Extrinsic and Intrinsic Evolution of Multifunctional Combinational Modules

Multifunctional digital circuits are circuits composed of polymorphic (multifunctional) gates. In addition to its standard logic function (such as NAND), a polymorphic gate exhibits another logic function (such as NOR) which is activated under a specific condition, for example, when Vdd, temperature or illumination reaches a certain level. This paper describes the evolutionary design of multifunctional combinational circuits at the gate level using a circuit simulator and in a field programmable gate array (FPGA). The FPGA-based implementation exhibits a significant speedup against a highly optimized software simulator.