A Compilation Framework for SRAM Computing-in-Memory Systems With Optimized Weight Mapping and Error Correction

Yichuan Bai, Yaqing Li, Heng Zhang, Aojie Jiang, Yuan Du, Li Du

Abstract: Deploying convolution-based algorithms into static random access memory (SRAM) computing-in-memory (CIM) systems faces various challenges, such as operator incompatibility and intrinsic nonideal error. This article proposes a compilation framework to address this issue. Efficient weight mapping strategies are introduced to improve the utilization of SRAM-CIM macro. The intrinsic nonideal errors of SRAM-CIM macro are also taken into consideration, and two efficient error correction schemes are proposed, which include calibration of computation voltage linear error (CCVLE) and the mitigation of analog-to-digital quantization error (MAQE). In addition, bit-width flexibility and signed-unsigned reconfigurability are also supported to facilitate the deployment of various convolution-based algorithms. ResNet18, finite impulse response (FIR) filtering, and Gaussian image filtering are deployed into a multimacro SRAM-CIM system. These algorithms serve as deployment representatives of convolutional neural network (CNN), digital signal processing (DSP), and digital image processing (DIP), respectively. The results show that the introduced weight mapping strategies improve the macro utilization by 63.29% and 21.10% for two types of frequently used convolution layers compared to the traditional strategy. Moreover, the proposed error correction schemes achieve similar algorithm accuracy to the floating-point results, and the deployment result of ResNet18 achieves 66.3–70.1% top-1 classification accuracy evaluated on the ImageNet dataset with different throughput tradeoffs.