Predicting and eliminating built-in test false alarms

Failures detected by built-in test equipment (BITE) occur because a BITE measurement noise or bias as well as actual hardware failures. A quantitative approach is proposed for setting built-in test (BIT) measurement limits and this method is applied to the specific case of a constant failure rate system whose BITE measurements are corrupted by Gaussian noise. Guidelines for setting BIT measurement limits are presented for a range of system MTBF (mean time between failures) times and BIT run times. The technique was applied to a BIT for an analog VLSI test system with excellent results, showing it to be a powerful tool for predicting tests with the potential for false alarms. It was discovered that, for this test case, false alarms are avoidable