Abstract
By their very nature, voltage/current excited Spin Waves (SWs) propagate
through waveguides without consuming noticeable power. If SW excitation
is performed by the continuous application of voltages/currents to the
input, which is usually the case, the overall energy consumption is
determined by the transducer power and the circuit critical path delay,
which leads to high energy consumption because of SWs slowness. However,
if transducers are operated in pulses the energy becomes circuit delay
independent and it is mainly determined by the transducer power and
delay, thus pulse operation should be targeted. In this paper, we
utilize a 3-input Majority gate (MAJ) to investigate the Continuous Mode
Operation (CMO), and Pulse Mode Operation (PMO). Moreover, we validate
CMO and PMO 3-input Majority gate by means of micromagnetic simulations.
Furthermore, we evaluate and compare the CMO and PMO Majority gate
implementations in term of energy. The results indicate that PMO
diminishes MAJ gate energy consumption by a factor of 18. In addition,
we describe how PMO can open the road towards the utilization of the
Wave Pipelining (WP) concept in SW circuits. We validate the WP concept
by means of micromagnetic simulations and we evaluate its implications
in term of throughput. Our evaluation indicates that for a circuit
formed by four cascaded MAJ gates WP increases the throughput by 3.6x.