A Novel Genetic Algorithm for Evolvable Hardware

Abstract

Abstract-Evolutionary algorithms are used for solving search and optimization problems. A new field in which they are also applied is evolvable hardware, which refers to a self-configurable electronic system. However, evolvable hardware is not widely recognized as a tool for solving real-world applications, because of the scalability problem, which limits the size of the system that may be evolved. In this paper a new genetic algorithm, particularly designed for evolving logic circuits, is presented and tested for its scalability. The proposed algorithm designs and optimizes logic circuits based on a Programmable Logic Array (PLA) structure. Furthermore it allows the evolution of large logic circuits, without the use of any decomposition techniques. The experimental results, based on the evolution of several logic circuits taken from three different benchmarks, prove that the proposed algorithm is very fast, as only a few generations are required to fully evolve the logic circuits. In addition it optimizes the evolved circuits better than the optimization offered by other evolutionary algorithms based on a PLA and FPGA structures.

Generalized Disjunction Decomposition for the Evolution of Programmable Logic Array Structures

“…For the first system the circuits are evolved using the briefly described genetic algorithm only (see Section 2.1), a larger description is given in [21]. The second system is made by decomposing the initial circuit using the generalized disjunction decomposition and then applies the described genetic algorithm, thus GDD+GA.…”

“…The first sub-section gives a brief description of the multi-population genetic algorithm which uses two different mechanisms to generate new individuals [21]. The second sub-section gives a concise introduction on the generalized disjunction decomposition; a complete description of the GDD is given in [20].…”

“…Furthermore, the chosen genetic algorithm has got something completely new: the construction of the chromosome from the elitism's pool (which contains the best chromosome of each population). A more detailed description of this algorithm is given in [21]. A particularity of the algorithm used is the reproduction mechanism that is depicted in Figure 2.…”

“…A modified version of GDD is here implemented together with a recently introduced genetic algorithm [21], which is designed for the evolution of PLA. A PLA structure (see Figure 1) has been chosen as it is a good structure for designing combinational logic circuits in VLSI and for its simplicity, regularity and flexibility.…”

“…The chosen genetic algorithm will also be briefly described. The system implemented here: modified GDD with the GA proposed in [21] it is novel and it was never implemented before. The experimental results, which are statistically relevant since they have been obtained over several simulations, prove that the generalized disjunction decomposition can improve scalability and evolvability for the evolution of large logic circuits.…”