Energy Efficient Memristor-Based Subtractors and Comparator for In-Memory Computing in MAGIC

Applications involving large datasets incur substantial energy costs due to frequent data transfers between memory and processing units. Utilizing memristors within a memristive crossbar to execute logic operations is a characteristic of In-Memory-Computing (IMC), resulting in improved processing speed and energy efficiency. This brief proposes MAGIC-based IMC-capable memristive subtractors optimized for area, speed, and energy consumption. The proposed high-speed MAGIC serial design is 33% faster than the current IMPLY-based serial subtractor. The 32-bit subtractor output is obtained in 449 serial steps and 294 parallel steps through the proposed MAGIC parallel subtractor design. Next, we use the proposed subtractor designs to create a comparator and implement max pooling operations. A $n$ -bit comparator, designed through the proposed subtractor, performs the comparison in $9n+3$ steps. Further, a n -bit max pooling operation for a $2 \times 2$ feature map takes $28n+2$ steps. Regarding energy consumption, the MAGIC design exhibits superior performance compared to other designs, demonstrating an average savings of 93% to 95% in comparison to the IMPLY-based subtractor and comparator designs. All the designs are functionally verified through simulations using the VTEAM model, and energy is calculated from these simulations.