Automatic test system for electrical characteristics of MCU (Microprogrammed Control Unit)

Abstract

The invention discloses a system for automatically testing electrical characteristics of an MCU (Microprogrammed Control Unit). The system comprises an upper computer software and hardware test board card, the upper computer software is used for establishing test excitation of simulation parameters of the to-be-tested chip, controlling the test instrument equipment and the hardware test board card, and connecting the upper computer software with the to-be-tested chip through a communication interface to perform data interaction so as to automatically complete test process control and test data analysis and processing; the hardware test board card comprises a test master control MCU, a signal switching array, an impedance control and voltage regulation module, a calibration module and a special interface. The test master control MCU controls the signal switching array to realize test channel switching; the impedance control and voltage regulation module is used for providing adjustable test voltage and impedance; the calibration module is used for realizing voltage and impedance self-calibration; the system has a self-calibration function and a test channel isolation function, and a special interface of the system is compatible with MCU products in different packaging forms.

Description

Technical Field

[0001] This invention relates to the field of integrated circuits, and in particular to an automated testing system for the electrical characteristics of MCUs. Background Technology

[0002] With the rapid development of integrated circuit technology, microcontrollers (MCUs) have evolved into highly integrated systems-on-chips (SoCs). A single chip integrates dozens of analog and mixed-signal functional modules, including a power management unit (PMU), bandgap reference (BG), analog-to-digital converter (ADC), digital-to-analog converter (DAC), operational amplifier (OPA), comparator (COMP), internal oscillator (RCH), external crystal oscillator interface (LXTAL), and LCD controller. During the sample verification phase, these chips require comprehensive testing of the electrical characteristics of each analog module to ensure the reliability and consistency of the product under complex application scenarios.

[0003] However, existing MCU electrical characteristic testing mainly relies on manual operation mode, which has the following significant drawbacks: First, the test coverage is severely incomplete: Each simulation module includes multiple electrical characteristic parameters, and each parameter needs to be tested under various environmental conditions. For example, the power supply module needs to cover the full range of VDD voltage (0~5.5V) and VBAT voltage (0~5.5V), and verify the power-on sequence, power-on slope, output level, and other multi-dimensional combinations. In manual testing mode, operators can only select a limited number of typical voltage points such as 1.8V, 3.3V, and 5.5V for verification of each parameter, and cannot cover all cross-conditions, resulting in low test coverage and difficulty in exposing potential defects under extreme operating conditions.

[0004] Second, the trade-off between testing efficiency and sample size is prominent: Electrical characteristic testing requires the coordinated use of multiple instruments and equipment, such as programmable power supplies, waveform generators, frequency counters, digital multimeters, and oscilloscopes. The manual process of configuring instrument parameters, switching test channels, and recording test data for each instrument is cumbersome and time-consuming. Faced with the market's demand for short time-to-market cycles, the verification department has to make trade-offs between testing depth and progress, further reducing the test sample size. However, the discrete characteristics of simulated parameters precisely require a large sample size for effective evaluation. This contradiction directly affects the accuracy of product quality risk assessment.

[0005] Third, test accuracy and stability are difficult to guarantee: Analog signals are extremely sensitive to impedance matching and electromagnetic crosstalk in the test path, especially for high-precision OPA, ADC and other modules. Impedance mismatch in test connection lines, signal crosstalk during multi-channel parallel testing, and the current shunting and voltage division effects caused by multiple chips under test sharing a power supply can all introduce significant measurement errors. Existing test platforms lack systematic self-calibration mechanisms and channel isolation designs, so the repeatability and accuracy of test results cannot be guaranteed.

[0006] Fourth, high costs associated with package compatibility adaptation: The MCU product line has numerous models, covering different package forms such as QFP, QFN, and BGA, with significant differences in pin definitions for each package. Traditional testing solutions require designing a separate test board for each package, resulting in large hardware investments, long development cycles, and hindering the flexible reuse of test resources, making it difficult to adapt to the parallel development pace of multiple models.

[0007] In summary, existing manual testing methods are no longer adequate to meet the comprehensive, efficient, accurate, and compatible requirements of highly integrated MCU chips for electrical characteristic verification, severely restricting the balance between product verification cycle and quality assurance capabilities. There is an urgent need for an automated, high-precision, and universal electrical characteristic testing solution. Summary of the Invention

[0008] The summary of this invention introduces a series of simplified concepts, all of which are simplifications of existing technologies in the field, and will be further explained in detail in the detailed description section. This summary is not intended to limit the key features and essential technical features of the claimed technical solution, nor is it intended to determine the scope of protection of the claimed technical solution.

[0009] The technical problem to be solved by the present invention is to provide a system that can accurately, stably and efficiently perform automated electrical characteristic testing on various analog modules in an MCU chip, achieving comprehensive coverage of test stimuli, automated scheduling of the test process, high-precision guarantee of test results, and compatibility testing of multi-packaged chips.

[0010] To solve the above-mentioned technical problems, the present invention provides an automated MCU electrical characteristic testing system, comprising: host computer software and hardware test boards; The host computer software is used to establish test stimuli for the simulated parameters of the chip under test, control the test instruments and equipment and the hardware test board, and connect to the chip under test through a communication interface (such as JLINK interface or UART interface) to perform data interaction, and automatically complete test process control, test data analysis and processing. The hardware test board includes a test main control MCU, a signal switching array, an impedance control and voltage regulation module, a calibration module, and a dedicated interface. The test master control MCU controls the signal switching array to switch test channels; The impedance control and voltage regulation module is used to provide adjustable test voltage and impedance; The calibration module is used to achieve self-calibration of voltage and impedance; This system features self-calibration and test channel isolation, and its dedicated interface is compatible with MCU products in different package types.

[0011] Preferably, the MCU electrical characteristic automated testing system is further improved in that the host computer software is developed based on Python, integrates the Pytest testing framework, and encapsulates the VISA device driver and Jlink / COM chip interface driver to realize the control of the instrument and the chip under test.

[0012] Preferably, in a further improved version of the MCU electrical characteristic automated testing system, the hardware test board consists of three parts: an interface module, a test array switching module, and a board-level test module. The interface module provides power and signal SMA connections with instruments and equipment, and serial and J-link connections with a PC. The test array switching module implements the signal switching array function. The board-level test module integrates the impedance control and voltage regulation module and the calibration module.

[0013] Preferably, in a further improved version of the MCU electrical characteristic automated testing system, the signal switching array is composed of relays, and the test master MCU controls the relays to select the chip under test connected to the PC or the test master MCU from the four test chip paths.

[0014] Preferably, in a further improved version of the MCU electrical characteristic automated testing system, the test master MCU of the hardware test board controls the digital potentiometer and voltage regulation module through the SPI interface. The host computer software sends setting commands to the test master MCU through the serial port. After parsing the commands, the test master MCU adjusts the impedance of the digital potentiometer or the output voltage and voltage rise / fall slope of the voltage regulation module through the SPI interface.

[0015] Preferably, the MCU electrical characteristic automated testing system is further improved, wherein the self-calibration function includes power-on self-calibration and periodic testing and comparison of Golden sample during testing, wherein the test master control MCU performs ADC conversion on the output voltage of the voltage regulation module and compares it with the input voltage of the instrument, submits the test error and issues an early warning.

[0016] Preferably, in a further improvement of the MCU electrical characteristic automated testing system, the dedicated interface is a unified plug-in interface, which connects the power supply, ground, communication interface and IO trigger signal of the chip under test pins to the test platform through a shorting cap, so as to adapt to the pin assignment of different chips.

[0017] Preferably, the MCU electrical characteristic automated testing system is further improved in that the host computer software integrates an analysis algorithm to collect test data and determine its rationality, and automatically select to perform retesting, calibration or optimization of test stimuli.

[0018] Preferably, the MCU electrical characteristic automated testing system is further improved by supporting multi-chip test scheduling and realizing batch automatic testing of multiple chips under test through a signal switching array.

[0019] Preferably, the MCU electrical characteristic automated testing system is further improved, and the electrical characteristic test case development process is as follows: configure and call the test instruments and equipment, develop the embedded program of the chip under test, set the chip status, traverse the test voltage, frequency and environmental parameters again, automatically obtain the test results returned by the instrument or the test results of the test main control MCU, and finally save the test data to a file.

[0020] This invention can achieve at least the following technical effects; 1. This invention can achieve comprehensive coverage of test stimuli and efficient parallel testing; The host computer software of this invention integrates a Python testing framework, which allows for programmable configuration of all instruments and equipment and scheduling of multiple stimuli to take effect simultaneously; the hardware test board controls the relay array through the main control MCU to realize the parallel testing channel switching of four chips under test, and combined with automated process control, greatly improves testing efficiency and coverage.

[0021] Therefore, the technical solution of this invention can automatically traverse all complex environmental parameter combinations (voltage, timing, slope, temperature, etc.) of all modules, breaking through the limitation of traditional manual testing that can only cover typical values, and significantly improving the completeness of testing.

[0022] 2. This invention can ensure high accuracy and anti-interference ability of test results; The hardware test board of this invention has a built-in calibration module. The main control MCU performs ADC sampling on the output of the voltage regulation module and compares it with the instrument input voltage to achieve dynamic self-calibration of voltage / impedance. It adopts a channel isolation design (relay on / off control, level conversion chip to prevent backflow) to physically isolate test signals and avoid mutual interference when multiple chips are tested in parallel. Combined with the Golden sample periodic comparison mechanism, it monitors test environment drift in real time and provides early warning, ensuring accuracy from the source.

[0023] Therefore, this invention can effectively eliminate test errors caused by factors such as connection line impedance, signal crosstalk, voltage division and current division, and ensure the accuracy and stability of test results for high-precision modules such as OPA and ADC.

[0024] 3. This invention enables intelligent analysis and automatic optimization of the testing process; The host computer software of this invention integrates an analysis algorithm module to judge the rationality of test data in real time and trigger an automatic retest mechanism; it can automatically call a calibration algorithm or adjust excitation parameters according to data deviation, forming a closed-loop control of "test-analysis-feedback-optimization" to reduce the misjudgment rate.

[0025] Therefore, this invention can automatically analyze the rationality of test data, intelligently decide on retesting, calibration or optimization of excitation parameters, reduce manual intervention and improve the level of intelligent testing.

[0026] 4. This invention can achieve compatibility and convenient adaptation of chips with multiple packages; The hardware test board of this invention provides a unified plug-in interface, brings out all pins, and pre-sets power, ground, communication interfaces and IO trigger signals in the PCB layout; the connection can be flexibly configured according to the specific chip pin assignment diagram by using jumper shorting caps, realizing "one board for multiple uses" and greatly improving the platform's versatility.

[0027] Therefore, this invention can be compatible with MCU products of different package types without replacing the motherboard, significantly reducing hardware adaptation costs and shortening test preparation time.

[0028] 5. This invention can realize the entire automated testing process of hardware and software collaboration; This invention employs a deeply coupled architecture between host computer software (Python process algorithm) and hardware test board: the host computer controls the instrument via the VISA protocol, configures the chip under test via JLink / UART, and controls the main control MCU of the hardware board via serial port commands; the main control MCU precisely controls board-level resources such as digital potentiometers and voltage regulation modules via the SPI interface, achieving seamless software and hardware collaboration and process automation. This invention constructs a complete automated test chain from stimulus generation, environment configuration, data acquisition to result processing, shortening the sample verification cycle and meeting the needs of rapid time-to-market. Attached Figure Description

[0029] The accompanying drawings are intended to illustrate the general characteristics of the methods, structures, and / or materials used in specific exemplary embodiments of the invention, supplementing the description in the specification. However, the drawings are schematic diagrams not drawn to scale and may not accurately reflect the precise structural or performance characteristics of any of the given embodiments. The drawings should not be construed as limiting or restricting the range of numerical values ​​or properties covered by exemplary embodiments of the invention. The invention will now be described in further detail with reference to the accompanying drawings and specific embodiments: Figure 1 This is a schematic diagram of the upper computer software functional architecture of a feasible embodiment of the present invention.

[0030] Figure 2 This is a schematic diagram of the host computer software architecture of a feasible embodiment of the present invention.

[0031] Figure 3 This is a functional diagram of the hardware test board. Figure 4 This is a schematic diagram of the electrical characteristic testing process of the present invention.

[0032] Figure 5 This is a flowchart of the test incentive development process of this invention. Detailed Implementation

[0033] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can fully understand other advantages and technical effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through different specific embodiments, and various details in this specification can also be applied based on different viewpoints, with various modifications or changes made without departing from the overall design concept of the invention. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. The following exemplary embodiments of the present invention can be implemented in many different forms and should not be construed as being limited to the specific embodiments set forth herein. It should be understood that these embodiments are provided to make the disclosure of the present invention thorough and complete, and to fully convey the technical solutions of these exemplary embodiments to those skilled in the art. It should be understood that when an element is referred to as "connected" or "combined" to another element, the element can be directly connected or combined to the other element, or there may be intermediate elements. The difference is that when an element is referred to as "directly connected" or "directly combined" to another element, there are no intermediate elements. Throughout the drawings, the same reference numerals always denote the same elements. Example

[0034] This invention provides an automated testing system for the electrical characteristics of an MCU, characterized in that it includes: host computer software and hardware test boards; The host computer software is used to establish test stimuli for the simulated parameters of the chip under test, control the test instruments and equipment and the hardware test board, and connect to the chip under test through the communication interface to perform data interaction, and automatically complete the test process control, test data analysis and processing. The hardware test board includes a test main control MCU, a signal switching array, an impedance control and voltage regulation module, a calibration module, and a dedicated interface. The test master control MCU controls the signal switching array to switch test channels; The impedance control and voltage regulation module is used to provide adjustable test voltage and impedance; The calibration module is used to achieve self-calibration of voltage and impedance; This system features self-calibration and test channel isolation, and its dedicated interface is compatible with MCU products in different package types.

[0035] Based on the above overall design concept, the specific implementation process is described below; An automated testing system for MCU electrical characteristics, characterized in that it includes: host computer software and hardware test boards; The host computer software is used to establish test stimuli for the simulated parameters of the chip under test, control the test instruments and equipment and the hardware test board, and connect to the chip under test through the communication interface to perform data interaction, and automatically complete the test process control, test data analysis and processing. The hardware test board includes a test main control MCU, a signal switching array, an impedance control and voltage regulation module, a calibration module, and a dedicated interface. The test master control MCU controls the signal switching array to switch test channels; The impedance control and voltage regulation module is used to provide adjustable test voltage and impedance; The calibration module is used to achieve self-calibration of voltage and impedance; This system features self-calibration and test channel isolation, and its dedicated interface is compatible with MCU products in different package types.

[0036] It consists of a host computer, a hardware test board, standard test instruments and equipment, and the MCU chip under test. The host computer connects to the standard test instruments and equipment (such as a programmable power supply, digital multimeter, signal generator, frequency counter, etc.) via USB / GPIB bus using the VISA protocol, and connects to the hardware test board and the MCU chip under test via UART / JLink interface. The hardware test board and the MCU chip under test are electrically connected through a unified plug-in interface.

[0037] The host computer generates the test process according to the test requirements and controls the hardware test board to complete channel switching and environmental stimulus configuration; standard test instruments and equipment provide precision voltage source, reference signal source and measurement function; the MCU chip under test outputs test signal in the configured state; after all data is collected by the host computer, it is analyzed, calibrated and judged and the results are output through the built-in algorithm.

[0038] The host computer software is developed using Python and adopts a modular plug-in architecture, with each functional module communicating through a standard interface. It integrates the Pytest testing framework and implements asynchronous task scheduling via the EPRC protocol. Test engineers write test scripts based on the test plan, declaring the required instrument and equipment resources within the scripts. The flow control module parses the scripts to generate task flows and schedules multiple instruments and equipment in parallel.

[0039] The VISA library is encapsulated to provide a standardized operating interface for instruments and equipment. A configuration class is defined for each device type, such as PowerSupplyConfig, which includes parameters such as voltage setpoints, rise rate, and current limits. The driver layer implements command caching and batch issuance.

[0040] It integrates the JLink SDK and PySerial library, supporting SWD interface register-level configuration and UART protocol communication. During ADC module testing, the host computer writes a configuration sequence (such as setting the ADC clock divider, sampling period, and reference voltage source selection) to the MCU under test via JLink, and then sends a start conversion command via UART. A built-in linear regression calibration algorithm triggers an early warning and pauses the test, prompting manual intervention.

[0041] Data is stored using the MsgPack binary serialization format, where each record contains a timestamp, excitation conditions, original sampled value, and calibrated value.

[0042] The hardware test board includes the following modules: 1. Interface module: Includes reliable connection to instruments and equipment: power supply and signal SMA port, as well as serial port and J-link interface for connection to PC.

[0043] 2. The test array switching module is controlled by a board-level main control chip that controls relays to select the DUT (Device Under Test) from the four DUT paths, connecting it to the PC or the main control MCU. The hardware test board provides a unified plug-in interface, allowing connection to DUT sub-boards with different package types. All pins of the test array switching module are brought out. Power, ground, communication interfaces, and I / O trigger signals are placed next to the pin signals on the PCB layout. Based on the pinout diagrams of different chips, power, ground, communication ports, and I / O ports of the DUT can be easily connected using shorting caps, achieving compatibility with chips of different package types.

[0044] 3. The board-level test module provides resources including a digital potentiometer, a voltage regulation module, and a digital-to-analog converter module for the main control MCU. The main control MCU controls the digital potentiometer and voltage regulation module via an SPI interface. The host computer sends setting commands to the main control MCU via a serial port. After command parsing, the main control MCU sets the potentiometer impedance or the voltage of the voltage regulation module, as well as the slope of voltage rise and fall, via SPI. The environment setting code for board-level testing can be extended within the embedded code framework of the main control MCU according to the test stimulus requirements.

[0045] To avoid impedance mismatch, crosstalk in signals during testing, and current shunting and voltage division of multiple test chips, the hardware test board design ensures reliable power supply connection. The main control MCU controls the relay's on / off connection signals to ensure signal isolation from the chips, guaranteeing error-free power consumption testing. Simultaneously, a level conversion chip ensures that there is no voltage difference between the signal and the power supply on chips without reverse current protection. The main control MCU can perform ADC conversion on the voltage output of the voltage regulation module and compare it with the same voltage input to the instrument, achieving self-calibration of the voltage regulation module. The cooperation between the hardware test board and the host computer software overcomes the inaccuracy problems encountered in common electrical characteristic tests, ensuring the accuracy of test results.

[0046] After the system is powered on, the host computer sends a command, and the main control MCU of the hardware test board controls the relay to disconnect all the circuits of the chip under test. The voltage regulation module outputs voltages in sequence, such as 0V, 1.25V, 2.5V, 3.75V, and 5V. The main control MCU collects the voltage values, and at the same time, the host computer reads the values ​​from the digital multimeter, fits the calibration curve, and stores it.

[0047] Insert a known, qualified Golden sample (e.g., chip ID: GS001) and run the preset key parameter test. If the test result deviation exceeds the threshold, the system determines it as environmental drift, triggers an audible and visual alarm, and rejects subsequent tests until manual confirmation and recalibration are required.

[0048] Multiple MCUs under test are inserted into the daughter board. The host computer scans the chip IDs and establishes batch records. When the test cases are executed: The process control module parses the test script and allocates instrument resources. The host computer writes the ADC configuration to chip 1 and starts the conversion via UART; simultaneously, it sends commands to the hardware board via serial port, causing the main control MCU to close the relay of chip 1, while keeping the other chips open. After chip 1 completes the conversion, the result is returned via UART, and the host computer records the data. If a data point deviates beyond the standard, the point is automatically retested; if the retest fails after two or more attempts, it is marked as an anomaly. After completing the test of all parameters of chip 1, the host computer sends a command to switch the relay to chip 2, and the above test is repeated until all chips have been tested.

[0049] After all data is corrected by the calibration module, it is stored in the database in batches. The data processing module automatically generates Excel reports.

[0050] Unless otherwise defined, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It will also be understood that, unless explicitly defined herein, terms such as those defined in a general dictionary shall be interpreted as having the meaning consistent with their meaning in the relevant field context, and not as having an idealized or overly formal meaning.

[0051] The present invention has been described in detail above through specific embodiments and examples, but these are not intended to limit the invention. Many modifications and improvements can be made by those skilled in the art without departing from the principles of the invention, and these should also be considered within the scope of protection of the present invention.

Claims

1. An automated testing system for the electrical characteristics of an MCU, characterized in that, include: Host computer software and hardware test boards; The host computer software is used to establish test stimuli for the simulated parameters of the chip under test, control the test instruments and equipment and the hardware test board, and connect to the chip under test through the communication interface to perform data interaction, and automatically complete test process control, test data analysis and processing. The hardware test board includes a test main control MCU, a signal switching array, an impedance control and voltage regulation module, a calibration module, and a dedicated interface. The test master control MCU controls the signal switching array to switch test channels; The impedance control and voltage regulation module is used to provide adjustable test voltage and impedance; The calibration module is used to achieve self-calibration of voltage and impedance; This system features self-calibration and test channel isolation, and its dedicated interface is compatible with MCU products in different package types.

2. The automated MCU electrical characteristic testing system as described in claim 1, characterized in that: The host computer software is developed based on Python, integrates the Pytest testing framework, and encapsulates VISA device drivers and Jlink / COM chip interface drivers to achieve control over instruments and the chip under test.

3. The automated MCU electrical characteristic testing system as described in claim 1, characterized in that: The hardware test board consists of three parts: an interface module, a test array switching module, and a board-level test module. The interface module provides power and signal SMA connections with instruments and equipment, as well as serial and J-link connections with a PC. The test array switching module implements the signal switching array function. The board-level test module integrates the impedance control and voltage regulation module and the calibration module.

4. The automated MCU electrical characteristic testing system as described in claim 1, characterized in that: The signal switching array is composed of relays. The test master control MCU controls the relays to select the chip under test connected to the PC or the test master control MCU from the four channels of the chip under test.

5. The automated MCU electrical characteristic testing system as described in claim 1, characterized in that: The test main control MCU of the hardware test board controls the digital potentiometer and voltage regulation module through the SPI interface. The host computer software sends setting commands to the test main control MCU through the serial port. After parsing the commands, the test main control MCU adjusts the impedance of the digital potentiometer or the output voltage and voltage rise / fall slope of the voltage regulation module through the SPI interface.

6. The automated MCU electrical characteristic testing system according to claim 1, characterized in that: The self-calibration function includes power-on self-calibration and periodic testing and comparison of the Golden sample during testing. The test main control MCU performs ADC conversion on the output voltage of the voltage regulation module and compares it with the input voltage of the instrument and equipment, submits the test error and issues an early warning.

7. The automated MCU electrical characteristic testing system as described in claim 1, characterized in that: The dedicated interface is a unified plug-in interface. By using a shorting cap, the power, ground, communication interface and IO trigger signal of the chip under test are connected to the test platform to adapt to the pin assignments of different chips.

8. The automated MCU electrical characteristic testing system as described in claim 1, characterized in that: The host computer software integrates analysis algorithms to collect test data and determine its rationality, and automatically selects to perform retesting, calibration, or optimization of test stimuli.

9. The automated MCU electrical characteristic testing system as described in claim 1, characterized in that, The system supports multi-chip test scheduling and enables batch automatic testing of multiple chips under test through a signal switching array.

10. The automated MCU electrical characteristic testing system as described in claim 1, characterized in that, The development process for electrical characteristic test cases is as follows: configure and call the test instruments and equipment, develop the embedded program for the chip under test, set the chip status, iterate through the test voltage, frequency and environmental parameters again, automatically obtain the test results returned by the instrument or the test results of the test main control MCU, and finally save the test data to a file.

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