  In this paper, we reviewed Spiking neural network (SNN) integrated circuit
designs and analyzed the trends among mixed-signal cores, fully digital cores
and large-scale, multi-core designs. Recently reported SNN integrated circuits
are compared under three broad categories: (a) Large-scale multi-core designs
that have dedicated NOC for spike routing, (b) digital single-core designs and
(c) mixed-signal single-core designs. Finally, we finish the paper with some
directions for future progress.
