Research On Test System Of Circuit Board Based On Testability Technology

With the development of today's technology,the design of circuit boards is becoming more and more sophisticated.At the same time,the pins of circuit boards are becoming denser and denser,and the internal structure of circuit boards is becoming more and more complicated.It has been founded that the internal structure of the digital circuit board is relatively simple,and there are just the digital signal"0"or"1"are passed inside.Therefore,by comparing the"0"and"1"states of the input and output signals,you can know the internal circuit board's problem of feet failure.At the same time,due to the gradual increase in the density of circuit board pins and the gradual complexity of the internal structure,it is more and more difficult to test the internal pins of the circuit board.The circuit board test system for testing the circuit board should also follow the circuit board's updated and continuously improved.Therefore,using the boundary scan test technology as the test method,the research and design of the boundary scan controller that can generate test signals that comply with both IEEE 1149.1 and IEEE 1149.7 standards,and the USB communication interface module and some peripheral circuits.The designed boundary scan controller has high test efficiency,and can communicate with the computer at the same time and is compatible with different levels of digital circuit boards,so that the test results can communicate with the computer and can connect different levels of circuit board;at the same time,an anti-misjudgment low confusion adaptive algorithm using boundary scan technology is designed.The designed adaptive algorithm can be used to grade the circuit according to the design principle of the algorithm,and the algorithm is relatively compact.To a certain extent,it can reach log₂?N+2?.The designed algorithm is resistant to misjudgment,the probability of fault confusion in detection is low,and it has high fault coverage and test rate;study a cluster test method to enable non-boundary scan devices that can be detected to improve the test coverage of the test system.