CN215376298U

CN215376298U - Multifunctional application device of USB interface of embedded equipment

Info

Publication number: CN215376298U
Application number: CN202120686303.9U
Authority: CN
Inventors: 梁运
Original assignee: Shenzhen Fenda Intelligent Technology Co ltd
Current assignee: Shenzhen Fenda Intelligent Technology Co ltd
Priority date: 2021-04-01
Filing date: 2021-04-01
Publication date: 2021-12-31
Anticipated expiration: 2031-04-01

Abstract

The utility model provides a multifunctional application device of an embedded device USB interface, wherein the input end of an analog switch chip is connected with a USB voltage line through a divider resistor, the source input end of the analog switch chip is connected with a USB differential signal line, the output end of the analog switch chip is connected with a clock line of a Jlink interface, a data line and a differential signal line of a micro control unit, the power end of the Jlink interface is connected with a voltage conversion chip, and the output end of the voltage conversion chip is connected with a voltage reference pin of the Jlink interface. The utility model increases the efficiency of upgrading the embedded equipment and reduces the risk that the embedded equipment becomes bricks due to the failure of upgrading; the embedded equipment can be used as a development platform, so that the development process can be reduced, and the development time and the development cost can be saved; when the embedded equipment has problems, the embedded equipment can be debugged directly through the JTAG port, and the embedded equipment is favorable for quickly positioning the problems.

Description

Multifunctional application device of USB interface of embedded equipment

Technical Field

The utility model relates to the technical field of embedded equipment, in particular to a multifunctional application device of an embedded equipment USB interface.

Background

The USB interface of the current embedded equipment only serves as a charging and USB communication function, and if program upgrading is needed, the USB interface needs to be realized by a Bluetooth or USB communication function in a code carrying mode; if function debugging and simulation are needed to be carried out on the embedded equipment, disassembly operation is needed, four JTAG lines are additionally led out, and burning debugging and simulation are carried out.

At present, many embedded devices also support a USB interface to perform program upgrade, but only use the communication function of the USB to perform code transportation, and need to divide the code into a bootloader and an APP on a software layer, and after the embedded device enters the bootloader, the embedded device can perform communication modes such as USB or bluetooth, but this mode cannot perform step-by-step debugging and emulation on the program through this interface.

SUMMERY OF THE UTILITY MODEL

In order to overcome the defects of the prior art, the utility model aims to provide a multifunctional application device of an embedded device USB interface, which solves the problems that when the program of the embedded device is upgraded, a code carrying mode is needed to be used, the embedded device is realized through a Bluetooth or USB communication function, when the function of the embedded device is debugged and simulated, the device needs to be dismounted, four JTAG lines are additionally led out, and the burning debugging and the simulation are carried out.

The utility model provides a multifunctional application device of an embedded device USB interface, which comprises an analog switch module and a JTAG conversion module, wherein the analog switch module comprises an analog switch chip and a divider resistor, the JTAG conversion module comprises a Jlink interface and a voltage conversion chip, the input end of the analog switch chip is connected with a USB voltage line through the divider resistor, the source input end of the analog switch chip is connected with a USB differential signal line, the output end of the analog switch chip is connected with a clock line of the Jlink interface, a data line and a differential signal line of a micro control unit, the power end of the Jlink interface is connected with the voltage conversion chip, and the output end of the voltage conversion chip is connected with a voltage reference pin of the Jlink interface.

Furthermore, the analog switch chip is a four-single-pole single-throw analog switch chip.

Further, the four-single-pole single-throw analog switch chip comprises two normally open switches and two normally closed switches.

Furthermore, the source input ends of two normally open switches of the four-single-pole single-throw analog switch chip are connected with a USB differential signal line, and the output ends of the two normally open switches of the four-single-pole single-throw analog switch chip are connected with the differential signal line of the micro control unit.

Furthermore, the source input ends of two normally closed switches of the four-single-pole single-throw analog switch chip are connected with a USB differential signal line, and the output ends of the two normally closed switches of the four-single-pole single-throw analog switch chip are connected with a clock line and a data line of the Jlink interface.

Furthermore, the divider resistor comprises a first divider resistor and a second divider resistor, one end of the first divider resistor and one end of the second divider resistor are connected in series with the USB voltage line, the other end of the first divider resistor and the second divider resistor are grounded, and the input end of the analog switch chip is connected between the first divider resistor and the second divider resistor.

Further, the analog switch chip adopts a MAX4753 chip or a DG2503 chip.

Further, the power supply terminal voltage of the Jlink interface is 5V.

Further, the 5V voltage of the power supply end of the Jlink interface outputs 3.3V or 1.8V voltage through the voltage conversion chip.

Further, the voltage conversion chip adopts a WL2815 chip.

Compared with the prior art, the utility model has the beneficial effects that:

the utility model provides a multifunctional application device of an embedded device USB interface, which increases the upgrading efficiency of the embedded device and reduces the risk that the embedded device is changed into bricks due to upgrading failure; the embedded equipment can be directly used as a development platform, so that the development process can be shortened, and the development time and the development cost can be saved; when the embedded equipment has problems, the embedded equipment can be debugged directly through the JTAG port, and the embedded equipment is favorable for quickly positioning the problems.

The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical solutions of the present invention more clearly understood and to implement them in accordance with the contents of the description, the following detailed description is given with reference to the preferred embodiments of the present invention and the accompanying drawings. The detailed description of the present invention is given in detail by the following examples and the accompanying drawings.

Drawings

The accompanying drawings, which are included to provide a further understanding of the utility model and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the utility model and together with the description serve to explain the utility model without limiting the utility model. In the drawings:

FIG. 1 is a schematic diagram of an analog switch module of the present invention;

FIG. 2 is a schematic diagram of the JTAG conversion module of the present invention.

Detailed Description

The present invention will be further described with reference to the accompanying drawings and the detailed description, and it should be noted that any combination of the embodiments or technical features described below can be used to form a new embodiment without conflict.

A multifunctional application device of an embedded device USB interface is disclosed, as shown in FIG. 1-FIG. 2, comprising an analog switch module and a JTAG conversion module, wherein the analog switch module comprises an analog switch chip and a divider resistor, the JTAG conversion module comprises a Jlink interface and a voltage conversion chip, the input end of the analog switch chip is connected with a USB voltage line (USB _ VBUS) through the divider resistor, voltage division is carried out by using the divider resistor, the source input end of the analog switch chip is connected with a USB differential signal line, the output end of the analog switch chip is connected with a clock line and a data line of the Jlink interface and a differential signal line of a micro control unit, the power end of the Jlink interface is connected with the voltage conversion chip, and the output end of the voltage conversion chip is connected with a voltage reference pin VTREF of the Jlink interface.

As shown IN fig. 1, the voltage dividing resistor includes a first voltage dividing resistor and a second voltage dividing resistor, the first voltage dividing resistor and the second voltage dividing resistor are connected IN series, one end of the first voltage dividing resistor is connected to the USB voltage line, the other end of the first voltage dividing resistor is grounded, and the input terminals (IN 1-IN 4) of the analog switch chip are connected between the first voltage dividing resistor and the second voltage dividing resistor.

As shown in fig. 1, the analog switch chip is a four-single-pole single-throw analog switch chip, such as a MAX4753 chip or a DG2503 chip, the four-single-pole single-throw analog switch chip includes two normally-open switches (SW1 and SW4) and two normally-closed switches (SW2 and SW3), source input terminals (S1 and S4) of the two normally-open switches of the four-single-pole single-throw analog switch chip are connected to USB differential signal lines (USB _ D-and USB _ D +), in fig. 1, S1 is connected to USB _ D-, S4 is connected to USB _ D +, output terminals (D1 and D4) of the two normally-open switches of the four-single-pole single-throw analog switch chip are connected to differential signal lines (MCU _ D-and MCU _ D +) of the micro control unit, in fig. 1, D1 is connected to MCU _ D-, D4 is connected to MCU _ D +, source input terminals (S2 and S3) of the two normally-closed analog switches of the four-single-pole single-throw analog switch chip are connected to USB differential signal lines (USB _ D +), in fig. 1, S2 is connected to USB _ D-, S3 is connected to USB _ D +, the output terminals (D2 and D3) of two normally closed switches of the four-pole single-throw analog switch chip are connected to the clock line SWDCLK and the data line SWDIO of the Jlink interface, in fig. 1, D2 is connected to SWDIO, and D3 is connected to SWDCLK.

The voltage of the power supply end of the Jlink interface is 5V, the 5V voltage of the power supply end of the Jlink interface outputs 3.3V or 1.8V voltage through the voltage conversion chip, and if the voltage conversion chip adopts a WL2815 chip. As shown in fig. 2, the 5V voltage of the Jlink interface of the JTAG switch module outputs a 3.3V voltage to the VTREF pin of the Jlink interface via the voltage conversion chip. If the voltage of the MCU system of the embedded device is 1.8V, a voltage conversion chip with the output of 1.8V can be selected. The pins SWDIO and SWDCLK are respectively led out to the USB _ D +, USB _ D-of the USB interface, and the VBUS pin of the USB interface is suspended.

The utility model utilizes the voltage difference of the power supply pin (VBUS pin) of the USB interface and the JTAG interface. Specifically, as shown in fig. 2, the active pins of the JTAG interface include SWDIO, SWCLK, GND, and VTREF. The GND is grounded, SWDIO and SWCLK are clock and data lines for data transmission, and VTREF is a voltage reference pin for determining a logic high voltage during data transmission.

Since the JLINK interface has a 5V power supply, the 5V voltage is converted into 3.3V voltage which is provided to the VTREF pin as the reference voltage, and can also be converted into 1.8V or other levels according to the system voltage, so that the JTAG interface pins from the JLINK switching module become SWDIO, SWCLK, GND and NULL.

As shown in fig. 1, since the voltage of the power pin of the USB interface is 5V, and the power pin (VBUS pin) of the JTAG interface converted by the JTAG adapter module is floating, the power pin is used for identification and selection. When the USB interface is plugged into the USB cable, IN 1-IN 4 are logic high, switches SW1 and SW4 are turned on, and SW2 and SW3 are turned off, so that the USB interface is used as a normal USB function for charging and USB communication. When the USB interface is connected with the JTAG interface, the IN 1-IN 4 are logic low level, the switch SW1 and the switch SW4 are switched off, the switch SW2 and the switch SW3 are switched on, the USB interface is used for the JTAG function, and the operations of burning, step-by-step debugging simulation and the like can be carried out on the watch through the USB interface.

If a universal USB interface function is needed, the USB cable is directly connected to the USB interface of fig. 1 to implement USB communication and charging functions. If a Jlink function is needed, the JTAG adapter board in fig. 2 is connected to the USB interface in fig. 1, so that the debugging and simulation function of Jlink can be realized. When the USB interface is plugged into the USB cable, IN 1-IN 4 are at high voltage, i.e. logic high level, switches SW1 and SW4 are turned on, and SW2 and SW3 are turned off, so that the USB interface is used as a normal USB function for charging and USB communication. When the USB interface is connected with the JTAG interface, the voltages of IN 1-IN 4 are zero and are logic low level, the switches SW1 and SW4 are turned off, and SW2 and SW3 are turned on, and at the moment, the USB interface is used for JTAG function, and the embedded equipment can be burned and debugged and simulated step by step through the interface.

The foregoing is merely a preferred embodiment of the utility model and is not intended to limit the utility model in any manner; those skilled in the art can readily practice the utility model as shown and described in the drawings and detailed description herein; however, those skilled in the art should appreciate that they can readily use the disclosed conception and specific embodiments as a basis for designing or modifying other structures for carrying out the same purposes of the present invention without departing from the scope of the utility model as defined by the appended claims; meanwhile, any changes, modifications, and evolutions of the equivalent changes of the above embodiments according to the actual techniques of the present invention are still within the protection scope of the technical solution of the present invention.

Claims

1. A multifunctional application device of an embedded device USB interface is characterized in that: the voltage conversion circuit comprises an analog switch module and a JTAG conversion module, wherein the analog switch module comprises an analog switch chip and a divider resistor, the JTAG conversion module comprises a Jlink interface and a voltage conversion chip, the input end of the analog switch chip is connected with a USB voltage line through the divider resistor, the source input end of the analog switch chip is connected with a USB differential signal line, the output end of the analog switch chip is connected with a clock line and a data line of the Jlink interface and a differential signal line of a micro control unit, the power supply end of the Jlink interface is connected with the voltage conversion chip, and the output end of the voltage conversion chip is connected with a voltage reference pin of the Jlink interface.

2. The multifunctional application apparatus of an embedded device USB interface of claim 1, wherein: the analog switch chip is a four-single-pole single-throw analog switch chip.

3. The multifunctional application apparatus of the USB interface of the embedded device according to claim 2, wherein: the four-single-pole single-throw analog switch chip comprises two normally open switches and two normally closed switches.

4. The multifunctional application apparatus of the embedded device USB interface of claim 3, wherein: the source input ends of two normally open switches of the four-single-pole single-throw analog switch chip are connected with a USB differential signal line, and the output ends of the two normally open switches of the four-single-pole single-throw analog switch chip are connected with the differential signal line of the micro control unit.

5. The multifunctional application apparatus of the embedded device USB interface of claim 3, wherein: the source input ends of two normally closed switches of the four-single-pole single-throw analog switch chip are connected with a USB differential signal line, and the output ends of the two normally closed switches of the four-single-pole single-throw analog switch chip are connected with a clock line and a data line of the Jlink interface.

6. The multifunctional application apparatus of an embedded device USB interface of claim 1, wherein: the voltage dividing resistor comprises a first voltage dividing resistor and a second voltage dividing resistor, one end of the first voltage dividing resistor is connected with the USB voltage line after the second voltage dividing resistor is connected in series, the other end of the first voltage dividing resistor is grounded, and the input end of the analog switch chip is connected between the first voltage dividing resistor and the second voltage dividing resistor.

7. The multifunctional application apparatus of an embedded device USB interface of claim 1, wherein: the analog switch chip adopts a MAX4753 chip or a DG2503 chip.

8. The multifunctional application apparatus of an embedded device USB interface of claim 1, wherein: and the voltage of a power supply end of the Jlink interface is 5V.

9. The multifunctional application apparatus of an embedded device USB interface of claim 8, wherein: and the 5V voltage of the power supply end of the Jlink interface outputs 3.3V or 1.8V voltage through the voltage conversion chip.

10. The multifunctional application apparatus of the USB interface of the embedded device according to claim 9, wherein: the voltage conversion chip adopts a WL2815 chip.