FPGA and ASIC square root designs for high performance and power efficiency

Floating-point square root is a fundamental operation in signal processing and various HPC applications. Since this is an expensive operation in resource and energy consumption, its efficient implementation should be of priority in future multicores that will face dark silicon issues. This paper presents a low-cost, low-power consumption design to calculate the square root using the IEEE754 single-precision floating-point format. Two versions of the design are investigated with and without clock gating (CG), respectively. Evaluation involves FPGA and ASIC technologies at 40 and 65 nm. Substantial performance growth and reduced power consumption are gained as compared to a popular iterative solution. The ASIC design demonstrates much lower power consumption, which at 40 nm is lower than that at 65 nm by about a threefold. At 40 nm, CG for the ASIC realization is justified primarily for low activity rates.