Delay fault coverage and performance tradeoffs
William K. C. Lam, A. Saldanha, Robert K. Brayton, Alberto L. Sangiovanni-Vincentelli · 1993
The main disadvantage of the path delay fault model is that to achieve 100% testability every path must be tested.Since the number of paths is usually exponential in circuit size, atl known analysis and synthesis techniques for 100% path delay fault testability are infeasible on most circuits.In this paper, we show that 100'%odelay fault testability is not necessary to guarantee the speed of a combinational circuit.There exist path delay faults which can never impact the circuit delay (computed using arty correct timing analysis method) unless some other path delay faults also affect i~hence these delay faults need not be considered in delay fault testing.Next, assuming only the existence of robust delay fault tests for a very small set of paths, we show how the circuit speed can be selected such that 100% robust delay fault coverage is achieved.