Modern electronics testing has a legacy of more than 40 years. The introduction of new technologies, especially nanometer technologies with 90nm or smaller geometry, has allowed the semiconductor industry to keep pace with the increased performance-capacity demands from consumers. As a result, semiconductor test costs have been growing steadily and typically amount to 40% of today's overall product cost. 

This book is a comprehensive guide to new VLSI Testing and Design-for-Testability techniques that will allow students, researchers, DFT practitioners, and VLSI designers to master quickly System-on-Chip Test architectures, for test debug and diagnosis of digital, memory, and analog/mixed-signal designs.

KEY FEATURES
* Emphasizes VLSI Test principles and Design for Testability architectures, with numerous illustrations/examples.
* Most up-to-date coverage available, including Fault Tolerance, Low-Power Testing, Defect and Error Tolerance, Network-on-Chip (NOC) Testing, Software-Based Self-Testing, FPGA Testing, MEMS Testing, and System-In-Package (SIP) Testing, which are not yet available in any testing book.
* Covers the entire spectrum of VLSI testing and DFT architectures, from digital and analog, to memory circuits, and fault diagnosis and self-repair from digital to memory circuits.
* Discusses future nanotechnology test trends and challenges facing the nanometer design era; promising nanotechnology test techniques, including Quantum-Dots, Cellular Automata, Carbon-Nanotubes, and Hybrid Semiconductor/Nanowire/Molecular Computing.
* Practical problems at the end of each chapter for students.

System-on-Chip Test Architectures: Nanometer Design for Testability

Industry has used scan-based designs widely to promote test quality. However, for larger designs, the growing test data volume has significantly increased test cost because of excessively long test times and elevated tester memory and external test channel requirements. To address these problems, researchers have proposed numerous test compression architectures. In this article, we propose a flexible scan test methodology called universal multicasting scan (UMC scan). It has three major features: First, it provides a better than state-of-the-art test compression ratio using multicasting. Second, it accepts any existing test patterns and doesn't need ATPG support. Third, unlike most previous multicasting schemes that use mapping logic to partition the scan chains into hard configurations, UMC scan's compatible scan chain groups are defined by control bits, as in the segmented addressable scan (SAS) architecture. We have developed several techniques to reduce the extra control bits so that the overall test compression ratio can approach that of the ideal multicasting scheme.

UMC-Scan Test Methodology: Exploiting the Maximum Freedom of Multicasting

Publisher Summary Numerous studies from academia and industry have shown the need to reduce power consumption during testing of digital and memory designs. This chapter discusses issues arising from excessive power consumption during test application and provides structural and algorithmic solutions that can alleviate the low-power test problems. Both structural and algorithmic solutions are described along with their impacts on parameters such as fault coverage, test time, area overhead, circuit performance penalty, and design flow modification. These solutions cover a broad spectrum of testing environments, including scan testing, scan-based built-in self-test (BIST), test-per-clock BIST, test compression, and memory testing. Although the solutions presented can be used to address most of the problems caused by excessive test power, not all problems have been solved. One concern is when multiple issues arise at the same time when developing low-power test solutions. For instance, almost all digital circuits today have scan chains and quite a few require test compression for test data volume reduction along with at-speed testing for screening timing defects. Thus far, solutions proposed to address the problem of low-power scan testing when both test compression and at-speed scan testing are used. Further, concerns arise from how testing is to be done when new low-power design techniques, such as dynamic power management and multiple-voltage design techniques, are employed. The idea of dynamic power management is to shut down parts of a design when they are idle.

Low-Power Testing

This paper presents segmented addressable scan (SAS), a test architecture that addresses test data volume, test application time, test power consumption, and tester channel requirements using a hardware overhead of a few gates per scan chain. Using SAS, this paper also presents systematic scan reconfiguration, a test data compression algorithm that is applied to achieve 10times to 40 times compression ratios without requiring any information from the automatic-test-pattern-generation tool about the unspecified bits. The architecture and the algorithm were applied to both single stuck as well as transition fault test sets

Scan Test Cost and Power Reduction Through Systematic Scan Reconfiguration

High power consumption in scan testing can cause undue yield loss which has increasingly become a serious problem for deep-submicron VLSI circuits. Growing evidence attributes this problem to shift timing failures, which are primarily caused by excessive switching activity in the proximities of clock paths that tends to introduce severe clock skew due to IR-drop-induced delay increase. This paper is the first of its kind to address this critical issue with a novel layout-aware scheme based on scan segmentation design, called LCTI-SS (Low-Clock-Tree-Impact Scan Segmentation). An optimal combination of scan segments is identified for simultaneous clocking so that the switching activity in the proximities of clock trees is reduced while maintaining the average power reduction effect on conventional scan segmentation. Experimental results on benchmark and industrial circuits have demonstrated the advantage of the LCTI-SS scheme.

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A novel scan segmentation design method for avoiding shift timing failure in scan testing

This paper presents a test architecture that addresses multiple problems faced in digital IC testing. These problems are test data volume, test application time, test power consumption, and tester channel requirements. With minimal hardware overhead, the architecture provides at least an order of magnitude reduction to each of the above problems. The architecture relies on scan chain segmentation and multiple-hot decoders.

M. Grinchuck

Papers

Segmented addressable scan architecture