Introducing Flexibility in Digital Circuit Evolution: Exploiting Undefined Values in Binary Truth Tables.

Evolutionary algorithms can be used to evolve novel digital circuit solutions. This paper proposes the use of flexible target truth tables, allowing evolution more freedom where values are undefined. This concept is applied to three test circuits with different distributions of ˵don΄t care″ values. Two strategies are introduced for utilising the undefined output values within the evolutionary algorithm. The use of flexible desired truth tables is shown to significantly improve the success of the algorithm in evolving circuits to perform this function. In addition, we show that this flexibility allows evolution to develop more hardware efficient solutions than using a fully-defined truth table. [ABSTRACT FROM AUTHOR]