Approximate Multiplier Design Using Novel Dual-Stage 4:2 Compressors

Abstract

High speed multimedia applications have paved way for a whole new area in high speed error-tolerant circuits with approximate computing. These applications deliver high performance at the cost of reduction in accuracy. Furthermore, such implementations reduce the complexity of the system architecture, delay and power consumption. This paper explores and proposes the design and analysis of two approximate compressors with reduced area, delay and power with comparable accuracy when compared with the existing architectures. The proposed designs are implemented using 45 nm CMOS technology and efficiency of the proposed designs have been extensively verified and projected on scales of area, delay, power, Power Delay Product (PDP), Error Rate (ER), Error Distance (ED), and Accurate Output Count (AOC). The proposed approximate 4 : 2 compressor shows 56.80% reduction in area, 57.20% reduction in power, and 73.30% reduction in delay compared to an accurate 4 : 2 compressor. The proposed compressors are utilised to implement 8 × 8 and 16 × 16 Dadda multipliers. These multipliers have comparable accuracy when compared with state-of-the-art approximate multipliers. The analysis is further extended to project the application of the proposed design in error resilient applications like image smoothing and multiplication.

Keywords

• Approximate 4:2~compressors
• approximate multipliers
• error resilient applications
• image processing