Multiplication Acceleration Through Twin Precision

We present the twin-precision technique for integer multipliers. The twin-precision technique can reduce the power dissipation by adapting a multiplier to the bitwidth of the operands being computed. The technique also enables an increased computational throughput, by allowing several narrow-width operations to be computed in parallel. We describe how to apply the twin-precision technique also to signed multiplier schemes, such as Baugh-Wooley and modified-Booth multipliers. It is shown that the twin-precision delay penalty is small (5%-10%) and that a significant reduction in power dissipation (40%-70%) can be achieved, when operating on narrow-width operands. In an application case study, we show that by extending the multiplier of a general-purpose processor with the twin-precision scheme, the execution time of a Fast Fourier Transform is reduced with 15% at a 14% reduction in datapath energy dissipation. All our evaluations are based on layout-extracted data from multipliers implemented in 130-nm and 65-nm commercial process technologies.