A two-step optical modified signed-digit adder for large-scale 2D data array using digit-decomposition-plane representation

Abstract

In this paper, parallel optical array adder for large-scale 2D Modified Sign-Digit (MSD) data array is proposed and implemented to limit the carry propagation to constant steps. The digit- decomposition-plane (DDP) representation technique is expanded to code the 2D array of the MSD number system. The design is based on the logical formulas which are newly derived according to the fundamental parallel addition algorithm for MSD number system using the features of the DDP coding technique. The optical implementations scheme is based on classical optical elements such as spatial light modulators, beam combiners, beam splitters, mirrors, light source arrays, and light detector arrays. The proposed algorithm and its optical architecture have useful intrinsic characteristics such as ultra-high speed, constant processing time, and parallel computation on large-scale data arrays. The simulation results insure that the proposed arithmetic unit is worked successfully.