• Title/Summary/Keyword: Logic circuits

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A Study on Minimization for Digital Circuits Using the Universal Logic Modules (ULM을 이용한 디지탈회로의 간소화에 관한 연구)

  • 박규태;김진복
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.13 no.4
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    • pp.12-17
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    • 1976
  • This paper deals with characteristics and analysis of the Universal Logic Modules as well as TULM, QULM and SULM. Studies are made on minimization in Storms of symmetric circuits and theoretical stuides are made by using the symmetric functions The symmetric circuits of the ULM are realized by employing 54/74 ICs, An oscillator circuit of 10KHz. is constructed based on the ULM. The experimental results gave a good agreement with the theoretical Minimization.

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CMOS Logic Circuits with Lower Subthreshold Leakage Current (낮은 Subthreshold 누설전류를 갖는 CMOS 논리회로)

  • Song Sang-Hun
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.53 no.10
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    • pp.500-504
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    • 2004
  • We propose a new method to reduce the subthreshold leakage current. By moving the operating point of OFF state MOSFETs through input-controlled voltage generators, logic circuits with much lower leakage current can be built with few extra components. SPICE simulation results for the new inverter show correct logic results without speed degradation compared to a conventional inverter.

Performance-driven Automatic Logic Synthesis System (성능 구동 논리 회로 자동 설계 시스템)

  • 이재형;황선영
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.28A no.1
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    • pp.74-84
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    • 1991
  • This paper presents an algorithm for technology-dependent logic optimization and technology mapping, and describes a performance-driven logic synthesis system, SILOS, implemented based on the proposed algorithm. The system analyzes circuits and resynthesizes the critical sections such that generated circuit operates opertes within time constraints, using only gate types supported by library for direct implementation. Experimental results show that the system can be a viable tool in synthesizing high-performance logic circuits.

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A Study of Train Powering/Braking Control by TCMS (TCMS에 의한 전동차 추진/제동 제어기법)

  • 한정수;박성호;김국진;박계서
    • Proceedings of the KSR Conference
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    • 1999.05a
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    • pp.291-298
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    • 1999
  • TCMS(Train Control & Management System) is the management system of train information which intensively control, monitor and test the main on-board equipments including propulsion/brake unit by the serial transmission line. TCMS reduces interface circuits and number of train lines by the software logic and utilizing serial communication method. This paper describes the method of powering and braking control by TCMS software logic, in comparison with the powering/braking control by conventional relay logic/hardwire circuits, and the software logic was verified by simulation test with TCMS simulator.

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A New Basic Element for Neural Logic Functions and Capability in Circuit Applications

  • Omura, Yasuhisa
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.2 no.1
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    • pp.70-81
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    • 2002
  • This paper describes a new basic element which shows a synaptic operation for neural logic applications and shows function feasibility. A key device for the logic operation is the insulated-gate pn-junction device on SOI substrates. The basic element allows an interface quite compatible to that of conventional CMOS circuits and vMOS circuits.

Design of Ternary Logic Circuits Based on Reed-Muller Expansions (Reed-Muller 전개식에 의한 3치 논리회로의 설계)

  • Seong, Hyeon-Kyeong
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.11 no.3
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    • pp.491-499
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    • 2007
  • In this paper, we present a design method of the ternary logic circuits based on Reed-Muller expansions. The design method of the presented ternary logic circuits checks the degree of each variable for the coefficients of Reed-Holler Expansions(RME) and determines the order of optimal control input variables that minimize the number of Reed-Muller Expansions modules. The order of optimal control input variables is utilized the computation of circuit cost matrix. The ternary logic circuits of the minimized tree structures to be constructed by RME modules based on Reed-Muller Expansions are realized using the computation results of its circuit cost matrix. This method is only performed under unit time in order to search for the optimal control input variables. Also, this method is able to be programmed by computer and the run time on programming is $3^n$.

Single-Electron Logic Cells and SET/FET Hybrid Integrated Circuits

  • Kim, S.J.;Lee, C.K.;Lee, J.U.;Choi, S.J.;Hwang, J.H.;Lee, S.E.;Choi, J.B.;Park, K.S.;Lee, W.H.;Paik, I.B.;Kang, J.S.
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.6 no.1
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    • pp.52-58
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    • 2006
  • Single-electron transistor (SET)-based logic cells and SET/FET hybrid integrated circuits have been fabricated on SOI chips. The input-output voltage transfer characteristic of the SET-based complementary logic cell shows an inverting behavior where the output voltage gain is estimated to be about 1.2 at 4.2K. The SET/FET output driver, consisting of one SET and three FETs, yields a high voltage gain of 13 and power amplification with a wide-range output window for driving next circuit. Finally, the SET/FET literal gate for a multi-valued logic cell, comprising of an SET, an FET and a constant-current load, displays a periodic voltage output of high/low level multiple switching with a swing as high as 200mV. The multiple switching functionality of all the fabricated logic circuits could be enhanced by utilizing a side gate incorporated to each SET component to enable the phase control of Coulomb oscillations, which is one of the unique characteristics of the SET-based logic circuits.

Test Generation for Combinational Logic Circuits Using Neural Networks (신경회로망을 이용한 조합 논리회로의 테스트 생성)

  • 김영우;임인칠
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.30A no.9
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    • pp.71-79
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    • 1993
  • This paper proposes a new test pattern generation methodology for combinational logic circuits using neural networks based on a modular structure. The CUT (Circuit Under Test) is described in our gate level hardware description language. By conferring neural database, the CUT is compiled to an ATPG (Automatic Test Pattern Generation) neural network. Each logic gate in CUT is represented as a discrete Hopfield network. Such a neual network is called a gate module in this paper. All the gate modules for a CUT form an ATPG neural network by connecting each module through message passing paths by which the states of modules are transferred to their adjacent modules. A fault is injected by setting the activation values of some neurons at given values and by invalidating connections between some gate modules. A test pattern for an injected fault is obtained when all gate modules in the ATPG neural network are stabilized through evolution and mutual interactions. The proposed methodology is efficient for test generation, known to be NP-complete, through its massive paralelism. Some results on combinational logic circuits confirm the feasibility of the proposed methodology.

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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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Computer Aided Design of Sequential Logic Circuits (Case of Synchronous Sequential Logic Circuits) (컴퓨터를 이용한 순차 논리 회로의 설계 (동기식 순차 논리 회로의 경우))

  • 김경식;조동섭;황희영
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.33 no.4
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    • pp.134-139
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    • 1984
  • This paper presents the computer program to design the synchronous sequential logic circuit. The computer program uses the MASK method to get the circuit of optimal cost. The computer program takes as an input, the minimal reduced state transition table where each state has its internal code. As an output,the optimal design of synchronous sequential logic circuit is generated for each flipflop type of JK,T,D, and RS respectively. And these circuits for 4 flipflop types are evaluated and sorted in ascending order of their costs, so that the user can select the proper flipflop type and its circuit. Furthermore,the proposed computer program may be applied to state assignment with its facility of cost evaluation.

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