• Title/Summary/Keyword: combinational logic

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Characteristic Graph를 利用한 組合論理回路의 故障診斷

  • 林寅七 = In-Chil Lim;李亮熙
    • Communications of the Korean Institute of Information Scientists and Engineers
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    • v.5 no.1
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    • pp.42-49
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    • 1987
  • This paper describes test-pattern generation and it;s sequence for fan out-free Combinational logic network with multiple faults. The method for detecting multiple faults, in systematic way, is established by using characteristic graphs. This method is applied even in the case of fan out-reconvergent combinational logic networks. In this case, the network is decomposed into a set of fan out-free sybnetworks so as to use the characteristic graphs, and minimal test patterns are generated seperately. The each test set is combined and the test pattern for fan out-reconvergent networks are derived. According to corresponding characteristic graph, additional test patterns to detect multiple faults are simply derived.

Fault Coverage Improvement of Test Patterns for Com-binational Circuit using a Genetic Algorithm (유전알고리즘을 이용한 조합회로용 테스트패턴의 고장검출률 향상)

  • 박휴찬
    • Journal of Advanced Marine Engineering and Technology
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    • v.22 no.5
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    • pp.687-692
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    • 1998
  • Test pattern generation is one of most difficult problems encountered in automating the design of logic circuits. The goal is to obtain the highest fault coverage with the minimum number of test patterns for a given circuit and fault set. although there have been many deterministic algorithms and heuristics the problem is still highly complex and time-consuming. Therefore new approach-es are needed to augment the existing techniques. This paper considers the problem of test pattern improvement for combinational circuits as a restricted subproblem of the test pattern generation. The problem is to maximize the fault coverage with a fixed number of test patterns for a given cir-cuit and fault set. We propose a new approach by use of a genetic algorithm. In this approach the genetic algorithm evolves test patterns to improve their fault coverage. A fault simulation is used to compute the fault coverage of the test patterns Experimental results show that the genetic algorithm based approach can achieve higher fault coverages than traditional techniques for most combinational circuits. Another advantage of the approach is that the genetic algorithm needs no detailed knowledge of faulty circuits under test.

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An efficient algorithm for the design of combinational circuits with low power consumption (저전력 소모 조합 회로의 설계를 위한 효율적인 알고리듬)

  • Kim, Hyoung;Choi, Ick-Sung;Seo, Dong-Wook;Heo, Hun;Hwang, Sun-Young
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.21 no.5
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    • pp.1221-1229
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    • 1996
  • This paper proposes a heuristic algorithm for low power implementation of combinational circuits. Selecting an input variable for a given function, the proposed algorithm performs Shannon exansion with respect to the variable to reduce the number of gates in the subcircuit realizing the coffactor function, reducting the power dissipation of the implemented circuit. experimental results for the MCNC benchmarks show that the proposed algorithm is effective by generating the circuits consuming the power 48.9% less on the average, when compared to the previous algorithm based on precomputation logic.

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On the Logical Simplification of Sequential Machines using Shift-Registers (쉬프트레지스터를 사용한 순서논리회로의 간단화에 관하여)

  • 이근영
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.15 no.4
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    • pp.7-13
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    • 1978
  • This paper is concerned with the realization of sequential machines using shift-register modules as their memory elements. Other methods were to select shift-registers under the specific conditions and didn't consider the complexity of combinational circuits driving them. By using an integer valued function, all shift-registers with minimum length could be selected and an optimum assignment with lowest complexity could be obtained by comparing the number of input lines of combinational logic circuits driving them.

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Testability of Current Testing for Open Faults Undetected by Functional Testing in TTL Combinational Circuits

  • Tsukimoto, Isao;Hashizume, Masaki;Mushiaki, Yukiko;Yotsuyanagi, Hiroyuki;Tamesada, Takeomi
    • Proceedings of the IEEK Conference
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    • 2002.07c
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    • pp.1972-1975
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    • 2002
  • A new test approach based on a supply current test method is proposed for testing open faults in bipolar logic circuits. In the approach, only the open faults are detected by the supply current test method, which are difficult to be detected by functional test methods. The effectiveness of the approach is examined experimentally on open fault detection in TTL combinational circuits. The results shows that higher fault coverage can be established by applying a small number of test input vectors of the supply current test method after test vectors of functional test methods based on stuck-at models.

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Analysis of Gate-Oxide Breakdown in CMOS Combinational Logics

  • Kim, Kyung Ki
    • Journal of Sensor Science and Technology
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    • v.28 no.1
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    • pp.17-22
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    • 2019
  • As CMOS technology scales down, reliability is becoming an important concern for VLSI designers. This paper analyzes gate-oxide breakdowns (i.e., the time-dependent dielectric-breakdown (TDDB) aging effect) as a reliability issue for combinational circuits with 45-nm technology. This paper shows simulation results for the noise margin, delay, and power using a single inverter-chain circuit, as well as the International Symposium on Circuits and Systems (ISCAS)'85 benchmark circuits. The delay and power variations in the presence of TDDB are also discussed in the paper. Finally, we propose a novel method to compensate for the logic failure due to dielectric breakdowns: We used a higher supply voltage and a negative ground voltage for the circuit. The proposed method was verified using the ISCAS'85 benchmark circuits.

A Study on the Multiple Output Circuit Implementation (다출력 회로 구현에 관한 연구)

  • Park, Chun-Myoung
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2013.05a
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    • pp.675-676
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    • 2013
  • This paper presents a design method for multiple-output combinational digital logic systems using time domain based on multiplexing and common multi-terminal extension decision diagrams. The common multi-terminal extension decision diagrams represents extension valued multiple-output functions, while time domain based on multiplexing systems transmit several signals on a single lines. The proposed method can reduce the 1)hardware, 2)logic levels and 3)pins. In the logic system design, we use two types of decision diagrams, that is the common binary decision diagrams and common multi-terminal extension decision diagrams.

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A Study on the Design of Binary to Quaternary Converter (2진-4치 변환기 설계에 관한 연구)

  • 한성일;이호경;이종학;김흥수
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.40 no.3
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    • pp.152-162
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    • 2003
  • In this paper, Binary to Quaternary Converter(BQC), Quaternary to Binary Converter(QBC) and Quaternary inverter circuit, which is the basic logic gate, have been proposed based on voltage mode. The BQC converts the two bit input binary signals to one digit quaternary output signal. The QBC converts the one digit quaternary input signal to two bit binary output signals. And two circuits consist of Down-literal circuit(DLC) and combinational logic block(CLC). In the implementation of quaternary inverter circuit, DLC is used for reference voltage generation and control signal, only switch part is implemented with conventional MOS transistors. The proposed circuits are simulated in 0.35 ${\mu}{\textrm}{m}$ N-well doubly-poly four-metal CMOS technology with a single +3V supply voltage. Simulation results of these circuit show 250MHz sampling rate, 0.6mW power consumption and maintain output voltage level in 0.1V.

A Construction of the Efficiency Switching Function (효율적인 스위칭함수 구성에 관한 연구)

  • Park, Chun-Myoung
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2018.05a
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    • pp.470-471
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    • 2018
  • This paper presents a design method for combinational digital logic systems using time domain based multiplexing and common multi-terminal extension decision diagrams. The proposed method can reduce the 1)hardware, 2)logic levels and 3)pins. In the logic system design, we use two types of decision diagrams(DDs), that is the common binary decision diagrams and CMTEDDs. Also, we propose an algorithms to derive common multiple-terminal binary decision diagrams from CBDDs, and CMTEDDs from CMTBDDs. The CMTEDDs over CBDDs is more compactness in terms of number of non-terminal nodes, where the nodes for output selection variables are not included in the non-terminal nodes. In the logic design, each non-terminal nodes of an CBDDs and an CMTEDDs is realized by a multiplexer(MUX). In addition, we compare the proposed TDBM realization with the conventional one.

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Efficient Test Compaction Algorithms for Combinational Logic Circuits (조합논리회로를 위한 효율적인 테스트 컴팩션 알고리즘)

  • Kim, Yun-Hong
    • Journal of KIISE:Computer Systems and Theory
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    • v.28 no.4
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    • pp.204-212
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    • 2001
  • 본 논문에서는 조합논리회로의 테스트 컴팩션을 위한 두 가지 효율적인 알고리즘을 제안한다. 제안된 알고리즘들은 각각 동적인 컴팩션 기법과 정적인 컴팩션 기법을 사용하고 있으며, 실험을 위해 기존의 ATPG시스템인 ATALANTA에 통합 구현하였다. ISCAS85와 ISCAS89(완전스캔 버전) 벤치마크 회로에 대한 실험에서 본 시스템은 기존에 발표된 다른 컴팩션 알고리즘에 비하여 보다 작은 테스트 집합을 보다 빠르게 생성하였으며, 실험 결과를 통하여 제안된 알고리즘들의 유효성을 입증할 수가 있었다.

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