A multilevel test approach and its application in microcomputer fault diagnosis

The multilevel test allows the complete testing for a circuit from the upper functional levels to the actual defective components. An approach for fault diagnosis of digital systems at hierarchical levels is presented, which employs bus observation technique and fuzzy neural networks to solve the acquirements of test information. It is shown that fault diagnosis can be done at any desired level by means of the analysis for fault information relativity and the testability of faults. The approach has been applied in a fault diagnosis system for a microcomputer; the experimental results show the effectiveness of the approach