MEET: Towards Memory-Efficient Temporal Sparse Deep Neural Networks

Deep Neural Networks (DNNs) are accurate but compute-intensive, leading to substantial energy consumption during inference. Exploiting temporal redundancy through \Delta-\Sigma convolution in video processing has proven to greatly enhance computation efficiency. However, temporal \Delta-\Sigma DNNs typically require substantial memory for storing neuron states to compute inter-frame differences, hindering their on-chip deployment. To mitigate this memory cost, directly compressing the states can disrupt the linearity of temporal \Delta-\Sigma convolution, causing accumulated errors in long-term \Delta-\Sigma processing. Thus, we propose MEET, an optimization framework for MEmory-Efficient Temporal \Delta-\Sigma DNNs. MEET transfers the state compression challenge to a well-established weight compression problem by trading fewer activations for more weights and introduces a co-design of network architecture and suppression method to optimize for mixed spatial-temporal execution. Evaluations on three vision applications demonstrate a reduction of 5.1~13.3 xin total memory compared to the most computation-efficient temporal DNNs, while preserving the computation efficiency and model accuracy in long-term \Delta-\Sigma processing. MEET facilitates the deployment of temporal \Delta-\Sigma DNNs within on-chip memory of embedded event-driven platforms, empowering low-power edge processing.