Ternary-Input Binary-Weight CNN Accelerator Design for Miniature Object Classification System with Query-Driven Spatial DVS
Yuyang Li, Swasthik Muloor, Jack Laudati, Nickolas Dematteis, Yidam Park, Hana Kim, Nathan Chang, Inhee Lee
TL;DR
This paper tackles miniature vision systems constrained by power and area by proposing a ternary-input binary-weight CNN accelerator (TBN) that partners with a reconfigurable spatial DVS, enabling efficient object recognition and tracking from a shared sensor. The architecture leverages sparsity-aware zero-skipping and XOR-based multipliers to drastically reduce data movement and MACs, while maintaining CIFAR-10-scale accuracy on DVS-formatted inputs. Key results show inference in 0.44 s at 1.6 mW with 82.56% top-1 accuracy and a FoM improvement of about 7× over prior miniature accelerators. The work demonstrates the practicality of integrating spatial DVS and TBN for low-power, mm-scale vision systems.
Abstract
Miniature imaging systems are essential for space-constrained applications but are limited by memory and power constraints. While machine learning can reduce data size by extracting key features, its high energy demands often exceed the capacity of small batteries. This paper presents a CNN hardware accelerator optimized for object classification in miniature imaging systems. It processes data from a spatial Dynamic Vision Sensor (DVS), reconfigurable to a temporal DVS via pixel sharing, minimizing sensor area. By using ternary DVS outputs and a ternary-input, binary-weight neural network, the design reduces computation and memory needs. Fabricated in 28 nm CMOS, the accelerator cuts data size by 81% and MAC operations by 27%. It achieves 440 ms inference time at just 1.6 mW power consumption, improving the Figure-of-Merit (FoM) by 7.3x over prior CNN accelerators for miniature systems.
