An Application Study On Testability Design Of The System On Chip

With the development in performance and integration of aero-engine digital control system,the design,manufacture and test of electronic engine controller is becoming more difficult than before. The kernel electronic circuits of electronic controller become more and more complex,so the traditional test method can not meet the need. The testing method based on boundary scan which is an international generic testing standard can provide a feasible solution to improve the testability of the electronic system. This method is becoming an important technology to realize system level test,board level test and build in test.On the basis of analyzing of the measurement based on boundary scan,a testing adapter with a boundary scan testing bus is designed. The design to the interface circuit of a test-bus controller with a host microcontroller and the communication circuit of the testing adapter to the host computer is the point. The software of the testing adapter is developed and implemented to load the test instructions and acquire the test responses.According to the idea of design for testability,a testing circuit including the kernel electronic circuits of electronic engine controller is designed, which can support different boundary scan testing mode. And some fault injection circuits are designed on the board to validate the efficiency of the fault detection based on boundary scan.Boundary scan testing experiments are carried out by the testing adapter and the kernel electronic circuits of the testing circuit,which can realize loading the instructions and validating the efficiency of the fault detection based on boundary scan. The fault injection is realized,which is based on the principle of boundary scan bus can change the level state of the chip pin. The result indicates that the technology based on boundary scan can solve the test problem of the high integration electronic circuits of electronic engine controller.