Design and Implementation of an Associative Memory with Smart Pixels

Abstract

A unipolar binary bidirectional associative memory (UBBAM) has been designed to associate input and output vectors in a manner of a content addressable memory. The neural network thus formed does not require inhibitory neurons and is well suited for optoelectronic implementa tion. The performance of the UBBAM has been shown to match that of the original BAM. The key device in the implementation of the UBBAM is a Smart Advanced Spatial Light Modulator (SASLM1), a ferroelectric liquid crystal (FELC) SLM driven by a silicon CMOS backplane. The smart pixel of the SASLM serves as a local processing unit which sets the state of its FELC modula tor according to some function of the optical signals incident upon the pixel's photodetector. The ac tion of each smart pixel is hence akin to a neuron's soma, and a matrix of such smart pixels therefore forms a powerful parallel processing hardware, significant in representing neuron fields, in real time, with minimal off-chip control and processing. The UBBAM model, the SASLM1 smart pixels and a proposed optical system will be described in this paper.