(An) energy efficient asynchronous interface with delay insensitive protocol for Globally Asynchronous Locally Synchronous (GALS) system

Abstract

In recent years, the demand for robust and high-performance edge devices has increased dramatically due to smart home and automation control applications. Typically, to design an edge device, chip designers use an extra timing margin to ensure the device's operation under the worst-case condition. However, this approach can lead to reduced performance and energy efficiency. Globally asynchronous locally synchronous system (GALS) can be used as an alternative approach to ensure the device operation while maintaining device performance. This paper presents an energy-efficient asynchronous interface with delay-insensitive protocol for data transfer between the synchronous island in the GALS system. As the prior delay-insensitive interface consumes significant energy and only supports short wire connection, two additional techniques are used to reduce interface energy and improve robustness. First, a non-return to zero handshaking scheme with half-swing signaling is used to reduce interface latency. Additionally, adaptive timing control is implemented to improve interface robustness. As a result, our energy-efficient asynchronous interface implemented using TSMC 65nm GP technology achieved 2.3x higher bandwidth and consumed 3.1x less energy than the prior delay-insensitive asynchronous interface.