This paper describes an investigation of potential advantages and risks of applying an aggressive asynchronous design methodology to Intel Architecture. RAPPID ("Revolving Asynchronous Pentium Processor Instruction Decoder"), a prototype IA32 instruction length decoding and steering unit, was implemented using self-timed techniques. RAPPID chip was fabricated on a 0.25µ CMOS process and tested successfully. Results show significant advantages---in particular, performance of 2.5-4.5 instructions/nS---with manageable risks using this design technology. RAPPID achieves three times the throughput and half the latency, dissipating only half the power and requiring about the same area as an existing 400MHz clocked circuit.

A cellular automaton is a decentralized computing model providing an excellent platform for performing complex computation with the help of only local information. Researchers, scientists and practitioners from different fields have exploited the CA paradigm of local information, decentralized control and universal computation for modeling different applications. This article provides a survey of available literature of some of the methodologies employed by researchers to utilize cellular automata for modeling purposes. The survey introduces the different types of cellular automata being used for modeling and the analytical methods used to predict its global behavior from its local configurations. It further gives a detailed sketch of the efforts undertaken to configure the local settings of CA from a given global situation; the problem which has been traditionally termed as the inverse problem. Finally, it presents the different fields in which CA have been applied. The extensive bibliography provided with the article will be of help to the new entrant as well as researchers working in this field.

Abstract — Swarm Intelligence (SI) is a relatively new paradigm being applied in a host of research settings to improve the management and control of large numbers of interacting entities such as communication, computer and sensor networks, satellite constellations and more. Attempts to take advantage of this paradigm and mimic the behavior of insect swarms however often lead to many different implementations of SI. The rather vague notions of what constitutes self-organized behavior lead to rather ad hoc approaches that make it difficult to ascertain just what SI is, assess its true potential and more fully take advantage of it. This article provides a set of general principles for SI research and development. A precise definition of self-organized behavior is described and provides the basis for a more axiomatic and logical approach to research and development as opposed to the more prevalent ad hoc approach in using SI concepts. The concept of Pareto optimality is utilized to capture the notions of efficiency and adaptability. A new concept, Scale Invariant Pareto Optimality is described and entails symmetry relationships and scale invariance where Pareto optimality is preserved under changes in system states. This provides a mathematical way to describe efficient tradeoffs of efficiency between different scales and further, mathematically captures the notion of the graceful degradation of performance so often sought in complex systems. Index Terms — swarm intelligence, self-organization, multiobjective optimization, Pareto optima, finite-state machines

This paper presents a case study in low-cost noninvasive Built-In Self Test (BIST) for RAPPID, a largescale 120,000-transistor asynchronous version of the Pentium R fl Pro Instruction Length Decoder, which runs at 3.6 GHz. RAPPID uses a synchronous 0.25 micron CMOS library for static and domino logic, and has no Design-for-Test hooks other than some debug features. We explore the use of Cellular Automata (CA) for on-chip test pattern generation and response evaluation. More specifically, we look for fast ways to tune the CA-BIST to the RAPPID design, rather than using pseudo-random testing. The metric for tuning the CA-BIST pattern generation is based on an abstract hardware description model of the instruction length decoder, which is independent of implementation details, and hence also independent of the asynchronous circuit style. Our CA-BIST solution uses a novel bootstrap procedure for generating the test patterns, which give complete coverage for this metric, and cover 94% of ...

Abstract. One-way hash functions are an important toolinachieving authentication and data integrity. The aim of this paper is to propose anovel one-way hash function based on cellular automata whose cryptographic properties have been extensivelystudiedover the past decade or so. Furthermore, security of the proposed one-way hash function is analyzed by the use of very recently published results on applications of cellular automata in cryptography. The analysis indicates that the one-way hash function is secure against all known attacks. An important feature of the proposed one-way hash function is that it is especially suitable for compact and fast implementation in hardware, which is particularly attractive to emerging security applications that employ smart cards, such asdigital identi cation cards and electronic cash payment protocols, 1

evaluate the randomness of these CCA PRNGs. The results show that their randomness is better than that of conventional CA and PCA PRNGs while they do not lose the structure simplicity of 1-d CA. Moreover, their randomness can be comparable to that of 2-d CA PRNGs. Furthermore, we integrate six different types of CCA PRNGs to form CCA PRNG groups to see if the randomness quality of such groups could exceed that of any individual CCA PRNG. Genetic Algorithm (GA) is used to evolve the configuration of the CCA PRNG groups. Randomness test results on the evolved CCA PRNG groups show that the randomness of the evolved groups is further improved compared with any individual CCA PRNG. Key words: cellular automata, randomness test, pseudorandom number generator, genetic algorithm

This paper proposes a novel one-way hash function that can serve as a tool in achieving authenticity and data integrity. The one-way hash function can be viewed as a representative of a family of fast dedicated one-way hash functions whose construction is based on linear cellular automata over GF(q). The design and analysis of security of the function is accomplished by the use of very recently published results on cellular automata and their applications in cryptography. The analysis indicates that the one-way hash function is secure against all known attacks. A promising property of the proposed one-way hash function is that it is especially suitable for compact and fast implementation.

A complete classification of the computational complexity of the fixed-point existence problem for boolean dynamical systems, i.e., finite discrete dynamical systems over the domain {0, 1}, is presented. For function classes F and graph classes G, an (F, G)-system is a boolean dynamical system such that all local transition functions lie in F and the underlying graph lies in G. Let F be a class of boolean functions which is closed under composition and let G be a class of graphs which is closed under taking minors. The following dichotomy theorems are shown: (1) If F contains the self-dual functions and G contains the planar graphs, then the fixed-point existence problem for (F, G)-systems with local transition function given by truth-tables is NP-complete; otherwise, it is decidable in polynomial time. (2) If F contains the self-dual functions and G contains the graphs having vertex covers of size one, then the fixed-point existence problem for (F, G)-systems with local transition function given by formulas or circuits is NP-complete; otherwise, it is decidable in polynomial time. 1

Abstract A novel Cellular Automata (CA) ⎯ Controllable CA (CCA) is proposed in this paper. Further, CCA are applied in Pseudorandom Number Generation. Randomness test results on CCA Pseudorandom Number Generators (PRNGs) show that they are better than 1-d CA PRNGs and can be comparable to 2-d ones. But they do not lose the structure simplicity of 1-d CA. Further, we develop several different types of CCA PRNGs. Based on the comparison of the randomness of different CCA PRNGs, we find that their properties are decided by the actions of the controllable cells and their neighbors. These novel CCA may be applied in other applications where structure non-uniformity or asymmetry is desired. Key words: cellular automata, randomness test, pseudorandom number generator, controllable, hybrid 1.

Several methods improving the fault coverage in mixed-mode BIST are presented in this paper. The test is divided into two phases: the pseudo-random and deterministic. Maximum of faults should be detected by the pseudo-random phase, to reduce the number of faults to be covered in the deterministic one. We study the properties of different pseudo-random pattern generators. Their successfulness in fault covering strictly depends on the tested circuit. We examine properties of LFSRs and cellular automata. Four methods enhancing the pseudo-random fault coverage have been proposed. Then we propose a universal method to efficiently compute test weights.