Evolution of Analog Circuits on Field Programmable Transistor Arrays

Evolvable Hardware (EHW) refers to HW design and self-reconfiguration using evolutionary/genetic mechanisms. The paper presents an overview of some key concepts of EHW, describing also a set of selected applications. A fine-grained Field Programmable Transistor Array (FPTA) architecture for reconfigurable hardware is presented as an example of an initial effort toward evolution-oriented devices. Evolutionary experiments in simulations and with a FPTA chip in-the-loop demonstrate automatic synthesis of electronic circuits. Unconventional circuits, for which there are no textbook design guidelines, are particularly appealing to evolvable hardware. To illustrate this situation, one demonstrates here the evolution of circuits implementing parametrical connectives for f izzy logics. In addition to synthesizing circuits for new functions, evolvable hardware can be used to preserve existing functions and achieve faulttolerance, determining circuit configurations that circumvent the faults and temperature effects as well. These characteristics are extremely important for enabling spacecraft to survive harsh environments and to have long life. Expanding reconfiguration to other types of spacecraft hardware (i.e. optics, MEMS, etc) could lead to evolvable space systems.