The Test Of Part-BS Circuit And The Test Point Optimization

With the development of very large scale integrated circuit technology, the densityof the circuit is more and more higher, it is hard to be achieved that the traditional testmethods based on the probe in very large scale integrated circuit test, boundary scantechnology uses the method base on virtual probes, its unique test method provides aneffective test solutions for very large scale integrated circuit, makes not only very largescale integrated circuit testing as a viable, and shorten the test time, reduce the test cost.However, the premise of boundary scan test is that integrated circuit should be in thecircuit with boundary scan function chips, but the actual situation of the circuit is not allconsistent, the boundary scan devices and not boundary scan devices composition notfully boundary scan of circuit will still exist for a long time in the future. The study ofnot fully boundary scan of the circuit board test question is more practical significanceto solve the problem of very large scale integrated circuit test. The major tasks of thethesis are research several difficult problems of not fully boundary scan circuit testing,its main research work and innovation as follows.1. Boundary scan of testing technology and the existing technical difficulties arediscussed, the part-BS board testing principle and technical problems are analyzed andstudied. The testability of part-BS board structure design optimization method and thepart-BS board test the basic principle and method.2. In the analysis of the test point part-BS board optimization method has themerits of the existing limitations, on the basis of fully consider the boundary scan of theactual not fully completely circuit is proposed based on failure mode and harm degreetest site optimization method, and through the mathematical deduction proved thismethod based on fault harm degree than the method suitable for wider range, and finallypresents the method of solving the basic train of thought.3.Analyzes the existing test vector generation algorithm advantages anddisadvantages, and put forward the better performance of such right value identificationalgorithm through the shift algorithm produces additional vector, the right value testpatterns such as mark, further improve the ability of confusion, generated test vector ofcomprehensive better performance.