USB interface control circuit

Abstract

The utility model relates to the technical field of USB (Universal Serial Bus) interfaces, in particular to a USB interface control circuit, which comprises a main control circuit, a switch switching circuit, a key circuit and a USB port circuit, the key circuit is electrically connected with the main control circuit, and the switch switching circuit is in communication connection with the main control circuit; the switch switching circuit is controlled through the main control circuit, and intelligent switching between the USB channel and the UART channel is achieved. Only a single USB port on the device is ingeniously utilized, the device is flexibly switched between two interface modes, physical disassembly of the device is avoided, and the risk of hardware damage is effectively reduced. Through the design, the user experience is greatly improved, the maintenance process is greatly simplified, the problems of physical damage, electrostatic damage, improper installation and the like possibly caused by disassembly are solved, and the integrity of equipment is powerfully guaranteed. The USB mode can be easily switched to the UART mode by a user through simple operation, necessary upgrading or debugging work can be completed, and the user does not need to worry about any physical damage to equipment.

Description

TECHNICAL FIELD

[0001] The utility model relates to USB interface technical field, concretely relates to a USB interface control circuit. BACKGROUND

[0002] In the current rapidly developing field of electronic products, in order to meet the needs of users for functionality and convenience, manufacturers are constantly exploring and adopting new technical means to optimize product performance. However, in this process, certain design limitations may affect user experience and the convenience of technical maintenance. This problem is particularly prominent when it comes to product firmware upgrades and debugging.

[0003] Some electronic devices, due to their specific design philosophy or cost control factors, choose not to support upgrading or debugging through Universal Serial Bus (USB), but rely on more traditional Universal Asynchronous Receiver / Transmitter (UART) serial ports to achieve these operations. UART, as a widely used interface standard, can effectively complete serial communication of data and is suitable for low to medium speed data transmission scenarios. However, this choice brings several significant problems.

[0004] Firstly, such devices usually only provide a USB port on the shell as the only external interface, without directly providing a physical interface for UART connection. This means that whenever firmware upgrades or debugging operations are needed for the device, technicians have to disassemble the device shell to access the UART interface on the internal circuit board. This process not only takes time and effort, but also greatly increases the risk of hardware damage. For example, it may cause physical damage such as scratches, cracks, or even breakage of the shell; more seriously, electrostatic discharge (ESD) during disassembly can cause permanent damage to internal electronic components. In addition, improper reassembly can also affect the overall performance and stability of the device. SUMMARY

[0005] The utility model discloses a USB interface control circuit with simple circuit structure to solve the defects and deficiencies of prior art.

[0006] To achieve the above-mentioned purpose, the utility model takes the technical scheme that a USB interface control circuit, including main control circuit, switch switching circuit, keying circuit and USB port circuit, the keying circuit is connected with main control circuit, the switch switching circuit is connected with main control circuit communication, the USB port circuit is connected with switch switching circuit.

[0007] Further, the main control circuit comprises a main control chip, a first resistor, a second resistor and a first capacitor, a fifth pin of the main control chip is electrically connected with the key circuit, a sixth pin, a seventh pin and an eighth pin of the main control chip are electrically connected with the switch switching circuit; one end of the first resistor is electrically connected with a fourth pin of the main control chip, and the other end of the first resistor is electrically connected with the switch switching circuit, one end of the second resistor is electrically connected with the switch switching circuit, and the other end of the second resistor is electrically connected with a third pin of the main control chip.

[0008] Further, the switch switching circuit comprises a switch chip, a second capacitor, a third capacitor, a third resistor, a fourth resistor and a fifth resistor; a first pin of the switch chip is connected with a 3.3V voltage, a fifth pin of the switch chip is grounded, the second capacitor and the third capacitor are connected in parallel, one end of the second capacitor and the third capacitor is electrically connected with the first pin of the switch chip, and the other end of the second capacitor and the third capacitor is electrically connected with the fifth pin of the switch chip; one end of the third resistor is electrically connected with a tenth pin of the switch chip, and the other end of the third resistor is grounded, one end of the fourth resistor is electrically connected with a second pin of the switch chip, and the other end of the fourth resistor is electrically connected with the sixth pin of the main control chip; one end of the fifth resistor is electrically connected with the first pin of the switch chip, and the other end of the fifth resistor is electrically connected with the fourth resistor; a third pin and a fourth pin of the switch chip are electrically connected with the USB port circuit, a sixth pin of the switch chip is electrically connected with the second resistor; a seventh pin of the switch chip is electrically connected with the first resistor, an eighth pin of the switch chip is electrically connected with the seventh pin of the main control chip, and a ninth pin of the switch chip is electrically connected with the eighth pin of the main control chip.

[0009] Further, the USB port circuit comprises a USB interface, a fourth capacitor, a fifth capacitor, a sixth capacitor, a seventh capacitor, an eighth capacitor, a sixth resistor, a seventh resistor, a fuse, a first TVS protection diode and a second TVS protection diode; one end of the sixth resistor is electrically connected with the second pin of the USB interface, and the other end is electrically connected with the fourth pin of the switch chip; one end of the seventh resistor is electrically connected with the third pin of the USB interface, and the other end is electrically connected with the third pin of the switch chip; one end of the fourth capacitor is grounded, and the other end is electrically connected with the second pin of the USB interface; one end of the fifth capacitor is grounded, and the other end is electrically connected with the third pin of the USB interface; one end of the fuse is connected with a 5V voltage, and the other end is electrically connected with the first pin of the USB interface; the sixth capacitor, the seventh capacitor and the eighth capacitor are connected in parallel, one end is grounded, and the other end is electrically connected with the fuse; one end of the first TVS protection diode is grounded, and the other end is electrically connected with the second pin of the USB interface; one end of the second TVS protection diode is grounded, and the other end is electrically connected with the third pin of the USB interface; the fourth pin, the fifth pin and the sixth pin of the USB interface are grounded.

[0010] Further, the key circuit comprises a key, a third TVS protection diode, an eighth resistor, a ninth resistor and a ninth capacitor; one end of the key is grounded, and the other end is electrically connected with one end of the eighth resistor; the other end of the eighth resistor is electrically connected with the fifth pin of the main control chip; one end of the third TVS protection diode is grounded, and the other end is electrically connected with the eighth resistor; one end of the ninth resistor is connected with a 3.3V voltage, and the other end is electrically connected with the eighth resistor; one end of the ninth capacitor is grounded, and the other end is electrically connected with the ninth resistor.

[0011] The utility model discloses a beneficial effect has:

[0012] The utility model provides a USB interface control circuit, through main control circuit controls switch switching circuit, realizes USB and UART channel's intelligent switching. Ingeniously utilize only single USB port on the equipment, flexible conversion between two interface modes, avoid the physical disassembly to the equipment, effectively reduce hardware damage risk. Such design greatly promotes user experience, not only greatly simplifies maintenance process, but also avoids the physical damage, electrostatic damage and improper installation etc. caused by disassembling machine, effectively guarantees the integrity of equipment. User only needs simple operation, can easily switch from USB mode to UART mode, completes necessary upgrade or debugging work, need not worry about any physical damage to the equipment. BRIEF DESCRIPTION OF DRAWINGS

[0013] Fig. 1The utility model discloses a USB interface control circuit's working principle block diagram.

[0014] Fig. 2 The utility model discloses a USB interface control circuit's working principle block diagram.

[0015] Fig. 3 The utility model discloses a USB interface control circuit's working principle block diagram.

[0016] Fig. 4 The utility model discloses a USB interface control circuit's working principle block diagram.

[0017] Fig. 5 The utility model discloses a USB interface control circuit's working principle block diagram. DETAILED DESCRIPTION

[0018] The technical scheme in the embodiments of the utility model will be described clearly and completely below in conjunction with the drawings in the embodiments of the utility model. Apparently, the described embodiments are only part of the embodiments of the utility model, not all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by the person skilled in the art without creative labor fall within the protection scope of the utility model.

[0019] It should be noted that all directionality indications (such as up, down, left, right, front, back, etc.) in the embodiments of the utility model are only used to explain the relative position relationship, movement condition, etc. between components in a certain specific posture (as shown in the drawings). If the specific posture changes, the directionality indications also change accordingly.

[0020] In addition, the description of "first", "second" and the like in the utility model is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features with "first", "second" can explicitly or implicitly include at least one of the features. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the realization of the person skilled in the art. When the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, and is not within the protection scope required by the utility model.

[0021] The utility model provides a kind of USB interface control circuit.

[0022] In the embodiments of the utility model, as Fig. 1-5As shown, the USB interface control circuit comprises a main control circuit, a switch switching circuit, a key circuit and a USB port circuit; the key circuit is electrically connected with the main control circuit, the switch switching circuit is in communication connection with the main control circuit, and the USB port circuit is electrically connected with the switch switching circuit.

[0023] In the embodiment, the main control circuit comprises a main control chip, a first resistor, a second resistor and a first capacitor, the fifth pin of the main control chip is electrically connected with the key circuit, the sixth pin, the seventh pin and the eighth pin of the main control chip are electrically connected with the switch switching circuit; one end of the first resistor is electrically connected with the fourth pin of the main control chip, and the other end is electrically connected with the switch switching circuit; one end of the second resistor is electrically connected with the switch switching circuit, and the other end is electrically connected with the third pin of the main control chip.

[0024] In the embodiment, the switch switching circuit comprises a switch chip, a second capacitor, a third capacitor, a third resistor, a fourth resistor and a fifth resistor; the first pin of the switch chip is connected with a 3.3V voltage, the fifth pin of the switch chip is grounded, the second capacitor and the third capacitor are in parallel connection, one end of which is electrically connected with the first pin of the switch chip, and the other end is electrically connected with the fifth pin of the switch chip; one end of the third resistor is electrically connected with the tenth pin of the switch chip, and the other end is grounded; one end of the fourth resistor is electrically connected with the second pin of the switch chip, and the other end is electrically connected with the sixth pin of the main control chip; one end of the fifth resistor is electrically connected with the first pin of the switch chip, and the other end is electrically connected with the fourth resistor; the third pin and the fourth pin of the switch chip are electrically connected with the USB port circuit, the sixth pin of the switch chip is electrically connected with the second resistor; the seventh pin of the switch chip is electrically connected with the first resistor, the eighth pin of the switch chip is electrically connected with the seventh pin of the main control chip, and the ninth pin of the switch chip is electrically connected with the eighth pin of the main control chip.

[0025] In the embodiment, the USB port circuit comprises a USB interface, a fourth capacitor, a fifth capacitor, a sixth capacitor, a seventh capacitor, an eighth capacitor, a sixth resistor, a seventh resistor, a fuse, a first TVS protection diode and a second TVS protection diode; one end of the sixth resistor is electrically connected to the second pin of the USB interface, and the other end is electrically connected to the fourth pin of the switch chip; one end of the seventh resistor is electrically connected to the third pin of the USB interface, and the other end is electrically connected to the third pin of the switch chip; one end of the fourth capacitor is grounded, and the other end is electrically connected to the second pin of the USB interface; one end of the fifth capacitor is grounded, and the other end is electrically connected to the third pin of the USB interface; one end of the fuse is connected to a 5V voltage, and the other end is electrically connected to the first pin of the USB interface; the sixth capacitor, the seventh capacitor and the eighth capacitor are connected in parallel, one end is grounded, and the other end is electrically connected to the fuse; one end of the first TVS protection diode is grounded, and the other end is electrically connected to the second pin of the USB interface; one end of the second TVS protection diode is grounded, and the other end is electrically connected to the third pin of the USB interface; the fourth pin, the fifth pin and the sixth pin of the USB interface are grounded.

[0026] In the embodiment, the key circuit comprises a key, a third TVS protection diode, an eighth resistor, a ninth resistor and a ninth capacitor; one end of the key is grounded, and the other end is electrically connected to one end of the eighth resistor; the other end of the eighth resistor is electrically connected to the fifth pin of the main control chip; one end of the third TVS protection diode is grounded, and the other end is electrically connected to the eighth resistor; one end of the ninth resistor is connected to a 3.3V voltage, and the other end is electrically connected to the eighth resistor; one end of the ninth capacitor is grounded, and the other end is electrically connected to the ninth resistor.

[0027] In order to solve the inconvenience and risk encountered by electronic equipment in the process of firmware upgrade and debugging, the application controls the switch chip through the main control chip to realize intelligent switching of the USB and UART channels. Ingeniously using only a single USB port on the device, it can flexibly switch between the two interface modes, avoiding physical disassembly of the device and effectively reducing the risk of hardware damage.

[0028] Specifically, the application focuses on the switching of the signal channel between the USB and UART signals of the main control chip and the USB port. USB_DP_M and USB_DM_M of the main control chip are USB interface signals, UART_TX_M and UART_RX_M are UART interface signals, KEY_SENSE is a notification signal of the key input to the main control chip, and USB_SW_M is a switching control signal output by the main control chip to the switch chip. Between the UART interface signals of the main control chip and the switch chip, the first resistor R6 and the second resistor R7 are connected in series, which play a key role in protection and signal matching.

[0029] The USB interface J1 is provided with DP and DM signal interfaces, VCC_5V is the power supply for the USB interface, and GND is the signal reference level. The first TVS protection diode D1 and the second TVS protection diode D2 bear the responsibility of electrostatic protection, the sixth resistor R1 and the seventh resistor R2 are used for buffering and protecting the interface, and the fourth capacitor C1 and the fifth capacitor C2 can filter out interference and improve signal quality.

[0030] K1 is a key, when it is in the default released state, it is pulled up to VCC_3V3 through the ninth resistor R9, at this time KEY_SENSE presents a high level. Once K1 is pressed, the key is turned on, KEY_SENSE is pulled down to ground through the eighth resistor R8 and K1, the level becomes low, and after the voltage fluctuation caused by key jitter is eliminated through the ninth capacitor C9, it is input to the main control chip. The third TVS protection diode D3 plays a role in electrostatic protection.

[0031] The third and fourth pins of the switch chip U2 constitute a signal output channel, connecting the DP and DM of the USB interface; the sixth and seventh pins are signal input channel HSD1, connecting the UART_TX_M and UART_RX_M of the main control chip; the eighth and ninth pins are signal input channel HSD2, connecting the USB_DP_M and USB_DM_M of the main control chip. The tenth pin of the switch chip U2 is the output enable pin, which is pulled down to ground through the third resistor R5, thereby opening the signal output channel of the switch chip. The second pin of the switch chip U2 is the input gating pin, which is pulled up to VCC_3V3 by the fourth resistor R4 and the fifth resistor R3 in the default state, at this time USB_SW_M is high, S=1, HSD2 input channel is opened, USB_DP_M and USB_DM_M of the main control chip are connected with DP and DM of the USB interface, and the user can normally use the USB function of the product through the USB interface.

[0032] By default, the only USB interface on the device is connected to the USB interface signal of the main control chip, ensuring that the user can normally use all USB-based functions of the device. When firmware upgrade or debugging is needed, the user can send a notification to the main control chip through the key to switch the communication mode. After receiving the switching instruction, the main control chip generates a corresponding control signal and sends it to the switch chip. The switch chip switches between the USB and UART interface signals according to the control signal received from the main control chip. Once the switching is completed, the USB interface is connected to the UART interface of the main control chip, and external devices (such as a PC) can communicate data, upgrade firmware, or perform debugging operations through the UART protocol via the USB interface.

[0033] Compared with the traditional disassembly upgrade and debugging method, the application greatly improves the user experience, greatly simplifies the maintenance process, and avoids physical damage, electrostatic damage, improper installation and other problems caused by disassembly, and effectively ensures the integrity of the device. The user only needs to perform a simple operation to easily switch from the USB mode to the UART mode and complete the necessary upgrade or debugging work without worrying about causing any physical damage to the device.

[0034] The above is only the preferred embodiment of the application, and does not limit the patent range of the application. Any equivalent structural transformation or direct / indirect application in other related technical fields based on the application concept of the application is included in the patent protection range of the application.

Claims

1. A USB interface control circuit, characterized by comprising: Including main control circuit, switch switching circuit, key circuit and USB port circuit;The key circuit is connected with the main control circuit, the switch switching circuit is connected with the main control circuit, the USB port circuit is connected with the switch switching circuit; The main control circuit includes main control chip, first resistance, second resistance and first capacitor, the fifth pin of the main control chip is connected with the key circuit, the sixth pin, the seventh pin and the eighth pin of the main control chip are connected with the switch switching circuit;One end of the first resistance is connected with the fourth pin of the main control chip, and the other end is connected with the switch switching circuit, one end of the second resistance is connected with the switch switching circuit, and the other end is connected with the third pin of the main control chip; The switch switching circuit includes switch chip, second capacitor, third capacitor, third resistance, fourth resistance and fifth resistance;The first pin of the switch chip is connected with 3.3V voltage, the fifth pin of the switch chip is grounded, the second capacitor and the third capacitor are connected in parallel, one end is connected with the first pin of the switch chip, and the other end is connected with the fifth pin of the switch chip;One end of the third resistance is connected with the tenth pin of the switch chip, and the other end is grounded, one end of the fourth resistance is connected with the second pin of the switch chip, and the other end is connected with the sixth pin of the main control chip;One end of the fifth resistance is connected with the first pin of the switch chip, and the other end is connected with the fourth resistance;The third pin and the fourth pin of the switch chip are connected with the USB port circuit, the sixth pin of the switch chip is connected with the second resistance;The seventh pin of the switch chip is connected with the first resistance, the eighth pin of the switch chip is connected with the seventh pin of the main control chip, and the ninth pin of the switch chip is connected with the eighth pin of the main control chip.

2. The USB interface control circuit according to claim 1, wherein, The USB port circuit includes a USB interface, a fourth capacitor, a fifth capacitor, a sixth capacitor, a seventh capacitor, an eighth capacitor, a sixth resistor, a seventh resistor, a fuse, a first TVS protection diode and a second TVS protection diode; one end of the sixth resistor is electrically connected with a second pin of the USB interface, and the other end is electrically connected with a fourth pin of the switch chip; one end of the seventh resistor is electrically connected with a third pin of the USB interface, and the other end is electrically connected with a third pin of the switch chip; one end of the fourth capacitor is grounded, and the other end is electrically connected with the second pin of the USB interface; one end of the fifth capacitor is grounded, and the other end is electrically connected with the third pin of the USB interface; one end of the fuse is connected with a 5V voltage, and the other end is electrically connected with a first pin of the USB interface; the sixth capacitor, the seventh capacitor and the eighth capacitor are connected in parallel, one end is grounded, and the other end is electrically connected with the fuse; one end of the first TVS protection diode is grounded, and the other end is electrically connected with the second pin of the USB interface; one end of the second TVS protection diode is grounded, and the other end is electrically connected with the third pin of the USB interface; the fourth pin, the fifth pin and the sixth pin of the USB interface are grounded.

3. The USB interface control circuit of claim 1, wherein, The key circuit includes a key, a third TVS protection diode, an eighth resistor, a ninth resistor and a ninth capacitor; one end of the key is grounded, and the other end is electrically connected with one end of the eighth resistor; the other end of the eighth resistor is electrically connected with a fifth pin of the main control chip; one end of the third TVS protection diode is grounded, and the other end is electrically connected with the eighth resistor; one end of the ninth resistor is connected with a 3.3V voltage, and the other end is electrically connected with the eighth resistor; one end of the ninth capacitor is grounded, and the other end is electrically connected with the ninth resistor.

Images