• Title/Summary/Keyword: combinational logic

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A Weighted Random Pattern Testing Technique for Path Delay Fault Detection in Combinational Logic Circuits (조합 논리 회로의 경로 지연 고장 검출을 위한 가중화 임의 패턴 테스트 기법)

  • 허용민;임인칠
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.32A no.12
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    • pp.229-240
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    • 1995
  • This paper proposes a new weighted random pattern testing technique to detect path delay faults in combinational logic circuits. When computing the probability of signal transition at primitive logic elements of CUT(Circuit Under Test) by the primary input, the proposed technique uses the information on the structure of CUT for initialization vectors and vectors generated by pseudo random pattern generator for test vectors. We can sensitize many paths by allocating a weight value on signal lines considering the difference of the levels of logic elements. We show that the proposed technique outperforms existing testing method in terms of test length and fault coverage using ISCAS '85 benchmark circuits. We also show that the proposed testing technique generates more robust test vectors for the longest and near-longest paths.

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A New Design Method for Verification Testability (검증 테스팅을 위한 새로운 설계 방법)

  • 이영호;정종화
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.29A no.4
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    • pp.91-98
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    • 1992
  • In this paper, a new heuristic algorithm for designing combinational circuits suitable for verification testing is presented. The design method consists of argument reduction, input partitioning, output partitioning, and logic minimization. A new heuristic algorithm for input partitioning and output partitioning is developed and applied to designing combinational circuits to demonstrate its effectiveness.

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Multiple Fault Detection in Combinational Logic Networks (조합논리회로의 다중결함검출)

  • 고경식;김흥수
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.12 no.4
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    • pp.21-27
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    • 1975
  • In this paper, a procedure for deriving of multiple fault detection test sets is presented for fan-out reconvergent combinational logic networks. A fan-out network is decomposed into a set of fan-out free subnetworks by breaking the internal fan-out points, and the minimal detecting test sets for each subnetwork are found separately. And then, the compatible tests amonng each test set are combined maximally into composite tests to generate primary input binary vectors. The technique for generating minimal test experiments which cover all the possible faults is illustrated in detail by examples.

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Design and Implementation of a Fault Simulation System for Mixed-level Combinational Logic Circuits (혼합형 조합 회로용 고장 시뮬레이션 시스템의 설계 및 구현)

  • Park, Yeong-Ho;Son, Jin-U;Park, Eun-Se
    • The Transactions of the Korea Information Processing Society
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    • v.4 no.1
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    • pp.311-323
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    • 1997
  • This paper presents a fast fault simulation system for detecting stuck-at faults in mixed-level combinational logic circuits with gale level and switch -level primitives. For a practical fault simulator, the types are not restricted to static switch-level and/or gate-level circuits, but include dynamic switch-level circuits. To efficiently handle the multiple signal contention problems at wired logic elements, we propose a six-valued logic system and its logic calculus which are used together with signal strength information. As a basic algorithm for the fault simulation process, a well -known gate-level parallel pattern single fault propagation(PPSFP) technique is extended to switch-level circuits in order to handle pass-transistor circuits and precharged logic circuits as well as static CMOS circuits. Finally, we demonstrate the efficiency of our system through the experimental results for switch-level ISCAS85 benchmark combinational circuits and various industrial mixed-level circuits.

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A Study on the fault Detection using output Sequence in Combinational Logic Networks (출력순자를 이용한 조합회로의 고장검출에 관한 연구)

  • Han, Hee;Park, Kue-Tae
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.17 no.4
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    • pp.31-37
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    • 1980
  • In this paper, we are concerned with the problems of fault- detection for combinational logic networks. The method which we can obtain the complete test sets using propagation of primitive test sets is presented by considering the relation between test sets of each line. A new method is proposed that can detect the fault through the observation of the output variance by applying only the test sets equivalent to the number of inputs We found that the method is much improved compared to the conventional fault detecting procedure that requires applying the complete test sets to the logic networks.

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A Study on Constructing the Multiple-Valued Combinational Logic Systems by Decision Diagram (결정 다이아그램에 의한 다치조합논리시스템 구성에 관한 연구)

  • 김이한;김성대
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.32B no.6
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    • pp.868-875
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    • 1995
  • This paper presents a method of constructing the multiple-valued combinational logic systems(MVCLS) by decision diagram. The switching function truth table of MVCLS is transformed into canonical normal form of sum-of-products(SOP) with literals at first. Next, the canonical normal form of SOP is transfered into multiple-valued logic decision diagram(MVLDD). The selecting of variable ordering is very important in this stage. The MVLDDs are quite different from each other according to the variable ordering. Sometimes the inadequate variable ordering produces a very large size of MVLDD means the large size of circuit implementation. An algorithm for generating the proper variable ordering produce minimal MVLDD and an example shows the verity of the algorithm. The circuits are realized with T-gate acceording to the minimal MVLDD.

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A Study on the Fault Detection in combinational Logic Networks with Fan-out (출력분기가 있는 조합논리회로의 고장검출에 과한 연구)

  • 임재탁;이근영
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.11 no.4
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    • pp.12-18
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    • 1974
  • In this paper, we are concerned with the problem of generating fault-detection experiment for combinational logic networks with fan-out. We establish the lower limit on the necessary number of fault-section tests and show how such experiments can be obtained by considering inversion parity from the output to the point whore fan-out exilts on the networks. Boolean difference is used advantageously.

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A Cost Model of Hierarchical Automatic Test Pattern Generation Algorithms for Combinational Logic Circuits (조합회로에 대한 계층 구조적 테스트 패턴 생성 알고리즘의 비용 모델)

  • Hyoung Bok Min
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.28A no.12
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    • pp.65-72
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    • 1991
  • A cost model of test generation is presented in this paper. The cost of flat gate-level and hierarchical modular level test generation for combinational logic circuits are modeled. The model shows that the cost of hierarchical test generation grows as GlogGunder some assuptions, while the cost of gate-level test generation grows $G^2<$/TEX>, where G is the number of gates in a circuit under test. The cost model derived in this paper is used to explain why some test generation techniques are faster and why hierarchical test generators should be faster than flat test generators on large circuits.

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Design and Simulation of Edge Painting Machine for Image Rasterization (Image rasterization을 위한 Edge Painting Machine의 설계 및 simulation)

  • Choi, Sang-Gil;Kim, Sung-Soo;Eo, Kil-Su;Kyung, Chong-Min
    • Proceedings of the KIEE Conference
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    • 1987.07b
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    • pp.1492-1494
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    • 1987
  • This paper describes a hardware architecture called Edge Painting Machine for real time generation of scan line images for raster scan graphics display. The Edge Painting Machine consists of Scanline Processor which converts polygon data sorted in their depth priority into a set of scan line commands for each scan line, and Edge Painting Tree which converts the scanline commands set into a raster line image. Edge painting tree has been designed using combinational logic circuit. The designed circuit has been simulated to verify the proper functioning. A salient feature of the EPT is that hardware composition is simple, because each processor is constituted by only combinational logic circuit.

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FPGA Implementation of Riindael Algorithm according to the Three S-box Implementation Methods (Rijndael S-box의 세 가지 구현 방법에 따른 FPGA 설계)

  • 이윤경;박영수;전성익
    • Proceedings of the IEEK Conference
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    • 2002.06b
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    • pp.281-284
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    • 2002
  • Rijndael algorithm is known to a new private key block cipher which is substitute for DES. Rijndael algorithm is adequate to both hardware and software implementation, so hardware implementation of Rijndael algorithm is applied to high speed data encryption and decryption. This paper describes three implementation methods of Rijndael S-box, which is important factor in performance of Rijndael coprocessor. It shows synthesis results of each S-box implementation in Xilinx FPGA. Tllc lilree S-box implementation methods are implementation using lookup table only, implementation using both lookup table and combinational logic, and implementation using combinational logic only.

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