Global versus Local Weak-Indication Self-Timed Function Blocks - A Comparative Analysis

TL;DR

This paper compares global and local weak-indication self-timed function blocks, analyzing their advantages and disadvantages in terms of power, latency, area, and performance using a ripple carry adder as an example.

Contribution

It provides a detailed comparative analysis of global versus local weak-indication self-timed function blocks, highlighting their respective benefits and trade-offs.

Findings

Global weak-indication reduces power, latency, and area.

Local weak-indication achieves data-dependent cycle time.

Trade-offs exist between power efficiency and performance.

Abstract

This paper analyzes the merits and demerits of global weak-indication self-timed function blocks versus local weak-indication self-timed function blocks, implemented using a delay-insensitive data code and adhering to 4-phase return-to-zero handshaking. A self-timed ripple carry adder is considered as an example function block for the analysis. The analysis shows that while global weak-indication could help in optimizing the power, latency and area parameters, local weak-indication facilitates the optimum performance in terms of realizing the data-dependent cycle time that is characteristic of a weak-indication self-timed design.