VLSI Design & Test Seminar, Spring 2007
Reconvergent Fanouts in Min-Max Delay Fault Simulation
Speaker: Hillary Grimes, email@example.com
Date: Wednesday, March 14, 2007
Time: 4:00 pm
Room: Broun 235
Delay testing verifies that a manufactured VLSI design meets its speed
requirements. Min-Max delay fault
simulation allows for process variations when simulating delay faults for
accurate evaluation of test quality.
Most Min-Max delay fault simulation algorithms today lack fanout
reconvergence analysis when certain time-correlations at the inputs of
reconvergent gates can guarantee no hazard will occur at the output. The result of incorrect hazard evaluation is
pessimism in detectable delay fault sizes.
In this talk, we examine an event-driven technique that propagates
hazard lists containing information about delay bounds from fanout points to
correctly evaluate hazards. Hazard list
propagation is similar to fault list propagation in concurrent fault
simulation. Results for benchmark
circuit c7552 show that 25% of critical gate delay faults are incorrectly
assumed detected when correlations are ignored.
About 50% of critical gate delay faults are incorrectly assumed detected
for c3540. This research is performed in
collaboration with Dr. S. Bose of Intel Corporation.