Indicating Asynchronous Multipliers

TL;DR

This paper explores the physical implementation of indicating asynchronous multipliers using 32/28-nm CMOS technology, comparing different handshake protocols and adder types to optimize performance and power efficiency.

Contribution

It introduces a modular, robust asynchronous multiplier design with analysis of various handshake protocols and adder types, highlighting the efficiency of weak-indication multipliers with RTO protocol.

Findings

Weak-indication multipliers are more efficient in cycle time and power-cycle time.

4-phase RTO handshake protocol outperforms RTZ in design metrics.

Biased weak-indication full adder enhances multiplier performance.

Abstract

Multiplication is a basic arithmetic operation that is encountered in almost all general-purpose microprocessing and digital signal processing applications, and multiplication is physically realized using a multiplier. This paper discusses the physical implementation of indicating asynchronous multipliers, which are inherently elastic and are robust to timing, process, and parametric variations, and are modular. We consider the physical implementation of many weak-indication asynchronous multipliers using a 32/28-nm CMOS technology by adopting the array multiplier architecture. The multipliers are synthesized in a semi-custom ASIC-design style. The 4-phase return-to-zero (RTZ) and the 4-phase return-to-one (RTO) handshake protocols are considered for the data communication. The multipliers are realized using strong-indication or weak-indication full adders. Strong-indication 2-input AND function is used to generate the partial products in the case of both RTZ and RTO handshaking. The full adders considered are derived from different indicating asynchronous logic design methods. Among the multipliers considered, a weak-indication asynchronous multiplier utilizing the biased weak-indication full adder is found to be efficient in terms of the cycle time and the power-cycle time product with respect to both RTZ and RTO handshaking. Also, the 4-phase RTO handshake protocol is found to be preferable than the 4-phase RTZ handshake protocol for achieving enhanced optimizations in the design metrics.