A Design Flow for Click-Based Asynchronous Circuits Design With Conventional EDA Tools

The “event-driven” feature of asynchronous circuits enables the circuits to work when and where needed, making it a good alternative to design low-power circuits. However, asynchronous circuits are not widely adopted as a consequence of the lack of support by conventional EDA tools. In this article, we propose a novel design flow to implement the Click-based asynchronous bundled-data circuits efficiently down to mask layout with conventional EDA tools. To ensure timing correctness, we put forward an adaptive delay matching (ADM) method and perform accurate static timing analysis for the circuits. Compared with other asynchronous toolsets, the proposed design flow is more efficient and convenient to implement asynchronous circuits. An asynchronous convolution neural network accelerator is implemented in TSMC 180- and 65-nm CMOS process, respectively, to verify the proposed design flow. The silicon test results show that the asynchronous accelerator has 30% less power in the computing array than the synchronous one in the TSMC 65-nm CMOS process, and the energy efficiency of the asynchronous and synchronous accelerators are 1.539 TOPS/W and 1.37 TOPS/W, respectively. The energy efficiency of the asynchronous accelerator in the TSMC 180-nm CMOS process is 133 GOPS/W.