PowerBit - Power aware arithmetic bit-width optimization

In this paper we present a novel method reducing the dynamic power consumption in FPGA-based arithmetic circuits by optimizing the bit-widths of the signals inside the circuit. The proposed method is implemented in the tool PowerBit, which makes use of macro models parameterized by word-level signal statistics to estimate the circuit power consumption during the optimization process. The power models used take in to account the generation and propagation of signal glitches through the circuit. The bit-width optimization uses a static analysis technique which is capable of providing guaranteed accuracy in the design outputs. We show that, for sample designs implemented on FPGAs that improvements of over 10% are possible for multiple bit-width allocated designs optimized for power compared to designs allocated uniform bit-widths.