CN215218988U

CN215218988U - GPIO's AC characteristic test system

Info

Publication number: CN215218988U
Application number: CN202023265479.1U
Authority: CN
Inventors: 王博; 许飞; 王景华
Original assignee: Suzhou Furuisi Information Technology Co ltd; GigaDevice Semiconductor Beijing Inc
Current assignee: Suzhou Furuisi Information Technology Co ltd; Zhaoyi Innovation Technology Group Co ltd
Priority date: 2020-12-29
Filing date: 2020-12-29
Publication date: 2021-12-17
Anticipated expiration: 2030-12-29

Abstract

The application provides an AC characteristic test system of GPIO, relates to the MCU field. The system comprises: the controller changes the load capacitance, voltage and pin speed according to different test conditions, extracts wave parameters by means of a waveform signal output by the GPIO, judges whether the frequency of the waveform signal output by the GPIO under the test conditions is the maximum output frequency of the GPIO, meets the designed driving capability, and has different modes aiming at different applications. The invention also comprises an upper computer which is electrically connected with the memory and the controller to achieve different test conditions for executing automatic tests. The invention greatly improves the working efficiency of workers and ensures the accuracy of the whole test result.

Description

GPIO's AC characteristic test system

Technical Field

The invention relates to the field of MCU (microprogrammed control Unit) testing, in particular to an AC (alternating current) characteristic testing system of a GPIO (general purpose input/output) to obtain the maximum output frequency of the GPIO.

Background

At present, more and more embedded products use a microcontroller MCU as a main control unit, a single chip cannot operate only by the MCU (or CPU) and a memory, and an electronic product can be controlled only by configuring peripheral functions, the MCU (or CPU) executes operations according to instructions, reads and writes data, and performs condition judgment, and the memory is used to store the instructions or the read data. In order to exchange signals with external sensors, switches, and the like, a peripheral function such as an "input/output port (I/O port)" is required. Among the "Input/Output ports (I/O ports)", an Input/Output port of a digital signal, i.e., "GPIO (General Purpose Input/Output)" is also called a "General Purpose I/O port", which is a very convenient port for Input/Output of a digital signal. The digital output sensor value and the ON/OFF value of the switch are transmitted to the input end of the singlechip, the operation result of the singlechip is displayed through the LED, and a signal for driving the motor to run is output.

At present, the GPIO test is mainly completed through manual operation and measurement of workers, the workers need to manually configure various test parameters, and then test and record various data of output square waves one by using oscilloscopes. The whole process is not only complicated, but also the operation is carried out manually, so omission and errors are avoided in the test recording process, the deviation of the test result is caused, and meanwhile, the working efficiency of workers is also low.

Disclosure of Invention

The application provides a GPIO's AC characteristic test system, has solved above-mentioned problem.

In order to solve the above technical problem, an embodiment of the present invention provides a GPIOAC feature, including:

a memory for storing instructions and test conditions;

the controller executes a test on the MCU to be tested according to the instruction and the test condition;

the load capacitance selection module is connected with the controller and is used for providing load capacitances with different sizes; and

the power supply module is connected with the controller and is used for providing power supply voltages with different sizes;

wherein the MCU to be tested is provided with a plurality of output driving circuits with different pin speeds,

the controller controls the load capacitor selection module to provide corresponding load capacitors, controls the power module to provide corresponding voltages and controls the MCU to be tested to set corresponding pin speeds according to different test conditions, the GPIO of the MCU to be tested outputs different waveform signals, and corresponding waveform parameters of the different waveform signals are stored in the memory.

Further, the waveform parameters include a rise time (Tr), a fall time (Tf), a frequency (1/T), and a duty ratio, and when Tr + Tf is less than 2/3T and the duty ratio is between 45% and 55%, the frequency is the GPIO maximum output frequency of the MCU to be tested under the corresponding test condition.

Furthermore, the test system further comprises a waveform analyzer connected with the GPIO of the MCU to be tested to acquire the waveform signal.

Furthermore, the instruction is to continuously test multiple groups of test conditions for the MCU to be tested, and the controller executes continuous automatic test for the MCU to be tested.

On the other hand, the test system further comprises an upper computer, the upper computer sends the instruction to the controller and stores the instruction in the memory, the upper computer is connected with the waveform analyzer through a USB bus, the waveform analyzer transmits and stores the waveform parameters to the upper computer, and the upper computer judges whether the frequency is the GPIO maximum output frequency of the MCU to be tested under the test condition according to the rise time (Tr), the fall time (Tf), the frequency (1/T) and the duty ratio of the waveform parameters.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments of the present invention will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to these drawings without inventive labor.

FIG. 1 is a schematic diagram of a system for testing the AC characteristic of GPIO in the present embodiment;

fig. 2 is a circuit diagram of a load capacitance selection module in the test system for AC characteristics of GPIO according to this embodiment.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Fig. 1 shows a schematic diagram of a system for testing the AC characteristic of GPIO according to an embodiment of the present invention. The system comprises: a memory (not shown), a controller 102, a load capacitance selection module 106, a power supply module 104, a waveform measuring instrument 108, and an upper computer 112.

The MCU110 to be tested has, for example, 20 pins (pins) P1-P20, the number of pins is different according to different MCUs, and each pin has a corresponding definition (pin definition). Taking the embodiment of the invention as an example, the P1 is used as a working voltage input port VDD of the MCU and connected to the power module, the controller controls the power module to provide different power supply voltages for the MCU to be tested, and the P2 is used as a ground voltage port GND. When the MCU to be tested uses I2C bus and the controller to transmit signals, 2 pins are used, such as P6 and P7, and P3-P5 and P8-P20 can be used as the normal joint of GPIO peripheral functions of the MCU; when the MCU to be tested uses the SPI bus to transmit signals with the controller, 4 pins are used, for example, P6-P9, and P3-P5 and P11-P20 can be used as the normal joint of the GPIO peripheral function of the MCU.

The AC characteristic test of the GPIO is to make the MCU output a wave (e.g., a square wave) with a certain frequency through the GPIO under a certain test condition, and determine whether the AC characteristic of the GPIO meets the requirements according to waveform parameters (e.g., rise time (Tr), fall time (Tf), frequency (1/T), and duty cycle), that is, whether the output driving circuit corresponding to the manufactured GPIO of the MCU meets the design requirements. The test conditions include, for example: the working voltage of MCU, the pin Speed (IO _ Speed) of GPIO to be tested, or called driving capability, and the load capacitance of GPIO. GPIOs are versatile. For example, the GPIO may be used to actuate, bit-bang, or otherwise control a device such as a button, indicator (e.g., LED), switch, or sensor. Aiming at different purposes, the GPIO has different drive circuit configurations and corresponds to different application modes. Different driving circuits are configured with different pin speeds (IO _ Speed), which means different driving capabilities. A plurality of output driving circuits with different pin speeds are arranged at the output part of the I/O port in the MCU, a user can select a proper driving circuit according to own needs and select different output driving modules by selecting the speed, so that the aims of optimal noise control and power consumption reduction are fulfilled. The pin speed of the GPIO is matched with the application requirement, the higher the speed configuration is, the higher the noise is, and the higher the power consumption is. For example: the high frequency driving circuit has high noise, and when the high output frequency is not needed, the low frequency driving circuit is selected, which is very favorable for improving the EMI efficiency of the system. Of course, if a higher frequency signal is to be outputted, but a lower frequency driving module is selected, a distorted output signal is likely to be obtained.

The test system of embodiments of the present invention may include one or more memories for storing instructions and test conditions, which may be stored in the same memory or in different memories. The memory may be provided inside the controller 102, and may store an operating program of the controller in addition to instructions and test conditions. The memory may be disposed outside the controller, for example, may be an upper computer 112, and the upper computer 112 is connected to the controller 102, and stores the waveform parameters of the GPIO output waveform signal in addition to the command and the test condition. A second memory may also be provided independently for storing the waveform parameters. The memory arranged outside the controller can also only store the parameters of the GPIO output waveform signals. The number, kind and location of the memory are not limited herein. The memory may be a RAM, NOR, or NAND, and the memory for storing the operation program may be a ROM.

The controller 102 is connected to the memory, the power module 104, the load capacitance selection module 106, and the MCU110 to be tested, and performs a test on the MCU110 to be tested according to the instructions and the test conditions, and when the instructions are to test multiple sets of test conditions on the MCU110 to be tested, the controller 102 performs a continuous automatic test on the MCU110 to be tested. For example: the controller 102 sets the load capacitance, the voltage or the pin speed according to a first test condition, the GPIO of the MCU110 to be tested outputs a first waveform signal, after the test of the first test condition is completed, the controller 102 changes the setting of one of the load capacitance, the voltage and the pin speed or changes all the settings according to a second test condition, the changed amount depends on the difference between the first test condition and the second test condition, when the GPIO outputs a second waveform signal, after the test of the second test condition is completed, the controller 102 changes the load capacitance, the voltage or the pin speed according to a third test condition, and so on until all the sets of test conditions are completed. Therefore, automatic test of the AC characteristic of the GPIO of the MCU is realized without manual setting

Parameters of the GPIO output waveform signal include, for example: the MCU to be tested comprises a rising time (Tr), a falling time (Tf), a period T (or a frequency 1/T) and a duty ratio, wherein when the Tr + Tf is less than 2/3T and the duty ratio is 45% -55%, the frequency is the GPIO maximum output frequency of the MCU to be tested under the test condition.

The controller 102 runs a program for testing the AC characteristics of the GPIO to implement a GPIO testing method. The test method comprises the following steps: s1, storing the instruction and the test condition in the memory; s2, according to the instruction and the test condition, the program on the controller 102 is run to make the controller 102 execute the test to the MCU110 to be tested, which includes the following steps:

s3, controlling the load capacitance selection module 106 to provide the load capacitance meeting the test condition to the GPIO of the MCU to be tested,

s4, the power supply module 104 is controlled to provide the power supply voltage meeting the test condition to the MCU110 under test,

s5, selecting the output driving circuit of the MCU to be tested to meet the pin speed of the test condition,

s6, obtaining the waveform signal output from the GPIO and extracting the parameter of the waveform signal,

and when the instruction enables the controller to execute a plurality of groups of test conditions on the MCU to be tested, repeating the steps S3-S6, and enabling the controller to execute continuous automatic test on the MCU to be tested.

The power module 104 is connected to the controller 102, and is configured to provide different supply voltages (i.e., operating voltages of the MCU) to the MCU110 to be tested, and the controller 102 changes the operating voltage provided to the MCU to be tested, the driving configuration of the GPIO to be tested, and one or more of load capacitance values of the GPIO to perform a test under a next test condition through the PMbus.

As shown in fig. 2, the load capacitance selection module 106 includes a plurality of switches (e.g., S1, S2 …) connected to the controller, each switch being connected to a different load capacitance (e.g., 10pF, 30pF …), the switches being controlled by the controller 102, the load capacitance selection module being configured to provide different load capacitances for GPIOs to be tested of the MCU110 to be tested, the load capacitances being capacitances loaded by the GPIOs as output terminals. The controller 102 selects a capacitor according to the test condition, and controls the switch corresponding to the selected capacitor to be closed and other switches to be opened. As another example, the load capacitance selection module includes a plurality of capacitors and a multiplexer. For another example, the load capacitance selection module is a circuit including a plurality of capacitors and a plurality of switches, and the connection relationship (series connection, parallel connection) of the plurality of capacitors is changed by changing the on/off of the switches, so that the equivalent capacitance of the circuit reaches the target capacitance value.

The embodiment further includes a waveform measuring instrument 108, such as an oscilloscope, a digital oscilloscope, or other configurations capable of analyzing waveform signal acquisition parameters, such as an FPGA and an ADC (analog-to-digital converter), which is connected to the GPIO to be tested, acquires the waveform signal output by the GPIO, extracts the parameters of the waveform signal, and transmits the parameters to the memory of the controller 102 or the memory of the upper computer 112 for storage.

In another embodiment, the oscilloscope is connected to an upper computer through a USB bus, the oscilloscope transmits and stores the wave parameters to the upper computer, and the upper computer determines whether the frequency is the GPIO maximum output frequency of the MCU to be tested under the test condition according to the rise time (Tr), the fall time (Tf), the period T (or the frequency 1/T), and the duty ratio of the waveform signal.

The driving configuration in this embodiment includes load capacitance, voltage, and pin speed. Various parameters under various test conditions for the AC characteristic test of the GPIO to be tested are preset in the controller or the memory in advance, and the parameters under each test condition are different; the controller can automatically configure various parameters aiming at the AC characteristic test of the GPIO to be tested, and determine the maximum output frequency of the GPIO under the test condition by matching with a preset judgment condition. The various parameters are for example: the power supply voltage may be 2.0V or 5.0V, the load capacitance may be 10pF, 30pF or 50pF, IO _ Speed is 2MHz, 10MHz or 40MHz, the measured wave compliance Tr + Tf of the GPIO output is less than 2/3T, and the duty ratio is between 45% and 55%, and the maximum output frequency results under each drive configuration test condition are as follows.

In this embodiment, the load capacitance selection module is connected to the GPIO to be tested and the controller 102, and according to the instruction and the test condition, the controller 102 controls the load capacitance selection module 106 to provide different load capacitances for the GPIO to be tested; thus, the current step of selecting the load capacitor by a manual jumper cap is omitted. The load capacitance selection module comprises: the circuit comprises a plurality of switches and a plurality of load capacitors, wherein each load capacitor has a different size. For example, as shown in fig. 2, one load capacitance is 10pF, the other load capacitance is 30pF, and so on. Of course, for simplicity of illustration, not all of the channels and load capacitances are shown in fig. 2, but only two of them are shown by way of example, as will be appreciated by those skilled in the art.

When the controller automatically configures the test conditions, the controller controls the on-off of the switch according to the target load capacitance value to provide the target load capacitance value for the GPIO to be tested, wherein the target load capacitance value is a load capacitance parameter provided for the GPIO to be tested under the first test condition aiming at the AC characteristic test of the GPIO to be tested. For example: when tests a, d, g, j, m and p are carried out, the controller conducts a channel of the load capacitor with the frequency of 10pF, disconnects channels of other load capacitors, and automatically configures the load capacitor of the GPIO to be tested by analogy to other tests.

In this embodiment, the power module 104 is connected to the MCU110 to be tested, and the power module 104 is configured to provide different power supply voltages to the MCU110 to be tested according to the instruction of the controller 102; therefore, the step that the direct current power supply needs to be manually adjusted to provide power supply voltage for the MCU to be tested at present is omitted. The power module may be a DC-DC power module that is connected to the controller 102 via a PMBus control bus. When the controller 102 automatically configures the test conditions, the output voltage value of the DC-DC power supply module is adjusted through the PMBus control bus according to the target power supply voltage value, which is the power supply voltage value of the MCU110 to be tested, and naturally, the target power supply voltage value is a power supply voltage parameter provided for the MCU to be tested under the first test condition for the AC characteristic test of the GPIO to be tested. For example: when tests a, b, c, g, h and i are carried out, the controller 102 regulates the output voltage value of the DC-DC power supply module to be 2.0V through the PMBus control bus, and the rest is repeated to other tests, so that the power supply voltage is automatically configured.

In an embodiment, the MCU110 to be tested and the controller 102 are connected via an I2C bus, and send different IO-Speed commands to the MCU110 to be tested according to the driving configuration via an I2C bus. For example: when testing a, b, c, d, e, f, after the MCU110 to be tested receives the instruction, the controller 102 sets the GPIO to be tested to IO _ Speed of 2MHz through I2C, and so on to other tests, so that IO _ Speed of the GPIO is automatically configured.

It should be noted that, in the embodiment of the present invention, the controller 102 may be another MCU, which is different from the MCU to be tested, and is an MCU that can normally operate, has correct functions, and has undergone various function tests, and of course, the controller 102 may also be other devices that can automatically configure various parameters under various test conditions and implement program and data processing, for example: FPGA, etc. If a qualified control MCU is used by the controller, the switch in the load capacitor selection module can be controlled through the GPIO of the control MCU.

Through the test system, the controller can automatically configure various parameters of the AC characteristic test aiming at the GPIO to be tested, so that a large amount of manual complicated operation is saved, the whole process is controlled by the controller, deviation and errors cannot occur, and compared with manual operation, the test system is high in efficiency and accuracy. In addition, the controller also receives a control instruction for controlling the operation of the system, which is sent by the upper computer, and executes the control instruction by combining various configured parameters, so that the AC characteristic test for the GPIO to be tested can be finally realized.

Since the data of the square wave output by the GPIO needs to be known naturally in the AC characteristic test for the GPIO, in this embodiment, the digital oscilloscope is connected to the GPIO to be tested and is used to collect the square wave output by the GPIO to be tested, extract the parameters of the square wave, and feed back the parameters of the square wave to the upper computer, so that the upper computer 112 and the controller 102 work together to realize the test for the AC characteristic of the GPIO to be tested.

In this embodiment, the digital oscilloscope is connected to the upper computer 112 through a USB bus, and sends the acquired parameters of the output square wave to the upper computer 112 through the USB bus. The upper computer 112 records the parameters of the test condition and the parameters of the output square wave. The upper computer 112 determines whether the square wave of the frequency meets a preset determination condition according to parameters (e.g., a rising time, a falling time, a period, and a duty ratio) of the output square wave.

Under the condition that the upper computer judges that the square wave of the frequency meets the preset judgment condition, the upper computer determines that the AC characteristic test aiming at the GPIO to be tested under the first test condition (such as test a) is completed, and sends a change instruction to the controller, wherein the change instruction is used for indicating the controller to configure various parameters aiming at the AC characteristic test aiming at the GPIO to be tested under the second test condition (such as test b). The preset judgment condition is as follows: the sum of the rising time Tr and the falling time Tf of the GPIO output square wave is less than 2/3 period T, and the duty ratio of the output square wave is between 45% and 55%.

If the test condition configured by the controller is the first test condition, the upper computer obtains that the sum of the Tr + Tf and the Tf of the square wave of the frequency is less than 2/3T through calculation, and the duty ratio (DutyCycle) is 45% -55%, the upper computer determines that the AC characteristic test aiming at the GPIO to be tested is completed under the first test condition, and the frequency of the square wave is the maximum output frequency under the first test condition. And then the upper computer sends a change instruction to the controller, wherein the change instruction is used for instructing the controller to configure various parameters of the AC characteristic test aiming at the GPIO to be tested under the second test condition, and the subsequent AC characteristic test is continued.

Naturally, under the condition that the square wave of the frequency does not meet the preset judgment condition, the upper computer sends a continuous test instruction to the controller, so that the controller sends an output frequency adjusting instruction to the MCU to be tested, and further the MCU to be tested adjusts the frequency of the output square wave of the GPIO to be tested to be a target output frequency value, wherein the target output frequency value is lower than the frequency value of the previous output square wave. This is because, in general, under each test condition, the GPIO output square wave to be tested of the MCU to be tested is output at the highest frequency, if the highest frequency meets the preset judgment condition under the test condition, the highest frequency is the maximum output frequency under the test condition, if the highest frequency does not meet the preset judgment condition under the test condition, the MCU to be tested adjusts the frequency of the output square wave of the GPIO to be tested to be a target output frequency lower than the highest frequency, if the target output frequency meets the preset judgment condition under the test condition, the target output frequency is the maximum output frequency under the test condition, and if the target output frequency does not meet the preset judgment condition under the test condition, the MCU to be tested adjusts the frequency of the output square wave of the GPIO again.

For example: when the controller automatically configures parameters with the supply voltage of 2.0V and the load capacitance of 10pF and IO _ Speed of 50MHZ under the first test condition, the following results are finally obtained: and the sum of Tr + Tf of the GPIO output square waves is less than 2/3T, and the DutyCycle is 45-55%, at the moment, the maximum frequency of the GPIO output square waves, namely 40MHZ, is the maximum output frequency under the first test condition, and the AC characteristic test for the GPIO to be tested under the first test condition is completed. And then the upper computer sends a change instruction to the controller, wherein the change instruction is used for instructing the controller to configure various parameters of the AC characteristic test aiming at the GPIO under the second test condition, and the subsequent AC characteristic test is continued.

If the final result is: and if the sum of Tr + Tf of the square waves output by the GPIO is greater than or equal to 2/3T or the DutyCycle is not 45-55%, reducing the frequency of the square waves output by the GPIO to 36 MHZ. And if the output square wave of 36MHZ meets the condition that the sum of Tr + Tf is less than 2/3T and the DutyCycle is 45% -55%, the 36MHZ is the maximum output frequency of the GPIO to be tested under the first test condition, and the AC characteristic test for the GPIO under the first test condition is finished. And then the upper computer sends a change instruction to the controller, wherein the change instruction is used for instructing the controller to configure various parameters of the AC characteristic test aiming at the GPIO to be tested under the second test condition, and the subsequent AC characteristic test is continued.

In another embodiment, the upper computer does not need to send a change instruction to the controller to test each parameter under the second test condition, and the controller can automatically configure each parameter under the second test condition to perform the AC characteristic test according to the test condition stored in the memory after the GPIO to be tested outputs different waveform signals. In the process, after the MCU to be tested adjusts the frequency of the output square wave of the GPIO to be tested to be a target output frequency lower than the highest frequency, the digital oscilloscope collects the parameters of the output square wave of the GPIO to be tested by taking the target output frequency value as the frequency and sends the parameters to the upper computer; and the upper computer judges whether the output square wave taking the target output frequency value as the frequency meets a preset judgment condition.

In summary, the system for testing the AC characteristic of the GPIO according to the embodiment of the present invention may automatically operate, automatically configure various parameters under various test conditions, and automatically record, calculate, and determine results of data, thereby finally achieving automatic completion of the AC characteristic test of the GPIO.

The embodiment of the invention also provides a method for testing the AC characteristic of the GPIO. The method may be performed by the system shown in fig. 1. And running the program on the controller to enable the controller to automatically execute the AC characteristic test of the GPIO to be tested of the MCU to be tested under a plurality of test conditions. Running the program on the controller causes the controller to perform the steps of: the load capacitor selection module is controlled to connect the load capacitor to the GPIO to be tested of the MCU to be tested, the power supply module is controlled to provide power supply voltage for the MCU to be tested, the MCU to be tested is controlled to set the GPIO to be tested to be appointed configuration, the MCU to be tested is controlled to output waves of the first frequency through the GPIO to be tested, and parameters of the waves of the first frequency output by the GPIO to be tested are acquired through the oscilloscope.

In one embodiment, running the program on the controller further causes the controller to perform the following steps. And the controller judges whether the wave of the first frequency meets a preset judgment condition according to the parameter of the wave of the first frequency. If the controller judges that the wave of the first frequency does not meet the preset judgment condition, the controller controls the MCU to be tested to output the wave of the second frequency through the GPIO to be tested, the second frequency is smaller than the first frequency, the controller obtains the parameter of the wave of the second frequency output by the GPIO to be tested through the oscilloscope, and judges whether the wave of the second frequency meets the preset judgment condition or not according to the parameter of the wave of the second frequency.

When the AC characteristic test under one test condition is completed, the controller performs the AC characteristic test under the next test condition by performing at least one of the following steps: controlling the MCU to be tested to change the configuration of the GPIO to be tested; controlling a load capacitance selection module to change the size of the target capacitance value; and controlling the power supply module to change the magnitude of the target power supply voltage.

It should be noted that the maximum output frequency measured by the test MCU is limited to 72MH, for example, the maximum output frequency measured by the test MCU is 72MH, and the maximum output frequency measured by the test m, n, o, p, q, r is also 72 MH.

In this embodiment, the controller is not limited to control the load capacitance selection module only through its GPIO during configuration, so as to control the load capacitance provided by the load capacitance selection module for the MCU to be tested, to adjust the DC-DC power module only through the PMBus control bus to provide the power supply voltage, and to send the target driving capability instruction to the MCU to be tested only through the I2C bus. All the ways of implementing the above automatic configuration fall within the protection scope of the technical solution of the present invention.

Through the embodiment, the system for testing the AC characteristic of the GPIO, disclosed by the invention, has the advantages that the controller automatically configures various parameters for the AC characteristic test of the GPIO to be tested, and the load capacitor selection module is connected with the controller and is used for providing load capacitors with different sizes for the GPIO to be tested; the power supply module is used for providing power supply voltages with different sizes for the MCU to be tested according to the instruction of the connection controller; the MCU to be tested is provided with a plurality of output driving circuits with different pin speeds, and the controller automatically sets the driving configuration of the GPIO to be tested according to different testing conditions. The controller (1) controls the load capacitor selection module to provide corresponding load capacitors, (2) controls the power supply module to provide corresponding voltages, and (3) controls the MCU to be tested to be set to corresponding pin speeds. Through the mode, various parameters of the AC characteristic test aiming at the GPIO to be tested can be automatically configured, and various test parameters do not need to be manually configured by a worker, so that the working efficiency of the worker is greatly improved.

In addition, the system adopts the digital oscilloscope to collect parameters of the square waves output by the GPIO to be tested and feed the parameters back to the upper computer, so that the upper computer and the controller work together to realize the test of the AC characteristic of the GPIO to be tested. By the mode, any data in the whole testing process does not need to be recorded and calculated manually, so that omission and errors cannot occur in the testing and recording process, and the accuracy of the whole testing result is also ensured.

Finally, it should also be noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, herein, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

While the present invention has been described with reference to the embodiments shown in the drawings, the present invention is not limited to the embodiments, which are illustrative and not restrictive, and it will be apparent to those skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. An AC characteristic test system of GPIO is characterized by comprising:

a memory for storing instructions and test conditions;

2. The test system of claim 1, wherein the waveform parameters comprise a rise time Tr, a fall time Tf, a frequency 1/T and a duty cycle, and when Tr + Tf <2/3T and the duty cycle is between 45% and 55%, the frequency is the GPIO maximum output frequency of the MCU under test under the corresponding test condition.

3. The test system of claim 1, further comprising a waveform analyzer connected to the GPIO of the MCU to be tested to obtain the waveform signal.

4. The test system according to claim 1, wherein the instruction is to continuously test multiple sets of test conditions for the MCU under test, and the controller performs continuous automatic testing for the MCU under test.

5. The test system of claim 1, wherein the drive configuration comprises a load capacitance, a voltage, and a pin speed.

6. The test system according to claim 1, wherein the load capacitance selection module comprises a plurality of capacitors with different load capacitance values, each capacitor is connected to the GPIO of the MCU under test through a switch, and the switch is controlled by the controller.

7. The test system of claim 3, further comprising an upper computer, wherein the upper computer sends the instruction to the controller and stores the instruction in the memory, the upper computer is connected with the waveform analyzer through a USB bus, the waveform analyzer transmits and stores the waveform parameters to the upper computer, and the upper computer judges whether the frequency is the GPIO maximum output frequency of the MCU to be tested under the test condition according to the rise time Tr, the fall time Tf, the frequency 1/T and the duty ratio of the waveform parameters.

8. The test system of claim 1, further comprising a second memory for storing the waveform parameters.

9. The test system of claim 1, wherein the controller is connected to the power module via a PMBus, and the controller is connected to the MCU under test via an I2C bus.