Synthesis of P-circuits for logic restructuring

Boolean functional decomposition techniques built on top of Shannon cofactoring are applied to obtain specialized 4-level forms called Projected Circuits, or P-circuits. We describe their minimization by heuristic and guaranteed approximation algorithms exploiting structural don't care conditions, and prove properties for special cases about cost estimation and testability. A specific application is synthesis for minimum switching activity, with small area penalty, where the decomposition moves toward the output critical signals with the highest switching activity. We report encouraging experiments for decomposition targeting power consumption or simply area.