An 82-nW 0.53-pJ/SOP Clock-Free Spiking Neural Network With 40-μs Latency for AIoT Wake-Up Functions Using a Multilevel-Event-Driven Bionic Architecture and Computing-in-Memory Technique - Ying Liu; Yufei Ma; Wei He; Wang, Zhixuan; Shen, Linxiao; Ru, Jiayoon; Ru HUANG; Ye, Le (IEEE Transactions on Circuits and Systems I: Regular Papers, 2023)