Abstract
In this paper, we propose an energy efficient SW based approximate 4:2
compressor comprising a 3-input and a 5-input Majority gate. We validate
our proposal by means of micromagnetic simulations, and assess and
compare its performance with one of the state-of-the-art SW, 45nm CMOS,
and Spin-CMOS counterparts. The evaluation results indicate that the
proposed compressor consumes 31.5\% less energy in
comparison with its accurate SW design version. Furthermore, it has the
same energy consumption and error rate as the approximate compressor
with Directional Coupler (DC), but it exhibits 3x lower delay. In
addition, it consumes 14% less energy, while having 17% lower average
error rate than the approximate 45nm CMOS counterpart. When compared
with the other emerging technologies, the proposed compressor
outperforms approximate Spin-CMOS based compressor by 3 orders of
magnitude in term of energy consumption while providing the same error
rate. Finally, the proposed compressor requires the smallest chip
real-estate measured in terms of devices.