An asynchronous loop structure based on the click element

We present a click-element-based asynchronous loop structure for control path of asynchronous micro-control unit (MCU). The loop, which has one-stage control circuit instead of cascade circuits, can be triggered by only one trigger signal and stopped by a preset number. To verify the loop structure, we design an asynchronous MCU simulated in FPGA. The experimental results show that the MCU can be precisely controlled and saves 37.5% working time and 91.5% flip-flop times at the cost of more logic elements.