Testing digital low-pass filters using oscillation-based test

In this paper, we propose a novel low-cost BIST scheme for testing low-pass FIR and IIR filters, based on the oscillation-based test (OBT). The OBT–BIST scheme developed here avoids test-pattern generation and tests the filter at-speed, without test-point insertion. We employ a systematic procedure for designing the oscillator and for obtaining the oscillation conditions in advance. The simulation results show high fault coverage for the filters under test, with low area overhead and acceptable test time.