Lattice-based cryptography relies heavily on the Number Theoretic Transform (NTT), whose performance is dominated by modular multiplication and data movement. This paper proposes BLCIM, the first Radix-16 Booth LUT-based compute-in-memory (CIM) NTT accelerator. We propose an algorithm that precomputes partial modular multiplications with fixed rotation factors and uses input Booth-encoded search results. Then, based on the Booth encoding, it decides whether to perform shifting and inversion to simplify modular multiplication. In addition to the proposed sparsity-aware and stage-skipping schemes, the Radix-16 Booth LUT-based algorithm significantly improves NTT performance at low energy cost. By implementing the algorithm on the SRAM-CIM architecture with a lightweight pipeline design, we achieved nearly 100% utilization for the NTT circuit during acceleration. Simulated in 28 nm CMOS technology, the proposed BLCIM achieves only 4.53% latency and 58.87% energy consumption of the latest work.

Recently, memory-augmented neural networks (MANNs) have gained significant attention as a critical solution for few-shot learning (FSL). These networks leverage external memory to store prior knowledge, thereby enhancing classification efficiency. Spin-transfer torque magnetic random access memory (STT-MRAM) is particularly suited for this application due to its compact cell size, excellent data retention, and scalability. In this article, we introduce a STT-MRAM-based near-memory computing (NMC) macro specifically designed for MANNs. Our approach incorporates several key innovations aimed at overcoming challenges in hardware implementation while improving MANN performance as follows: 1) a parallel computing architecture within the NMC to expedite$L1$distance computations; 2) a memory invert coding (MIC) and self-termination write (STW) scheme that reduce write operations and energy consumption, addressing the issues of frequent writes and high write currents during the training phase of MANNs; 3) a dynamic offset-compensation sense amplifier (DOC-SA) and high-throughput switch-capacitor (HTSC) readout scheme to improve read accuracy and throughput, tackling low read margins and limited readout bandwidth; 4) an exploration of MANN architectures validates the reusability of the NMC macro. The optimized matching-networks (MCHnets)-based structure achieves an accuracy exceeding 90% in five-way and eight-way Omniglot classification tasks. Fabricated with a 40-nm CMOS technology, our design achieves classification accuracies of 96.37% for eight-way-five-shot tasks and 93.72% for 16-way-five-shot tasks on the Omniglot dataset utilizing the optimized MCHnet, showcasing an impressive energy efficiency of 6.47 TOPS/W at the basis of 16-bit$L1$distance computing in the classification tasks of MANN.

Memory-augmented neural network (MANN) has gained attention as a pivotal solution for few-shot learning (FSL). Among the candidates for associative memory in MANN accelerators, spin-transfer torque magnetic random-access memory (STT-MRAM) stands out for its compact cell area, long data retention time, and excellent scalability. In this paper, we propose an STT-MRAM near-memory computing (NMC) macro for MANN acceleration. The macro contains following innovations: 1) An array-level parallel computing architecture for L1 distance calculation. 2) A low-area-overhead memory-invert coding technique to reduce write energy consumption. 3) A configurable dynamic offset-compensation sense amplifier (CDOC-SA) to improve classification accuracy. Fabricated in 40nm CMOS process, our macro demonstrates an energy efficiency of 6.47 TOPS/W, achieving the classification accuracy of 98.3% and 93% for 8-way-5-shot tasks and 16-way-5-shot tasks on the Omniglot dataset.

With the development of AI applications, there is a demand for high parallel similarity priority calculation, like in MANNs. TCAM, as a type of memory for high parallel searching work, is suitable to perform the task. However, the CMOS based TCAMs suffer from area overhead, static power consumption and data-loss while power failure. The SOT-MRAM presents a promising alternative for TCAM design due to its nonvolatility, low area overhead and no static power consumption. But, its low on/off ratio results in low sensing margin which limits its processing speed. To address the challenges, we propose a novel TCAM structure with high sensing margin, parallelism and low energy consumption. This work proposes the followings: (1) A novel 6T-2MTJ sot-mram based TCAM structure is proposed. Simulations show it has a 2-3x improvement in sensing margin over other MRAM based ones, 1.37x improvement in searching energy (fJ/bit) over other nonvolatile technologies based ones, and 23% area reduction over other CMOS based ones. (2) A segmented power supply scheme is presented to meet the parallelism need of MANNs which improves the parallelism by 4-8x compared to no segmented one.