Bitstream-Driven Built-In Characterization for Analog and Mixed-Signal Embedded Circuits

The conventional analog and mixed-signal production testing of system-on-a-chip systems provides limited controllability and observability because automatic test equipment (ATE) access is limited to device under test (DUT) ballouts. More importantly, production mixed-signal testing, due to long test times and expensive ATE, represents a substantial portion of the total manufacturing costs. This brief presents a cost-effective and advanced-signature-based dynamic test method that uses a built-in self-test (BIST) platform that enhances the controllability and observability of mixed-signal embedded systems. The BIST platform includes a simple on-chip signature generator that comprises a clipper and a single-bit comparator. This brief precisely predicts the dynamic nonlinearity of individual mixed-signal circuits connected in a loopback configuration by clipping the loopback-path signal to efficiently give the loopback response a different weighting. The clipped behavior of the loopback-path signal is translated to a bitstream signature by the comparator. The signature and the loopback response allow us to efficiently split the loopback performance into individual DUT performances by solving the DUT characteristic equations using the on-chip digital-signal-processor core. Hardware measurements were performed to show that the proposed method can be practically applied in production.