Unified Architecture for Double/Two-Parallel Single Precision Floating Point Adder

Abstract

Floating point (F.P.) addition is a core operation for a wide range of applications. This brief presents an area-efficient, dynamically configurable, multiprecision architecture for F.P. addition. We propose an architecture of a double precision (DP) adder, which also supports a dual (two parallel) single precision (SP) computational feature. Key components involved in the F.P. adder architecture, such as comparator, swap, dynamic shifters, leading one-detector (LOD), mantissa adders/subtractors, and rounding circuit, have been redesigned to efficiently enable resource sharing for both precision operands with minimal multiplexing circuitry. The proposed design supports both normal and sub-normal numbers. The proposed architecture has been synthesized for OSUcells Cell 0.18 μm technology ASIC implementation. Compared to a standalone DP adder with two SP adders, the proposed unified architecture can reduce the hardware resources by ≈ 35%, with a minor delay overhead. Compared to previous works, the proposed dual mode architecture has 40% smaller area × delay, and has better area and delay overhead over only DP adder.