LAC: A Novel Lightweight Asynchronous Controller with Optimized Phase Shift

There is an increasing demand for low-power processors in the domain of Internet of Things (IoT) and neuromorphic chips, asynchronous circuits are gaining popularity due to their low power consumption and event-driven nature. However, due to the handshake mechanism, phase shifts exist among the local pulses generated by the handshake controllers, which limit the further reduction of power consumption of the asynchronous circuit. In this paper, we propose a novel lightweight asynchronous controller (LAC), which can be used for the control path of two-phase bundled-data asynchronous circuits. The LAC features a simple structure, low power consumption and small area, effectively reducing phase shifts between local pulses and making it suitable for wide-ranging applications. To verify the proposed controller, we designed an asynchronous RISC-V processor. The implementation results show that for the same performance, the asynchronous processor can reduce the average power consumption by 17.0% and 8.53% respectively compared to the synchronous one and the click-based asynchronous processor.