Our paper has been accepted by IEEE Access

Our paper, “Hardware-Aware Early Termination for Low-Latency Spiking Neural Network Inference,” has been accepted for publication in IEEE Access.

Abstract: Spiking Neural Networks (SNNs) provide a natural computation model for neuromorphic hardware, but fixed-timestep inference can execute substantial redundant temporal computation. This work proposes a hardware-aware early termination (ET) framework that determines the stopping time from accumulated output-spike statistics without exporting internal continuous neuron states to the termination controller. A spike-ratio confidence metric is combined with a minimum observation timestep to suppress low-evidence early decisions. To improve the temporal quality of the output spikes used by ET, Time-Weighted Spike Alignment Training (TW-SAT) applies stronger supervision to earlier instantaneous output spikes through a normalized exponentially decaying schedule. Experiments on MNIST, Fashion-MNIST, N-MNIST, and DVS128 Gesture are repeated with three independently trained models. At comparable accuracy, dynamic ET consistently requires fewer executed timesteps than validation-selected fixed cutoffs. On MNIST, ET with TW-SAT reaches 98.53 ± 0.05% accuracy with an average of 2.04 ± 0.01 timesteps under an algorithm-level Tmax = 100 setting. A complete FPGA implementation on an Artix-7 device preserves timing closure with only 1.68% additional LUTs and 1.86% additional FFs. Under the deployed Tmax = 20 hardware configuration, cycle-accurate simulation shows that ET reduces the average latency from 12.74 μs to 3.35 μs and increases effective throughput from 78.5 to 298.5 kFPS, corresponding to a 3.80× improvement. These results show that output-spike-based termination provides a low-overhead control path for reducing SNN inference latency while retaining a spike-observable hardware interface.

Figure. Overview of spike-based early termination. The output spikes are accumulated over time to compute the confidence Γ(t). The termination condition is checked only after the minimum observation timestep Tmin. Once Γ(t) reaches the threshold θ, inference stops at Tstop and the remaining timesteps are skipped. If the condition is not satisfied within the decision window,
inference is forced to stop at Tcut.