435 research outputs found

    Fault Testing for Reversible Circuits

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    Applications of reversible circuits can be found in the fields of low-power computation, cryptography, communications, digital signal processing, and the emerging field of quantum computation. Furthermore, prototype circuits for low-power applications are already being fabricated in CMOS. Regardless of the eventual technology adopted, testing is sure to be an important component in any robust implementation. We consider the test set generation problem. Reversibility affects the testing problem in fundamental ways, making it significantly simpler than for the irreversible case. For example, we show that any test set that detects all single stuck-at faults in a reversible circuit also detects all multiple stuck-at faults. We present efficient test set constructions for the standard stuck-at fault model as well as the usually intractable cell-fault model. We also give a practical test set generation algorithm, based on an integer linear programming formulation, that yields test sets approximately half the size of those produced by conventional ATPG.Comment: 30 pages, 8 figures. to appear in IEEE Trans. on CA

    Network Fault Detection Using Test Packet Generation: A Survey

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    Networks are becoming larger and a lot of advanced, yet directors think about various tools like ping and traceroute to correct issues. Instead of using different tools to debug the network problems, we introduced an automatic and systematic scheme for testing and debugging networks known as Automatic test Packet Generation (ATPG). This automated approach fetches router configurations to generate a device-independent model. The model is employed to get a minimum set of test packets to analyse each link in the network. The detected failures trigger a separate mechanism to localize the fault by sporadically sending test packets. ATPG will notice each operational (e.g., incorrect firewall rule) and performance problems. ATPG complements however goes on the far side earlier add static checking (which cannot observe functional or performance faults) or fault localization (which solely localizes faults given liveness results). DOI: 10.17762/ijritcc2321-8169.150315

    Boolean Satisfiability in Electronic Design Automation

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    Boolean Satisfiability (SAT) is often used as the underlying model for a significant and increasing number of applications in Electronic Design Automation (EDA) as well as in many other fields of Computer Science and Engineering. In recent years, new and efficient algorithms for SAT have been developed, allowing much larger problem instances to be solved. SAT “packages” are currently expected to have an impact on EDA applications similar to that of BDD packages since their introduction more than a decade ago. This tutorial paper is aimed at introducing the EDA professional to the Boolean satisfiability problem. Specifically, we highlight the use of SAT models to formulate a number of EDA problems in such diverse areas as test pattern generation, circuit delay computation, logic optimization, combinational equivalence checking, bounded model checking and functional test vector generation, among others. In addition, we provide an overview of the algorithmic techniques commonly used for solving SAT, including those that have seen widespread use in specific EDA applications. We categorize these algorithmic techniques, indicating which have been shown to be best suited for which tasks

    Logic Locking based Trojans: A Friend Turns Foe

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    Logic locking and hardware Trojans are two fields in hardware security that have been mostly developed independently from each other. In this paper, we identify the relationship between these two fields. We find that a common structure that exists in many logic locking techniques has desirable properties of hardware Trojans (HWT). We then construct a novel type of HWT, called Trojans based on Logic Locking (TroLL), in a way that can evade state-of-the-art ATPG-based HWT detection techniques. In an effort to detect TroLL, we propose customization of existing state-of-the-art ATPG-based HWT detection approaches as well as adapting the SAT-based attacks on logic locking to HWT detection. In our experiments, we use random sampling as reference. It is shown that the customized ATPG-based approaches are the best performing but only offer limited improvement over random sampling. Moreover, their efficacy also diminishes as TroLL's triggers become longer, i.e., have more bits specified). We thereby highlight the need to find a scalable HWT detection approach for TroLL.Comment: 9 pages, double column, 8 figures, IEEE forma

    Progress Toward Efficient Laminar Flow Analysis and Design

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    A multi-fidelity system of computer codes for the analysis and design of vehicles having extensive areas of laminar flow is under development at the NASA Langley Research Center. The overall approach consists of the loose coupling of a flow solver, a transition prediction method and a design module using shell scripts, along with interface modules to prepare the input for each method. This approach allows the user to select the flow solver and transition prediction module, as well as run mode for each code, based on the fidelity most compatible with the problem and available resources. The design module can be any method that designs to a specified target pressure distribution. In addition to the interface modules, two new components have been developed: 1) an efficient, empirical transition prediction module (MATTC) that provides n-factor growth distributions without requiring boundary layer information; and 2) an automated target pressure generation code (ATPG) that develops a target pressure distribution that meets a variety of flow and geometry constraints. The ATPG code also includes empirical estimates of several drag components to allow the optimization of the target pressure distribution. The current system has been developed for the design of subsonic and transonic airfoils and wings, but may be extendable to other speed ranges and components. Several analysis and design examples are included to demonstrate the current capabilities of the system

    Programming a Distributed System Using Shared Objects

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    Building the hardware for a high-performance distributed computer system is a lot easier than building its software. The authors describe a model for programming distributed systems based on abstract data types that can be replicated on all machines that need them. Read operations are done locally, without requiring network traffic. Writes can be done using a reliable broadcast algorithm if the hardware supports broadcasting; otherwise, a point-to-point protocol is used. The authors have built such a system based on the Amoeba microkernel, and implemented a language, Orca, on top of it. For Orca applications that have a high ratio of reads to writes, they measure good speedups on a system with 16 processors

    An investigation of defect detection using random defect excitation and deterministic defect observation in complex integrated logic circuits

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    Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to [email protected], referencing the URI of the item.Includes bibliographical references: leaves 22-23.aWhenever integrated circuits are manufactured, a certain percentage of those circuits will be defective. Defective circuits present problems for both the manufacturers who wish to maintain a good reputation with their customers and the consumers who depend upon the correct operation of the products they buy. Thus, testing must be done to detect which parts are defective so that they are not sold to unwitting consumers. Most current testing methods involve generating test patterns that will detect single stuck-at faults. Unfortunately, however, the single stuck-at fault model cannot adequately describe all of the potential defects that may occur. The requirements for exciting a fault vary depending upon the specific model (stuck-at, bridge, etc.) being used, but the observation of the fault always requires that the erroneous logic value be propagated to a primary output. The proposed new method of automatic test pattern generation involves deterministically observing all of the sites in the circuit as many times as possible while randomly exciting the defects which may occur. This research demonstrates the importance of site observation on the detection of defects and shows some of the inefficiencies and shortcomings of the current stuck-at fault ATPG
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