This work presents NeuDW-CIM, a highly efficient neuromorphic Compute-in-Memory (CIM) macro for Spiking Neural Networks (SNNs) implemented in 65 nm CMOS. The design introduces a custom twin 9T bit-cell for ternary in-puts/weights and a reconfigurable non-linear In-Memory ADC (IMA). The macro supports two specialized modes: 1) Nonlinear Dendrite (NLD) mode, which utilizes reconfigurable IMA to emulate biological dendritic functions, achieving measured accuracies of 97.2% on N-MNIST and 95.5% on DVS Gesture; and 2) Top-K Winner (KWN) mode, featuring an early-stopping mechanism that reduces IMA conversion latency by 30% and digital LIF latency by 10x. Benefiting from the sparse update in KWN mode, NeuDW-CIM achieves a measured energy efficiency (EE) of 0.8 pJ/SOP (1.6x improvement).
翻译:本文提出了NeuDW-CIM,一款基于65纳米CMOS工艺实现的高效神经形态存算一体(CIM)宏单元,专用于脉冲神经网络(SNN)。该设计采用定制的双管9T(twin 9T)存储单元以支持三值输入/权重,并集成了可重构的非线性存内模数转换器(IMA)。该宏单元支持两种专用模式:1)非线性树突(NLD)模式,利用可重构IMA模拟生物树突功能,在N-MNIST和DVS Gesture数据集上分别达到97.2%和95.5%的实测准确率;2)Top-K胜出者(KWN)模式,该模式采用早停机制,使IMA转换延迟降低30%,数字LIF延迟降低10倍。得益于KWN模式下的稀疏更新特性,NeuDW-CIM实现了0.8 pJ/SOP的实测能效(EE),较同类方案提升1.6倍。