• Title/Summary/Keyword: Logic Circuit

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VHDL modeling considering routing delay in antifuse-based FPGAs (안티퓨즈 FPGA의 배선지연시간을 고려한 VHDL 모델링)

  • 백영숙;조한진;박인학;김경수
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.33A no.5
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    • pp.180-187
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    • 1996
  • This paper describes a post-layout simulation method using VHDL and C for verifying the architecture of antifuse-based FPGAs and the dedicated CAD system. An antifuse-based FPGA consists of programming circuitry including decoding logic, logic modules, segmented tracks, antifuses and I/O pads. The VHDL model which includes all these elements is used for logic verification and programming verification of the implemented circuit by reconstructing the logic circuit from the bit-stream generated from layout tool. The implemented circuit comprises of logic modules and routing networks. Since the routing delay of the complex networks is comparable to the delay of the logic module in the FPGA, the accurate post-layout simulation is essential to the FPGA system. In this paper, the C program calculates the delay of the routing netowrks using SPICE, elmore or horowitz delay models and the results feedback to the VHDL simulation. Critical path anc be found from this post-layout simulation results.

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Acceleration Techniques for Cycle-Based Login Simulation (사이클 기반 논리시뮬레이션 가속화 기법 연구)

  • Park, Young-Ho;Park, Eun-Sei
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.50 no.1
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    • pp.45-50
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    • 2001
  • With increasing complexity of digital logic circuits, fast and accurate verification of functional behaviour becomes most critical bottleneck in meeting time-to-market requirement. This paper presents several techniques for accelerating a cycle-based logic simulation. The acceleration techniques include parallel pattern logic evaluation, circuit size reduction, and the partition of feedback loops in sequential circuits. Among all, the circuit size reduction plays a critical role in maximizing logic simulation speedup by reducing 50% of entire circuit nodes on the average. These techniques are incorporated into a levelized table-driven logic simulation system rather than a compiled-code simulation algorithm. Finally, experimental results are given to demonstrate the effectiveness of the proposed acceleration techniques. Experimental results show more than 27 times performance improvement over single pattern levelized logic simulation.

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Sub-One volt DC Power Supply Expandable 4-bit Adder/Subtracter System using Adiabatic Dynamic CMOS Logic Circuit Technology

  • Takahashi, Kazukiyo;Yokoyama, Michio;Shouno, Kazuhiro;Mizunuma, Mitsuru
    • Proceedings of the IEEK Conference
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    • 2002.07c
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    • pp.1543-1546
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    • 2002
  • The expandable 4 bit adder/subtracter IC was designed using the adiabatic and dynamic CMOS logic (ADCL) circuit as the ultra-low power consumption basic logic circuit and the IC was fabricated using a standard 1.2 ${\mu}$ CMOS process. As the result the steady operation of 4 bit addition and subtraction has been confirmed even if the frequency of the sinusoidal supply voltage is higher than 10MHz. Additionally, by the simulation, at the frequency of 10MHz, energy consumption per operation is obtained as 93.67pJ (ar addition and as 118.67pJ for subtraction, respectively. Each energy is about 1110 in comparison with the case in which the conventional CMOS logic circuit is used. A simple and low power oscillation circuit is also proposed as the power supply circuit f3r the ADCL circuit. The oscillator operates with a less one volt of DC supply voltage and around one milli-watts power dissipation.

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The Optimization of Current Mode CMOS Multiple-Valued Logic Circuits (전류구동 CMOS 다치 논리 회로설계 최적화연구)

  • Choi, Jai-Sock
    • Journal of the Institute of Convergence Signal Processing
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    • v.6 no.3
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    • pp.134-142
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    • 2005
  • The implementation of Multiple-Valued Logic(MVL) based on Current-Mode CMOS Logic(CMCL) circuits has recently been achieved. In this paper, four-valued Unary Multiple-Valued logic functions are synthesized using current-mode CMOS logic circuits. We properly make use of the fact that the CMCL addition of logic values represented using discrete current values can be performed at no cost and that negative logic values are readily available via reversing the direction of current flow. A synthesis process for CMCL circuits is based upon a logically complete set of basic elements. Proposed algorithm results in less expensive realization than those achieved using existing techniques in terms of the number of transistors needed. As an alternative to the cost-table techniques Universal Unary Programmable Circuit (UUPC) for a unary function is also proposed.

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Introduction to HILO-3 Logic Simulator

  • Jang, Deok-Ho;Kim, Yong-Ju;Gwak, Myeong-Sin;Lee, Cheol-Dong;Yu, Yeong-Uk
    • ETRI Journal
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    • v.8 no.1
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    • pp.44-52
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    • 1986
  • The main features of HILO-3 logic simulator are introduced. It is regarded as one of the most powerful logic simulator available now in electronic industry. The major functions and concepts are reviewed with some examples; circuit description using HDL (Hardware Description Language), waveform description using WDL (Waveform Description Language) and fault-free simulation for static RAM circuit. This program is expected to help the system designers, integrated circuit designers and test engineers.

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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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A DESIGN OF MULTIPLE-VALUED SOFT-HARDWARE LOGIC CIRCUITS USING NEURON MOS TRANSISTOR

  • M.Fukui;T.Kutsuwa;Ha, K.rashima;K.Kobori
    • Proceedings of the IEEK Conference
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    • 2000.07a
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    • pp.191-194
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    • 2000
  • A level of integration will increase, if the number of elements of the circuit can be reduced. We aim to design the circuit of the new system for any further integration by using Neuron MOS Transistor. In this paper, we consider to introduce Soft-Hardware Logic and multiple-valued logic to the design methods for reducing the number of elements and inner wiring. We have designed 4-valued add-subtracter circuit using above logic. We discuss the design methods, features, and characteristics of this circuit by SPICE simulation.

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High speed wide fan-in designs using clock controlled dual keeper domino logic circuits

  • Angeline, A. Anita;Bhaaskaran, V.S. Kanchana
    • ETRI Journal
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    • v.41 no.3
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    • pp.383-395
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    • 2019
  • Clock Controlled Dual keeper Domino logic structures (CCDD_1 and CCDD_2) for achieving a high-speed performance with low power consumption and a good noise margin are proposed in this paper. The keeper control circuit comprises an additional PMOS keeper transistor controlled by the clock and foot node voltage. This control mechanism offers abrupt conditional control of the keeper circuit and reduces the contention current, leading to high-speed performance. The keeper transistor arrangement also reduces the loop gain associated with the feedback circuitry. Hence, the circuits offer less delay variability. The design and simulation of various wide fan-in designs using 180 nm CMOS technology validates the proposed CCDD_1 and CCDD_2 designs, offering an increased speed performance of 7.2% and 8.5%, respectively, over a conventional domino logic structure. The noise gain margin analysis proves good robustness of the CCDD structures when compared with a conventional domino logic circuit configuration. A Monte Carlo simulation for 2,000 runs under statistical process variations demonstrates that the proposed CCDD circuits offer a significantly reduced delay variability factor.

A Study on the Parallel Ternary Logic Circuit Design to DCG Property with 2n nodes ($2^n$개의 노드를 갖는 DCG 특성에 대한 병렬3치 논리회로 설계에 관한 연구)

  • Byeon, Gi-Yeong;Park, Seung-Yong;Sim, Jae-Hwan;Kim, Heung-Su
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.37 no.6
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    • pp.42-49
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    • 2000
  • In this paper, we propose the parallel ternary logic circuit design algorithm to DCG Property with 2$^n$ nodes. To increase circuit integration, one of the promising approaches is the use of multiple-valued logic(MVL). It can be useful methods for the realization of compact integrated circuit, the improvement of high velocity signal processing using parallel signal transmission and the circuit design algorithm to optimize and satisfy the circuit property. It is all useful method to implement high density integrated circuit. In this paper, we introduce matrix equation to satisfy given DCG with 2$^n$ nodes, and propose the parallel ternary logic circuit design process to circuit design algorithm. Also, we propose code assignment algorithm to satisfy for the given DCG property. According to the simulation result of proposed circuit design algorithm, it have the following advantage ; reduction of the circuit signal lines, computation time and costs.

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