On-Chip Trainable 1.4M 6T2R PCM Synaptic Array with 1.6K Stochastic LIF Neurons for Spiking RBM

Autor: Scott C. Lewis, Atsuya Okazaki, Kohji Hosokawa, Junka Okazawa, Megumi Ito, Wanki Kim, Masatoshi Ishii, U. Shin, Wilfried Haensch, Matthew J. BrightSky, Malte J. Rasch, Akiyo Nomura, Sungchul Kim
Rok vydání: 2019
Předmět:
Zdroj: 2019 IEEE International Electron Devices Meeting (IEDM).
Popis: A fully silicon-integrated restricted Boltzmann machine (RBM) with event-driven contrastive divergence (eCD) algorithm is implemented using novel stochastic leaky integrate-and-fire (LIF) neuron circuits and 6-transistor/2- PCM-resistor (6T2R) unit cells on 90-nm CMOS technology. A bidirectional asynchronous spiking signaling scheme over an analog-weighted phase change memory (PCM) crossbar enables spike-timing-dependent plasticity (STDP) as a local weight update rule. This results in concurrent massively- parallel neuronal computation for low-power on-chip training and inference. Experimental image classification using 100 handwritten digit images from the MNIST database demonstrates 92% training accuracy. SPICE simulation abstracted from the fabricated design indicates 8.95 power. A projection to 28-nm technology gives 5.39 pJ per synaptic operation.
Databáze: OpenAIRE