Energy-aware probabilistic multiplier: design and analysis

Probabilistic CMOS is considered to be a promising technology for substantial energy savings for computing devices, such as DSPs and graphics chips. The basic principle is to relax the energy requirement by allowing possibly incorrect computation results. For devices with probabilistic components, energy should be assigned to each component wisely, in order to achieve a good trade-off between energy consumption and correctness of the outputs. Recently, a few schemes have been proposed for energy assignment of ripple-carry adders, which are often based on intuitive arguments. In the present paper, we extend the idea of energy assignment to probabilistic multipliers. We focus on a fundamental type of multipliers, known as array multipliers. We derive some analytical results. Guided by these results, we devise an energy assignment scheme. We also find that energy assignment for array multipliers and ripple-carry adders can be quite different, due to differences in their structures. To our best knowledge, our work here is the first attempt in the literature to consider energy assignment for multipliers. Some examples, including digital image enhancement, are presented to demonstrate the effectiveness of the proposed scheme.