Selective Multiple Capture Test (SMART) XLBIST

Logic BIST (LBIST) is increasingly deployed to realize test cost reduction and silicon life-cycle management. Xtolerant LBIST (XLBIST) expanded applicability to almost any design in the presence of unknown (X) values. XLBIST is crucial for many applications, particularly mission-critical applications such as aerospace/defense, automotive, telecommunications in-dustries etc. The optimization of test-time and test-cost are very important to reduce the overall latencies during In-System Test. In this paper, we introduce ATPG-driven multiple capture-clock selection which greatly increases XLBIST coverage per pattern. This helps in achieving the targeted coverage numbers with lesser number of seeds, greatly helping in test-cost reduction. Results with this novel solution on several big designs demonstrate consistent XLBIST coverage improvement even in presence of high X densities.