Hardware Accelerated Vision Transformer via Heterogeneous Architecture Design and Adaptive Dataflow Mapping

Vision transformer (ViT) models have demonstrated remarkable advantages in visual tasks. However, the ViT model contains various types of operators, and its sophisticated model structure imposes substantial computational complexity and storage burden. Existing hardware solutions still fail to fully unleash the ViT acceleration potential due to the mismatch between operators and hardware architectures, suffering from inefficient dataflow mapping. This work proposes HDViT, a full-fledged heterogeneous hardware accelerator on FPGA, to enhance the ViT acceleration by comprehensively analyzing and addressing the challenges of heterogeneous architecture design. Specifically, HDViT first develops a heterogeneous architecture design that is composed of multiple processing engines (PEs) to accelerate various operators in the ViT model. Then, HDViT devises a hybrid-oriented dataflow mapping strategy to reduce data transmission granularity and alleviate storage resource pressure. Lastly, to achieve the latency balancing among multiple PEs, we formulate the HDViT architecture and implement an automated exploration process to identify optimized parallelism parameters that satisfy computation and storage demands while enhancing the heterogeneous architectural performance. Experimental results indicate that HDViT achieves significant performance speedups of 2.16$\times$ and 3.51$\times$ compared to previous heterogeneous and unified accelerators, respectively. HDViT also achieves a maximum of 98.46% hardware utilization.