Design And Implementation Of Boundary-Scan Test Software For Digital-Analog Hybrid Circuit

With the continuous improvement of circuit board integration,traditional test methods have been unable to meet the test requirements of high-density circuit boards.The emergence of boundary-scan technology provides an efficient way to solve the test problems of high-density circuit boards.Since the development of boundary-scan technology,a complete test theory has been formed,including IEEE 1149.1,IEEE1149.4,IEEE 1149.5,IEEE 1149.6,IEEE 1149.7 standards etc.The research on boundary-scan technology in foreign countries started early,so boundary-scan test software products have been developed.Although the boundary-scan test software has also been developed in China,due to the technology blockade,there is still a certain gap between domestic software and foreign mature software.Therefore,it is of great significance to develop boundary-scan test software with various test functions and independent intellectual property rights.Based on the actual project "Development of xxx equipment fault diagnosis system",thesis studies the design and implementation of the boundary-scan test software for digital-analog hybrid circuits.The main research contents of this paper include:1.The design of the overall software program.Thesis analyzes the requirements of the software,and designs the overall structure of the software based on the functions that the software should have.The software is divided into three functional modules:test file analysis module,digital circuit diagnostic module,digital-analog hybrid chip AD/DA diagnosis module,and thesis designs the project configuration file and user graphical interface according to the test requirements.2.Research and implementation of test file analysis methods.Thesis introduces the theories of boundary-scan chains and testable networks,analyzes the format of test files,studies the methods of obtaining testable networks from netlist files and BSDL files,and obtains the distance between device pins from PCB report files.writing program realizes the test file analysis method.3.Research and realization of the boundary-scan diagnosis method of the digital circuit.Thesis proposes a structural test vector generation algorithm based on genetic algorithm,and compares the compactness index and completeness index of the algorithm with other algorithms through simulation analysis,and verifies effectiveness of the algorithm.The algorithm and three classic algorithms are integrated into the digital circuit diagnosis module of the software,and the program is written to realize the software's test vector generation function and test result diagnosis function.4.Realization of AD/DA boundary-scan diagnosis method of the digital-analog hybrid chip.Thesis introduces the scan chain and test vector generation algorithm suitable for AD/DA boundary-scan test,realizes the testing method of the digital-analog hybrid chip AD/DA based on IEEE 1149.1 standard by programming.It makes up for the shortcomings of the existing commercial boundary-scan test software that cannot implement digital-analog mixed circuit testing based on the IEEE 1149.4 standard because the chip does not support the IEEE 1149.4 standard.5.Software testing and verification.In the test verification system built by the project,functional tests were performed on the software's test file analysis module,digital circuit diagnostic module,and digital-analog hybrid chip AD/DA diagnostic module.Randomly inject faults in the digital circuit test board and the hybrid circuit test board and use the software to diagnose the faults.After repeating 40 sets of experiments,the point estimation and interval estimation methods are used to calculate the test fault detection rate and fault isolation rate.The results show that both the fault detection rate and isolation rate meet the project index requirements,which verifies the effectiveness of the software.