Self-adaptive external input voltage adjustable GPIO (General Purpose Input / Output) circuit

Abstract

The invention provides a self-adaptive external input voltage adjustable GPIO (General Purpose Input / Output) circuit, which comprises a signal transmission module, the input end of the signal transmission module is used for inputting an external input signal, the output end of the signal transmission module is used for being electrically connected with an internal chip, and the signal transmission module comprises a first switching device; the external input signal is a signal input into the input and output circuit by an external circuit; the input end of the voltage control module is used for inputting an external input signal, the output end of the voltage control module is electrically connected with the control end of the first switching device, and the voltage control module is used for driving the first switching device to be switched on under the condition that the voltage of the external input signal is greater than a preset voltage; the voltage of the signal input to the internal chip by the signal transmission module is smaller than or equal to the preset voltage. The circuit can realize self-bias voltage protection when a chip is not powered on, can prevent overvoltage when the chip works normally, can broaden the regulation range of IO threshold voltage, and can meet the actual application requirements.

Description

Technical Field

[0001] The present application relates to the field of IO and ESD protection, and in particular to a GPIO circuit with adaptive external input voltage and adjustable voltage. Background Art

[0002] Commonly used unidirectional GPIO structures such as Figure 2 As shown, the PAD input terminal receives a control signal from outside the chip, and this signal is converted into a low-voltage signal that the chip can receive, and is transmitted to the internal register of the system through the output terminal (O terminal).

[0003] The power supply of the unidirectional input IO provided by general process manufacturers is 1.8v, that is, the unidirectional GPIO can only receive input signals in the 1.8v domain. When the voltage of the input signal is greater than 1.8v, the existing unidirectional GPIO structure will cause overvoltage in the components inside the IO, causing failure or damage of the components, making the IO circuit unable to work normally, and the threshold voltage (vth) of the existing IO input hysteresis circuit cannot be adjusted, which limits the recognition range of the input signal in actual applications, greatly limiting the flexibility and scope of application of product applications. Summary of the invention

[0004] The main purpose of the present application is to provide a GPIO circuit with an adaptive external input voltage that can at least solve the problem in the prior art that the GPIO can only receive fixed low-voltage input signals and cannot identify and receive high-voltage input signals.

[0005] In order to achieve the above-mentioned purpose, according to one aspect of the present application, there is provided a GPIO circuit with an adaptive external input voltage and adjustable voltage, comprising: a signal transmission module, wherein the input end of the signal transmission module is used to input an external input signal, and the output end of the signal transmission module is used to be electrically connected to an internal chip, the signal transmission module comprises a first switching device, and the external input signal is a signal input from an external circuit to an input-output circuit; a voltage control module, wherein the input end of the voltage control module is used to input the external input signal, and the output end of the voltage control module is electrically connected to the control end of the first switching device, and the voltage control module is used to drive the first switching device to conduct when the voltage of the external input signal is greater than a preset voltage, so that the voltage of the signal input from the signal transmission module to the internal chip is less than or equal to the preset voltage.

[0006] Optionally, the voltage control module includes: a step-down module, wherein the input end of the step-down module is used to input the external input signal, the ground end of the step-down module is grounded, and the step-down module is used to reduce the voltage of the external input signal to a target voltage when the voltage of the external input signal is greater than a preset voltage; an automatic high voltage selector, wherein the first input end of the automatic high voltage selector is used to input a power supply voltage, the second input end of the automatic high voltage selector is electrically connected to the output end of the step-down module, and the output end of the automatic high voltage selector is electrically connected to the control end of the first switching device.

[0007] Optionally, the step-down module includes: a first voltage-dividing module, wherein the first end of the first voltage-dividing module is used to input the external input signal; a second voltage-dividing module, wherein the first end of the second voltage-dividing module is electrically connected to the second end of the first voltage-dividing module; a second switching device, wherein the control end of the second switching device is used to input a second drive signal, wherein the first end of the second switching device is electrically connected to the first end of the second voltage-dividing module and the second end of the first voltage-dividing module, respectively, and the second end of the second switching device is electrically connected to the second end of the second voltage-dividing module; a third voltage-dividing module, wherein the first end of the third voltage-dividing module is electrically connected to the second end of the second switching device and the second end of the second voltage-dividing module, respectively, and the second end of the third voltage-dividing module is grounded; a voltage-stabilizing module, wherein the first end of the voltage-stabilizing module is electrically connected to the first end of the first voltage-dividing module, and the second end of the voltage-stabilizing module is electrically connected to the first end of the second voltage-dividing module and the second end of the first voltage-dividing module, respectively; and an energy storage module, wherein the first end of the energy storage module is electrically connected to the second end of the second switching device and the second end of the second voltage-dividing module, respectively, and the second end of the energy storage module is grounded.

[0008] Optionally, the automatic high voltage selector includes: a third switching device, the control end of the third switching device is electrically connected to the output end of the step-down module, the first end of the third switching device is used to input the power supply voltage, and the second end of the third switching device is electrically connected to the control end of the first switching device; a fourth switching device, the control end of the fourth switching device is electrically connected to the first end of the third switching device, the first end of the fourth switching device is electrically connected to the output end of the step-down module, and the second end of the fourth switching device is electrically connected to the control end of the first switching device.

[0009] Optionally, the signal transmission module further includes: a current limiting module, a first end of the current limiting module is used to input the external input signal, and a second end of the current limiting module is electrically connected to the first end of the first switch device.

[0010] Optionally, the signal transmission module further includes: an IO module, an input end of the IO module is electrically connected to the second end of the first switch device, and an output end of the IO module is electrically connected to the internal chip.

[0011] Optionally, the IO module includes: a first limit voltage adjustment module, a first end of the first limit voltage adjustment module is electrically connected to the output end of the signal transmission module, and a second end of the first limit voltage is electrically connected to a first IO internal circuit; a second limit voltage adjustment module, a first end of the second limit voltage adjustment module is electrically connected to the output end of the signal transmission module, a second end of the second limit voltage adjustment module is electrically connected to a third end of the first limit voltage adjustment module, and a third end of the second limit voltage adjustment module is electrically connected to a second IO internal circuit; a third limit voltage adjustment module, a first end of the third limit voltage adjustment module is electrically connected to the internal chip, and a second end of the third limit voltage adjustment module is electrically connected to a third IO internal circuit.

[0012] Optionally, the first limit voltage adjustment module includes: a fifth switch device, a first end of the fifth switch device is electrically connected to the first IO internal circuit, and a control end of the fifth switch device is electrically connected to the output end of the signal transmission module; a sixth switch device, a first end of the sixth switch device is electrically connected to the second end of the fifth switch device, a control end of the sixth switch device is electrically connected to the output end of the signal transmission module, and a second end of the sixth switch device is electrically connected to the internal chip; a seventh switch device, a control end of the seventh switch device is used to input a first control signal, a first end of the seventh switch device is respectively electrically connected to the first end of the sixth switch device and the second end of the fifth switch device, and a second end of the seventh switch device is electrically connected to the first IO internal circuit; an eighth switch device, a control end of the eighth switch device is used to input a second control signal, a first end of the eighth switch device is respectively electrically connected to the first end of the sixth switch device and the second end of the fifth switch device, and a second end of the eighth switch device is electrically connected to the first IO internal circuit.

[0013] Optionally, the second limit voltage adjustment module includes: a ninth switch device, a first end of the ninth switch device is electrically connected to the second IO internal circuit, and a control end of the ninth switch device is electrically connected to the output end of the signal transmission module; a tenth switch device, a first end of the tenth switch device is electrically connected to the second end of the ninth switch device, a control end of the tenth switch device is electrically connected to the output end of the signal transmission module, and a second end of the tenth switch device is electrically connected to the internal chip; an eleventh switch device, a control end of the eleventh switch device is used to input a third control signal, a first end of the eleventh switch device is electrically connected to the first end of the tenth switch device and the second end of the ninth switch device, respectively, and a second end of the eleventh switch device is electrically connected to the second IO internal circuit; a twelfth switch device, a control end of the twelfth switch device is used to input a fourth control signal, a first end of the twelfth switch device is electrically connected to the first end of the tenth switch device and the second end of the ninth switch device, respectively, and a second end of the twelfth switch device is electrically connected to the second IO internal circuit.

[0014] Optionally, the third limit voltage adjustment module includes: a switch module, a first end of the switch module is electrically connected to the internal chip, and a control end of the switch module is used to input a fifth control signal; a thirteenth switch device, a first end of the thirteenth switch device is electrically connected to the second end of the switch module, the control end of the thirteenth switch device is used to input a sixth control signal, and a second end of the thirteenth switch device is electrically connected to the third IO internal circuit; a fourteenth switch device, a first end of the fourteenth switch device is electrically connected to the first end of the thirteenth switch device and the second end of the switch module respectively, the control end of the fourteenth switch device is used to input a seventh control signal, and the second end of the fourteenth switch device is electrically connected to the third IO internal circuit.

[0015] Applying the technical solution of the present application, the above-mentioned adaptive external input voltage adjustable GPIO circuit, a signal transmission module, the input end of the signal transmission module is used to input the external input signal, the output end of the signal transmission module is used to be electrically connected to the internal chip, the signal transmission module includes a first switching device, the external input signal is a signal input from the external circuit to the input-output circuit; a voltage control module, the input end of the voltage control module is used to input the external input signal, the output end of the voltage control module is electrically connected to the control end of the first switching device, the voltage control module is used to drive the first switching device to conduct when the voltage of the external input signal is greater than a preset voltage, so that the voltage of the signal input from the signal transmission module to the internal chip is less than or equal to the preset voltage. The circuit uses a 3.3v external input signal to generate a self-bias voltage, so that the ends of the components at the interface are at a safe bias voltage when the chip is not powered on. At the same time, when the circuit is working normally, the anti-overvoltage mechanism can convert the 3.3v input signal into a 1.8v safe signal to avoid overvoltage damage to the circuit. The programmable adjustment mechanism of the hysteresis inverter input threshold voltage greatly broadens the adjustment range, solving the problem in the prior art that the GPIO can only receive fixed low-voltage input signals and cannot identify and receive high-voltage input signals. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings constituting part of the present application are used to provide a further understanding of the present application. The exemplary embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0017] Figure 1 A schematic diagram of the structure of a GPIO circuit with an adaptive external input voltage adjustable according to an embodiment of the present application is shown;

[0018] Figure 2 A schematic diagram of the structure of a unidirectional GPIO in the prior art is shown;

[0019] Figure 3 A schematic diagram of the structure of a voltage control module provided according to an embodiment of the present application is shown;

[0020] Figure 4 A schematic structural diagram of an adaptive input-stage voltage conversion circuit provided according to an embodiment of the present application is shown;

[0021] Figure 5 A schematic diagram of the structure of an IO module provided according to an embodiment of the present application is shown;

[0022] Figure 6 A schematic structural diagram of a Smith inverter with adjustable VTH provided according to an embodiment of the present application is shown.

[0023] The above drawings include the following reference numerals:

[0024] 10. Signal transmission module; 20. Voltage control module; 21. Voltage reduction module; 22. Automatic high voltage selector; 30. IO module; 31. First limit voltage adjustment module; 32. Second limit voltage adjustment module; 33. Third limit voltage adjustment module; R0. First voltage divider module; R1. Second voltage divider module; R3. Third voltage divider module; R5. Current limiting module; C0. Voltage stabilizing module; C1. Energy storage module; NM1. First switch device; POC. Second switch device; PM0. Third switch device; PM1. Switch module; PM2. Fourth switch device; PM3. Thirteenth switch device; PM4. Fourteenth switch device; P1. Fifth switch device; P2. Sixth switch device; P3. Seventh switch device; P33. Eighth switch device; N1. Ninth switch device; N2. Tenth switch device; N3. Eleventh switch device; N33. Twelfth switch device. DETAILED DESCRIPTION

[0025] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0026] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0027] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present application described here. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0028] As introduced in the background technology, in actual applications, it is required that without providing an indication signal to indicate to the system whether the input signal is 1.8v or 3.3v, this IO can adapt to the external input level. It can receive both 1.8v and 3.3v signals without overvoltage damaging the internal devices of the chip, and accurately identify "0" or "1" and transmit it to the register inside the chip. The prior art requires an additional signal to indicate whether the external input signal is in the 1.8v domain or the 3.3v domain. The current GPIO circuit can only work normally when the input signal level is 1.8v, and the threshold voltage (vth) of the IO input hysteresis circuit cannot be adjusted. In order to solve the problem in the prior art that the GPIO can only receive fixed low-voltage input signals and cannot identify and receive high-voltage input signals, the embodiments of the present application provide a GPIO circuit with an adaptive external input voltage that is adjustable.

[0029] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0030] Figure 1 Schematic diagram of the structure of the GPIO circuit with adjustable external input voltage according to the embodiment of the present application. Figure 1 As shown, the GPIO circuit with adaptive external input voltage adjustment includes: a signal transmission module 10, the input end of the signal transmission module 10 is used to input the external input signal, the output end of the signal transmission module 10 is used to be electrically connected to the internal chip, the signal transmission module 10 includes a first switch device, and the external input signal is a signal input from the external circuit to the input-output circuit; a voltage control module 20, the input end of the voltage control module 20 is used to input the external input signal, the output end of the voltage control module 20 is electrically connected to the control end of the first switch device, and the voltage control module 20 is used to drive the first switch device to conduct when the voltage of the external input signal is greater than the preset voltage, so that the voltage of the signal input from the signal transmission module 10 to the internal chip is less than or equal to the preset voltage.

[0031] The above-mentioned adaptive external input voltage adjustable GPIO circuit of the present application, a signal transmission module, the input end of the above-mentioned signal transmission module is used to input the external input signal, the output end of the above-mentioned signal transmission module is used to be electrically connected to the internal chip, the above-mentioned signal transmission module includes a first switching device, the above-mentioned external input signal is a signal input from the external circuit to the input-output circuit; a voltage control module, the input end of the above-mentioned voltage control module is used to input the above-mentioned external input signal, the output end of the above-mentioned voltage control module is electrically connected to the control end of the above-mentioned first switching device, and the above-mentioned voltage control module is used to drive the above-mentioned first switching device to conduct when the voltage of the above-mentioned external input signal is greater than the preset voltage, so that the voltage of the signal input from the above-mentioned signal transmission module to the above-mentioned internal chip is less than or equal to the above-mentioned preset voltage. The circuit uses a 3.3v external input signal to generate a self-bias voltage, so that the ends of the components at the interface are at a safe bias voltage when the chip is not powered on. At the same time, when the circuit is working normally, the anti-overvoltage mechanism can convert the 3.3v input signal into a 1.8v safe signal to avoid overvoltage damage to the circuit. The programmable adjustment mechanism of the hysteresis inverter input threshold voltage greatly broadens the adjustment range, solving the problem in the prior art that the GPIO can only receive fixed low-voltage input signals and cannot identify and receive high-voltage input signals.

[0032] Figure 2 The commonly used unidirectional GPIO structure in the prior art is given, in which the PAD end is used as a pin connected to an external circuit, configured as an input or output, and used to communicate with other devices or circuits. In this structure, it can be used to receive control signals from outside the chip. The above signal is converted into a low-voltage signal that can be received by the digital module (digital core) through the unidirectional GPIO structure, and transmitted from the O end to the internal register of the system.

[0033] Furthermore, the PAD end is usually made of metal or other conductive materials to ensure good electrical connection. In a unidirectional GPIO structure, the PAD end can usually only perform unidirectional communication, that is, it can only receive or send signals, but not perform bidirectional communication at the same time, which limits the flexibility and scope of application of the circuit application.

[0034] In some instances, such as Figure 3As shown, the voltage control module includes: a step-down module 21, the input end of the step-down module 21 is used to input the external input signal, the ground end of the step-down module 21 is grounded, and the step-down module 21 is used to reduce the voltage of the external input signal to a target voltage when the voltage of the external input signal is greater than a preset voltage; an automatic high voltage selector 22, the first input end of the automatic high voltage selector 22 is used to input a power supply voltage, the second input end of the automatic high voltage selector 22 is electrically connected to the output end of the step-down module 21, and the output end of the automatic high voltage selector 22 is electrically connected to the control end of the first switching device NM1.

[0035] Among them, the step-down module can effectively solve the overvoltage problem and avoid the failure or damage of components. The automatic high voltage selector can automatically select between the voltages of the two input terminals and use the high voltage as the output signal of the output terminal.

[0036] Furthermore, the voltage control module divides the input signal from the PAD end into two paths for processing: one path is used to generate a control signal for the gate of the first switching device through an adaptive control channel, and the other path is used as a signal input channel to be transmitted to the internal IO circuit through the voltage reduction of the first switching device.

[0037] In some instances, such as Figure 4 As shown, the step-down module includes: a first voltage-dividing module R0, wherein the first end of the first voltage-dividing module R0 is used to input the external input signal; a second voltage-dividing module R1, wherein the first end of the second voltage-dividing module R1 is electrically connected to the second end of the first voltage-dividing module R0; a second switching device POC, wherein the control end of the second switching device POC is used to input the second drive signal, wherein the first end of the second switching device POC is electrically connected to the first end of the second voltage-dividing module R1 and the second end of the first voltage-dividing module R0, respectively, and the second end of the second switching device POC is electrically connected to the second end of the second voltage-dividing module R1; a third voltage-dividing module R3, wherein the control end of the second switching device POC is used to input the second drive signal, wherein the first end of the second switching device POC is electrically connected to the first end of the second voltage-dividing module R1 and the second end of the first voltage-dividing module R0, respectively, and the second end of the second switching device POC is electrically connected to the second end of the second voltage-dividing module R1; and a third voltage-dividing module R4, wherein the control end of the second switching device POC is electrically connected to the second end of the second voltage-dividing module R4. The first end of the third voltage-dividing module R3 is electrically connected to the second end of the second switching device POC and the second end of the second voltage-dividing module R1, respectively, and the second end of the third voltage-dividing module R3 is grounded; a voltage-stabilizing module C0, the first end of the voltage-stabilizing module C0 is electrically connected to the first end of the first voltage-dividing module R0, and the second end of the voltage-stabilizing module C0 is electrically connected to the first end of the second voltage-dividing module R1 and the second end of the first voltage-dividing module R0, respectively; an energy storage module C1, the first end of the energy storage module C1 is electrically connected to the second end of the second switching device POC and the second end of the second voltage-dividing module R1, respectively, and the second end of the energy storage module C1 is grounded.

[0038] Among them, the step-down module first performs a resistor voltage division process on the signal from the PAD end, and converts the above signal into a safe voltage Vxx in the 1.8v domain. Specifically, when the voltage of the PAD end signal is 3.3v, Vxx is 1.8v, which is used to bias the gate of the first switching device; when the chip is not powered on, no matter the voltage of the PAD end signal is 1.8v or 3.3v, Vxx is used to bias the gate of the first switching device, that is, the drain-source voltage (vds), gate-source voltage (vgs) and gate-drain voltage (vgd) of the first switching device can be kept at a safe level, all less than 1.98v+10%, thereby avoiding overvoltage and protecting the first switching device.

[0039] The maximum value of the safety voltage is 1.98v+10%. In extreme cases, the conduction time is relatively short, and the time at the maximum value is very short, which can also avoid overvoltage.

[0040] in addition, Figure 4 The first voltage dividing module R0, the second voltage dividing module R1 and the third voltage dividing module R3 shown in the figure can all be a resistor, or multiple resistors connected in parallel or in series. The present application takes a single resistor as an example.

[0041] In some instances, such as Figure 4 As shown, the automatic high voltage selector includes: a third switch device PM0, the control end of the third switch device PM0 is electrically connected to the output end of the step-down module, the first end of the third switch device PM0 is used to input the power supply voltage, and the second end of the third switch device PM0 is electrically connected to the control end of the first switch device NM1; a fourth switch device PM2, the control end of the fourth switch device PM2 is electrically connected to the first end of the third switch device PM0, the first end of the fourth switch device PM2 is electrically connected to the output end of the step-down module, and the second end of the fourth switch device PM2 is electrically connected to the control end of the first switch device NM1.

[0042] Among them, after the chip is powered on, the control signal of the gate of the first switching device needs to be converted into a stable 1.8V power supply for control. The automatic high voltage selector can achieve the above requirements. Its two input terminals are the power supply voltage and Vxx generated by voltage division.

[0043] Specifically, Figure 4As shown, the automatic high voltage selector is composed of two interlocked third switch devices PM0 and fourth switch device PM2. The above structure can automatically select between the voltages of the two input terminals, select the high voltage and send it to the output terminal as the output signal. This output signal is called sel_v18 and is used to bias the gate of the first switch device NM1. However, after the chip is powered on, if the two input terminals of the above structure are 1.8v at the same time, the potential of its output terminal sel_v18 is uncertain. Therefore, the power-on completion indication signal POC inside the chip is used to pull Vxx down to a certain intermediate potential to ensure that the high voltage selector can determine to select vcc18, that is, the power supply voltage is 1.8v, and the bias voltage is always stable at 1.8v to bias the gate of the first switch device NM1, so that IO enters the normal working mode.

[0044] In addition, if Figure 4 As shown, R6 is a pull-down resistor. Adjusting the pull-down resistor R6 is used to control vs to be adjusted to a suitable voltage so that the drain-source voltage (vds), gate-source voltage (vgs) and gate-drain voltage (vgd) of the first switching device NM1 are all less than 1.8V.

[0045] When the circuit is working normally, when the PAD signal is 3.3v, it must be converted into a 1.8v signal before the subsequent circuit can process the above signal, such as Figure 4 As shown, the gate of the first switch device NM1 is biased by the sel_v18 signal to make it in a conducting state to achieve the above requirements. Here, the low threshold and good withstand voltage characteristics of the field effect tube are utilized, and it is easy to achieve the requirement of passing the 1.8v voltage, and also the requirement of converting the 3.3v voltage signal into a 1.8v domain signal when it passes.

[0046] In some instances, such as Figure 4 As shown, the signal transmission module further includes a current limiting module R5, a first end of the current limiting module R5 is used to input the external input signal, and a second end of the current limiting module R5 is electrically connected to a first end of the first switch device NM1.

[0047] Among them, the current limiting module R5 is used for current limiting protection to prevent excessive current from damaging components. In addition, like the voltage divider module, the current limiting module R5 can be a resistor or multiple resistors connected in parallel or in series. This application takes a single resistor as an example.

[0048] In some instances, such as Figure 5 As shown, the signal transmission module further includes an IO module 30, an input end of the IO module 30 is electrically connected to the second end of the first switch device NM1, and an output end of the IO module 30 is electrically connected to the internal chip.

[0049] The IO module is used to receive low-voltage signals and transmit them to the internal register of the system through the O terminal. The IO module can receive both 1.8v and 3.3v signals without providing a level indication signal, and can accurately identify and convert them into logic voltage "1" or "0". In addition, the threshold voltage (vth) of the input hysteresis circuit can be adjusted, which broadens the recognition range of the input signal.

[0050] In some instances, such as Figure 6 As shown, the IO module includes: a first limit voltage adjustment module 31, a first end of the first limit voltage adjustment module 31 is electrically connected to the output end of the signal transmission module, and a second end of the first limit voltage is electrically connected to the first IO internal circuit; a second limit voltage adjustment module 32, a first end of the second limit voltage adjustment module 32 is electrically connected to the output end of the signal transmission module, a second end of the second limit voltage adjustment module 32 is electrically connected to the third end of the first limit voltage adjustment module 31, and a third end of the second limit voltage adjustment module 32 is electrically connected to the second IO internal circuit; a third limit voltage adjustment module 33, a first end of the third limit voltage adjustment module 33 is electrically connected to the internal chip, and a second end of the third limit voltage adjustment module 33 is electrically connected to the third IO internal circuit.

[0051] The recognition of the high and low levels of the GPIO is achieved through a hysteresis Smith inverter. Figure 6 As shown, the first limit voltage adjustment module 31 is used to control the high level limit vth+, the second limit voltage adjustment module 32 is used to control the low level limit vth- of the hysteresis window, and the third limit voltage adjustment module 33 can be used to control vth. This adjustment mechanism can greatly broaden the adjustment range of the threshold voltage of the existing IO and can identify a wider range of input signals.

[0052] Specifically, vth+ is the limit value used to judge the actual voltage converted into the logic voltage "1", that is, when the actual voltage is greater than vth+, the logic voltage input into the internal chip is "1"; vth- is the limit value used to judge the actual voltage converted into the logic voltage "0", that is, when the actual voltage is less than vth-, the logic voltage input into the internal chip is "0"; in some cases, only one vth needs to be determined, that is, when it is greater than vth, the logic voltage input into the internal chip is "1", and when it is less than vth, the logic voltage input into the internal chip is "0".

[0053] In some instances, such as Figure 6As shown, the first limit voltage adjustment module includes: a fifth switch device P1, a first end of the fifth switch device P1 is electrically connected to the first IO internal circuit, and a control end of the fifth switch device P1 is electrically connected to the output end of the signal transmission module; a sixth switch device P2, a first end of the sixth switch device P2 is electrically connected to the second end of the fifth switch device P1, a control end of the sixth switch device P2 is electrically connected to the output end of the signal transmission module, and a second end of the sixth switch device P2 is electrically connected to the internal chip; a seventh switch device P3, a control end of the seventh switch device P3 is electrically connected to the output end of the signal transmission module; The first end of the seventh switch device P3 is electrically connected to the first end of the sixth switch device P2 and the second end of the fifth switch device P1, and the second end of the seventh switch device P3 is electrically connected to the internal circuit of the first IO; the eighth switch device P33, the control end of the eighth switch device P33 is used to input the second control signal, the first end of the eighth switch device P33 is electrically connected to the first end of the sixth switch device P2 and the second end of the fifth switch device P2, and the second end of the eighth switch device P33 is electrically connected to the internal circuit of the first IO.

[0054] Among them, the vth- of the hysteresis window is related to the ratio of P1 to P3. In order to adjust vth-, a P33 branch is added, and the size ratio of the MOS tube is changed through the corresponding switch, thereby controlling the change of vth- of the hysteresis window. In addition, the internal circuit structure of IO is the existing technical structure.

[0055] In some instances, such as Figure 6As shown, the second limit voltage adjustment module includes: a ninth switch device N1, a first end of the ninth switch device N1 is electrically connected to the second IO internal circuit, and a control end of the ninth switch device N1 is electrically connected to the output end of the signal transmission module; a tenth switch device N2, a first end of the tenth switch device N2 is electrically connected to the second end of the ninth switch device N1, a control end of the tenth switch device N2 is electrically connected to the output end of the signal transmission module, and a second end of the tenth switch device N2 is electrically connected to the internal chip; an eleventh switch device N3, a control end of the eleventh switch device N3 is electrically connected to the output end of the signal transmission module; When the third control signal is input, the first end of the above-mentioned eleventh switch device N3 is electrically connected to the first end of the above-mentioned tenth switch device N2 and the second end of the above-mentioned ninth switch device N1, respectively, and the second end of the above-mentioned eleventh switch device N3 is electrically connected to the internal circuit of the above-mentioned second IO; the twelfth switch device N33, the control end of the above-mentioned twelfth switch device N33 is used to input the fourth control signal, the first end of the above-mentioned twelfth switch device N33 is electrically connected to the first end of the above-mentioned tenth switch device N2 and the second end of the above-mentioned ninth switch device N1, respectively, and the second end of the above-mentioned twelfth switch device N33 is electrically connected to the internal circuit of the above-mentioned second IO.

[0056] Among them, the vth+ of the hysteresis window is related to the ratio of N1 to N3. In order to adjust vth+, the N33 branch is added, and the size ratio of the MOS tube is changed through the corresponding switch, thereby controlling the change of vth+ in the hysteresis window.

[0057] In some instances, such as Figure 6 As shown, the third limit voltage adjustment module includes: a switch module PM1, a first end of the switch module PM1 is electrically connected to the internal chip, and a control end of the switch module PM1 is used to input a fifth control signal; a thirteenth switch device PM3, a first end of the thirteenth switch device PM3 is electrically connected to a second end of the switch module PM1, a control end of the thirteenth switch device PM3 is used to input a sixth control signal, and a second end of the thirteenth switch device PM3 is electrically connected to the third IO internal circuit; a fourteenth switch device PM4, a first end of the fourteenth switch device PM4 is electrically connected to a first end of the thirteenth switch device PM3 and a second end of the switch module PM1, respectively, a control end of the fourteenth switch device PM4 is used to input a seventh control signal, and a second end of the fourteenth switch device PM4 is electrically connected to the third IO internal circuit.

[0058] When the hysteresis function is turned off, VTH can be adjusted by enabling the added third limit voltage adjustment module. In some cases, we can enable the first limit voltage adjustment module, the second limit voltage adjustment module and the third limit voltage adjustment module at the same time to adjust VTH together.

[0059] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity 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, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0060] From the above description, it can be seen that the above embodiments of the present application achieve the following technical effects:

[0061] The above-mentioned adaptive external input voltage adjustable GPIO circuit of the present application, a signal transmission module, the input end of the above-mentioned signal transmission module is used to input the external input signal, the output end of the above-mentioned signal transmission module is used to be electrically connected to the internal chip, the above-mentioned signal transmission module includes a first switching device, the above-mentioned external input signal is a signal input from the external circuit to the input-output circuit; a voltage control module, the input end of the above-mentioned voltage control module is used to input the above-mentioned external input signal, the output end of the above-mentioned voltage control module is electrically connected to the control end of the above-mentioned first switching device, and the above-mentioned voltage control module is used to drive the above-mentioned first switching device to conduct when the voltage of the above-mentioned external input signal is greater than the preset voltage, so that the voltage of the signal input from the above-mentioned signal transmission module to the above-mentioned internal chip is less than or equal to the above-mentioned preset voltage. The circuit uses a 3.3v external input signal to generate a self-bias voltage, so that the ends of the components at the interface are at a safe bias voltage when the chip is not powered on. At the same time, when the circuit is working normally, the anti-overvoltage mechanism can convert the 3.3v input signal into a 1.8v safe signal to avoid overvoltage damage to the circuit. The programmable adjustment mechanism of the hysteresis inverter input threshold voltage greatly broadens the adjustment range, solving the problem in the prior art that the GPIO can only receive fixed low-voltage input signals and cannot identify and receive high-voltage input signals.

[0062] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A GPIO circuit with adaptive external input voltage adjustable, characterized in that: include: A signal transmission module, wherein the input end of the signal transmission module is used to input an external input signal, the output end of the signal transmission module is used to be electrically connected to an internal chip, the signal transmission module comprises a first switch device, and the external input signal is a signal input from an external circuit to an input-output circuit; A voltage control module, wherein the input end of the voltage control module is used to input the external input signal, the output end of the voltage control module is electrically connected to the control end of the first switching device, and the voltage control module is used to drive the first switching device to conduct when the voltage of the external input signal is greater than a preset voltage, so that the voltage of the signal input from the signal transmission module to the internal chip is less than or equal to the preset voltage.

2. The GPIO circuit according to claim 1, characterized in that: The voltage control module comprises: A step-down module, wherein an input terminal of the step-down module is used to input the external input signal, a ground terminal of the step-down module is grounded, and the step-down module is used to reduce the voltage of the external input signal to a target voltage when the voltage of the external input signal is greater than a preset voltage; An automatic high voltage selector, wherein the first input terminal of the automatic high voltage selector is used to input the power supply voltage, the second input terminal of the automatic high voltage selector is electrically connected to the output terminal of the step-down module, and the output terminal of the automatic high voltage selector is electrically connected to the control terminal of the first switching device.

3. The GPIO circuit according to claim 2, characterized in that: The step-down module comprises: A first voltage dividing module, wherein a first end of the first voltage dividing module is used to input the external input signal; a second voltage dividing module, wherein a first end of the second voltage dividing module is electrically connected to a second end of the first voltage dividing module; a second switch device, wherein the control end of the second switch device is used to input a second drive signal, the first end of the second switch device is electrically connected to the first end of the second voltage divider module and the second end of the first voltage divider module respectively, and the second end of the second switch device is electrically connected to the second end of the second voltage divider module; a third voltage dividing module, wherein a first end of the third voltage dividing module is electrically connected to a second end of the second switch device and a second end of the second voltage dividing module respectively, and a second end of the third voltage dividing module is grounded; A voltage stabilizing module, wherein a first end of the voltage stabilizing module is electrically connected to a first end of the first voltage dividing module, and a second end of the voltage stabilizing module is electrically connected to a first end of the second voltage dividing module and a second end of the first voltage dividing module respectively; An energy storage module, wherein a first end of the energy storage module is electrically connected to a second end of the second switch device and a second end of the second voltage divider module respectively, and a second end of the energy storage module is grounded.

4. The GPIO circuit according to claim 2, characterized in that: The automatic high voltage selector comprises: a third switch device, wherein a control end of the third switch device is electrically connected to the output end of the step-down module, a first end of the third switch device is used to input the power supply voltage, and a second end of the third switch device is electrically connected to the control end of the first switch device; A fourth switch device, wherein the control end of the fourth switch device is electrically connected to the first end of the third switch device, the first end of the fourth switch device is electrically connected to the output end of the buck module, and the second end of the fourth switch device is electrically connected to the control end of the first switch device.

5. The GPIO circuit according to claim 1, characterized in that: The signal transmission module also includes: A current limiting module, wherein a first end of the current limiting module is used to input the external input signal, and a second end of the current limiting module is electrically connected to a first end of the first switch device.

6. The GPIO circuit according to claim 1, characterized in that: The signal transmission module also includes: An IO module, wherein the input end of the IO module is electrically connected to the second end of the first switch device, The output end of the IO module is electrically connected to the internal chip.

7. The GPIO circuit according to claim 6, characterized in that: The IO module includes: A first limit voltage adjustment module, wherein a first end of the first limit voltage adjustment module is electrically connected to an output end of the signal transmission module, and a second end of the first limit voltage is electrically connected to an internal circuit of the first IO; a second limit voltage adjustment module, wherein a first end of the second limit voltage adjustment module is electrically connected to the output end of the signal transmission module, a second end of the second limit voltage adjustment module is electrically connected to a third end of the first limit voltage adjustment module, and a third end of the second limit voltage adjustment module is electrically connected to a second IO internal circuit; A third limit voltage adjustment module, wherein a first end of the third limit voltage adjustment module is electrically connected to the internal chip, and a second end of the third limit voltage adjustment module is electrically connected to a third IO internal circuit.

8. The GPIO circuit according to claim 7, characterized in that: The first limit voltage adjustment module includes: a fifth switch device, wherein a first end of the fifth switch device is electrically connected to the first IO internal circuit, and a control end of the fifth switch device is electrically connected to the output end of the signal transmission module; a sixth switch device, wherein a first end of the sixth switch device is electrically connected to a second end of the fifth switch device, a control end of the sixth switch device is electrically connected to an output end of the signal transmission module, and a second end of the sixth switch device is electrically connected to the internal chip; a seventh switch device, wherein a control end of the seventh switch device is used to input a first control signal, a first end of the seventh switch device is electrically connected to a first end of the sixth switch device and a second end of the fifth switch device, respectively, and a second end of the seventh switch device is electrically connected to an internal circuit of the first IO; An eighth switching device, wherein the control end of the eighth switching device is used to input a second control signal, the first end of the eighth switching device is electrically connected to the first end of the sixth switching device and the second end of the fifth switching device, respectively, and the second end of the eighth switching device is electrically connected to the first IO internal circuit.

9. The GPIO circuit according to claim 7, characterized in that: The second limit voltage adjustment module includes: a ninth switch device, wherein a first end of the ninth switch device is electrically connected to the second IO internal circuit, and a control end of the ninth switch device is electrically connected to the output end of the signal transmission module; a tenth switch device, wherein a first end of the tenth switch device is electrically connected to a second end of the ninth switch device, a control end of the tenth switch device is electrically connected to an output end of the signal transmission module, and a second end of the tenth switch device is electrically connected to the internal chip; an eleventh switch device, wherein the control end of the eleventh switch device is used to input a third control signal, the first end of the eleventh switch device is electrically connected to the first end of the tenth switch device and the second end of the ninth switch device, respectively, and the second end of the eleventh switch device is electrically connected to the second IO internal circuit; A twelfth switching device, wherein the control end of the twelfth switching device is used to input a fourth control signal, the first end of the twelfth switching device is electrically connected to the first end of the tenth switching device and the second end of the ninth switching device respectively, and the second end of the twelfth switching device is electrically connected to the second IO internal circuit.

10. The GPIO circuit according to claim 7, characterized in that: The third limit voltage adjustment module includes: a switch module, wherein a first end of the switch module is electrically connected to the internal chip, and a control end of the switch module is used to input a fifth control signal; a thirteenth switch device, wherein a first end of the thirteenth switch device is electrically connected to a second end of the switch module, a control end of the thirteenth switch device is used to input a sixth control signal, and a second end of the thirteenth switch device is electrically connected to an internal circuit of the third IO; A fourteenth switch device, wherein the first end of the fourteenth switch device is electrically connected to the first end of the thirteenth switch device and the second end of the switch module respectively, the control end of the fourteenth switch device is used to input a seventh control signal, and the second end of the fourteenth switch device is electrically connected to the third IO internal circuit.

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