A full adder structure without cross-wiring in quantum-dot cellular automata with energy dissipation analysis

Quantum-dot cellular automata (QCA) is the appearance of new technology and can be a suitable alternative to semiconductor transistor technology. In this paper, the new structure of the two-input XOR gate is presented, which is the modified version of the three-input XOR gate. This structure can be used to design various useful QCA circuits. By utilizing this gate, we design and implement a new full adder structure with 90-degree cells. This structure is designed in a single layer without cross-wiring. The operation of the proposed structure has been verified by QCADesigner version 2.0.3 and energy dissipation investigated by QCAPro tool. We also compared the effectiveness of our structure with the two previous structures.     

Novel low power reversible binary incrementer design using quantum-dot cellular automata

This paper demonstrates the design of n-bit novel low power reversible binary incrementer in Quantum-Dot Cellular Automata (QCA). The comparison of quantum cost in quantum gate based approach and in QCA based design agreed the cost efficient implementation in QCA. The power dissipation by proposed circuit is estimated, which shows that the circuit dissipates very low heat energy suitable for reversible computing. All the circuits are evaluated in terms of logic gates, circuit density and latency that confirm the faster operating speed at nano scale. The reliability of the circuit under thermal randomness is explored which describes the efficiency of the circuit.     

Novel efficient full adder and full subtractor designs in quantum cellular automata

In this study, two new full adder/full subtractor designs based on quantum-dot cellular automata technology have been proposed. By means of the presented equation for SUM and SUBTRACT operations, the new high-speed, low power, and cost efficient designs have been achieved. Even if the three-level design has a lower cell count, occupies less area, and operates at a higher speed, the one-layer design is far more feasible. Analysis of the temperature and energy consumption of the proposed design indicates that the proposed approaches are superior to those of previous works.

     

A novel design of 8-bit adder/subtractor by quantum-dot cellular automata

Application of quantum-dot is a promising technology for implementing digital systems at nano-scale. QCA supports the new devices with nanotechnology architecture. This technique works based on electron interactions inside quantum-dots leading to emergence of quantum features and decreasing the problem of future integrated circuits in terms of size. In this paper, we will successfully design, implement and simulate a new full adder based on QCA with the minimum delay, area and complexities. Also, new XOR gates will be presented which are used in 8-bit controllable inverter in QCA. Furthermore, a new 8-bit full adder is designed based on the majority gate in the QCA, with the minimum number of cells and area which combines both designs to implement an 8-bit adder/subtractor in the QCA. This 8-bit adder/subtractor circuit has the minimum delay and complexity. Being potentially pipeline, the QCA technology calculates the maximum operating speed.     

Computation in reversible cellular automata

A reversible cellular automaton (RCA) is a subclass of a CA such that its global function is injective. It is considered as an abstract spatiotemporal model of a reversible physical system. In spite of the strong constraint of reversibility, an RCA has a high ability of information processing. In this survey, we overview the past studies on RCAs, and discuss how computing is performed in them. We can see even very simple RCAs have computation-universality.     

Design of dual-edge triggered flip-flops based on quantum-dot cellular automata

Quantum-dot cellular automata (QCA) technology has been widely considered as an alternative to complementary metal-oxide-semiconductor (CMOS) due to QCA’s inherent merits.Many interesting QCA-based logic circuits with smaller feature size,higher operating frequency,and lower power consumption than CMOS have been presented.However,QCA is limited in its sequential circuit design with high performance flip-flops.Based on a brief introduction of QCA and dual-edge triggered (DET) flip-flop,we propose two original QCA-based D and JK DET flip-flops,offering the same data throughput of corresponding single-edge triggered (SET) flip-flops at half the clock pulse frequency.The logic functionality of the two proposed flip-flops is verified with the QCADesigner tool.All the proposed QCA-based DET flip-flops show higher performance than their SET counterparts in terms of data throughput.Furthermore,compared with a previous DET D flip-flop,the number of cells,covered area,and time delay of the proposed DET D flip-flop are reduced by 20.5%,23.5%,and 25%,respectively.By using a lower clock pulse frequency,the proposed DET flip-flops are promising for constructing QCA sequential circuits and systems with high performance.     

Towards modular binary to gray converter design using LTEx module of quantum-dot cellular automata

A modular approach to realize the ultra-fast quantum-dot cellular automata (QCA) generic binary to gray converter is presented in this paper. The novel designs here validated fully exploit the intrinsic repetitive capabilities of the Layered T Exclusive OR (LTEx) module in the QCA domain. An efficient logic formulation of QCA design metrics like O-Cost and delay is proposed for the n-bit QCA binary to gray converter designs. The QCA implementation of n-bit LTEx binary to gray converter is compared with the conventional converters. An attempt has been made to enhance the speed of modular binary to gray converter designs. The proposed 4, 8, 16, 32, 64-bit binary to gray converters need 4.35, 15.88, 15.96, 15.7, 16.68% less O-cost and 11.57, 2.61, 9.32, 12.64, 29.25% less effective area, respectively. Thus the proposed layouts offer the smaller feature size, reduced circuit complexity exploiting the modular based design approach. The simulation results have been carried out in the renowned computer aided design tool, namely QCADesigner 2.0.3 with gallium arsenide heterostructure based parameter environment.

     

Block cipher based on reversible cellular automata

We propose a new encryption algorithm relying on reversible cellular automata (CA). The behavior complexity of CA and their parallel nature makes them interesting candidates for cryptography. The proposed algorithm belongs to the class of symmetric key systems. Marcin Seredynski: He is a Ph.D. student at University of Luxembourg and Polish Academy of Sciences. He received his M.S. in 2004 from Faculty of Electronics and Information Technology in Warsaw University of Technology. His research interests include cryptography, cellular automata, nature inspired algorithms and network security. Currently he is working on intrusion detection algorithms for ad-hoc networks. Pascal Bouvry, Ph.D.: He earned his undergraduate degree in Economical & Social Sciences and his Master degree in Computer Science with distinction (’91) from the University of Namur, Belgium. He went on to obtain his Ph.D. degree (’94) in Computer Science with great distinction at the University of Grenoble (INPG), France. His research at the IMAG laboratory focussed on Mapping and scheduling task graphs onto Distributed Memory Parallel Computers. Next, he performed post-doctoral researches on coordination languages and multi-agent evolutionary computing at CWI in Amsterdam. He gained industrial experience as manager of the technology consultant team for FICS in the banking sector (Brussels, Belgium). Next, he worked as CEO and CTO of SDC (Ho Chi Minh city, Vietnam) in the telecom, semi-conductor and space industry. After that, He moved to Montreal Canada as VP Production of Lat45 and Development Director for MetaSolv Software in the telecom industry. He is currently serving as Professor in the group of Computer Science and Communications (CSC) of the Faculty of Sciences, Technology and Communications of Luxembourg University and he is heading the Intelligent & Adaptive Systems lab. His current research interests include: ad-hoc networks & grid-computing, evolutionary algorithms and multi-agent systems.     

多粒度可逆细胞自动机模型的数据加密方法

为了克服以往对细胞自动机的研究局限于单粒度细胞单元的问题,引入了多粒度细胞的概念,并结合可逆细胞自动机提出了一种基于多粒度可逆细胞自动机的加密算法.在该算法中,扩展的可逆细胞自动机具有足够多的规则,从而保证了安全的密钥空间;细胞单元通过"分裂-重组"实现自身粒度大小的动态调整,并依此来提高细胞自动机动力学特性的复杂性,实现了快速加、解密.同构的硬件结构使该算法具有很强的实用性,仿真实验表明,该加密算法具有较高的安全性.     

Representation of reversible cellular automata with block permutations

We demonstrate the structural invertibility of all reversible one- and two-dimensional cellular automata. More precisely, we prove that every reversible two-dimensional cellular automaton can be expressed as a combination of four block permutations, and some shift-like mappings. Block permutations are very simple functions that uniformly divide configurations into rectangular regions of equal size and apply a fixed permutation on all regions.     

Efficient exhaustive listings of reversible one dimensional cellular automata

This paper looks at an algebraic formulation of one dimensional cellular automata. Using the formulation connections to combinatorial structures and graph theory become clear. Strong results about uniqueness and isomorphism allows us to outline effective algorithms for the generation of exhaustive lists of reversible one dimensional cellular automata, and to count the number of distinct examples that exist. These algorithms use the “orderly algorithm” methods to avoid the pitfalls of brute force searches.     

Simulating reversible Turing machines and cyclic tag systems by one-dimensional reversible cellular automata

In this paper, we investigate how 1-D reversible cellular automata (RCAs) can simulate reversible Turing machines (RTMs) and cyclic tag systems (CTSs). A CTS is a universal string rewriting system proposed by M. Cook. First, we show that for any m-state n-symbol RTM there is a 1-D 2-neighbor RCA with a number of states less than (m+2n+1)(m+n+1) that simulates it. It improves past results both in the number of states and in the neighborhood size. Second, we study the problem of finding a 1-D RCA with a small number of states that can simulate any CTS. So far, a 30-state RCA that can simulate any CTS and works on ultimately periodic infinite configurations has been given by K. Morita. Here, we show there is a 24-state 2-neighbor RCA with this property.     

Pyroclastic flows modelling using cellular automata

Cellular automata (CA) and derived computational paradigms represent an alternative approach to differential equations to model and simulating complex fluid dynamical systems, whose evolution depends on the local interactions of their constituent parts. A new notion of CA was developed according to an empirical method for modelling macroscopic phenomena; its application to PYR, a CA model for simulating pyroclastic flows, generated PYR2, which permitted an improvement of the model and a more efficient implementation. PYR2 was utilised for the 1991 eruption of Mt. Pinatubo in the Philippines islands and for the 1996 eruption of the Soufriere Hills in the Montserrat Island. Results of the simulations are satisfactory if the comparison between real and simulated event is performed, considering the area involved by the event and the variations of thickness of the deposit, as generated by collapsing volcanic columns.     

Text compression using two-dimensional cellular automata

This paper presents an elegant mathematical model using simple matrix algebra for characterising the behaviour of two-dimensional nearest neighbourhood linear cellular automata with periodic boundary conditions. Based on this mathematical model, the VLSI architecture of a Cellular Automata Machine (CAM) has been proposed for text compression. Experimental results of comparisons with adaptive Huffman coding scheme also presented.     

Applying inherent capabilities of quantum-dot cellular automata to design: D flip-flop case study

Nowadays, quantum cellular automata (QCA) has been considered as the pioneer technology in next generation computer designs. QCA provides the computer computations at nano level using molecular components as computation units. Although the QCA technology provides smaller chip area and eliminates the spatial constraints than earlier CMOS technology, but different characteristics and design limitations of QCA architectures have led to essential attentions in replacement of traditional structures with QCA ones. Inherent information flow control, limited wire length, and consumed area are of such features and restrictions. In this paper, D flip-flop structure has been considered and we have proposed two new D flip-flop structures which employ the inherent capabilities of QCA in timing and data flow control, rather than ordinary replacement of CMOS elements with equivalent QCA ones. The introduced structures involve small number of cells in contrast to earlier proposed ones in presence of the same or even lower input to output delay. The proposed structures are simulated using the QCADesigner and the validity of them has been proved.     

Design and implementation of multiplication algorithm in quantum-dot cellular automata with energy dissipation analysis

The Journal of Supercomputing - QCA is an emerging nanotechnology for the design of digital system circuits based on electron interactions. QCA is used to design nanoscale circuits. Multiplier...     

An order-preserving property of additive invariants for Takesue-type reversible cellular automata

We show that, for a large and important class of reversible, one-dimensional cellular automata, the set of additive invariants exhibits an algebraic structure. More precisely, if f and g are one-dimensional, reversible cellular automata of the kind considered by Takesue (1989) [1], we show that the component-wise maximum ∨ on these automata is such that ψ(f)⊆ψ(f∨g), where ψ(f) denotes the set of additive invariants of f and ⊆ denotes the inclusion relation between real subspaces.     

Z-Voter: a novel high-impedance voter for efficient realization of tristate logic in quantum-dot cellular automata technology

The Journal of Supercomputing - Regardless of the technology, the tristate logic is a crucial concept which facilitate bidirectional shared media access as an essential requirement for development...     

Designing layout–timing independent quantum-dot cellular automata (QCA) circuits by global asynchrony

The concept of clocking for QCA, referred to as the four-phase clocking, is widely used. However, inherited characteristics of QCA, such as the way to hold state, the way to synchronize data flows, and the way to power QCA cells, make the design of QCA circuits quite different from VLSI and introduce a variety of new design challenges and the most severe challenges are due to the fact that the overall timing of a QCA circuit is mainly dependent upon its layout. This fact is commonly referred to as the “layout = timing” problem. To circumvent the problem, a novel self-timed QCA circuit design methodology referred to as the Globally Asynchronous, Locally Synchronous (GALS) Design for QCA is proposed in this paper. The proposed technique can significantly reduce the layout–timing dependency from the global network of QCA devices in a circuit; therefore, considerably flexible QCA circuit design and floorplanning will be possible.