Exploiting Memory-Level Parallelism in Reconfigurable Accelerators

As memory accesses increasingly limit the overall performance of reconfigurable accelerators, it is important for high level synthesis (HLS) flows to discover and exploit memory-level parallelism. This paper develops 1) a framework where parallelism between memory accesses can be revealed from runtime profile of applications and provided to a high level synthesis flow, and 2) a novel multi-accelerator/multi-cache architecture to support parallel memory accesses, taking advantage of the high aggregated memory bandwidth found in modern FPGA devices. Our experimental results have shown that for 10 accelerators generated from 9 benchmark applications, circuits using our proposed memory structure achieve on average 52% improved performance over accelerators using a traditional memory interface. We believe that our study represents a solid advance towards achieving memory-parallel embedded computing on hybrid CPU+FPGA platforms.