A circuit and method for activating a download mode of a microcontroller unit MCU

Abstract

The embodiment of the present invention provides a circuit and method for activating the download mode of a microcontroller unit (MCU), wherein the circuit includes: an activation unit, a power-on unit, and a power supply unit. When the download mode of the microcontroller unit MCU needs to be activated, a download signal is input into the activation unit and the power-on unit; the activation unit generates an activation signal according to the download signal and applies it to the download mode activation pin; after the activation signal is generated, the power-on unit generates a power-on signal according to the download signal and applies it to the power-on pin, so that the MCU is powered on and enters the download mode. The download signal enters the activation unit to generate an activation signal and applies it to the download mode activation pin, and then the power-on unit generates a power-on signal according to the download signal to power on the MCU. After the MCU is powered on, it can smoothly enter the download mode, allowing the microcontroller unit MCU to automatically enter the download mode, which solves the problem that manual control is required to activate the microcontroller unit MCU to enter the download mode.

Description

Technical Field

[0001] The present invention relates to the field of communication technology, and more particularly to a circuit and method for activating a download mode of a micro control unit (MCU). Background Art

[0002] The current electronic price tag is an electronic label that displays price information in supermarkets, convenience stores, pharmacies, etc. It is mainly placed on the shelf and can replace the electronic display device of traditional paper price tags. Each electronic shelf label is connected to the computer database of the mall through a wired or wireless network, and the latest commodity price is displayed on the screen of the electronic shelf label.

[0003] However, due to cost considerations, the microcontroller units (MCU) currently installed on electronic price tags do not have the function of direct downloading. Every time a download operation needs to be performed on the MCU, the entire machine needs to be disassembled and the MCU needs to be manually controlled to enter the download mode to process the download information. The download efficiency is slow, which affects production and after-sales maintenance. Summary of the invention

[0004] The technical problem to be solved by the present invention is that the current control microcontroller unit MCU does not have the function of automatically controlling it to enter the download mode and requires manual control to make it enter the download mode. To solve this technical problem, a circuit and method for activating the download mode of the microcontroller unit MCU are provided.

[0005] In order to solve the above technical problems, the present invention provides a circuit for activating a download mode of a micro control unit MCU, the circuit comprising: an activation unit, a power-on unit and a power supply unit, the activation unit is connected to the download mode activation pin of the MCU, the power-on unit is connected to the power-on pin of the MCU; the power supply unit is used to provide a power-on working voltage to the MCU;

[0006] When the download mode of the microcontroller unit MCU needs to be activated, a download signal is input into the activation unit and the power-on unit;

[0007] The activation unit generates an activation signal according to the download signal and applies the activation signal to the download mode activation pin;

[0008] After the activation signal is generated, the power-on unit generates a power-on signal according to the download signal and applies it to the power-on pin, so that the MCU is powered on and enters the download mode.

[0009] Optionally, the activation unit includes: a first RC circuit and a first NMOS tube connected in parallel;

[0010] One end of the first RC circuit is connected to the input end of the download signal, and the other end is connected to the gate of the first NMOS tube;

[0011] The source of the first NMOS tube is connected to the download mode activation pin, and the drain is grounded.

[0012] Optionally, the power-on unit includes: a control unit and a signal transmission unit; the control unit includes a second RC circuit connected in parallel and a second NMOS tube; the signal transmission unit includes a first PMOS tube;

[0013] One end of the second RC circuit is connected to the input end of the download signal, and the other end is connected to the gate of the second NMOS tube; the source of the second NMOS tube is connected to the gate of the first PMOS tube, and the drain is grounded;

[0014] The source of the first PMOS tube is connected to the input end of the download signal, and the drain is connected to the power-on pin.

[0015] Optionally, the power supply unit includes: a switch unit and a power input unit; the switch unit includes a third RC circuit connected in parallel, and a second PMOS tube;

[0016] One end of the third RC circuit is connected to the input end of the download signal, and the other end is connected to the gate of the second PMOS tube;

[0017] The source of the second PMOS tube is connected to the power input unit, and the drain is connected to the power-on pin.

[0018] Optionally, the download signal is a high level signal.

[0019] Optionally, the circuit further includes a protection resistor, one end of which is grounded, and the other end of which is connected to the download signal input end of the activation unit and the download signal input end of the power-on unit.

[0020] Optionally, the circuit further includes a pull-down resistor, one end of the pull-down resistor is grounded, and the other end is connected to the power-on pin.

[0021] Furthermore, the present invention also provides a method for activating a download mode of a micro control unit MCU, the method comprising a circuit including an activation unit, a power-on unit and a power supply unit;

[0022] When the download mode of the microcontroller unit MCU needs to be activated, a download signal is input into the activation unit and the power-on unit;

[0023] The activation unit generates an activation signal according to the download signal and applies the activation signal to the download mode activation pin of the MCU;

[0024] After the activation signal is generated, the power-on unit generates a power-on signal according to the download signal and applies the power-on signal to the power-on pin, so that the power supply unit powers on the MCU and enters the download mode.

[0025] Optionally, the activation unit, the power-on unit and the power supply unit are all connected to the input end of the download signal.

[0026] Optionally, the download signal is a high level signal.

[0027] Beneficial Effects

[0028] The embodiment of the present invention provides a circuit and method for activating the download mode of a microcontroller unit (MCU), wherein the circuit includes: an activation unit, a power-on unit and a power supply unit, wherein the activation unit is connected to the download mode activation pin of the MCU, and the power-on unit is connected to the power-on pin of the MCU; the power supply unit is used to provide a power-on working voltage to the MCU; when the download mode of the microcontroller unit MCU needs to be activated, a download signal is input into the activation unit and the power-on unit; the activation unit generates an activation signal according to the download signal and applies it to the download mode activation pin; after the activation signal is generated, the power-on unit generates a power-on signal according to the download signal and applies it to the power-on pin, so that the MCU is powered on and enters the download mode. When the MCU needs to activate the download mode, the download signal enters the activation unit to generate the activation signal and applies it to the download mode activation pin, and then the power-on unit will generate the power-on signal according to the download signal to power on the MCU. At this time, since the activation signal is applied to the download mode activation pin of the MCU, the MCU can smoothly enter the download mode after it is powered on, so that the microcontroller unit MCU automatically enters the download mode, which solves the problem that manual control is required to activate the microcontroller unit MCU to enter the download mode. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0030] Figure 1 A schematic diagram of the structure of a circuit for activating a download mode of a micro control unit MCU provided by a first embodiment of the present invention;

[0031] Figure 2 A schematic structural diagram of another circuit for activating a download mode of a micro control unit MCU provided by the first embodiment of the present invention;

[0032] Figure 3 A schematic flow chart of a method for activating a download mode of a micro control unit MCU provided in a second embodiment of the present invention. DETAILED DESCRIPTION

[0033] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0034] In the subsequent description, the suffixes such as "module", "component" or "unit" used to represent elements are only used to facilitate the description of the present invention, and have no specific meanings. Therefore, "module", "component" or "unit" can be used in a mixed manner.

[0035] The terminal may be implemented in various forms. For example, the terminal described in the present invention may include mobile terminals such as mobile phones, tablet computers, laptop computers, PDAs, portable media players (PMPs), navigation devices, wearable devices, smart bracelets, pedometers, etc., as well as fixed terminals such as digital TVs and desktop computers.

[0036] The following description will be made by taking a mobile terminal as an example, and those skilled in the art will appreciate that, in addition to components specifically used for mobile purposes, the configuration according to the embodiments of the present invention can also be applied to fixed-type terminals.

[0037] First embodiment

[0038] Figure 1 A schematic diagram of the circuit composition for activating a download mode of a microcontroller unit MCU provided in this embodiment, wherein the circuit 100 comprises: an activation unit 110, a power-on unit 120 and a power supply unit 130, wherein the activation unit 110 is connected to a download mode activation pin 150 of the MCU, and the power-on unit 120 is connected to a power-on pin 160 of the MCU; the power supply unit 130 is used to provide a power-on working voltage to the MCU; when the download mode of the microcontroller unit MCU needs to be activated, a download signal 140 is input into the activation unit 110 and the power-on unit 120; the activation unit 110 generates an activation signal according to the download signal 140 and applies it to the download mode activation pin 150; after the activation signal is generated, the power-on unit 120 generates a power-on signal according to the download signal 140 and applies it to the power-on pin 160, so that the MCU is powered on and enters the download mode.

[0039] It is necessary to activate the download mode of the microcontroller unit MCU and generate a download signal, wherein the download signal is generated in a manner including but not limited to, by a specific key or when the download interface of the terminal detects activation.

[0040] When the download signal is input to the activation unit, the activation unit will generate a corresponding activation signal according to the download signal. After the activation signal is applied to the download mode activation pin of the MCU, the MCU will enter the download mode when it is powered on next time.

[0041] After the activation unit generates an activation signal, the activation signal will be continuously applied to the download mode activation pin of the MCU to keep the MCU in the download mode activated state. At this time, the power-on unit will generate a power-on signal and apply it to the power-on pin to power on the MCU. Since the power-on unit generates the power-on signal later than the activation unit generates the activation signal, it is ensured that the MCU can smoothly enter the download mode when it is powered on.

[0042] In some other embodiments, the activation unit includes: a first RC circuit and a first NMOS transistor connected in parallel; one end of the first RC circuit is connected to the input end of the download signal, and the other end is connected to the gate of the first NMOS transistor;

[0043] The source of the first NMOS tube is connected to the download mode activation pin, and the drain is grounded.

[0044] In some other embodiments, the power-on unit includes: a control unit and a signal transmission unit; the control unit includes a second RC circuit connected in parallel, and a second NMOS transistor; the signal transmission unit includes a first PMOS transistor;

[0045] One end of the second RC circuit is connected to the input end of the download signal, and the other end is connected to the gate of the second NMOS tube; the source of the second NMOS tube is connected to the gate of the first PMOS tube, and the drain is grounded;

[0046] The source of the first PMOS tube is connected to the input end of the download signal, and the drain is connected to the power-on pin.

[0047] In some other embodiments, the power supply unit includes: a switch unit and a power input unit; the switch unit includes a third RC circuit connected in parallel, and a second PMOS tube;

[0048] One end of the third RC circuit is connected to the input end of the download signal, and the other end is connected to the gate of the second PMOS tube;

[0049] The source of the second PMOS tube is connected to the power input unit, and the drain is connected to the power-on pin.

[0050] In other embodiments, the download signal is a high level signal.

[0051] In some other embodiments, the circuit further includes a protection resistor, one end of which is grounded, and the other end of which is connected to the download signal input end of the activation unit and the download signal input end of the power-on unit.

[0052] In some other embodiments, the circuit further includes a pull-down resistor, one end of the pull-down resistor is grounded, and the other end is connected to the power-on pin.

[0053] The specific structure of a circuit provided by the present invention can also be found in the attached specification. Figure 2 , Figure 2 A schematic structural diagram of another circuit for activating the download mode of a micro control unit MCU provided in this embodiment. Figure 2 Among them, R3, C3 and Q3 constitute an activation unit 110, R2, C2, Q2 and VT2 constitute a power-on unit 120, R1, C1, VT1 and P1 constitute a power supply unit 130, VBUS is used to output a download signal, VCC_IN is the power-on pin of the MCU, and UBOOT is the download mode activation pin of the MCU. Figure 2 The specific connection relationship of each component is as follows: the system power supply VDD_5V is connected to the source of PMOS tube VT1, the control electrode (gate) of PMOS tube VT1 is connected to the VBUS power supply of USB after RC parallel connection, and the drain of PMOS tube VT1 is connected to the MCU power supply VCC_MCU. The source of PMOS tube VT2 is connected to the USB power supply VBUS power supply, the drain of PMOS tube VT2 is connected to the MCU power supply VCC_MCU, the control electrode (gate) of PMOS tube VT2 is connected to the source of NMOS tube Q2, the drain of NMOS tube Q2 is connected to the ground signal, and the control electrode (gate) of NMOS tube Q2 is connected to the VBUS power supply of USB after passing through RC current R2 and C2. A pull-down resistor R4 is connected to the MCU power supply VCC_MCU power supply to quickly discharge residual charge. The source of NMOS tube Q3 is connected to the UBOOT signal of the MCU chip, the drain of NMOS tube Q3 is connected to the ground signal, and the control electrode (gate) of NMOS tube Q3 is connected to the VBUS power supply of USB after RC parallel connection. According to the above circuit structure provided by the embodiment of the present invention, when VBUS has a high level output, the high level will make Q3 in the circuit turn on first, and after Q3 is turned on, the circuit of Q2 will be turned on. The turning on of Q3 will apply a low level to the UBOOT pin to make the UBOOT pin in the download mode activation state, and the turning on of Q2 will make the VBUS level output to VCC_MCU through VT2, thereby powering on the MCU.

[0054] This embodiment (beneficial effects).

[0055] The present embodiment provides a circuit for activating the download mode of a microcontroller unit MCU, the circuit comprising: an activation unit, a power-on unit and a power supply unit, the activation unit is connected to the download mode activation pin of the MCU, and the power-on unit is connected to the power-on pin of the MCU; the power supply unit is used to provide a power-on working voltage to the MCU; when the download mode of the microcontroller unit MCU needs to be activated, the download signal is input into the activation unit and the power-on unit; the activation unit generates an activation signal according to the download signal and applies it to the download mode activation pin; after the activation signal is generated, the power-on unit generates a power-on signal according to the download signal and applies it to the power-on pin, so that the MCU is powered on and enters the download mode. When the MCU needs to activate the download mode, the download signal enters the activation unit to generate the activation signal and applies it to the download mode activation pin, and then the power-on unit will generate the power-on signal according to the download signal to power on the MCU. At this time, since the activation signal is applied to the download mode activation pin of the MCU, the MCU can smoothly enter the download mode after it is powered on, so that the microcontroller unit MCU automatically enters the download mode, which solves the problem that manual control is required to activate the microcontroller unit MCU to enter the download mode.

[0056] Second embodiment

[0057] The present embodiment provides a method for activating a download mode of a microcontroller unit (MCU), the method comprising a circuit including an activation unit, a power-on unit and a power supply unit; when the download mode of the microcontroller unit MCU needs to be activated, a download signal is input into the activation unit and the power-on unit; the activation unit generates an activation signal according to the download signal and applies it to the download mode activation pin of the MCU; after the activation signal is generated, the power-on unit generates a power-on signal according to the download signal and applies it to the power-on pin, so that the power supply unit powers on the MCU and enters the download mode.

[0058] See also Figure 3 , Figure 3 A basic flow chart of a method for activating a microcontroller unit MCU download mode provided in this embodiment. The method for activating a microcontroller unit MCU download mode comprises the following steps:

[0059] S100: Inputting a download signal into the activation unit and the power-on unit.

[0060] When the download mode of the microcontroller unit MCU needs to be activated, a download signal needs to be generated, wherein the download signal is generated in a manner including but not limited to, by a specific key or when the download interface of the terminal detects activation.

[0061] S200: The activation unit generates an activation signal according to the download signal and applies the activation signal to the download mode activation pin of the MCU.

[0062] When the download signal is input to the activation unit, the activation unit will generate a corresponding activation signal according to the download signal. After the activation signal is applied to the download mode activation pin of the MCU, the MCU will enter the download mode when it is powered on next time.

[0063] S300: After the activation signal is generated, the power-on unit generates a power-on signal according to the download signal and applies it to the power-on pin, so that the power supply unit powers on the MCU and enters the download mode.

[0064] After the activation unit generates an activation signal, the activation signal will be continuously applied to the download mode activation pin of the MCU to keep the MCU in the download mode activated state. At this time, the power-on unit will generate a power-on signal and apply it to the power-on pin to power on the MCU. Since the power-on unit generates the power-on signal later than the activation unit generates the activation signal, it is ensured that the MCU can smoothly enter the download mode when it is powered on.

[0065] In some other embodiments, the activation unit, the power-on unit and the power supply unit are all connected to the input end of the download signal.

[0066] In other embodiments, the download signal is a high level signal.

[0067] This embodiment (beneficial effects).

[0068] The embodiment of the present invention provides a method for activating a download mode of a microcontroller unit (MCU), the method comprising a circuit comprising an activation unit, a power-on unit and a power supply unit; when the download mode of the microcontroller unit MCU needs to be activated, a download signal is input into the activation unit and the power-on unit; the activation unit generates an activation signal according to the download signal and applies it to the download mode activation pin of the MCU; after the activation signal is generated, the power-on unit generates a power-on signal according to the download signal and applies it to the power-on pin, so that the power supply unit powers on the MCU and enters the download mode. When the MCU needs to activate the download mode, the download signal enters the activation unit to generate the activation signal and applies it to the download mode activation pin, and then the power-on unit will generate the power-on signal according to the download signal to power on the MCU. At this time, since the activation signal is applied to the download mode activation pin of the MCU, the MCU can smoothly enter the download mode after being powered on, so that the microcontroller unit MCU automatically enters the download mode, which solves the problem that manual control is required to activate the microcontroller unit MCU to enter the download mode.

[0069] Third embodiment

[0070] In order to facilitate understanding of the specific working process of a circuit for activating a microcontroller unit MCU download mode provided in an embodiment of the present invention, this embodiment is based on the attached Figure 2The specific working process of the circuit is explained below.

[0071] When it is necessary to download to the MCU of the smart terminal, the USB cable is inserted into the USB interface of the smart terminal. When the smart terminal is plugged into the USB cable, the VBUS on the USB cable presents a 5V voltage. The 5V voltage of the USB VBUS passes through the C3 capacitor to quickly boost the control electrode voltage of the NMOS tube Q3 to 5V. When the control electrode voltage of the NMOS tube Q3 begins to conduct during the rising process, it is fully conducted when the turn-on voltage reaches the turn-on threshold, so the UBOOT signal is a low-level signal. Subsequently, the 5V voltage of the USB VBUS passes through the RC filter circuit R2C2, so that the control electrode voltage of the NMOS tube Q2 is slowly boosted to 5V. The control electrode voltage of the NMOS tube Q2 begins to conduct during the rising process, and it is fully conducted when the turn-on voltage reaches the turn-on threshold, so the source of the NMOS tube Q2 is at a low level. When the source of the NMOS tube Q2 is at a low level, that is, after the control electrode of the PMOS tube Q2 is at a low level, the PMOS tube Q2 is in a conducting state, so the 5V voltage of the USB VBUS passes through the PMOS tube VT2 and reaches VCC_MCU to power on the MCU. During the MCU power-on process, the UBOOT signal is detected to be at a low level, so the MCU enters the download mode.

[0072] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0073] The serial numbers of the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0074] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, a magnetic disk, or an optical disk), and includes a number of instructions for enabling a terminal (which can be a mobile phone, a computer, a server, an air conditioner, or a network device, etc.) to execute the methods described in each embodiment of the present invention.

[0075] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation modes, which are merely illustrative rather than restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are within the protection of the present invention.

Claims

1. A circuit for activating a download mode of a microcontroller unit MCU, characterized in that: The circuit includes: an activation unit, a power-on unit and a power supply unit, wherein the activation unit is connected to the download mode activation pin of the MCU, and the power-on unit is connected to the power-on pin of the MCU; the power supply unit is used to provide a power-on working voltage to the MCU; wherein the activation unit includes a first RC circuit and a first NMOS tube in parallel, the power-on unit includes a control unit and a signal transmission unit, and the power supply unit includes a switch unit and a power input unit; one end of the first RC circuit is connected to the input end of the download signal, and the other end is connected to the gate of the first NMOS tube; the source of the first NMOS tube is connected to the download mode activation pin, and the drain is grounded; the control unit includes a second RC circuit in parallel, and a second NMOS tube; the signal transmission unit includes a first PMOS tube; one end of the second RC circuit is connected to the input end of the download signal, and the other end is connected to the gate of the second NMOS tube; the source of the second NMOS tube is connected to the gate of the first PMOS tube, and the drain is grounded; the source of the first PMOS tube is connected to the input end of the download signal, and the drain is connected to the power-on pin; the switch unit includes a third RC circuit connected in parallel, and a second PMOS tube; one end of the third RC circuit is connected to the input end of the download signal, and the other end is connected to the gate of the second PMOS tube; the source of the second PMOS tube is connected to the power input unit, and the drain is connected to the power-on pin; When the download mode of the microcontroller unit MCU needs to be activated, a download signal is input into the activation unit and the power-on unit; The activation unit generates an activation signal according to the download signal and applies the activation signal to the download mode activation pin; After the activation signal is generated, the power-on unit generates a power-on signal according to the download signal and applies the power-on signal to the power-on pin, so that the MCU is powered on and enters the download mode.

2. The circuit according to claim 1, characterized in that The download signal is a high level signal.

3. The circuit according to claim 2, characterized in that The circuit further comprises a protection resistor, one end of which is grounded, and the other end of which is connected to the download signal input end of the activation unit and the download signal input end of the power-on unit.

4. The circuit according to claim 2, characterized in that The circuit also includes a pull-down resistor, one end of which is grounded, and the other end of which is connected to the power-on pin.

5. A method for activating a download mode of a microcontroller unit MCU, characterized in that: The method includes a circuit including an activation unit, a power-on unit and a power supply unit; wherein the activation unit includes a first RC circuit and a first NMOS tube connected in parallel, the power-on unit includes a control unit and a signal transmission unit, and the power supply unit includes a switch unit and a power input unit; one end of the first RC circuit is connected to the input end of the download signal, and the other end is connected to the gate of the first NMOS tube; the source of the first NMOS tube is connected to the download mode activation pin, and the drain is grounded; the control unit includes a second RC circuit and a second NMOS tube connected in parallel; the signal transmission unit includes a first PMOS tube; the One end of the second RC circuit is connected to the input end of the download signal, and the other end is connected to the gate of the second NMOS tube; the source of the second NMOS tube is connected to the gate of the first PMOS tube, and the drain is grounded; the source of the first PMOS tube is connected to the input end of the download signal, and the drain is connected to the power-on pin; the switch unit includes a third RC circuit and a second PMOS tube in parallel; one end of the third RC circuit is connected to the input end of the download signal, and the other end is connected to the gate of the second PMOS tube; the source of the second PMOS tube is connected to the power input unit, and the drain is connected to the power-on pin; When the download mode of the microcontroller unit MCU needs to be activated, a download signal is input into the activation unit and the power-on unit; The activation unit generates an activation signal according to the download signal and applies the activation signal to the download mode activation pin of the MCU; After the activation signal is generated, the power-on unit generates a power-on signal according to the download signal and applies it to the power-on pin, so that the power supply unit powers on the MCU and enters the download mode.

6. The method according to claim 5, characterized in that The activation unit, the power-on unit and the power supply unit are all connected to the input end of the download signal.

7. The method according to claim 6, characterized in that The download signal is a high level signal.

Images