Evolvable Hardware in Silicon

Evolvable systems in silicon are third generation hardware in terms of flexibility and fault-tolerance. The first generation was fixed silicon: once a device was fabricated its structure was forever fixed. Reconfigurable hardware came as a second generation: new configurations could be downloaded changing the function of the device and also bypassing faulty areas, if any. The third generation is that of self-configurable, evolvable hardware (EHW), and adds the automatic reconfiguration feature, enabling truly adaptive hardware. This chapter addresses current efforts in building and using evolvable chips. The first section refers to evolutionary algorithms for evolvable hardware. The second section describes the JPL evolvable hardware testbed and the JPL Field Programmable Transistor Array (FPTA) chip designed and used for circuit evolution in silicon. The third section addresses the application of evolvable hardware for adaptive filtering and noise cancellation. The fourth section discusses the importance of fault-tolerant hardware in space and describes the evolvable hardware approach for faulttolerant design of a 4-bit data converter. The final section concludes the work.