Cap: Configurable Resistive Associative Processor For Near-Data Computing

Internet of Things is capable of generating huge amount of data, causing high overhead in terms of energy and performance if run on traditional CPUs and GPUs. This inefficiency comes from the limited cache size and memory bandwidth which result in large amount of data movement through memory hierarchy. In this paper, we propose a configurable associative processor, called CAP, which accelerates computation using multiple parallel memory-based cores capable of approximate or exact matching. CAP is integrated next to the main memory so it fetches the data directly from DRAM. To exploit data locality, CAMs adaptively split into highly and less frequent components and update at runtime. To further improve the CAP efficiency, we integrate a novel signature-based associative memory (SIGAM) beside each processing cores, to store highly frequent patterns and in runtime retrieve them in exact or approximate modes. Our experimental evaluations show that the CAP in approximate (exact) mode can achieve 9.4x and 5.3x (7.2x and 4.2x) energy improvement, and 4.1x and 1.3x speeds up compare to AMD GPU and ASIC CMOS-based designs while providing acceptable quality of service.