About the correlation between logical identified faulty gates and their layout characteristics

Electronics play a significant role in modern society in various areas of our daily lives. Companies producing embedded nano-electronic systems have responded to the ever-increasing demand for high-performance chips with the development and production of structurally complex design, both in terms of the number of gates they are composed of and how they are arranged on the silicon surface. Especially devices intended for safety-critical fields, such as the Automotive field, require a thorough and precise testing process before they are fielded. This paper proposes a correlation analysis between candidate faulty logical gates as possible sources of a given failure identified during the Manufacturing Test Flow and their layout characteristics on the silicon. It is meaningful feedback for manufacturers about the quality of their applied tests. The experimental results are reported for data regarding a production lot of an Automotive System-on-Chip belonging to the SPC58 family produced by STMicroelectronics

Parallel Multithread Analysis of Extremely Large Simulation Traces

With the explosion in the size of off-the-shelf integrated circuits and the advent of novel techniques related to failure modes, commercial Automatic Test Pattern Generator and fault simulation engines are often insufficient to measure the coverage of particular metrics. Consequently, a general working framework consists of storing simulation traces during the analysis phase and collecting test statistics from post-processing. Unfortunately, typical simulation traces can be hundreds of gigabytes long, and their analysis can require several days, even on large and powerful computational servers. In this paper, we propose a set of strategies to mitigate the evaluation time and the memory needed to analyze huge dump files stored in the standard Value Change Dump format. We concentrate on burn-in-related metrics that current commercial fault simulators and Automatic Test Pattern Generators cannot evaluate. We show how to divide the analysis process into several concurrent pipeline stages. We revise the logic process of each stage and all principal intermediate data structures, to adopt smart parallelization with very low contention and extremely low overhead. We exploit several low-level optimizations from modern programming techniques to reduce computation time and balance the different pipeline phases. We analyze simulation traces up to almost 250 GBytes computing different testing metrics. Overall, we can keep under control the memory usage, and we show time improvements of over two orders of magnitude compared to previously adopted state-of-the-art tools

Innovative methods for Burn-In related Stress Metrics Computation

Burn-In equipment provide both external and internal stress to the device under test. External stress, such as thermal stress, is provided by a climatic chamber or by socket-level local temperature forcing tools, and aims at aging the circuit material, while internal stress, such as electrical stress, consists in driving the circuit nodes to produce a high internal activity. To support internal stress, Burn-In test equipment is usually characterized by large memory capabilities required to store precomputed patterns that are then sequenced to the circuit inputs. Because of the increasing complexity and density of the new generations of SoCs, evaluating the effectiveness of the patterns applied to a Device under Test (DUT) through a simulation phase requires long periods of time. Moreover, topology-related considerations are becoming more and more important in modern high-density designs, so a way to include this information into the evaluation has to be devised. In this paper we show a feasible solution to this problem: the idea is to load in the DUT a pattern not by shifting inside of it a bit at a time but loading the entire pattern at once inside of it; this kind of procedure allows for conservative stress measures, thus it fits for stress analysis purposes. Moreover, a method to take the topology of the DUT into account when calculating the activity metrics is proposed, so to obtain stress metrics which can better represent the activity a circuit is subject to. An automotive chip accounting for about 20 million of gates is considered as a case of study. Resorting to it we show both the feasibility and the effectiveness of the proposed methodology

Test, Reliability and Functional Safety Trends for Automotive System-on-Chip

This paper encompasses three contributions by industry professionals and university researchers. The contributions describe different trends in automotive products, including both manufacturing test and run-time reliability strategies. The subjects considered in this session deal with critical factors, from optimizing the final test before shipment to market to in-field reliability during operative life