Research On Application Of Testability Technology In Airborne Circuit Board

With the development of the application of airborne electronic equipment in the field of aviation,the complexity of the increasingly powerful airborne electronic equipment is also increasing,which makes the test more difficult.The application of testability design in airborne electronic equipment simplifies the test of airborne electronic equipment,reduces the utilization rate of external test equipment,and improves the controllability and observability of equipment test.Therefore,how to use testability design technology to improve the test efficiency of airborne electronic equipment,reduce the test cost and power consumption,has become the current research and concern.First of all,through the analysis of testability design method,this paper considers that test vector is the key factor affecting test efficiency,and its rationality will directly affect test accuracy,test efficiency,test cost and test power consumption.Secondly,aiming at the problems of low test efficiency,high fault confusion rate and high error rate of test vector matrix formed by MSCA algorithm,equal weight algorithm and minimum weight maximum difference algorithm,an optimization method for test matrix is proposed.The experimental results show that the optimized test matrix effectively reduces the rate of fault confusion and misjudgment,reduces the test time and improves the test efficiency.Thirdly,aiming at the storage space occupied by test vectors and the slow transmission speed,a coding compression method based on test excitation vectors proposed.The application of this method can effectively reduce the length of test excitation vectors and compress the storage space of vectors.The decoding circuit,which integrates the new coding method makes the data,can be quickly input into the scan chain of the circuit under test,thus saving nearly 37% of the storage space and about 80% of the test time.Finally,a test system designed based on the boundary scan method in testability design technology.Combined with the two-test vector optimization methods proposed in this paper,the test system used to test the circuit extracted from the airborne circuit board.The test results show that the test efficiency of the system has been effectively improved and in line with expectations.