This work presents a new fault grading heuristic based on the critical path tracing technique that tackles the problems associated to fan-out reconverging nodes (FORN's) without using forward propagation of the fault effects. To determine the criticality status of a fanout reconverging node that can differ from that of its fan-out branches (FOB's), we use the concepts of evidencing and masking paths. Using the statistics from exact fault simulations, heuristic rules are derived for the generation of masking and evidencing paths. The results obtained on benchmark circuits show: a) good accuracy on fault coverage estimate; b) computation time linear in the number of gates and comparable to that of the fault-free simulation. © 1991 IEEE
A Novel Critical Path Heuristic for Fast Fault Grading
OLIVO, Piero;
1991
Abstract
This work presents a new fault grading heuristic based on the critical path tracing technique that tackles the problems associated to fan-out reconverging nodes (FORN's) without using forward propagation of the fault effects. To determine the criticality status of a fanout reconverging node that can differ from that of its fan-out branches (FOB's), we use the concepts of evidencing and masking paths. Using the statistics from exact fault simulations, heuristic rules are derived for the generation of masking and evidencing paths. The results obtained on benchmark circuits show: a) good accuracy on fault coverage estimate; b) computation time linear in the number of gates and comparable to that of the fault-free simulation. © 1991 IEEEI documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.