DMA-circular: an enhanced high level programmable DMA controller for optimized management of on-chip local memories

This paper presents DMA-circular, a novel DMA controller for optimized memory management for on-chip local memories. DMA-circular embeds the functionality of caches into the DMA controller and applies aggressive optimizations using novel hardware. DMA-circular anticipates the computation requirements in terms of data transfers and performs buffer management for data that is mapped to the local memory. The explicit hardware support accelerates the most common actions related to the management of a local memory while the cache functionalities enable a high level of programmability for the DMA-circular. The evaluation is done on several high performance kernels from the NAS benchmark suite. Compared to traditional DMA controllers, results show speedups from 1.20x to 2x, keeping the control code overhead under 15% of the kernels' execution time and also reducing the energy consumption up to 40%.