A BDD proposal for Probabilistic Switching Activity Estimation

Switching activity computation is a essential stage for dynamic power estimation. Binary decision diagrams (BDD) are widely used in probabilistic activity estimation. However, the BDD size used for switching activity increases significantly in respect to the logic function BDDs. In this paper we propose a new BDD structure for activity computations in which important size reductions are achieved with no accuracy loss. The proposal includes the definition of a BDD activity operator. This operator has been implemented in a BDD package and then, in an automated tool. This implementation has permitted the analysis of several circuits and has corroborated the size reductions and the accuracy of the result