. At this time, the second preset power supply will be directly output to the channel selection pin SEL2 of the multiplexing module SW through the turned-on first controllable switch Q1, so that the channel selection pin SEL2 is in a high level state. Even if the self-recovery button J11 is turned off, the entire selection signal generating module can maintain this state, and the channel selection pin SEL2 is kept in a high level state. Afterwards, if the user presses the self-recovery button J11 again, the self-recovery button J11 is turned on again, and the first capacitor C1 will also discharge at this time. However, since the first controllable switch Q1 is turned on, the first capacitor C1 is not charged, so the control end of the second controllable switch Q2 will be quickly pulled down by the third resistor R3 connected to the ground, causing the second controllable switch Q2 to be turned off, and the first controllable switch Q1 is turned off accordingly, so that the channel selection pin SEL2 is in a low level state. Even if the self-recovery button J11 is turned off, the entire selection signal generation module can maintain this state, and the channel selection pin SEL2 remains in a low level state. The initial state of the first controllable switch Q1 can also be turned off, and its working principle is similar to the above, and this application will not repeat it here.

[0113] Specifically, the setting of this peripheral circuit can realize the key monitoring of the self-recovery key J11 and the switching instruction of the multiplexing module SW for the communication channel. The peripheral circuit composed of this discrete component realizes the device selection signal, which is more reliable, and there is no need to worry about the program running away or the influence of the program burning operation process on the device selection signal during the generation and patch operation. The controllable switch is used to realize the latching and interlocking of the key state, so that the multiplexing device can directly realize the switching of the communication channel through a single key. The whole circuit structure is simple and easy to implement. The cost of the adopted devices is low, which simplifies the BOM (Bill of Materials) solution and reduces the design cost.

[0114] As an optional embodiment, the selection signal generating module further includes:

[0115] The pull-down resistor R11 has its first end connected to the first end of the first resistor R1, the first end of the first controllable switch Q1, and the device selection pin of the multiplexing module SW respectively, and its second end is grounded;

[0116] and / or,

[0117] The bias resistor R12 has its first end connected to the second end of the first controllable switch Q1, and its second end connected to the control end of the first controllable switch Q1.

[0118] It is not difficult to understand that in order to ensure that when the first controllable switch Q1 is turned off, the channel selection pin SEL2 can quickly convert from a high level to a low level, a pull-down resistor R11 connected to the channel selection pin SEL2 can be additionally provided in the selection signal generation module. When the first controllable switch Q1 is turned on, the channel selection pin SEL2 can maintain a high level based on the second preset power supply. When the first controllable switch Q1 is turned off, the channel selection pin SEL2 can be quickly pulled down to a low level by the pull-down resistor R11 to achieve a fast transition. At the same time, in order to ensure the stable operation of the first controllable switch Q1, a bias resistor R12 can also be additionally provided between the control end and the second end of the first controllable switch Q1, and the bias resistor R12 is used to provide a suitable static operating point for the first controllable switch Q1, thereby ensuring the stability and reliability of the device selection signal input to the multiplexing module SW through the channel selection pin SEL2. The specific types and implementation manners of the pull-down resistor R11 and the bias resistor R12 are not particularly limited in this application.

[0119] Specifically, by additionally providing the pull-down resistor R11 and / or the bias resistor R12, the accuracy and reliability of the device selection signal input to the multiplexing module SW can be further improved, and the control error caused by unstable signals or slow transitions can be minimized as much as possible, ensuring the accuracy and reliability of the multiplexing device; the circuit structure is simple and easy to implement, which is beneficial to the simple implementation of the entire multiplexing device.

[0120] As an optional embodiment, the selection signal generation module further includes:

[0121] A voltage dividing circuit, with its first input terminal connected to the second preset power supply and to the second end of the first controllable switch Q1, its second input terminal grounded, and its output terminal connected to the first end of the self-resetting button J11 and the first end of the first capacitor C1 respectively;

[0122] and / or,

[0123] The second capacitor C2 has its first terminal connected to the second terminal of the self - recovery button J11, the second terminal of the first resistor R1, the first terminal of the second resistor R2, and the control terminal of the second controllable switch Q2 respectively, and its second terminal is connected to the second terminal of the first capacitor C1, the second terminal of the second resistor R2, the first terminal of the third resistor R3, and the second terminal of the second controllable switch Q2 respectively.

[0124] It can be understood that, in order to avoid the impact on the first capacitor C1 when the second preset power supply charges the first capacitor C1, a voltage - dividing circuit can also be added directly between the second preset power supply and the first capacitor C1. After dividing the voltage of the second preset power supply by the voltage - dividing circuit and then outputting it to the first capacitor C1, the safety and reliability during the charging of the first capacitor C1 can be ensured. At the same time, in order to ensure the stable control of the first capacitor C1 over the second controllable switch Q2, a second capacitor C2 can also be added between the control terminal and the second terminal of the second controllable switch Q2 to achieve the stability of the voltage at the control terminal of the second controllable switch Q2 by using the second capacitor C2. The specific types and implementation methods of the voltage - dividing resistors and the second capacitor C2 are not particularly limited in this application. As Figure 9 shown, the voltage - dividing circuit can specifically be implemented by using the series - connected resistor R13 and resistor R14.

[0125] Specifically, through the setting of the voltage - dividing resistors and the second capacitor C2, the circuit can be further protected, the accuracy and reliability of the entire selection signal generation module can be improved, the circuit structure is simple and easy to implement, which is beneficial to the simple implementation of the entire multiplexing device.

[0126] As a specific embodiment, such as Figure 9As shown in the figure, both the first controllable switch Q1 and the second controllable switch Q2 are implemented using triodes. When the multiplexing module SW connects the computer and the display device, the master device M, which is the computer, provides a voltage of 5V (V5V = 5V) to the selection signal generation module through the HDMI channel. In the initial state, the first controllable switch Q1 is off, and the first capacitor C1 is charged (the first end of the first capacitor C1 is positive). The charging circuit is V5V -> resistor R13 -> first capacitor C1 -> third resistor R3 -> GND. If the self - reset button J11 is pressed, the first capacitor C1 discharges (the second end of the first capacitor C1 is negative). The discharge path is: the first end of the first capacitor C1 -> self - reset button J11 -> second resistor R2 / second capacitor C2 / second controllable switch Q2 -> third resistor R3. At this time, the base voltage of the second controllable switch Q2 is greater than the emitter voltage, and the second controllable switch Q2 conducts. Then, the emitter voltage of the first controllable switch Q1 is greater than the base voltage, and the first controllable switch Q1 conducts. SEL2 = 5V. The base of the second controllable switch Q2 is pulled up to 5V through the first resistor R1. After that, the self - reset button J11 is released, and SEL2 remains 5V. As described above, when the self - reset button J11 is pressed again, the first capacitor C1 discharges (at this time, the second end of the first capacitor C1 is positive). The discharge path is the second end of the first capacitor C1 -> second resistor R2 -> self - reset button J11 -> the first end of the first capacitor C1. At this time, the emitter voltage of the second controllable switch Q2 is greater than the collector voltage, the second controllable switch Q2 turns off, the first controllable switch Q1 turns off, and SEL2 = 0V. After that, the self - reset button J11 is released, and SEL2 remains 0V. The pull - down resistor R11 is used to control SEL2 to maintain a pulled - down low level in the initial state. The bias resistor R12 is used to maintain the initial state of the first controllable switch Q1 and control the default collector of the first controllable switch Q1 to be pulled up to the emitter. The channel selection pin SEL2 controls the communication channel switching of the multiplexing module SW. When SEL2 is at a low level, the communication channel corresponding to computer Connector 0 and the communication channel corresponding to display device Connector 1 are conducted. When SEL2 is at a high level, the communication channel corresponding to computer Connector 0 and the communication channel corresponding to display device Connector 2 are conducted.

[0127] To solve the above - mentioned technical problems, the present invention also provides a switching system, including a master device, a multiplexing device as described above, and several slave devices. The master device is connected to the several slave devices through the multiplexing device.

[0128] For the introduction of a switching system provided by the present invention, please refer to the embodiments of the above - mentioned multiplexing device, and the present invention will not be elaborated herein.

[0129] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts among the embodiments can be referred to each other. It should also be noted that in this specification, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the existence of additional identical elements in the process, method, article or device comprising the element.

[0130] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the broadest scope consistent with the principles and novel features disclosed herein.

Claims

1. A multiplexing device, characterized in that, Including: A multiplexing module, with a first data terminal connected to the master device and second data terminals respectively connected to a plurality of slave devices; A configuration capacitor, with a first terminal connected to the configuration pin of the multiplexing module and a second terminal grounded; The multiplexing module is configured to start charging the configuration capacitor when a preset state of the device selection signal is detected, stop charging when the voltage of the configuration capacitor does not reach the preset voltage and the preset state of the device selection signal is detected again or when the voltage of the configuration capacitor reaches the preset voltage; and disconnect the communication channel between itself and all the slave devices when the configuration capacitor is in the charging state and the voltage of the configuration capacitor does not reach the preset voltage; when the voltage of the configuration capacitor reaches the preset voltage, select a corresponding communication channel to conduct from a plurality of the slave devices according to the received device selection signal to switch the slave device for information transmission with the master device.

2. The multiplexing device according to claim 1, wherein The multiplexing module includes: An enable signal generation module, with an input terminal receiving the device selection signal and signal output terminals respectively connected to the enable terminals of the communication channels corresponding to each of the slave devices; A delay module, with an input terminal connected to the logical output terminal of the enable signal generation module, a first output terminal connected to the control terminal of the enable signal generation module, and a second output terminal connected to the first terminal of the configuration capacitor, for starting to charge the configuration capacitor when a preset state of the device selection signal is detected and outputting a flip signal to the enable signal generation module when the voltage of the configuration capacitor reaches the preset voltage; discharging the configuration capacitor when the voltage of the configuration capacitor does not reach the preset voltage and the preset state of the device selection signal is detected again or when the device selection signal is not detected; The enable signal generation module is configured to control the disconnection of the initially-conducted communication channel when a preset state of the device selection signal is detected, and control the conduction of the target communication channel according to the device selection signal when receiving the flip signal; when the flip signal is not received and the preset state of the device selection signal is detected again, control the conduction of the initial communication channel.

3. The multiplexing device according to claim 2, characterized in that, The delay module includes: A charging switch, with a control terminal connected to the logical output terminal of the enable signal generation module and a first terminal connected to a first preset power supply, for conducting based on the control of the enable signal generation module when the enable signal generation module detects a preset state of the device selection signal, and turning off when the enable signal generation module receives the flip signal or when the enable signal generation module does not receive the flip signal and the preset state of the device selection signal is detected again; A discharging switch, with a first terminal grounded and a control terminal connected to the logical output terminal of the enable signal generation module, for turning off based on the control of the enable signal generation module when the enable signal generation module detects a preset state of the device selection signal, and conducting when the enable signal generation module receives the flip signal or when the enable signal generation module does not receive the flip signal and the preset state of the device selection signal is detected again; A comparison module, with its first input terminal connected to the second terminal of the charging switch and the second terminal of the discharging switch respectively, and its second input terminal connected to a preset voltage, is configured to output a first level signal as a flip signal when the voltage of the configuration capacitor reaches the preset voltage, and output a second level signal when the voltage of the configuration capacitor does not reach the preset voltage; the first level signal and the second level signal are opposite to each other.

4. The multiplexing device according to claim 3, characterized in that The delay module further includes: A constant current source, with its input terminal connected to a first preset power supply and its output terminal connected to the first terminal of the charging switch, is configured to output a preset current to charge the configuration capacitor when the charging switch is turned on.

5. The multiplexing device according to claim 1, characterized in that, It further includes: A power supply module, with its input terminal connected to the power supply pin of the main device, its first output terminal connected to the power supply pin of the multiplexing module, and its second output terminal connected to the power supply pins of each of the sub-devices respectively, is configured to supply power to the multiplexing module and each of the sub-devices when the main device is powered on. Both the sub-devices and the main device include hot-swap detection pins. The hot-swap detection pin of the sub-device is configured to generate a detection signal based on the power supply of the power supply module. The hot-swap detection pin of the main device is configured to obtain the detection signal based on the communication channel between itself and the multiplexing module and the communication channels that are in a conducting state between the multiplexing module and each of the sub-devices, so as to obtain the connection state of the sub-devices.

6. The multiplexing device according to any one of claims 1 to 5, characterized in that, It further includes: A selection signal generation module, with its output terminal connected to the device selection pin of the multiplexing module, is configured to generate a device selection signal.

7. The multiplexing device according to claim 6, wherein The selection signal generation module includes: A self-recovery button, which is configured to conduct when pressed. A first controllable switch, with its first terminal connected to the device selection pin of the multiplexing module. A first capacitor, with its first terminal connected to a second preset power supply and connected to the first terminal of the self-recovery button and the second terminal of the first controllable switch respectively, is configured to charge based on the second preset power supply when the first controllable switch is turned off, and discharge when the self-recovery button conducts. A second controllable switch, with its first terminal connected to the control terminal of the first controllable switch, is configured to conduct when the first controllable switch is turned off and the self-recovery button conducts, so as to control the first controllable switch to conduct; and turn off when the first controllable switch conducts and the self-recovery button conducts, so as to control the first controllable switch to turn off. A first resistor, with its first terminal connected to the first terminal of the first controllable switch. A second resistor, with its first terminal connected to the second terminal of the self-recovery button, the second terminal of the first resistor, and the control terminal of the second controllable switch respectively. A third resistor, with its first terminal connected to the second terminal of the first capacitor, the second terminal of the second resistor, and the second terminal of the second controllable switch respectively, and its second terminal grounded.

8. The multiplexing device according to claim 7, wherein The selection signal generation module further includes: A pull-down resistor, with its first terminal connected to the first terminal of the first resistor, the first terminal of the first controllable switch, and the device selection pin of the multiplexing module respectively, and its second terminal grounded. And / or A bias resistor, with its first terminal connected to the second terminal of the first controllable switch and its second terminal connected to the control terminal of the first controllable switch.

9. The multiplexing device according to claim 7, wherein The selection signal generation module further includes: A voltage dividing circuit, with its first input terminal connected to a second preset power supply and also connected to the second terminal of the first controllable switch, its second input terminal grounded, and its output terminal connected to the first terminal of the self - restoring button and the first terminal of the first capacitor; And / or A second capacitor, with its first terminal connected to the second terminal of the self - restoring button, the second terminal of the first resistor, the first terminal of the second resistor, and the control terminal of the second controllable switch, and its second terminal connected to the second terminal of the first capacitor, the second terminal of the second resistor, the first terminal of the third resistor, and the second terminal of the second controllable switch.

10. A switching system, characterized in that, Comprising a master device, a multiplexing device as described in any one of claims 1 to 9, and a plurality of slave devices, wherein the master device is connected to the plurality of slave devices through the multiplexing device.

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