In this work, we propose SEE-MCAM, scalable and compact multi-bit CAM (MCAM) designs that utilize the three-terminal ferroelectric FET (FeFET) as the proxy. By exploiting the multi-level-cell characteristics of FeFETs, our proposed SEE-MCAM designs enable multi-bit associative search functions and achieve better energy efficiency and performance than existing FeFET-based CAM designs. We validated the functionality of our proposed designs by achieving 3 bits per cell CAM functionality, resulting in 3x improvement in storage density. The area per bit of the proposed SEE-MCAM cell is 8% of the conventional CMOS CAM. We thoroughly investigated the scalability and robustness of the proposed design. Evaluation results suggest that the proposed 2FeFET-1T SEE-MCAM achieves 9.8x more energy efficiency and 1.6x less search latency compared to the CMOS CAM, respectively. When compared to existing MCAM designs, the proposed SEE-MCAM can achieve 8.7x and 4.9x more energy efficiency than ReRAM-based and FeFET-based MCAMs, respectively. Benchmarking results show that our approach provides up to 3 orders of magnitude improvement in speedup and energy efficiency over a GPU implementation in accelerating a novel quantized hyperdimensional computing (HDC) application.

翻译：本文提出SEE-MCAM，一种利用三端铁电场效应管（FeFET）实现的可扩展紧凑型多位CAM（MCAM）设计。通过利用FeFET的多级单元特性，所提出的SEE-MCAM设计实现了多位关联搜索功能，并在能效和性能上优于现有基于FeFET的CAM设计。我们通过实现每单元3位CAM功能验证了所提设计的可行性，存储密度提升3倍。所提SEE-MCAM单元的每比特面积仅为传统CMOS CAM的8%。本文深入研究了该设计的可扩展性与鲁棒性。评估结果表明，与CMOS CAM相比，所提出的2FeFET-1T SEE-MCAM能效提升9.8倍，搜索延迟降低1.6倍。与现有MCAM设计相比，SEE-MCAM的能效较基于ReRAM和FeFET的MCAM分别提升8.7倍和4.9倍。基准测试显示，在加速新型量化超维计算（HDC）应用时，本方法相较于GPU实现的加速比和能效提升高达三个数量级。