UPIM: Unipolar Switching Logic for High Density Processing-in-Memory Applications

Internet of Things (IoT) has built a network with billions of connected devices which generate massive volumes of data. Processing large data on existing systems requires significant costs for data movements between processors and memory due to limited cache capacity and memory bandwidth. Processing-In-Memory (PIM) is a promising solution to address the issue. Prior techniques that enable the computation in non-volatile memory (NVM) are designed on a bipolar switching mode, which suffers from a high sneak current in a crossbar array (CBA) structure. In this paper, we propose a unipolar-switching logic for high-density PIM applications, called UPIM. Our design exploits a unipolar-switching mode of memristor devices which can be operated in 1D1R structure hence suppresses the sneak current that exists in prior PIM technologies. Moreover, UPIM takes advantages of a 3D vertical crossbar array (CBA) structure to increase memory utilization per unit area for high-density applications. Our evaluation on a wide range of applications shows that the UPIM achieves up to 31.3× energy saving and 113.8× energy-delay product (EDP) improvement as compared to a recent GPGPU architecture. As compared to the state-of-the-art PIM design based on the bipolar switching mode, our design achieves 3.1× lower energy consumption.