An Integrated Rational Arithmetic Unit

Abstract

Based on the classical Euclidian Algorithm, we develop the foundations of an arithmetic unit performing Add, Subtract, Multiply and Divide on rational operands. The unit uses one unified algorithm for all operations, including rounding. A binary implementation, based on techniques known from the SRT division, is described. Finally, a hardware implementation using ripple-free, carry-save addition is analyzed, and adapted to a floating-slash representation of the rational operands.