Analysis and detection of timing failures in an experimental Test Chip

A 25 k gate Test Chip was designed and manufactured to evaluate different test methods for scan-designed circuits. The design of the chip, the experiment, and preliminary experimental results were presented at ITC'95. This paper presents results for different clock speeds and clocking modes (at-speed and delay), and uses this data to characterize the behavior of the defective parts. It was found that timing-related defects are common, and the escape rate for different test techniques on these parts is discussed.