A new testability model of electronic system and its application

Testability is an important design feature of systems and equipment. To improve the ability of self diagnosis and external diagnosis in the system, the research of testability should be done, which can ensure the state of system and isolate the fault effectively. The method of testability analysis based on model is widely used. According the requirement of the testability in electronic system, combining with Multi-signal Flow Graph model and function and failure mode, a testability model for electronic, ESTIM, is proposed. The model is closer to the physical model on the mode of expression. Then the difficulty of modeling is decreased. According to schematic, on the basis of electrical circuit connecting topology structure, ESTIM model is prone to accomplish the testability analysis and acquire the testability parameters. How to build and calculate the model is described in detail. And the application method of ESTIM is illustrated by analyzing the digital pressure altimeter.