The Perplexus bio-inspired reconfigurable circuit Andres Upegui, Yann Thoma, Eduardo Sanchez, Andres Perez-Uribe HEIG-VD, Yverdon-les-Bains, Switzerland (andres.upegui, yann.thoma, eduardo.sanchez, andres.perez-uribe)@heig-vd.ch Juan Manuel Moreno, Jordi Madrenas UPC, Barcelona, Spain (moreno, madrenas)@eel.upc.edu Abstract This paper introduces the ubichip, a custom recon- figurable electronic device capable of implementing bio- inspired circuits featuring growth, learning, and evolution. The ubichip is developed in the framework of Perplexus, a European project that aims to develop a scalable hard- ware platform made of bio-inspired custom reconfigurable devices for simulating large-scale complex systems. In this paper, we describe the configurability and architectural mechanisms that will allow the implementation of evolv- able and developmental cellular and neural systems in an efficient way. These mechanisms are dynamic routing, self- reconfiguration, and a neural-friendly logic cell’s architec- ture. 1. Introduction The Perplexus project [12] aims to develop a scalable hardware platform made of custom reconfigurable devices endowed with bio-inspired capabilities. This platform will enable the simulation of large-scale complex systems and the study of emergent complex behaviors in a virtually un- bounded wireless network of computing modules. The Perplexus platform will consist thus in a scal- able network of ubiquitous computing modules (ubidules) equipped with wireless communication capabilities and rich sensory elements. The platform will be modular for allow- ing the application developer to customize his platform set- up. In this way the application developer can easily build his system setup by selecting what to plug to the ubidule from a set of peripherals. These peripherals can be different com- munication interfaces (wifi, bluetooth), sensors, actuators, cameras, or flash memories. This modularity is guaranteed by the use of standard interfaces such as USB. At the heart of these ubidules, we will use a custom reconfigurable electronic device capable of implementing bio-inspired mechanisms such as growth, learning, and evo- lution. These bio-inspired mechanisms will be possible thanks to reconfigurability mechanisms like dynamic rout- ing, distributed self-reconfiguration, and a simplified con- nectivity. Such an infrastructure will provide several advan- tages compared to classical software simulations: speed- up, an inherent real-time interaction with the environment, self-organization capabilities, simulation in the presence of uncertainty, and distributed multi-scale simulations. Our modeling framework will be tested on three application do- mains: biologically-plausible developing neural networks modeling, culture dissemination modeling, and cooperative collective robotics [12]. Recent work in this field is the POEtic tissue [16], a re- configurable hardware platform for rapidly prototyping bio- inspired systems that employ POE principles [13], which has been developed in the framework of the European project POEtic. The POEtic chip has been specifically de- signed to ease the development of bio-inspired applications. The limitations exhibited by the POEtic tissue suggest several architectural and configurability features to be im- proved. These improvements may lead us to a reconfig- urable platform better suited for supporting the bio-inspired principles that we want our devices to mimic. Before discussing the hardware mechanisms that will be considered for the design of our ubichip, in section 2 we will introduce some concepts and issues concerning bio- inspired hardware, also known as POE hardware [13], and we will also present the desired bio-inspired features to be supported by the ubichip. Then, in section 3, we will de- scribe the hardware mechanisms that will allow the imple- mentation of such bio-inspired systems. 2. POE Hardware Living beings, unlike engineered systems, exhibit a high level of adaptability and robustness thanks to several bi- ological mechanisms: reproduction, learning, self-repair, growth, and evolution. It would be thus desirable to in- clude such mechanisms in human-designed systems in or- Second NASA/ESA Conference on Adaptive Hardware and Systems(AHS 2007) 0-7695-2866-X/07 $25.00 © 2007