Truth-table look-up parallel data processing using an optical content-addressable memory

Abstract

The extension of truth-table look-up processing beyond primitive operations (such as addition) to higher-level operations (such as discrete matched filtering) is presented. Use of the residue system and logical minimization techniques to reduce the required number of reference patterns stored in a content-addressable memory is illustrated for 16-bit full-precision addition. Multilevel coding of the numbers is introduced as a method to achieve further truth-table reduction. The required number of reference patterns for implementing the residue addition and multiplication operations are provided for all moduli from 2 through 32 with 2-, 3-, and 5-level coding. An optical holographic implementation of a system that processes multilevel coded numbers is presented.