CN107818067B

CN107818067B - Interface multiplexing system

Info

Publication number: CN107818067B
Application number: CN201710996827.6A
Authority: CN
Inventors: 蒲周平; 叶声明; 陈啟俊; 黄勇; 李钢祥
Original assignee: Guangzhou Xike Medical Technology Co Ltd; Guangzhou Shiyuan Electronics Thecnology Co Ltd
Current assignee: Guangzhou Shichuang Display Technology Co.,Ltd.
Priority date: 2017-10-20
Filing date: 2017-10-20
Publication date: 2020-01-10
Anticipated expiration: 2037-10-20
Also published as: CN107818067A

Abstract

The embodiment of the invention discloses an interface multiplexing system, which comprises an MCU module, a switch module and k access modules, wherein the switch module comprises a analog switches, and the MCU module comprises a IO interfaces; each analog switch comprises a public end, a control end and f switching ends, the public end of each analog switch is correspondingly connected with each IO interface of the MCU module, and each switching end of each analog switch is respectively connected with one of the access modules; each analog switch is used for connecting a common end of the analog switch with one of the switching ends according to a control signal received by a control end of the analog switch, so that the corresponding IO interface is connected with one of the access modules through the analog switch; k is larger than or equal to 1, a is larger than or equal to 1, f is larger than or equal to 2, the problem of resource waste caused by excessive occupation of the IO interface of the existing MCU can be effectively solved, the multiplexing of the IO interface can be realized, and the practicability is high.

Description

Interface multiplexing system

Technical Field

The invention relates to the field of single-chip microcomputers, in particular to an interface multiplexing system.

Background

In the medical display device, the medical display device often needs to have a lamp box function, that is, when a doctor takes an X-ray film, the X-ray film is inserted into a film clip of the medical display device. When the MCU in the medical display detects that the film is inserted through the detection switch, the display picture is switched into a highlighted white field picture, and then the medical display enters a lamp box mode. The medical display has a user interface, which is two types of mechanical keys and touch keys, as a common display. The touch key is used as one of user interfaces, and the problem of upgrading a touch key program exists in the research and development process or the later maintenance process. The existing schemes mainly comprise the following two types:

(1) as shown in fig. 1, the detection switch for the lamp box mode is connected to the medical display MCU, and the touch key MCU is not connected to the medical display MCU. The medical display MCU opens the lamp box function when detecting that the detection switch is triggered, the touch key MCU does not occupy the IO interface of the medical display MCU, the touch key MCU program is cured, and the function of later upgrading is not available. The touch key has no upgrading function, and although the touch key can realize the interaction with a user, the touch key has the problem that the program upgrading cannot be carried out. If upgrading is needed, dismantling is needed, and maintenance cost and difficulty in the later period are increased.

(2) As shown in fig. 2, the detection switch for the light box mode is connected to the medical display MCU, and the medical display MCU turns on the light box function when detecting that the detection switch is triggered; the touch key upgrading interface is connected with the medical display MCU and used for upgrading the touch key MCU program during research and development and later maintenance. The detection switch and the touch key MCU respectively occupy the IO interface of the medical display MCU, so that the resource waste problem of the IO interface can be caused, and meanwhile, the medical display MCU is far away from the touch key MCU, so that the condition that wires in the machine are increased can be caused, and the assembly is not facilitated.

Disclosure of Invention

The embodiment of the invention aims to provide an interface multiplexing system, which can effectively solve the problem of resource waste caused by excessive occupation of the existing IO interface and can realize the multiplexing of the IO interface.

In order to achieve the above object, an embodiment of the present invention provides an interface multiplexing system, including an MCU module, a switch module and k access modules, where the switch module includes a analog switches, and the MCU module includes a IO interfaces; each analog switch comprises a public end, a control end and f switching ends, the public end of each analog switch is correspondingly connected with each IO interface of the MCU module, and each switching end of each analog switch is respectively connected with one of the access modules; each analog switch is used for connecting a common terminal of the analog switch with one of the switching terminals according to a control signal received by a control terminal of the analog switch, so that the corresponding IO interface is connected with one of the access modules through the analog switch; wherein k is more than or equal to 1, a is more than or equal to 1, and f is more than or equal to 2.

Compared with the prior art, the interface multiplexing system disclosed by the invention has the advantages that the common end of each analog switch is correspondingly connected with each IO interface of the MCU module, and each switching end of each analog switch is respectively connected with one of the access modules; each analog switch is used for making analog switch's common port and one of them switch over the end connection according to the control signal that analog switch's control end received to make correspond the IO interface passes through analog switch and one of them the access module is connected, can effectively solve current MCU's IO interface and occupy too much and cause the problem of wasting of resources, can realize the multiplexing of IO interface, and the practicality is strong.

As an improvement of the above scheme, a is 1, the analog switch is a single-pole double-throw switch, f is 2, and each switching terminal of the analog switch is correspondingly connected to each access module.

As an improvement of the above scheme, a is 1, the analog switch is a single-pole triple-throw switch, f is 3, and each switching end of the analog switch is correspondingly connected to each access module.

As an improvement of the above scheme, a is 2, the switch module includes a first analog switch and a second analog switch, the first analog switch and the second analog switch are both single-pole double-throw switches, and f is k is 2, then the k access modules include a first access module and a second access module, the MCU module includes a first IO interface and a second IO interface, the first analog switch includes a first common terminal, a first switching terminal, a second switching terminal and a first control terminal, the second analog switch includes a second common terminal, a third switching terminal, a fourth switching terminal and a second control terminal, the first IO interface is connected to the first common terminal, and the second IO interface is connected to the second common terminal; the first switching end and the third switching end are respectively connected with the first access module, and the second switching end and the fourth switching end are respectively connected with the second access module;

when a first control end of the first analog switch receives a high-level signal, the first common end is connected with a first switching end, so that the first IO interface is connected with the first access module through the first analog switch; when the first control end receives a low level signal, the first common end is connected with the second switching end, so that the first IO interface is connected with the second access module through the first analog switch; when a second control end of the second analog switch receives a high-level signal, the second common end is connected with the third switching end, so that the second IO interface is connected with the first access module through the second analog switch; when the second control terminal receives a low level signal, the second common terminal is connected with the fourth switching terminal, so that the second IO interface is connected with the second access module through the second analog switch.

As an improvement of the above solution, the interface multiplexing system further includes a first dc power supply, a first resistor, a second resistor, a first detection switch, and a second detection switch, wherein a first end of the first detection switch is connected to the first dc power supply through the first resistor, a first end of the second detection switch is connected to the first dc power supply through the second resistor, a second end of the first detection switch is connected to ground, and a second end of the second detection switch is connected to ground; the first end part of the first detection switch is connected with the first control end, and the first end part of the second detection switch is connected with the second control end;

when the first detection switch is closed, the first end part of the first detection switch outputs a low-level signal to the first control end, so that the first common end is connected with the second switching end; when the first detection switch is turned off, the first end of the first detection switch outputs a high-level signal to the first control end, so that the first common end is connected with the first switching end;

when the second detection switch is closed, the first end of the second detection switch outputs a low-level signal to the second control end, so that the second common end is connected with the fourth switching end; when the second detection switch is turned off, the first end of the second detection switch outputs a high level signal to the second control end, so that the second common end is connected with the third switching end.

As an improvement of the above scheme, the second access module includes a first ground terminal and a second ground terminal, the second switching terminal is connected to ground through the first ground terminal, and the fourth switching terminal is connected to ground through the second ground terminal.

As an improvement of the above scheme, the interface multiplexing system further includes a second dc power supply, a third resistor, a fourth resistor, a fifth resistor, and a sixth resistor, where the second dc power supply is connected to the first common terminal through the third resistor, the second dc power supply is connected to the second common terminal through the fourth resistor, the third dc power supply is connected to the first switching terminal through the fifth resistor, and the third dc power supply is connected to the third switching terminal through the sixth resistor; when the first detection switch and the second detection switch are turned off, the first end of the first detection switch outputs a high level signal to the first control end of the first analog switch, and the first end of the second detection switch outputs a high level signal to the second control end of the second analog switch, so that the first common end of the first analog switch is connected with the first switching end of the first analog switch, the second common end of the second analog switch is connected with the third switching end of the second analog switch, and the levels of the first IO interface and the second IO interface are both high levels; when the first detection switch and the second detection switch are closed, the first end of the first detection switch outputs a low level signal to the first control end of the first analog switch, and the first end of the second detection switch outputs a low level signal to the second control end of the second analog switch, so that the first common end of the first analog switch is connected with the second switching end of the first analog switch, the second common end of the second analog switch is connected with the fourth switching end of the second analog switch, and the levels of the first IO interface and the second IO interface are both low levels.

As an improvement of the above scheme, the first access module is a touch key device, the touch key device includes a first upgrade interface and a second upgrade interface, the first upgrade interface is connected to the first switching end of the first analog switch, and the second upgrade interface is connected to the third switching end of the second analog switch.

As an improvement of the above scheme, the interface multiplexing system further comprises a display screen, and the display screen is connected with the MCU module;

the MCU module is used for detecting whether an upgrade file is accessed or not when the computer is started; when the upgrade file is detected to be accessed, setting the first IO interface and the second IO interface as output modes, confirming that the first IO interface and the second IO interface are both connected with the touch key equipment, and upgrading the touch key equipment through the first IO interface and the second IO interface; when the upgrade file is not detected, setting the first IO interface and the second IO interface as input modes; under the condition that the first IO interface and the second IO interface are in an input mode, the level of the first IO interface and the level of the second IO interface are detected at preset frequency, and when the level of the first IO interface and the level of the second IO interface are detected to be low level at any moment, the highlight mode of the display screen is started.

As an improvement of the above scheme, the closing of the detection switch is triggered by the insertion of a film in front of the display screen, and the opening of the detection switch is triggered by the extraction of the film in front of the display screen.

Drawings

Fig. 1 is a schematic structural diagram of a conventional medical display device.

Fig. 2 is another schematic structural diagram of a conventional medical display device.

Fig. 3 is a schematic structural diagram of an interface multiplexing system in embodiment 1 of the present invention.

Fig. 4 is a schematic structural diagram of an interface multiplexing system in embodiment 2 of the present invention.

Fig. 5 is a schematic diagram of an implementation process in embodiment 2 of the present invention.

Fig. 6 is a schematic diagram of another embodiment of the present invention in example 2.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without any inventive step, are within the scope of the present invention.

Referring to fig. 3, which is a schematic structural diagram of an interface multiplexing system provided in embodiment 1 of the present invention, including an MCU module 11, a switch module 12, and k access modules 13, where the switch module 12 includes a analog switches 120, and the MCU module 11 includes a IO interfaces; each analog switch 120 includes a common terminal, a control terminal, and f switching terminals, the common terminal of each analog switch 120 is correspondingly connected to each IO interface of the MCU module 11, and each switching terminal of each analog switch 120 is connected to one of the access modules 13; each analog switch 120 is configured to connect the common terminal of the analog switch 120 to one of the switching terminals according to a control signal received by the control terminal of the analog switch 120, so that the corresponding IO interface is connected to one of the access modules 13 through the analog switch 120; wherein k is more than or equal to 1, a is more than or equal to 1, and f is more than or equal to 2.

It should be noted that the switch module 12 may be implemented by a chip, and the chip may include a plurality of one-to-many analog switches, or a plurality of one-to-many analog switches, such as a double-pole four-throw switch, etc., but it is still recognized that the plurality of one-to-many analog switches are formed by a plurality of one-to-many analog switches. It should be noted that, the analog switch is a switch that uses a MOS transistor to turn off or on a signal link, so as to complete a signal switching function in the signal link, and the analog switch is called an analog switch because its function is similar to a switch and is implemented by the characteristics of an analog device.

Based on the above scheme, through the switching of the common terminal of each analog switch 120, the multiplexing of the IO interface can be realized, the practicability is strong, the realization is easy, and the problem of effectively solving

Preferably, a is 1, the analog switch 120 is a single-pole triple-throw switch, and f is 3, and each switching terminal of the analog switch is correspondingly connected to each of the access modules 13. It can be understood that, when the analog switch 12 is a single-pole triple-throw switch, there are a common terminal and three switching terminals, each switching terminal is correspondingly connected to each access module 13, and the IO interface of the MCU module 11 can be controlled to be connected to one of the access modules 13 by controlling a control signal, so that the IO interface can be multiplexed with the three access modules.

Preferably, a is 1, the analog switch is a single-pole double-throw switch 120, f is 2, and each switching terminal of the analog switch 120 is correspondingly connected to each access module 13. The k access modules 13 include a first access module and a second access module, and the f switching terminals include a first switching terminal and a second switching terminal; the first switch end of the analog switch 120 is connected to the first access module, the second switch end of the analog switch 120 is connected to the second access module, and f is 2. When the control terminal of the analog switch 120 receives a high level signal, the common terminal of the analog switch 120 is connected to the first switching terminal of the analog switch 12, so that the IO interface of the MCU module 11 is connected to the first access module through the analog switch 120; when the control terminal of the analog switch 120 receives a low level signal, the common terminal of the analog switch 120 is connected to the second switching terminal of the analog switch 120, so that the IO interface of the MCU module 11 is connected to the second access module through the analog switch 120. The high level and the low level are used as control signals, so that the controllability is high, the circuit is simple, the realization and the popularization are easy, and the practicability is higher.

Referring to fig. 4, which is a schematic structural diagram of an interface multiplexing system in embodiment 2 of the present invention, including an MCU module 11, a switch module 12, a first access module 131, and a second access module 132; a is 2, the switch module 12 includes a first analog switch 121 and a second analog switch 122, both the first analog switch 121 and the second analog switch 122 are single-pole double-throw switches, and f is k is 2, then the k access modules include a first access module 131 and a second access module 132, the MCU module 11 includes a first IO interface IO1 and a second IO interface IO2, the first analog switch 121 includes a first common terminal G1, a first switching terminal C1, a second switching terminal C2 and a first control terminal S0, the second analog switch 122 includes a second common terminal G2, a third switching terminal C3, a fourth switching terminal C4 and a second control terminal S1, the first IO interface IO1 is connected to the first common terminal G1, and the second IO interface 2 is connected to the second common terminal G2; the first switch terminal C1 and the third switch terminal C3 are respectively connected to the first access module 131, and the second switch terminal C2 and the fourth switch terminal C4 are respectively connected to the second access module 132.

It will be appreciated that the first analog switch 121 and the second analog switch 122 together form a double pole, four throw switch.

When the first control terminal S0 of the first analog switch 121 receives a high-level signal, the first common terminal G1 is connected to the first switch terminal C1, so that the first IO interface IO1 is connected to the first access module 131 through the first analog switch 121; when the first control terminal S0 receives a low level signal, the first common terminal G1 is connected to the second switch terminal C2, so that the first IO interface IO1 is connected to the second access module 132 through the first analog switch 121; when the second control terminal S1 of the second analog switch 122 receives a high-level signal, the second common terminal G2 is connected to the third switching terminal C3, so that the second IO interface IO2 is connected to the first access module 131 through the second analog switch 122; when the second control terminal S1 receives a low level signal, the second common terminal G2 is connected to the fourth switch terminal C4, so that the second IO interface IO2 is connected to the second access module 132 through the second analog switch 122.

The interface multiplexing system further comprises a first direct current power supply VCC1, a first resistor R1, a second resistor R2, a first detection switch SW1 and a second detection switch SW2, wherein a first end of the first detection switch SW1 is connected with the first direct current power supply VCC1 through the first resistor R1, a first end of the second detection switch SW2 is connected with the first direct current power supply VCC1 through the second resistor R2, a second end of the first detection switch SW1 is connected with ground, and a second end of the second detection switch SW2 is connected with ground; a first end of the first detecting switch SW1 is connected to the first control terminal S0, and a first end of the second detecting switch SW2 is connected to the second control terminal S1;

it is understood that when the first sensing switch SW1 is closed, the first terminal of the first sensing switch SW1 outputs a low level signal to the first control terminal S0, so that the first common terminal G1 is connected to the second switching terminal C2; when the first sensing switch SW1 is turned off, the first terminal of the first sensing switch SW1 outputs a high level signal to the first control terminal S0, thereby connecting the first common terminal G1 to the first switching terminal C1;

similarly, when the second sensing switch SW2 is closed, the first terminal of the second sensing switch SW2 outputs a low level signal to the second control terminal S1, so that the second common terminal G2 is connected to the fourth switching terminal C4; when the second sensing switch SW2 is turned off, the first terminal of the second sensing switch outputs a high level signal to the second control terminal S1, so that the second common terminal G2 is connected to the third switching terminal C3.

The second access module 132 includes a first ground terminal I1 and a second ground terminal I2, the second switch terminal C2 is connected to ground through the first ground terminal I1, and the fourth switch terminal C4 is connected to ground through the second ground terminal I2.

The interface multiplexing system further includes a second dc power VCC2, a third dc power VCC3, a third resistor R3, a fourth resistor R4, a fifth resistor R5 and a sixth resistor R6, the second dc power VCC2 passes through the third resistor R3 and the first common terminal G1 are connected, the second dc power VCC2 passes through the fourth resistor R4 and the second common terminal G2 is connected, the third dc power VCC3 passes through the fifth resistor R5 and the first switch terminal C1 is connected, and the third dc power VCC3 passes through the sixth resistor R6 and the third switch terminal C3 is connected.

The switch module 12 specifically works as follows: as shown in fig. 5, when the first detection switch SW1 and the second detection switch SW2 are turned off, the first end of the first detection switch SW1 outputs a high level signal to the first control terminal S0 of the first analog switch 121, and the first end of the second detection switch SW2 outputs a high level signal to the second control terminal S1 of the second analog switch 122, so that the first common terminal G1 of the first analog switch 121 is connected to the first switching terminal C1 of the first analog switch 121, the second common terminal G2 of the second analog switch 122 is connected to the third switching terminal C3 of the second analog switch 122, and then the levels of the first IO interface IO1 and the second IO interface IO2 are both high; as shown in fig. 6, when the first detection switch SW1 and the second detection switch SW2 are closed, the first end of the first detection switch SW1 outputs a low level signal to the first control terminal S0 of the first analog switch 121, and the first end of the second detection switch SW2 outputs a low level signal to the second control terminal S1 of the second analog switch 122, so that the first common terminal G1 of the first analog switch 121 is connected to the second switching terminal C2 of the first analog switch 121, the second common terminal G2 of the second analog switch 122 is connected to the fourth switching terminal C4 of the second analog switch 122, and then the levels of the first IO interface IO1 and the second IO interface IO2 are both low levels.

Preferably, the first access module 131 is a touch key device, the touch key device includes a first upgrade interface T1 and a second upgrade interface T2, the first upgrade interface T1 is connected to the first switching terminal C1 of the first analog switch 121, and the second upgrade interface T2 is connected to the third switching terminal C3 of the second analog switch 122.

It is understood that the interface multiplexing system preferably further includes a display screen, and the display screen is connected to the MCU module 11. In medical display devices, the display screen has a light box function, and a common application is that when a film (X-ray film) is inserted, the display automatically switches to a highlighted white field picture. In this embodiment, the first detecting switch SW1 and the second detecting switch SW2 are used to detect whether a film is inserted into a film clip of a medical display, that is, the first detecting switch SW1 and the second detecting switch SW2 are triggered to be closed when the film is inserted into the front of the display screen, and the first detecting switch SW1 and the second detecting switch SW2 are triggered to be opened when the film is pulled out of the front of the display screen.

Through the above scheme, the first detection switch SW1 and the second detection switch SW2 are no longer used as control signals for directly controlling the MCU to turn on the light box, but are used as control signals of the analog switch 12, and the MCU detects the level of the IO interface to determine whether to turn on the light box, and the specific process is as follows:

when starting up, detecting whether an upgrade file is accessed; when the upgrade file access is detected, setting the first IO interface IO1 and the second IO interface IO2 as output modes, confirming that the first IO interface IO1 and the second IO interface IO2 are both connected with the touch key device, and performing upgrade operation on the touch key device through the first IO interface IO1 and the second IO interface IO 2; when the upgrade file is not detected, setting the first IO interface IO1 and the second IO interface IO2 as input modes; under the condition that first IO interface IO1 and second IO interface IO2 are input mode, detect with predetermined frequency the level of first IO interface IO1 and second IO interface IO2, detect at any moment when the level of first IO interface IO1 and second IO interface IO2 is the low level, then open the high bright mode of display screen.

Based on the scheme, under the condition of saving IO interface resources, the touch key equipment can be upgraded without disassembling the machine, and the method is simple, feasible and high in practicability. On the other hand, the first detection switch SW1 and the second detection switch SW2 are not directly connected with the MCU module 11, so that the anti-static performance of the whole device is enhanced. In addition, the multiplexing of IO interface can also reduce built-in wire rod, more does benefit to the assembly when practicing thrift the consumptive material.

In another preferred embodiment, the first access module 131 includes a seventh resistor and an eighth resistor, one end of the seventh resistor is connected to the second switching terminal C2C2, and the other end of the seventh resistor is connected to ground; one end of the eighth resistor is connected to the fourth switching terminal C4C4, and the other end of the eighth resistor is connected to ground. The seventh resistor and the eighth resistor can be used as protection resistors to prevent short circuit caused by circuit failure.

In another preferred embodiment, the second access module 132 may further include 4 detection switches, and the number of the analog switches 120 (for example, 2 analog switches or 4 analog switches) may be adjusted according to the needs of actual situations, which is not described herein again.

To sum up, the embodiment of the present invention discloses an interface multiplexing system, wherein a common terminal of each analog switch is correspondingly connected to each IO interface of the MCU module, and each switching terminal of each analog switch is connected to one of the access modules; each analog switch is used for making according to the control signal that analog switch's control end received analog switch's common port and one of them the switching end is connected to make correspond the IO interface passes through analog switch and one of them the access module is connected, can effectively solve current MCU's IO interface and occupy too much and cause the problem of wasting of resources, can realize the multiplexing of IO interface, the practicality is strong.

While the foregoing is directed to the preferred embodiment of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention.

Claims

1. An interface multiplexing system is characterized by comprising an MCU module, a switch module and k access modules, wherein the switch module comprises a analog switches, and the MCU module comprises a IO interfaces; each analog switch comprises a public end, a control end and f switching ends, the public end of each analog switch is correspondingly connected with each IO interface of the MCU module, and each switching end of each analog switch is respectively connected with one of the access modules; each analog switch is used for connecting a common end of the analog switch with one of the switching ends according to a control signal received by a control end of the analog switch, so that the corresponding IO interface is connected with one of the access modules through the analog switch; wherein k is more than or equal to 1, a is more than or equal to 1, and f is more than or equal to 2.

2. The interface multiplexing system according to claim 1, wherein a-1, the analog switch is a single-pole double-throw switch, and f-k-2, and each switching terminal of the analog switch is correspondingly connected to each access module.

3. The interface multiplexing system according to claim 1, wherein a-1, the analog switch is a single-pole-triple-throw switch, and f-k-3, and each switching terminal of the analog switch is correspondingly connected to each access module.

4. The interface multiplexing system according to claim 1, wherein a is 2, the switch module includes a first analog switch and a second analog switch, the first analog switch and the second analog switch are both single-pole double-throw switches, and f is k is 2, then the k access modules include a first access module and a second access module, the MCU module includes a first IO interface and a second IO interface, the first analog switch includes a first common terminal, a first switching terminal, a second switching terminal and a first control terminal, the second analog switch includes a second common terminal, a third switching terminal, a fourth switching terminal and a second control terminal, the first IO interface is connected to the first common terminal, and the second IO interface is connected to the second common terminal; the first switching end and the third switching end are respectively connected with the first access module, and the second switching end and the fourth switching end are respectively connected with the second access module;

5. The interface multiplexing system of claim 4, further comprising a first DC power supply, a first resistor, a second resistor, a first detection switch, and a second detection switch, wherein a first end of the first detection switch is connected to the first DC power supply through the first resistor, a first end of the second detection switch is connected to the first DC power supply through the second resistor, a second end of the first detection switch is connected to ground, and a second end of the second detection switch is connected to ground; the first end part of the first detection switch is connected with the first control end, and the first end part of the second detection switch is connected with the second control end;

6. The interface multiplexing system of claim 5,

the second access module comprises a first grounding end and a second grounding end, the second switching end is connected with the ground through the first grounding end, and the fourth switching end is connected with the ground through the second grounding end.

7. The interface multiplexing system of claim 6, wherein the interface multiplexing system further comprises a second dc power supply, a third resistor, a fourth resistor, a fifth resistor, and a sixth resistor, wherein the second dc power supply is connected to the first common terminal through the third resistor, the second dc power supply is connected to the second common terminal through the fourth resistor, the third dc power supply is connected to the first switching terminal through the fifth resistor, and the third dc power supply is connected to the third switching terminal through the sixth resistor; when the first detection switch and the second detection switch are disconnected, the first end of the first detection switch outputs a high level signal to the first control end of the first analog switch, and the first end of the second detection switch outputs a high level signal to the second control end of the second analog switch, so that the first common end of the first analog switch is connected with the first switching end of the first analog switch, the second common end of the second analog switch is connected with the third switching end of the second analog switch, and the levels of the first IO interface and the second IO interface are both high levels; when the first detection switch and the second detection switch are closed, the first end of the first detection switch outputs a low level signal to the first control end of the first analog switch, and the first end of the second detection switch outputs a low level signal to the second control end of the second analog switch, so that the first common end of the first analog switch is connected with the second switching end of the first analog switch, the second common end of the second analog switch is connected with the fourth switching end of the second analog switch, and then the levels of the first IO interface and the second IO interface are both low levels.

8. The interface multiplexing system of claim 7, wherein the first access module is a touch key device, the touch key device comprises a first upgrade interface and a second upgrade interface, the first upgrade interface is connected to the first switching end of the first analog switch, and the second upgrade interface is connected to the third switching end of the second analog switch.

9. The interface multiplexing system of claim 8, wherein said interface multiplexing system further comprises a display screen, said display screen being connected to said MCU module;

10. The interface multiplexing system of claim 9 wherein the closing of the detection switch is triggered by the insertion of film in front of the display screen and the opening of the detection switch is triggered by the extraction of film out of front of the display screen.