Adam Crha

Synthesis Methodology of Polymorphic Circuits Using Polymorphic NAND/NOR Gates

In this paper, a novel approach dealing with the issues of multifunctional (polymorphic) logic circuits synthesis is presented. Crucial notion behind the polymorphic concept resides in the fact that such kind of circuit is able to perform more than one logic function, while the underlying structure keeps its arrangement untouched. The outlined behaviour is established by means of utilizing special multifunctional components (gates) during circuit design phase, where the individual connections among them remains unchanged (no reconfiguration takes place). The exact function, which the circuit is purposely executing at a given moment, is determined by the actual operating environment (e.g. supply voltage, temperature or a special signal). The proposed synthesis method is based on a formal Boolean representation of corresponding functions. Its main advantage can be recognized in strictly rigid and algorithmic notation with the employment of minimization techniques, which is in a direct contrast to competitive solutions, predominantly based on heuristic approaches.

Synthesis tool for design of complex polymorphic circuits

This paper is dealing with research activities carried out in the domain of unconventional, polymorphic electronics. Main attention is focused on the logic synthesis aspects of complex polymorphic circuits. The introductory part elucidates a fundamental concept of polymorphic electronics and highlights its important properties. In addition, substantial advantages of this paradigm in comparison to conventional circuit design approach are discussed together with an identification of possible shortcomings. Main contribution of this paper is the proposal and implementation of a synthesis technique which makes it feasible to achieve an area-efficient results in case of complex polymorphic circuit involving hundreds of gates. Finally, accomplished experimental results and their analysis is provided.

Innovative methods for through holes plating

The main aim of this work was to investigate the influence of additional parameters in plating process of through-holes technology. Vacuum, ultrasound and the combination of both was used during the activation process of holes surface. Therefore, research was focused on the activation process, which was revealed as the cause of plating problems. The samples used in this work were prepared with reverse pulse plating.

Modelling and physical implementation of ambipolar components based on organic materials

Systematic effort dedicated to the exploration of feasible ways how to permanently come up with even more space-efficient implementation of digital circuits based on conventional CMOS technology node may soon reach the ultimate point, which is mostly given by the constraints associated with physical scaling of fundamental electronic components. One of the possible ways how to mitigate this problem can be recognized in deployment of multifunctional circuit elements. In addition, the polymorphic electronics paradigm, with its considerable independence on a particular technology, opens a way how to fulfil this objective through the adoption of emerging semiconductor materials and advanced synthesis methods. In this paper, main attention is focused on various aspects standing behind the conception of polymorphic electronics together with a number of important benefits that can be obtained with the introduction of ambipolar elements. Besides that, relevant equivalent circuit models of the selected ambipolar components are presented in conjunction with the experimental results. However, key aspect depicting the novelty of the presented approach is primarily based on the hybrid combination of an initial chip infrastructure platform with the subsequent deposition of suitable organic semiconductor layer showing ambipolar property. Finally, the applicability for construction of real multifunctional circuits is assessed.

NOVEL APPROACH TO SYNTHESIS OF LOGIC CIRCUITS BASED ON MULTIFUNCTIONAL COMPONENTS

Abstract Multifunctional logic continuously becomes an important way how to implement compact and cheap circuits with intrinsic reconfiguration features. Polymorphic electronics concept with its substantial technological independency opens a way to fulfil this objective through the adoption of emerging semiconductor technologies and advanced synthesis methods. The paper comes with a proposal of a novel synthesis method oriented on the exploitation of polymorphic electronics principles. Key part of it is based on Boolean divisor identification and function kernelling technique. The proposed method is evaluated with several test circuits.

Towards implementation of logic circuits based on intrinsically reconfigurable organic transistors

Nowadays, electronic circuits based on wide range of organic materials with semiconductor properties are still perceived as a somewhat unconventional design approach and fabrication technology. However, it could potentially deliver many significant advantages. Materials for organic electronics are typically lighter, flexible, easier to handle and less expensive in comparison with traditional inorganic materials used in electronics (e.g. copper and silicon used for conventional CMOS process). Previously reported research achievements in that particular domain also indicate that some of the organic semiconductor materials could be used for construction of organic field-effect transistors (OFET) that exhibit rather peculiar ability of ambipolar charge conduction. Fundamental electronic structures of such type also suggest the perspective of their utilization as the key building blocks for so called multifunctional logic elements or even more complex polymorphic circuits. In this paper, main focus is given to the introduction of organic transistor devices with the ambipolar property that would allow to further increase the efficiency of multifunctional circuit design and synthesis techniques. Important aspect depicting the novelty of the proposed approach is primarily based on the adoption of hybrid combination of the traditional silicon substrate with the deposition of suitable organic semiconductor layer. In addition, custom chip carrier platform was also developed for this purpose. Finally, the paper is concluded with review of the achieved results and suggestion of further research directions.

Toward efficient synthesis method of multifunctional logic circuits

The continuous effort how to achieve space-efficient implementation of a digital circuits may soon arrive at the physical limits behind the scaling of fundamental building components. One possible response to this problem can be recognized in adoption of so called multifunctional logic, which also comes with the intrinsically embedded reconfiguration features. Polymorphic electronics concept with its substantial technological independence opens a way to fulfil this objective through the adoption of emerging semiconductor technologies and advanced synthesis methods. This paper is dealing with a proposal of a novel synthesis method oriented on the exploitation of polymorphic electronics principles. Key part of it is based on Boolean divisor identification and function kernelling technique. Proposed method is evaluated with several test circuits.

Implementation of a Cellular Automaton with Globally Switchable Rules

Cellular automata represent a discrete model of a computational machine with the inherent concept of totally distributed state transitional function. Previous studies have indicated that well-devised type of a global influence turns out to be an important factor in terms of improving the overall efficiency of a computation process within automata. In this context, polymorphic electronics is an approach that introduces a specific way of a global control to the circuit, not by means of using a dedicated global signal but through employing an inherent environmental variable. In our case the global information is uniformly propagated through the existing voltage supply rail, which is naturally available to all individual cells of a given automaton. It seems that the suggested approach may be very useful for the implementation of enhanced cellular automata. In this paper, the real hardware implementation of a cellular automaton using polymorphic chip and the obtained experimental results are presented together with a subsequent discussion.