A MIXED-ANALOG-DIGITAL MULTICHIP SYSTEM FOR LARGE-SCALE NEURAL SIMULATIONS
In this paper, we describe the design of
Neurogrid, a neuromorphic system for simulating large-scale neural models in
real time. Neuromorphic systems realize the function of biological neural
systems by emulating their structure. Designers of such systems face three
major design choices: 1) whether to emulate the four neural elements-axonal
arbor, synapse, dendritic tree, and soma-with dedicated or shared electronic
circuits; 2) whether to implement these electronic circuits in an analog or
digital manner; and 3) whether to interconnect arrays of these silicon neurons
with a mesh or a tree network. The choices we made were: 1) we emulated all neural
elements except the soma with shared electronic circuits; this choice maximized
the number of synaptic connections; 2) we realized all electronic circuits
except those for axonal arbors in an analog manner; this choice maximized
energy efficiency; and 3) we interconnected neural arrays in a tree network;
this choice maximized throughput. These three choices made it possible to
simulate a million neurons with billions of synaptic connections in real
time-for the first time-using 16 Neurocores integrated on a board that consumes
three watts.
Published in: Proceedings
of the IEEE (Volume:102 , Issue:
5 )
Date of Publication:
May 2014
Page(s):
699 - 716
ISSN
:
0018-9219
INSPEC
Accession Number:
14267024
Digital
Object Identifier :
Date
of Publication :
24 April 2014
Date
of Current Version :
28 April 2014
Issue
Date :
May 2014
Sponsored
by :
Publisher:
IEEE
