• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.5A
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• pp.554-565
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• 2004

In this paper, we implement single cycle and multi cycle adders. We can compare area and time by using the implemented adders. The size of adders is 64, 128, 256-bits. The architecture of hybrid adders is that the carry-out of small adder groups can be interconnected by utilizing n carry propagate unit. The size of small adder groups is selected in three formats - 4, 8, 16-bits. These adders were implemented with Verilog HDL with top-down methodology, and they were verified by behavioral model. The verified models were synthesized with a Samsung 0,35(um), 3.3(V) CMOS standard cell library while a using Synopsys Design Compiler. All adders were synthesized with group or ungroup. The optimized adder for a Crypto-processor included Smart Card IC is that a 64-bit RCA based on 16-bit CLA. All small adder groups in this optimized adder were synthesized with group. This adder can operate at a clock speed of 198 MHz and has about 961 gates. All adders can execute operations in this won case conditions of 2.7 V, 85 $^{\circ}C$.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.8
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• pp.34-41
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• 2002

This paper describes a scalable implementation method of a word-based RSA cryptoprocessor using pseudo carry look-ahead adder The basic organization of the modular multiplier consists of two layers of carry-save adders (CSA) and a reduced carry generation and Propagation scheme called the pseudo carry look-ahead adder for the high-speed final addition. The proposed modular multiplier does not need complicated shift and alignment blocks to generate the next word at each clock cycle. Therefore, the proposed architecture reduces the hardware resources and speeds up the modular computation. We implemented a single-chip 1024-bit RSA cryptoprocessor based on the word-based modular multiplier with 256 datapaths in 0.5${\mu}{\textrm}{m}$ SOG technology after verifying the proposed architectures using FPGA with PCI bus.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.7 no.3
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• pp.291-300
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• 2017

Quantum-dot cellular automata(QCA) is a computing model designed to be similar to cellular automata, and an alternative technology for next generation using high performance and low power consumption. QCA is undergoing various studies with recent experimental results, and it is one of the paradigms of transistors that can solve device density and interconnection problems as nano-unit materials. An XOR gate is a gate that operates so that the result is true when either one of the logic is true. The proposed XOR gate consists of five layers. The first layer consists of OR gates, the third and fifth layers consist of AND gates, and the second and fourth layers are designed as passages in the middle. The half adder consists of an XOR gate and an AND gate. The proposed half adder is designed by adding two cells to the proposed XOR gate. The proposed half adder consists of fewer cells, total area, and clock than the conventional half adder.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.7 no.10
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• pp.895-903
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• 2017

Quantum Cellular Automata(QCA) is one of the proposed techniques as an alternative solution to the fundamental limitations of CMOS. QCA has recently been extensively studied along with experimental results, and is attracting attention as a nano-scale size and low power consumption. Although the XOR gates proposed in the previous paper can be designed using the minimum area and the number of cells, there is a disadvantage that the number of added cells is increased due to the stability and the accuracy of the result. In this paper, we propose a gate that supplement for the drawbacks of existing XOR gates. The XOR gate of this paper reduces the number of cells by arranging AND gate and OR gate with square structure and propose a half-adder by adding two cells that serve as simple inverters using the proposed XOR gate. Also This paper use QCADesginer for input and result accuracy. Therefore, the proposed half-adder is composed of fewer cells and total area compared to the conventional half-adder, which is effective when used in a large circuit or when a half - adder is needed in a small area.

• JSTS:Journal of Semiconductor Technology and Science
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• v.17 no.2
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• pp.302-317
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• 2017

This paper proposes a new full adder design based on pass-transistor logic that offers ultra-low power dissipation and superior variability together with low transistor count. The pass-transistor logic allows device count reduction through direct logic realization, and thus leads to reduction in the node capacitances as well as short-circuit currents due to the absence of supply rails. Optimum transistor sizing alleviates the adverse effects of process variations on performance metrics. The design is subjected to a comparative analysis against existing designs based on Monte Carlo simulations in a SPICE environment, using the 22-nm CMOS Predictive Technology Model (PTM). The proposed ULP adder offers 38% improvement in power in comparison to the best performing conventional designs. The trade-off in delay to achieve this power saving is estimated through the power-delay product (PDP), which is found to be competitive to conventional values. It also offers upto 79% improvement in variability in comparison to conventional designs, and provides suitable scalability in supply voltage to meet future demands of energy-efficiency in portable applications.

• The Transactions of the Korea Information Processing Society
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• v.3 no.5
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• pp.1187-1197
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• 1996

In this work, two-dimensional FIR digital filter is designed and simulated using research and educational CAD tools. The two-dimensional digital filter consists mainly of one-dimensional digital filter and line memory. To speed up one-dimensional digital filter, multiplications are carried out on the basis of hardwired-shifting methods by the digital filter coefficients represented in CSD formats, while carry-save adder and Manchester adder are used in addition. It is found that the designed digital filter operates up to 30 Mhz in VHDL simulation and operates normally in IRSIM simulation for the layout made by Berkeley CAD tools.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.6
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• pp.43-51
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• 2004

An optical parallel modified signed-digit(MSD) number adder system is proposed by using triple rail-coding input patterns and serial arrangement method of symbolic substitution. By combing overlapped arithmetic results. which are produced by encoding MSD input as triple rail-coding patterns. into the same patterns, symbolic substitution rules are reduced and also by using serialized and space-shifted input patterns in optical experiments, the optical adder without space-shifting operation, NOR operation and threshold operation is implemented.

• Journal of IKEEE
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• v.7 no.1 s.12
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• pp.56-62
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• 2003

In this paper, we designed a adder and a multiplier using current mode T-gate on $GF(2^2)$. The T-gate is consisted of current mirror and pass transistor, the designed 4-valued T-gate used adder and multiplier on $GF(2^2)$. We designed its under 1.5um CMOS standard technology. The unit current of the circuits is 15㎂, and power supply is 3.3V VDD. The proposed current mode CMOS operator have a advantage of module by T-gate`s arrangement, and so we easily implement multi-valued operator.

• JSTS:Journal of Semiconductor Technology and Science
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• v.16 no.4
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• pp.497-505
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• 2016

The two-dimensional (2D) Discrete Cosine Transform (DCT) is used widely in image and video processing systems. The perception of human visualization permits us to design approximate rather than exact DCT. In this paper, we propose a digital implementation of 16-point approximate 2D DCT architecture based on one-dimensional (1D) DCT and Modified Gate Diffusion Input (MGDI) technique. The 8-point 1D Approximate DCT architecture requires only 12 additions for realization in digital VLSI. Additions can be performed using the proposed 8 transistor (8T) MGDI Full Adder which reduces 2 transistors than the existing 10 transistor (10T) MGDI Full Adder. The Approximate MGDI 2D DCT using 8T MGDI Full adders is simulated in Tanner SPICE for $0.18{\mu}m$ CMOS process technology at 100MHZ.The simulation result shows that 13.9% of area and 15.08 % of power is reduced in the 8-point approximate 2D DCT, 10.63 % of area and 15.48% of power is reduced in case of 16-point approximate 2D DCT using 8 Transistor MGDI Full Adder than 10 Transistor MGDI Full Adder. The proposed architecture enhances results in terms of hardware complexity, regularity and modularity with a little compromise in accuracy.

• Journal of information and communication convergence engineering
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• v.9 no.4
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• pp.435-440
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• 2011

This paper propose the method of constructing the highly efficiency adder and multiplier systems over finite fields. The addition arithmetic operation over finite field is simple comparatively because that addition arithmetic operation is analyzed by each digit modP summation independently. But in case of multiplication arithmetic operation, we generate maximum k=2m-2 degree of ${\alpha}^k$ terms, therefore we decrease k into m-1 degree using irreducible primitive polynomial. We propose two method of control signal generation for the purpose of performing above decrease process. One method is the combinational logic expression and the other method is universal signal generation. The proposed method of constructing the highly adder/multiplier systems is as following. First of all, we obtain algorithms for addition and multiplication arithmetic operation based on the mathematical properties over finite fields, next we construct basic cell of A-cell and M-cell using T-gate and modP cyclic gate. Finally we construct adder module and multiplier module over finite fields after synthesizing ${\alpha}^k$ generation module and control signal CSt generation module with A-cell and M-cell. Next, we constructing the arithmetic operation unit over finite fields. Then, we propose the future research and prospects.