Operation Method of Multi-Computer Switcher and Routing Device

Abstract

The present invention provides an operation method for a multi-computer switcher and a routing device. The multi-computer switcher includes a controller and a routing device. The routing device includes a plurality of channel circuits and a multiplexer. The first ends of these channel circuits are coupled to a plurality of selection ports of the routing device. The selection ends of the multiplexer are coupled to the second ends of these channel circuits. The common end of the multiplexer is coupled to the common port of the routing device. The multiplexer selects one of these channel circuits to couple the second end of the selected channel circuit to the common port. The selected channel circuit selectively provides a first attenuation level. The unselected channel circuits among these channel circuits selectively provide a second attenuation level higher than the first attenuation level.

Description

Technical Field

[0001] The present invention relates to a routing device, and more particularly to a multi-computer switcher and an operation method of a routing device. Background Art

[0002] A Keyboard / Video / Mouse (KVM) switcher, also known as a multi-computer switcher, refers to a device that can share the same set of peripheral devices among multiple hosts. Among them, the peripheral devices may include one or more of devices such as a keyboard, a screen, a mouse, a speaker, etc. Generally, a multi-tasker (such as a dual four-channel analog multi-tasker, such as 74HC4052) is provided in the KVM switcher to switch the connection between multiple hosts and peripheral devices. However, due to various reasons, crosstalk problems may occur between different selection terminals of the multi-tasker. For example, the signal (such as sound, image, text data, etc.) transmitted by the current selection terminal of the multi-tasker will be leaked into the transmission channels of other selection terminals (non-current selection terminals) of the multi-tasker, and become return path noise. Summary of the Invention

[0003] In view of this, the present invention provides a multi-computer switcher and an operation method of a routing device to effectively attenuate return path noise.

[0004] In an embodiment according to the present invention, the multi-computer switcher includes a controller and a routing device. The controller is used to issue a plurality of control signals and a selection signal. The routing device is coupled to the controller. The routing device includes a plurality of selection ports, a plurality of channel circuits, a common port, and a multi-tasker. The first end of each channel circuit is respectively coupled to one of these selection ports. Based on these control signals, a selected channel circuit among these channel circuits selectively provides a first attenuation degree. An unselected channel circuit among these channel circuits selectively provides a second attenuation degree higher than the first attenuation degree. The multi-tasker has a plurality of selection terminals and a common terminal. Each selection terminal of the multi-tasker is respectively coupled to the second end of one of these channel circuits. The common terminal is coupled to the common port. The multi-tasker selects the selected channel circuit from these channel circuits based on the selection signal to couple the second end of the selected channel circuit to the common port.

[0005] In an embodiment according to the present invention, the operation method of the routing device includes: a multiplexer selects a selected channel circuit from multiple channel circuits of the routing device to couple the selected channel circuit to a common port of the routing device, wherein the first end of each channel circuit is respectively coupled to one of the multiple selection ports of the routing device, and the multiple selection ends of the multiplexer are respectively coupled to the second end of one of these channel circuits; the selected channel circuit selectively provides a first attenuation level; and an unselected channel circuit among these channel circuits selectively provides a second attenuation level higher than the first attenuation level.

[0006] Based on the above, the channel circuits of the routing device described in the embodiments of the present invention can selectively provide different attenuation levels to the signals passing through the channels according to whether they are selected. For example, the unselected channel circuits can selectively provide a higher attenuation level (the second attenuation level) to effectively reduce noise / crosstalk. The selected channel circuits can selectively provide a lower attenuation level (the first attenuation level). BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 is a circuit block diagram of a multi-computer switcher according to an embodiment of the present invention;

[0008] Figure 2 is a flowchart of an operation method of a routing device according to an embodiment of the present invention;

[0009] Figure 3 is a circuit block diagram of a channel circuit according to an embodiment of the present invention;

[0010] Figure 4 is an illustration according to an embodiment of the present invention Figure 3 of the circuit block diagram of the controllable current path circuit shown;

[0011] Figure 5 is a circuit block diagram of a channel circuit according to another embodiment of the present invention;

[0012] Figure 6 is an illustration according to an embodiment of the present invention Figure 5 of the circuit block diagram of the controllable current path circuit shown;

[0013] Figure 7 is a circuit block diagram of a channel circuit according to still another embodiment of the present invention;

[0014] Figure 8 is a circuit block diagram of a channel circuit according to yet another embodiment of the present invention;

[0015] Figure 9 is an illustration according to an embodiment of the present inventionFigure 8 Schematic diagram of the circuit block of the voltage dividing circuit shown

[0016] Figure 10 Description according to another embodiment of the present invention Figure 8 Schematic diagram of the circuit block of the voltage dividing circuit shown

[0017] Figure 11 Description according to another embodiment of the present invention Figure 8 Schematic diagram of the circuit block of the voltage dividing circuit shown

[0018] Description of reference numerals

[0019] 100: Multi-computer switch

[0020] 101: Routing device

[0021] 102: Controller

[0022] 110_1, 110_n, 300, 600, 900, 1000: Channel circuit

[0023] 120: Multiplexer

[0024] 310, 610, 910: Controllable current path circuit

[0025] 1010: Voltage dividing circuit

[0026] C1, C2, C3, C4, Cn: Selection terminal

[0027] CM: Common terminal

[0028] COM: Common port

[0029] P1, P2, P3, P4, Pn: Selection port

[0030] R1, R2, R101, R102, R103, R104, R105: Resistor

[0031] S1, S2, S3, S4, Sn: Control signal

[0032] S210, S220: Step

[0033] SM: Selection signal

[0034] SW, SW1, SW2: Switch

[0035] VSS: Reference voltage Detailed implementation manner

[0036] Reference will now be made in detail to exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numerals are used in the drawings and the description to refer to the same or like parts.

[0037] As used throughout this specification (including the claims), the term "coupled (or connected)" can refer to any direct or indirect means of connection. For example, if the first device is described as being coupled (or connected) to the second device, it should be interpreted that the first device can be directly connected to the second device, or the first device can be indirectly connected to the second device through other devices or some means of connection. The terms "first", "second", etc. mentioned throughout this specification (including the claims) are used to name components or to distinguish different embodiments or scopes, rather than to limit the upper or lower limits of the number of components, nor to limit the order of the components. Additionally, wherever possible, components / elements / steps with the same reference numerals in the drawings and the embodiments represent the same or similar parts. Components / elements / steps with the same reference numerals or the same terms in different embodiments can be referred to each other's relevant descriptions.

[0038] Due to various reasons, crosstalk problems may occur between different select terminals of a multiplexer. For example, the signal transmitted by the current select terminal of the multiplexer will leak into the transmission channels of other select terminals (non-current select terminals) of the multiplexer and become return path noise. To reduce the return path noise, in some embodiments, voltage-dividing resistors are provided in the transmission channels connected to each select terminal of the multiplexer. That is, attenuation is provided in these transmission channels to reduce the return path noise. However, the resistance value of the voltage-dividing resistor depends on the impact degree of the return path noise on different hosts, so the design is difficult. Moreover, the voltage-dividing resistors configured in the transmission channels will reduce the amplitude of the current transmission signal, so an additional power amplifier needs to be configured in the signal path connected to the common terminal of the multiplexer, thereby increasing the cost of a computer switch (also known as a KVM switch). In addition, the said additional power amplifier will amplify the background noise and reduce the signal-to-noise ratio.

[0039] Figure 1FIG. 0 is a schematic block diagram of a multi-computer switch 100 according to an embodiment of the present invention. The multi-computer switch 100 shown includes a routing device 101 and a controller 102. The controller 102 can issue a plurality of control signals (such as control signals S1 to Sn) and selection signals (such as selection signal SM) to the routing device 101. In some embodiments, the multi-computer switch 100 can allow a user to input instructions through an operation interface (not shown), and the controller 102 can issue the control signals S1 to Sn and the selection signal SM correspondingly according to the instructions input by the user. The number of the control signals S1 to Sn and the selection signal SM can be determined according to design requirements, and this embodiment is not limited.

[0040] According to different design requirements, the controller 102 can be implemented in the form of hardware, firmware, software (i.e., programs), or a combination of multiple ones of the foregoing. In terms of hardware form, the controller 102 can be implemented as a logic circuit on an integrated circuit. The related functions of the controller 102 can be implemented as hardware using a hardware description language (such as Verilog HDL or VHDL) or other suitable programming languages. For example, the related functions of the controller 102 can be implemented in various logic blocks, modules, and circuits of one or more microcontrollers, microprocessors, application-specific integrated circuits (ASICs), digital signal processors (DSPs), field-programmable gate arrays (FPGAs), and / or other processing units. In terms of software form and / or firmware form, the related functions of the controller 102 can be implemented as programming codes, such as using general programming languages (such as C, C++ or assembly language) or other suitable programming languages. The programming codes can be recorded / stored in a "non-transitory computer-readable medium", such as including read-only memory, tape, disk, card, semiconductor memory, programmable logic circuit, and / or storage device. A computer, a central processing unit, a microcontroller, or a microprocessor can read and execute the programming codes from the non-transitory computer-readable medium to achieve the related functions.

[0041] In Figure 1In the illustrated embodiment, the routing device 101 can be coupled to the controller 102 to receive control signals S1 to Sn and selection signal SM. The routing device 101 includes a plurality of selection ports (such as selection ports P1 to Pn), a plurality of channel circuits (such as channel circuits 110_1 to 110_n), a multiplexer 120, and a common port COM. The number n of the selection ports P1 to Pn and the channel circuits 110_1 to 110_n can be determined according to design requirements, and this embodiment is not limited. According to actual applications, the selection ports P1 to Pn can be coupled to a plurality of hosts, such as servers, workstations, personal computers, laptops, or other hosts. According to design requirements, in some embodiments, the layout positions of the channel circuits 110_1 to 110_n of the routing device 101 can be closer to the selection ports P1 to Pn.

[0042] In this embodiment, each of the channel circuits 110_1 to 110_n has a first end and a second end. The first end of each of these channel circuits 110_1 to 110_n is coupled to a corresponding selection port among the selection ports P1 to Pn of the routing device 101. For example, the first end of the channel circuit 110_1 is coupled to the selection port P1, and the first end of the channel circuit 110_n is coupled to the selection port Pn. The multiplexer 120 has a plurality of selection terminals (such as selection terminals C1 to Cn) and a common terminal (such as common terminal CM). Each of the selection terminals C1 to Cn is respectively coupled to the second end of a corresponding channel circuit among the channel circuits 110_1 to 110_n. For example, the selection terminal C1 of the multiplexer 120 is coupled to the second end of the channel circuit 110_1, and the selection terminal Cn of the multiplexer 120 is coupled to the second end of the channel circuit 110_n. The common terminal CM of the multiplexer 120 is coupled to the common port COM of the routing device 101. According to actual applications, the common port COM can be coupled to a peripheral device, such as a keyboard, a screen, a mouse, a speaker, or other devices.

[0043] In this embodiment, the multiplexer 120 can select one channel circuit from these channel circuits 110_1 to 110_n based on the selection signal SM issued by the controller 102, so as to couple the second end of the selected channel circuit to the common port COM. The channel circuits 110_1 to 110_n can selectively provide different attenuation degrees for the signals passing through the channel circuits 110_1 to 110_n respectively based on the control signals S1 to Sn issued by the controller 102. For example, the multiplexer 120 can select the channel circuit 110_1 based on the control signal S1, and the selected channel circuit 110_1 can selectively provide a lower attenuation degree (the first attenuation degree) based on the control signal S1. In addition, other channel circuits (unselected channel circuits, such as the channel circuit 110_n) can also selectively provide a second attenuation degree higher than the first attenuation degree based on the control signal (such as Sn). In this way, when the signal passing through the selected channel circuit 110_1 crosstalks to other channel circuits 110_n, the channel circuit 110_n can provide a higher attenuation degree (the second attenuation degree), so that the return path noise generated by crosstalk can be attenuated to a greater extent to solve the problem of crosstalk. Regarding the implementation details of the channel circuits 110_1 to 110_n, reference can be made to the following multiple embodiments.

[0044] Figure 2 is a schematic flowchart of an operation method of a routing device according to an embodiment of the present invention. Please refer to Figure 1 and Figure 2 . In step S210, the multiplexer 120 in the routing device 101 can select one channel circuit from the channel circuits 110_1 to 110_n in the routing device 101 according to the selection signal SM, and couple the second end of the selected channel circuit to the common port COM of the routing device 101. In step S220, the selected channel circuit among the channel circuits 110 to 110_n can selectively provide the first attenuation degree, and one (or more) unselected channel circuits among the channel circuits 110 to 110_n can selectively provide a second attenuation degree higher than the first attenuation degree.

[0045] Figure 3 is a schematic circuit block diagram of a channel circuit 300 according to an embodiment of the present invention. Figure 3 The shown channel circuit 300 can be used as Figure 1 any one of the channel circuits 110_1 to 110_n in Figure 3 The shown channel circuit 300 can refer to Figure 1 the relevant description of any one of the shown channel circuits 110_1 to 110_n, Figure 3 The shown selection port P2 can refer to Figure 1Description regarding any one of the selection ports P1 to Pn shown Figure 3 The multiplexer 120 shown can be referred to Figure 1 Description regarding the multiplexer 120 shown, and / or Figure 3 The selection terminal C2 shown can be referred to Figure 1 Description regarding any one of the selection terminals C1 to Cn shown Figure 1 Any one of the channel circuits 110_1 to 110_n shown can be referred to Figure 3 Description regarding the channel circuit 300 shown

[0046] In Figure 3 The embodiment shown, the channel circuit 300 can be coupled between a corresponding selection port (such as selection port P2) of the routing device 101 and a corresponding selection terminal (such as selection terminal C2) among the selection terminals C1 to Cn of the multiplexer 120. In Figure 3 The embodiment shown, the channel circuit 300 can include a resistor R1 and a controllable current path circuit 310. The first end of the resistor R1 is coupled to the selection port P2, and the second end of the resistor R1 is coupled to the selection terminal C2 of the multiplexer 120. According to the actual design, in Figure 3 The embodiment shown, the controllable current path circuit 310 can be coupled to the first end of the resistor R1. The controllable current path circuit 310 can be controlled by a corresponding control signal (such as control signal S2) among the control signals S1 to Sn. According to the control signal S2 issued by the controller 102, the controllable current path circuit 310 can change the signal attenuation degree of the channel circuit 300. For example, when the controller 102 and the multiplexer 120 select the channel circuit 300, the controllable current path circuit 310 can not absorb current (at this time the channel circuit 300 has a first attenuation degree). When the controller 102 and the multiplexer 120 do not select the channel circuit 300, the controllable current path circuit 310 can absorb current from the first end of the resistor R1. For example, the voltage dividing resistor (to be described in detail later) of the controllable current path circuit 310 can pull down the voltage of the first end of the resistor R1 (at this time the channel circuit 300 has a higher second attenuation degree). Based on the voltage dividing operation of the controllable current path circuit 310 and the resistor R1, the return path noise from the corresponding selection terminal C2 to the selection port P2 can be attenuated as much as possible.

[0047] Figure 4 Is described according to an embodiment of the present invention Figure 3 The circuit block diagram of the controllable current path circuit 310 shown. In Figure 4In the illustrated embodiment, the controllable current path circuit 310 may include a resistor R2 (voltage dividing resistor) and a switch SW. A first end of the switch SW may be coupled to a first end of the resistor R1. A first end of the resistor R2 is coupled to a second end of the switch SW. A second end of the resistor R2 may be coupled to a reference voltage VSS (such as a ground voltage or other fixed voltage). In this embodiment, the switch SW may be controlled by a control signal S2 of the controller 102 to change the attenuation degree of the channel circuit 300. For example, when the control signal S2 indicates that the channel circuit 300 is the selected channel circuit, the switch SW is turned off. At this time, the channel circuit 300 attenuates the signal passing through the resistor R1 with a first attenuation degree. In contrast, when the control signal S2 indicates that the channel circuit 300 is an unselected channel circuit, the switch SW is turned on. At this time, the channel circuit 300 attenuates the signal passing through the resistor R1 with a second attenuation degree (higher than the first attenuation degree). Therefore, the signal amplitude of the return path noise from the corresponding selection end C2 to the selection port P2 can be reduced as much as possible. In some other embodiments, the positions of the resistor R2 and the switch SW may be interchanged, and are not limited to Figure 4 the illustrated coupling manner.

[0048] Figure 5 FIG. 6 is a schematic circuit block diagram of a channel circuit 600 according to another embodiment of the present invention. Figure 5 The illustrated channel circuit 600 may be used as Figure 1 an implementation example of any one of the channel circuits 110_1 to 110_n in Figure 5 The illustrated channel circuit 600 may refer to Figure 1 the relevant description of any one of the illustrated channel circuits 110_1 to 110_n, Figure 5 The illustrated selection port P2 may refer to Figure 1 the relevant description of any one of the illustrated selection ports P1 to Pn, Figure 5 The illustrated multiplexer 120 may refer to Figure 1 the relevant description of the illustrated multiplexer 120, and (or) Figure 5 The illustrated selection end C2 may refer to Figure 1 the relevant description of any one of the illustrated selection ends C1 to Cn. Figure 1 Any one of the illustrated channel circuits 110_1 to 110_n may refer to Figure 5 the relevant description of the illustrated channel circuit 600.

[0049] In this embodiment, the channel circuit 600 can be coupled between the corresponding selection port (e.g., selection port P2) of the routing device 101 and the corresponding selection terminal (e.g., selection terminal C2) of the multiplexer 120. According to the design requirements, the channel circuit 600 can include a resistor R1 and a controllable current path circuit 610. The first end of the resistor R1 is coupled to the selection port P2, and the second end of the resistor R1 is coupled to the selection terminal C2 of the multiplexer 120. Figure 6 The illustrated channel circuit 600, resistor R1, and controllable current path circuit 610 can be analogized with reference to Figure 3 the relevant descriptions of the illustrated channel circuit 300, resistor R1, and controllable current path circuit 310. Different from Figure 3 the illustrated embodiment is that Figure 5 the illustrated controllable current path circuit 610 can be coupled to the second end of the resistor R1. According to the control signal S2 issued by the controller 102, the controllable current path circuit 610 can change the signal attenuation degree of the channel circuit 600. For example, when the controller 102 and the multiplexer 120 select the channel circuit 600, the controllable current path circuit 610 can not draw current (at this time, the channel circuit 600 has a first attenuation degree). When the controller 102 and the multiplexer 120 do not select the channel circuit 600, the controllable current path circuit 610 can draw current from the second end of the resistor R1. For example, the voltage dividing resistor (detailed later) of the controllable current path circuit 610 can pull down the voltage of the second end of the resistor R1 (at this time, the channel circuit 600 has a higher second attenuation degree). Based on the voltage dividing operation of the controllable current path circuit 610 and the resistor R1, the noise from the selection port P2 to the corresponding selection terminal C2 can be attenuated as much as possible.

[0050] Figure 6 is described according to an embodiment of the present invention Figure 5 The circuit block diagram of the illustrated controllable current path circuit 610. In Figure 6In the illustrated embodiment, the controllable current path circuit 610 may include a resistor R2 and a switch SW. The first end of the switch SW may be coupled to the second end of the resistor R1. The first end of the resistor R2 is coupled to the second end of the switch SW. The second end of the resistor R2 may be coupled to a reference voltage VSS (e.g., ground voltage or other fixed voltage). The switch SW may be controlled by a control signal S2 of the controller 102 to change the attenuation level of the channel circuit 600. For example, when the control signal S2 indicates that the channel circuit 600 is the selected channel circuit, the switch SW is open. At this time, the channel circuit 600 attenuates the signal passing through the resistor R1 with a first attenuation level. In contrast, when the control signal S2 indicates that the channel circuit 600 is an unselected channel circuit, the switch SW is closed. At this time, the channel circuit 600 attenuates the signal passing through the resistor R1 with a second attenuation level (higher than the first attenuation level). Therefore, the signal amplitude of the noise from the selection port P2 to the corresponding selection terminal C2 can be reduced as much as possible. In some other embodiments, the positions of the resistor R2 and the switch SW may be interchanged, and are not limited to Figure 6 the illustrated coupling manner.

[0051] Figure 7 FIG. is a circuit block diagram of a channel circuit 900 according to another embodiment of the present invention. Figure 7 The illustrated channel circuit 900 may be used as Figure 1 an implementation example of any one of the channel circuits 110_1 to 110_n in Figure 7 The illustrated channel circuit 900 may refer to Figure 1 the relevant description of any one of the illustrated channel circuits 110_1 to 110_n, Figure 7 The illustrated selection port P3 may refer to Figure 1 the relevant description of any one of the illustrated selection ports P1 to Pn, Figure 7 The illustrated multiplexer 120 may refer to Figure 1 the relevant description of the illustrated multiplexer 120, and (or) Figure 7 The illustrated selection terminal C3 may refer to Figure 1 the relevant description of any one of the illustrated selection terminals C1 to Cn. Figure 1 Any one of the illustrated channel circuits 110_1 to 110_n may refer to Figure 7 the relevant description of the illustrated channel circuit 900.

[0052] In this embodiment, the channel circuit 900 may be coupled between a corresponding selection port (e.g., selection port P3) of the routing device 101 and a corresponding selection terminal (e.g., selection terminal C3) of the multiplexer 120. In Figure 7In the illustrated embodiment, the channel circuit 900 may include a resistor R1, a resistor R2, and a controllable current path circuit 910. A first end of the resistor R1 is coupled to the selection port P3. A first end of the resistor R2 is coupled to a second end of the resistor R1. A second end of the resistor R2 is coupled to a selection terminal C3 of the multiplexer 120. The controllable current path circuit 910 may be coupled to the second end of the resistor R1 and the first end of the resistor R2. The controllable current path circuit 910 may be controlled by a corresponding one of the control signals S1 to Sn (e.g., the control signal S3). According to the control signal S3 issued by the controller 102, the controllable current path circuit 910 may change the signal attenuation degree of the channel circuit 900.

[0053] For example, when the controller 102 and the multiplexer 120 select the channel circuit 900, the controllable current path circuit 910 may not draw current (at this time, the channel circuit 900 has a first attenuation degree). When the controller 102 and the multiplexer 120 do not select the channel circuit 900, the controllable current path circuit 910 may draw current from the second end of the resistor R1 and the first end of the resistor R2. For example, a voltage dividing resistor (to be described in detail later) of the controllable current path circuit 910 may pull down the voltage of the second end of the resistor R1 (at this time, the channel circuit 900 has a higher second attenuation degree). Based on the voltage dividing operation of the controllable current path circuit 910, the return path noise from the corresponding selection terminal C3 to the selection port P3 may be attenuated, and the noise from the selection port P3 to the corresponding selection terminal C3 may also be attenuated.

[0054] Figure 8 It is a circuit block diagram of a channel circuit 1000 according to another embodiment of the present invention. Figure 8 The illustrated channel circuit 1000 may be used as Figure 1 an implementation example of any one of the channel circuits 110_1 to 110_n. Figure 8 The illustrated channel circuit 1000 may refer to Figure 1 the relevant description of any one of the illustrated channel circuits 110_1 to 110_n, Figure 8 the illustrated selection port P4 may refer to Figure 1 the relevant description of any one of the illustrated selection ports P1 to Pn, Figure 8 the illustrated multiplexer 120 may refer to Figure 1 the relevant description of the illustrated multiplexer 120, and (or) Figure 8 the illustrated selection terminal C4 may refer to Figure 1 the relevant description of any one of the illustrated selection terminals C1 to Cn. Figure 1 Any one of the illustrated channel circuits 110_1 to 110_n may refer to Figure 8 the relevant description of the illustrated channel circuit 1000.

[0055] In Figure 8 the illustrated embodiment, the channel circuit 1000 can be coupled between a corresponding selection port (e.g., selection port P4) among the selection ports P1 - Pn of the routing device 101 and a corresponding selection terminal (e.g., selection terminal C4) among the selection terminals C1 - Cn of the multiplexer 120. The channel circuit 1000 can include a switch SW1, a switch SW2, and a voltage dividing circuit 1010. The common terminal of the switch SW1 is coupled to the selection port P4. The common terminal of the switch SW2 is coupled to the selection terminal C4 of the multiplexer 120. The voltage dividing circuit 1010 is coupled between the first selection terminal of the switch SW1 and the first selection terminal of the switch SW2. The second selection terminal of the switch SW2 is coupled to the second selection terminal of the switch SW1. According to the design requirements, the switches SW1 and SW2 can be controlled by a corresponding control signal (e.g., both are controlled by the control signal S4) among the control signals S1 - Sn. The switches SW1 and SW2 can change the signal attenuation degree provided by the channel circuit 1000 according to the control signal S4 issued by the controller 102. For example, when the control signal S4 indicates that the channel circuit 1000 is the selected channel circuit, the switch SW1 and the switch SW2 can bypass the voltage dividing circuit 1010 and electrically connect the selection port P4 to the selection terminal C4 of the multiplexer 120. At this time, the signal attenuation degree of the channel circuit 1000 is the first attenuation degree.

[0056] In contrast, when the control signal S4 indicates that the channel circuit 1000 is an unselected channel circuit, the switch SW1 can couple the selection port P4 to the voltage dividing circuit 1010, and the switch SW2 can couple the selection terminal C4 of the multiplexer 120 to the voltage dividing circuit 1010. At this time, the signal attenuation degree of the channel circuit 1000 is the second attenuation degree (greater than the first attenuation degree). The channel circuit 1000 attenuates the signal passing through the channel circuit 1000 with a higher second attenuation degree. Therefore, the signal amplitude of the return path noise from the corresponding selection terminal C4 to the selection port P4 can be reduced, and / or the signal amplitude of the noise from the selection port P4 to the corresponding selection terminal C4 can be reduced.

[0057] Figure 9 is described according to an embodiment of the present invention Figure 8 The circuit block diagram of the illustrated voltage dividing circuit 1010. In Figure 9In the illustrated embodiment, the voltage dividing circuit 1010 may include a resistor R101 and a resistor R102. A first end of the resistor R101 is coupled to a first selection end of the switch SW1. A second end of the resistor R101 is coupled to a first selection end of the switch SW2. A first end of the resistor R102 may be coupled to the first end of the resistor R101. A second end of the resistor R102 is coupled to a reference voltage VSS (such as a ground voltage or other fixed voltage). When the control signal S4 indicates that the channel circuit 1000 is an unselected channel circuit, a signal will flow through the voltage dividing circuit 1010. At this time, the signal amplitude of the return path noise from the corresponding selection end C4 to the selection port P4 can be divided and reduced.

[0058] Figure 10 is described according to another embodiment of the present invention Figure 8 The circuit block diagram of the illustrated voltage dividing circuit 1010. In this embodiment, the voltage dividing circuit 1010 may include a resistor R101 and a resistor R102. Figure 10 The illustrated voltage dividing circuit 1010, resistor R101 and resistor R102 may be referred to Figure 9 The illustrated voltage dividing circuit 1010, resistor R101 and resistor R102 can be analogized. Different from Figure 9 is that Figure 10 The first end of the illustrated resistor R102 may be coupled to the second end of the resistor R101. When the control signal S4 indicates that the channel circuit 1000 is an unselected channel circuit, a signal will flow through the voltage dividing circuit 1010. At this time, the signal amplitude of the noise from the selection port P4 to the corresponding selection end C4 can be divided and reduced.

[0059] Figure 11 is described according to another embodiment of the present invention Figure 8 The circuit block diagram of the illustrated voltage dividing circuit 1010. As Figure 11 , the voltage dividing circuit 1010 may include a resistor R103, a resistor R104, and a resistor R105. A first end of the resistor R103 is coupled to a first selection end of the switch SW1. A first end of the resistor R104 is coupled to a second end of the resistor R103. A second end of the resistor R104 is coupled to a first selection end of the switch SW2. A first end of the resistor R105 is coupled to the second end of the resistor R103 and the first end of the resistor R104. A second end of the resistor R105 is coupled to the reference voltage VSS. When the controller 102 and the multiplexer 120 do not select the channel circuit 1000, a signal will flow through the voltage dividing circuit 1010. Based on the voltage dividing operation of the voltage dividing circuit 1010, the return path noise from the corresponding selection end C4 to the selection port P4 can be attenuated, and the noise from the selection port P4 to the corresponding selection end C4 can also be attenuated.

[0060] In summary, the channel circuits in the embodiments of the present invention can selectively provide different attenuation degrees to the signals passing through the channels according to whether they are selected. For example, the unselected channel circuits can selectively provide a higher second attenuation degree to effectively reduce noise / crosstalk. The selected channel circuits can selectively provide a lower first attenuation degree.

[0061] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A multi-computer switcher, characterized in that, the multi-computer switcher includes: a controller for issuing a plurality of control signals and selection signals; and a routing device coupled to the controller, wherein the routing device includes: a plurality of selection ports; a plurality of channel circuits, wherein each of the plurality of channel circuits has a first end and a second end, the first end of each of the plurality of channel circuits is respectively coupled to one of the plurality of selection ports, and based on the plurality of control signals, a selected channel circuit among the plurality of channel circuits selectively provides a first attenuation degree, while a non-selected channel circuit among the plurality of channel circuits selectively provides a second attenuation degree higher than the first attenuation degree; a common port; and a multiplexer having a plurality of selection ends and a common end, wherein each of the plurality of selection ends of the multiplexer is respectively coupled to the second end of one of the plurality of channel circuits, the common end is coupled to the common port, and the multiplexer selects the selected channel circuit from the plurality of channel circuits based on the selection signal to couple the second end of the selected channel circuit to the common port.

2. The multi-computer switcher according to claim 1, characterized in that, any one of the plurality of channel circuits includes: a first resistor having a first end coupled to one of the plurality of selection ports, wherein the second end of the first resistor is coupled to one of the plurality of selection ends of the multiplexer; and a controllable current path circuit coupled to the first end or the second end of the first resistor, wherein the controllable current path circuit is controlled by a corresponding one of the plurality of control signals.

3. The multi-computer switcher according to claim 2, characterized in that, the controllable current path circuit includes: a switch having a first end coupled to the first end or the second end of the first resistor, wherein the switch is controlled by the corresponding control signal; and a second resistor having a first end coupled to the second end of the switch, wherein the second end of the second resistor is coupled to a reference voltage.

4. The multi-computer switcher according to claim 2, characterized in that, the controllable current path circuit includes: a second resistor having a first end coupled to the first end or the second end of the first resistor; and a switch having a first end coupled to the second end of the second resistor, wherein the second end of the switch is coupled to a reference voltage, and the switch is controlled by the corresponding control signal.

5. The multi-computer switcher according to claim 1, characterized in that, any one of the plurality of channel circuits includes: a first resistor having a first end coupled to one of the plurality of selection ports; a second resistor having a first end coupled to the second end of the first resistor, wherein the second end of the second resistor is coupled to one of the plurality of selection ends of the multiplexer; and A controllable current path circuit is coupled to the second end of the first resistor and the first end of the second resistor, wherein the controllable current path circuit is controlled by a corresponding control signal among the plurality of control signals.

6. The multi-computer switch according to claim 5, wherein, the controllable current path circuit includes: a switch, a first end of which is coupled to the second end of the first resistor and the first end of the second resistor, wherein the switch is controlled by the corresponding control signal; and a third resistor, a first end of which is coupled to the second end of the switch, wherein a second end of the third resistor is coupled to a reference voltage.

7. The multi-computer switch according to claim 1, wherein, any one of the plurality of channel circuits includes: a first switch having a first selection end, a second selection end and a first common end, wherein the first common end of the first switch is coupled to one of the plurality of selection ports, and the first switch is controlled by a corresponding control signal among the plurality of control signals; a second switch having a third selection end, a fourth selection end and a second common end, wherein the second common end of the second switch is coupled to one of the plurality of selection ends of the multiplexer, the fourth selection end of the second switch is coupled to the second selection end of the first switch, and the second switch is controlled by the corresponding control signal; and a voltage dividing circuit coupled between the first selection end of the first switch and the third selection end of the second switch.

8. The multi-computer switch according to claim 7, wherein, the voltage dividing circuit includes: a first resistor, a first end and a second end of which are respectively coupled to the first selection end of the first switch and the third selection end of the second switch; and a second resistor, a first end of which is coupled to the first end or the second end of the first resistor, wherein a second end of the second resistor is coupled to a reference voltage.

9. The multi-computer switch according to claim 7, wherein, the voltage dividing circuit includes: a first resistor having a first end coupled to the first selection end of the first switch; a second resistor having a first end coupled to the second end of the first resistor, wherein a second end of the second resistor is coupled to the third selection end of the second switch; and a third resistor having a first end coupled between the second end of the first resistor and the first end of the second resistor, wherein a second end of the third resistor is coupled to a reference voltage.

10. An operating method of a routing device, wherein, the operating method includes: selecting, by a multiplexer, a selected channel circuit from a plurality of channel circuits of the routing device to couple the selected channel circuit to a common port of the routing device, wherein a first end of each of the plurality of channel circuits is respectively coupled to one of a plurality of selection ports of the routing device, and a plurality of selection ends of the multiplexer are respectively coupled to a second end of one of the plurality of channel circuits; The first attenuation level is selectively provided by the selected channel circuit; and The second attenuation level higher than the first attenuation level is selectively provided by one of the plurality of unselected channel circuits.

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