USB interface multiplexing circuit

Abstract

The utility model provides a universal serial bus (USB) interface multiplexing circuit, which comprises a USB physical interface, a double-pole-double-throw switch connected with the USB physical interface and a main control chip connected with the double-pole-double-throw switch, and is characterized in that the USB physical interface comprises a power supply port, a grounding port and two paths of data ports, the double-pole double-throw switch comprises two paths of data input ports, four paths of data output ports, a switch enabling port and a switch control port, and the two paths of data input ports of the double-pole double-throw switch are respectively connected with the two paths of data ports of the USB physical interface; the four data output ports of the double-pole-double-throw switch comprise two USB data ports and two UART data ports, and the switch selection port of the double-pole-double-throw switch is used for selecting the two data input ports of the double-pole-double-throw switch to be conducted with the two USB data ports or the two UART data ports. According to the USB interface multiplexing circuit provided by the utility model, UART (Universal Asynchronous Receiver / Transmitter) communication also can be carried out on the USB interface.

Description

Technical Field

[0001] This utility model relates to the field of electronic devices, specifically a USB interface multiplexing circuit. Background Technology

[0002] In electronic devices, the USB (Universal Serial Bus) protocol is a widely used data transmission method, found in various electronic devices such as mobile phones, PDAs (Personal Digital Assistants), tablets, and laptops. These devices typically have a USB interface for connecting a USB data cable, enabling data transmission between the device and the USB cable. A USB data cable includes a VBUS cable, a D+ cable, a D- cable, and a GND port.

[0003] In addition, the UART (Universal Asynchronous Receiver / Transmitter) protocol is widely used in the development and debugging of electronic devices. Electronic devices are often equipped with a UART interface for connecting UART data lines, thereby enabling data transmission between the electronic device and the UART data lines. A UART data line includes at least two lines: RXT and TXD. The RXT line is used to receive serial data, and the TXD line is used to transmit serial data.

[0004] If both USB and UART interfaces are provided on an electronic device, then two interfaces are required, which will affect the appearance of the electronic device and will not meet the requirements for a thinner design. Utility Model Content

[0005] The purpose of this invention is to provide a USB interface multiplexing circuit, so that UART communication can also be performed on the USB interface.

[0006] In this embodiment of the invention, a USB interface multiplexing circuit is provided, comprising a double-pole double-throw switch connected to a USB physical interface and a main control chip connected to the double-pole double-throw switch. The USB physical interface includes a power port, a ground port, and two data ports. The double-pole double-throw switch includes two data input ports, four data output ports, a switch enable port, and a switch control port. The two data input ports of the double-pole double-throw switch are respectively connected to the two data ports of the USB physical interface. The four data output ports of the double-pole double-throw switch include two USB data ports. The system includes two UART data ports. The enable port of the double-pole double-throw switch is used to control the double-pole double-throw switch to be on or off. The select port of the double-pole double-throw switch is used to select whether the two data input ports of the double-pole double-throw switch are connected to the two USB data ports or the two UART data ports. Multiple GPIO ports of the main control chip are respectively connected to the four data output ports, the enable port, and the control port of the double-pole double-throw switch, for controlling the switching state of the double-pole double-throw switch and processing the USB or UART data input from the USB physical interface.

[0007] In this embodiment of the present invention, the power port of the USB physical interface is connected to a 5V DC power supply, and the ground port of the USB physical interface is grounded through inductor L2.

[0008] In this embodiment of the invention, the double-pole double-throw switch further includes a power port connected to a 3.3V DC power supply and a grounding port.

[0009] In this embodiment of the invention, the double-pole double-throw switch is an SGM7224.

[0010] In this embodiment of the present invention, the two data ports of the USB physical interface are grounded through TVS diodes D1 and D2, respectively.

[0011] In this embodiment of the present invention, the two data ports of the USB physical interface are respectively connected to the two data input ports of the double-pole double-throw switch via impedance matching resistors R5 and R7.

[0012] Compared with existing technologies, the USB interface multiplexing circuit of this invention uses a double-pole double-throw switch to convert the two data ports of the USB interface into either a USB data port or a UART data port, thereby realizing the multiplexing of the USB interface and enabling UART data communication on the USB interface. Furthermore, the state of the double-pole double-throw switch is controlled by the main control chip, allowing active control of the USB interface state and supporting dynamic configuration of the interface state. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of a USB interface multiplexing circuit using an embodiment of the present invention.

[0014] Figure 2 This is a schematic diagram of the structure of a double-pole double-throw switch that implements an embodiment of this utility model.

[0015] Figure 3 This is a schematic diagram illustrating the working state of the double-pole double-throw switch in this embodiment of the present invention. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0017] The implementation of this utility model will be described in detail below with reference to specific embodiments.

[0018] like Figure 1 As shown in the embodiment of this utility model, a USB interface multiplexing circuit is provided, which includes a USB physical interface J1 connected to the USB physical interface, a double-pole double-throw switch U1 connected to the USB physical interface, and a main control chip U2 connected to the double-pole double-throw switch.

[0019] The USB physical interface J1 includes a power port VCC, a ground port GND, and two data ports DN and DP. The power port VCC of the USB physical interface J1 is connected to a 5V DC power supply, and the ground port GND of the USB physical interface is grounded through inductor L2. The two data ports DN and DP of the USB physical interface J1 are grounded through TVS diodes D1 and D2, respectively.

[0020] The double-pole double-throw switch U1 includes two data input ports D+ and D-, four data output ports HSD+, HSD-, TX+, and TX-, a switch enable port OE, and a switch control port S. The two data input ports D+ and D- of the double-pole double-throw switch are connected to the two data ports of the USB physical interface, respectively. The four data output ports of the double-pole double-throw switch, including two USB data ports and two UART data ports, are connected through impedance matching resistors R5 and R7.

[0021] Furthermore, the double-pole double-throw switch U1 also includes a power port connected to a 3.3V DC power supply and a grounding port. In this embodiment of the invention, the double-pole double-throw switch is an SGM7224. Of course, other types of switches can also be used, and this invention does not impose any limitations on this.

[0022] The main control chip U2 has multiple GPIO ports that are connected to the four data output ports, switch enable port, and switch control port of the double-pole double-throw switch, respectively, to control the switching state of the double-pole double-throw switch U1 and process the USB or UART data input from the USB physical interface J1.

[0023] like Figure 2 As shown, the enable port OE of the double-pole double-throw switch U1 is used to control the double-pole double-throw switch U2 to be turned on or off. The selector port S of the double-pole double-throw switch U1 is used to select whether the two data input ports of the double-pole double-throw switch are connected to the two USB data ports or the two UART data ports.

[0024] like Figure 3 As shown, the control chip U2 controls the state of the double-pole double-throw switch U1 (high level for disconnection, low level for conduction) by controlling the switch enable port OE of the double-pole double-throw switch U1, and uses the selection S signal to achieve channel switching, with three operating states:

[0025] When OE is low and S signal is low, the double-pole double-throw switch U1 conducts the USB signal (HSD1+, HSD1-), enabling the USB signal to be turned on and the product to be recognized after being plugged into a USB device.

[0026] When OE is low and S is high, the double-pole double-throw switch U1 conducts the UART signal (TX, RX), enabling the UART signal to be turned on, allowing optical modems and routers to connect to PCs and other devices for communication debugging.

[0027] When OE is high and S signal is high / low, the double-pole double-throw switch U1 is not working, the USB signal and UART signal cannot pass through the switch, and the USB interface is in an idle standby state.

[0028] In summary, the USB interface multiplexing circuit of this invention uses a double-pole double-throw switch to convert the two data ports of the USB interface into either a USB data port or a UART data port, thereby realizing the multiplexing of the USB interface and enabling UART data communication on the USB interface. Furthermore, the state of the double-pole double-throw switch is controlled by the main control chip, allowing for active control of the USB interface state and supporting dynamic configuration of the interface state.

[0029] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A USB interface multiplexing circuit, characterized in that, The system includes a double-pole double-throw (DPDT) switch connected to a USB physical interface and a main control chip connected to the DPDT switch. The USB physical interface includes a power port, a ground port, and two data ports. The DPDT switch includes two data input ports, four data output ports, a switch enable port, and a switch control port. The two data input ports of the DPDT switch are respectively connected to the two data ports of the USB physical interface. The four data output ports of the DPDT switch include two USB data ports and two UART data ports. The double-pole double-throw switch has a switch enable port for controlling whether it is turned on or off, and a switch selection port for selecting whether its two data input ports are connected to the two USB data ports or the two UART data ports. The main control chip is connected to the four data output ports, the switch enable port, and the switch control port of the double-pole double-throw switch, respectively, and is used to control the switch state of the double-pole double-throw switch and process the USB or UART data input from the USB physical interface.

2. The USB interface multiplexing circuit of claim 1, wherein, The power port of the USB interface is connected to a 5V DC power supply, and the ground port of the USB physical interface is grounded through inductor L2.

3. The USB interface multiplexing circuit of claim 1, wherein, The double-pole double-throw switch also includes a power port connected to a 3.3V DC power supply and a grounding port.

4. The USB interface multiplexing circuit of claim 1, wherein, The double-pole double-throw switch is an SGM7224.

5. The USB interface multiplexing circuit of claim 1, wherein, The two data ports of the USB interface are grounded through TVS diodes D1 and D2, respectively.

6. The USB interface multiplexing circuit of claim 1, wherein, The two data ports of the USB interface are respectively connected to the two data input ports of the double-pole double-throw switch via impedance matching resistors R5 and R7.

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