A fault is defined to have occurred when any circuit variable assumes a value 1, 0, or x which differs from that expected, that. International journal of computer trends and technology. Perl script file to take spice decks and inject faults into the circuit and. Path sensitization for combinational logic circuits one powerful approach to test generation relies on path sensitizing, the applica tion of input such that the output depends directly on the condition of the lead being tested. Z f t however, f is undetectable if zx z f x for all x cool. New techniques are presented for generating faultdetection experiments for combinational logic networks. Efficient test compaction for combinational circuits based on. Researchers have proposed various methods to generate ndetect tests, but not much work is done on minimizing them. Diagnostic test pattern generation and fault simulation. The main problem that limits their use is their size. Both algorithms can be used to identify difficulttotest faults and to quickly construct test sets for specific faults. In the case of using errorcorrecting codes in the combinational circuits a single fault can influence multiple outputs and correction leads to a wrong data output. Agrawal the objective of the research reported in this thesis is to develop new test generation algorithms using mathematical optimization techniques.
The framework described here models all important factors involved in transient fault propagation in logic circuits in a unified manner and allows for comprehensive probabilistic analysis of circuit reliability. The pseudoexhaustive test of sequential circuits test. Nasa documents, on june, a complete shutdown of secondary power to all three central computer. Fault detection and test minimization methods for combinational circuits a survey. Fault equivalence in combinational logic networks edward j. Towards this end, we devise a concurrent fault detection method for random combinational logic that reduces hardware overhead at the cost of introducing fault detection latency. Fault detection circuits ird mechanalysis developed fault detection circuitry for case mounted transducers such as. Let f be the set of stuckat1 faults s1 and stuckat0 faults s0, where s. Fault detection and diagnostic test set minimization mohammed ashfaq shukoor master of science, may 9, 2009 b.
Bounding fault detection probabilities in combinational. A very big number of fault detection models already have been projected in digital logic circuits 10, 11. Numerous researches have indicated that analog circuit fault diagnosis is a significant fundamental for design validation and performance evaluation in the integrated circuit manufacturing fields. A 1 is entered at the intersection of a row and column if the corresponding test detects the. International journal of computer trends and technology volume2issue2 2011 issn. Functional test generation for delay faults in combinational circuits. Methods of fault detection in this chapter most of the major techniques of fault detection are described. Efficient test compaction for combinational circuits based.
Functional fault equivalence and diagnostic test generation. Fault diagnosis in sequential circuits 19 which distinguishes the most faults which have not yet been distinguished, should be selected first. Detection of opens in cmos circuits is not as complicated as that of shorts. The low power test approach can detect any combinational stuckat fault within the basic building cell of the. Keywords combinational circuits, fault detection, genetic algorithm, ilp, stuckatfaults, test minimization.
For generating tests, however, the dalgorithm needs modification. This insures that the systems credibility is not damaged from false alarms and false machinery trips. Coordinated science laboratory, university of illinois at urbanachampaign. That is, a detection test in this case must consist of applying certain signals at the circuits external input terminals and ob. Pdf on jan 1, 2016, ali abbass zoraghchian and others published a fault detection method for combinational circuits find, read and cite all the research you need on researchgate.
The errorcorrecting codes are often used for data paths. Single stuckat model is the most common model for fault detection. This paper proposes and evaluates a logic level faulttolerant method based on parity for designing combinational circuits. Memory devices are special sequential circuits for which a wide variety of testing. Instead of tesl sets one has 10 apply pseudoelthaustive test sequences of a limited length, which provides wellknown benefits as far as faultcoverage. In particular, the dilions whereby two different faults can produce the same alteration in. Deductive fault simulator for combinational circuits. Detection of multiple faults in combinational logic networks. It is assumed that all testing must be performed on the external terminals of the circuits. An ndetect test set detects each stuckat fault by at least n different vectors. Two algorithms, the complete cutting algorithm and the gate blocking algorithm, are presented that always produce true lower bounds on the detection probability of a fault. Generate the collapsed fault list using equivalence and dominance relations. Abstracthe problem of designing test schedules for the testing or diagnosis of a small number of nontransient faults in combinational digital circuits switching networks is considered in detail.
Basic concept of fault detection and location in sequential. Design of errorresilient logic gates with reinforcement using implications xijing han, marco donato, r. Atpg for iddq andor voltage testing of combinational circuits using an arbitrary fault library for basic gates e. Fault testing and diagnosis in combinational digital circuits. Minimizing ndetect tests for combinational circuits. As one of the foremost stages in fault diagnosis, feature extraction methods are closely related to the efficiency of fault diagnosis. The procedure of fault diagnosis for analog circuits can be generally classified into four stages. Effects of redundancy on fault detection and diagnosis in combinational logic circuits. Testing of a stuckopen fault requires a twopattern test, consisting of an initialization and a test vector. New approach framework in this paper we presented a new approach to design fault tolerant combinational circuits. Bounding fault detection probabilities in combinational circuits. Miklos institute of informatics sas, bratislava, slovakia email. Clegg, member, ieee abstractthis paper is a study of the effects of faults on the logical operation of combinational acyclic logic circuits.
Fault diagnosis is the combinational problem of quickly localizing failures as soon as they are detected in systems. Pdf combinational networks with no internal fanout are considered from the. This paper presents a new hybrid faulttolerant architecture for robustness improvement of digital cmos circuits and systems. Iris bahar, alexander zaslavsky, william patterson school of engineering brown university providence, ri 02906 abstract operating circuits in the subthreshold region can save power, but at the cost of higher susceptibility to noise. Functional test generation for delay faults in combinational circuits irith pomeranz and sudhakar m. Fast hazard detection in combinational circuits abstract in designing asynchronous circuits it is critical to ensure that circuits are free of hazards in the speci. An algorithm for generating test sets to detect all the multiple stuckat faults in combinational logic circuits is presented. Multiple fault detection for combinational logic circuits ieee xplore. Fault detection in asynchronous sequential circuits. Dudam2 amit kumar sinha3 1,2,3department of vlsi design 1,3vel tech university, chennai, india 2pune institute of computer technology, pune abstractin any circuit that comprises the logic gates. The concept of a pseudoelthaustive test for sequential circuits is introduced in a similar way as it is used for combinational networks. This document is highly rated by students and has been viewed 3464 times. The fault list, and input pattern set have to be read from files, and. The method is based on reduced observation width replication rowr of the circuit, suf.
Testing 2 fault model stuckat model assume selected wires gate input or output are stuck at logic value 0 or 1 models curtain kinds of fabrication flaws that short circuit. Pdf fault detection and test minimization methods for. The later includes the design of parity preserving reversible circuits which gained signi. Effects of redundancy on fault detection and diagnosis in.
Detection of faults in f is sufficient for stating that the circuit is stuckat fault free. Cost effective design and fabrication of reliable cmos vlsi chips require understanding of various cmos technologies, logic families, failure modes, fault detection methods and design for testability methods. Fault detection techniques 3 12 fault detection techniques 12. In this paper, three new algorithms for detecting hazards in combinational circuits are proposed. A fault detection method for combinational circuits.
Assume a logic circuit with minput and noutput lines. Pdf a fault detection method for combinational circuits. This algorithm generates a test set using a set of functions, called representative functions, which consists of much fewer functions than all possible multiple stuckat fault functions, but is sufficient for test generation. International journal of computer trends and technology volume2issue2 2011. Redundancy fault detection second generation faults. It targets all kinds of errors in combinational part of logic circuits and thus, can be combined with advanced seu protection techniques for sequential elements while reducing the power consumption. Fault detection and diagnostic test set minimization. Fault diagnosis for analog circuits by using eemd, relative. Fault detection and design for testability of cmos logic.
Pdf multiple fault detection in combinational networks. Jul 19, 2015 may 04, 2020 basic concept of fault detection and location in sequential circuits notes edurev is made by best teachers of. A circuit that contains an undetectable fault is a. This paper presents a new hybrid fault tolerant architecture for robustness improvement of digital cmos circuits and systems.
Concurrent fault detection in random combinational logic purdue. The framework described here models all important factors involved in transient fault propagation in logic circuits in a unified manner and allows for comprehensive probabilistic. Fault diagnosis and logic debugging using boolean satisfiability. Circuit fault diagnosis is the problem of identifying a minimumsized set of components that, if faulty, explains an observation of incorrect outputs given a set of inputs. In our case, we consider that a fault is easier to observe when it is closer to a. Functional test generation for delay faults in combinational. Circuits have full scan and tests are generated for application in loc mode. A fault table is a table in which there is a row for every possible test i. Multiple fault detection in twolevel multioutput circuits springerlink. Multiple fault detection for combinational logic circuits.
Fault detection in combinational circuits using boolean. Logical deviations electrical and computer engineering. This paper focuses on the problem of bounding fault detection probabilities in combinational circuits. These algorithms minimize test vector sets of a combinational logic circuit for fault detection and diagnosis, respectively. Abadir3 sep seyedi1 abstract fault equivalence is an essential concept in digital design with signi. New approach framework in this paper we presented a new approach to design faulttolerant combinational circuits. Exact functional fault collapsing in combinational logic circuits abstract fault equivalence is an essential concept in digital vlsi design with signi. Localization of single gate design errors in combinational. A stuckopen fault in a combinational circuit may induce a sequential behaviour in the circuit. The objective of the research reported in this thesis is to develop new test generation algorithms using mathematical optimization techniques. Fault diagnosis in sequential circuits sciencedirect. The proposed method is similar to duplication, wherein a replica of the circuit acts as a predictor that immediately. Group name roll project name number pla to andxor format. Defectoriented modulelevel fault diagnosis in digital circuits.
Redundancy fault f is detectable if there exists a test t that detects it i. Since electronic circuits are employed in a wide range of applications, concurrent test methods of various cost and ef. Fault detection and design for testability of cmos logic circuits. Fault detection in parity preserving reversible circuits. A fault detection method for combinational circuits aliabbasszoraghchian1, moslem didehban2, mohammadreza mehrabian3 1. Soft error, transient fault, faulttolerance, combinational circuits. Every fault, whether a stuck type fault or a transistor fault, is represented in the model as a stuck fault at a certain gate input. Minimal test set for stuckat faults in vlsi ntrs nasa. Pdf single stuck line is a deficiency model utilized as a part of computerized circuits. Online multiple fault detection in reversible circuits.
Kohavi, detection of multiple faults in combinational logic. A number of heuristics are presented that keep the method. Multiple transient faults in combinational and sequential. Functional fault equivalence and diagnostic test generation in combinational logic circuits using conventional atpg andreas veneris1. Design a twovalued deductive fault simulator for combinational circuits, which can accept input circuit description in iscas85 format. Exact functional fault collapsing in combinational logic circuits. In contrast to the welldeveloped diagnostic methods for digital circuits, diagnosis for analog circuits is an extremely difficult problem and an active research due to the. Agarwal, functional test generation for sequential circuits, proc. The first algorithm generates a minimized fault detection test set.
Department of computer engineering and information technology amirkabir university. For fault detection, the test which detects the most faults which have not yet been detected, is the best choice. This thesis is concerned with the detection of non transient faults in linear sequential circuits lsc over gf2 8. Printed in great britain fault detection in combinational circuits using boolean matrices suresh rm and k. Ndetect tests are of practical interest because of their ability to improve the defect coverage. Instead of tesl sets one has 10 apply pseudoelthaustive test sequences of a limited length, which provides wellknown benefits as far as fault coverage.
Defectoriented modulelevel fault diagnosis in digital. Testing of logic circuits fault models test generation and coverage fault detection design for test cs 150 fall 2005 lec. Pdf online multiple fault detection in reversible circuits. Karpovsky abstract for many devices and circuits even single faults can result in errors of a large hamming weight at the output of. Design of errorresilient logic gates with reinforcement. There are some circuits where even if there is a fault in certain places, they still work.
Fault detection in combinational circuits using a compressed fault table. A new hybrid faulttolerant architecture for digital cmos. Towards this end, we devise a concurrent fault detection method for random combinational logic that reduces hardware overhead. Detection of multiple faults in combinational logic networks ieee.
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