Techniques For Assessing Fault Model And Test Quality In Automatic Test Pattern Generation For Integrated Circuits

Assessing Fault Model and Test Quality

For many years, the dominant fault model in automatic test pattern gen eration (ATPG) for digital integrated circuits has been the stuck-at fault model. The static nature of stuck-at fault testing when compared to the extremely dynamic nature of integrated circuit (IC) technology has caused many to question whether or not stuck-at fault based testing is still viable. Attempts at answering this question have not been wholly satisfying due to a lack of true quantification, statistical significance, and/or high computational expense. In this monograph we introduce a methodology to address the ques tion in a manner which circumvents the drawbacks of previous approaches. The method is based on symbolic Boolean functional analyses using Or dered Binary Decision Diagrams (OBDDs). OBDDs have been conjectured to be an attractive representation form for Boolean functions, although cases ex ist for which their complexity is guaranteed to grow exponentially with input cardinality. Classes of Boolean functions which exploit the efficiencies inherent in OBDDs to a very great extent are examined in Chapter 7. Exact equa tions giving their OBDD sizes are derived, whereas until very recently only size bounds have been available. These size equations suggest that straight forward applications of OBDDs to design and test related problems may not prove as fruitful as was once thought.

Proceedings of the ... European Test Conference

Testing for Small-Delay Defects in Nanoscale CMOS Integrated Circuits

Advances in design methods and process technologies have resulted in a continuous increase in the complexity of integrated circuits (ICs). However, the increased complexity and nanometer-size features of modern ICs make them susceptible to manufacturing defects, as well as performance and quality issues. Testing for Small-Delay Defects in Nanoscale CMOS Integrated Circuits covers common problems in areas such as process variations, power supply noise, crosstalk, resistive opens/bridges, and design-for-manufacturing (DfM)-related rule violations. The book also addresses testing for small-delay defects (SDDs), which can cause immediate timing failures on both critical and non-critical paths in the circuit. Overviews semiconductor industry test challenges and the need for SDD testing, including basic concepts and introductory material Describes algorithmic solutions incorporated in commercial tools from Mentor Graphics Reviews SDD testing based on "alternative methods" that explores new metrics, top-off ATPG, and circuit topology-based solutions Highlights the advantages and disadvantages of a diverse set of metrics, and identifies scope for improvement Written from the triple viewpoint of university researchers, EDA tool developers, and chip designers and tool users, this book is the first of its kind to address all aspects of SDD testing from such a diverse perspective. The book is designed as a one-stop reference for current industrial practices, research challenges in the domain of SDD testing, and recent developments in SDD solutions.