Optical modified signed-digit addition based on binary logical operations

Abstract

We propose here the realization of modified signed-digit (MSD) addition using traditional binary logical operations. The trinary logical operations required in MSD additions can be considered as the ‘signed’ version of the logical XOR and AND operations performed in binary addition. Therefore, MSD additions can be implemented by binary logic gates if the sign information is extracted first and then restored to the binary output. This approach results in an efficient design of optical arithmetic and logic unit (ALU) as the binary logic gates can be commonly used to perform both logic and arithmetic operations.