functional test generation for delay faults in combinational circuits
Abstract: We propose a functional fault model for delay faults in combinational circuits and describe a functional test generation procedure based on this model. The proposed method is most suitable when a gate-level description of the circuit-under-test, necessary for employing existing gate-level delay fault test generators, is not available. It is also suitable for generating tests in early design stages of a circuit, before a gate-level implementation is selected. It can also potentially be employed to supplement conventional test generators for gate-level circuits to reduce the cost of branch and bound strategies. A parameter called /spl Delta/ is used to control the number of functional faults targeted and thus the number of tests generated. If /spl Delta/ is unlimited, the functional test set detects every robustly testable path delay fault in any gate-level implementation of the given function. An appropriate subset of tests can be selected once the implementation is known. The test sets generated for various values of /spl Delta/ are fault simulated on gate-level realizations to demonstrate their effectiveness.
functional test generation functional testing functional test generation test test generation generation delay faults delays fault combinational circuits circuits abstraction functional fault model fault model model method design implementation cost strategies control values fault simulated simulation gate-level realizations demonstrate effect logic testing branch-and-bound logic cad test generators