A hierarchical approach to effective test generation for VHDL behavioral models

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Virginia Tech


This thesis describes the development of the Hierarchical Behavioral Test Generator (HBTG) for the testing of VHDL behavioral models. HBTG uses the Process Model Graph of the VHDL behavioral model as the base for test generation. Test sets for individual processes of the model are precomputed and stored in the design library. Using this information, HBTG hierarchically constructs a test sequence that tests the functionality of the model. The test sequence generated by HBTG is used for the simulation of the model. Various features present in HBTG and the implementation of the algorithm are discussed. The idea of an effective test sequence for a VHDL behavioral model is proposed. A system is presented to evaluate the quality of the test sequence generated by the algorithm. Test sequences and coverage results are given for several models. Some suggestions for future improvements to the tools are made. The HBTG forms part of a complete CAD system for rapid development and testing of VHDL behavioral models.