This paper presents a 1024-bit self-adaptive memory address decoder based on Dual Mode Logic (DML) design style to allow working in two modes of operation (i.e., dynamic for high-performance and static for energy-saving). The main novelty of this work relies on the design of a controlling mechanism that mixes both of these modes of operation to simultaneously benefit from their inherent advantages. When performance is the primary target, the mixed operating mode is enabled, and the self-adjustment mechanism identifies at run time the logic gates that have to work in the energy-efficient mode (i.e., static mode), while those belonging to the critical path operate in the faster dynamic mode. Moreover, our address decoder can run in the fully static mode for the lowest energy consumption when speed is not a primary concern. A 65 nm CMOS technology was exploited to simulate and compare our solution with other logically equivalent dynamic and static designs. Operated in the mixed mode, the proposed circuit exhibits negligible speed reduction (8.7%) in comparison with a dynamic logic based design while presenting significantly reduced energy consumption (28%). On the contrary, further energy is saved (29%) with respect to conventional logic styles when our design runs in its energy efficient mode.
1 January 2026 in IEEE Journal on Emerging and Selected Topics in Circuits and Systems
Application domains, such as machine learning and big data analytics, impose significant computational challenges to contemporary Von Neumann architectures. To address this issue, logic-in-memory (LiM) has been raised as a promising alternative that targets computing within memory arrays, aimed at alleviating the memory wall, optimizing data transfer, and enabling massive parallelism. Spin-transfer torque magnetic tunnel junction (STT-MTJ) based memory is an emerging memory technology that enables efficient processing using memory. This paper proposes AM5, a novel LiM architecture leveraging MRAM NAND crossbar technology to support in-memory arithmetic operations efficiently. The proposed LiM scheme is designed using a commercial 28nm process node and a Verilog-A-based double-barrier MTJ compact model. Evaluation results show that AM5 consumes about 98 fJ/40.7 fJ/DMTJ per evaluation/write cycle (4.2-4.4 ns/1.9 ns). Additionally, the proposed architecture proposes an in-situ error correction mechanism to mitigate variability, yielding reliable arithmetic operations. These findings show better energy (∼ 6× lower, on average) and competitive latency (∼ 1.3× faster, on average) figures of AM5 compared to other LiM designs based on MTJ-based technology. When used as a LiM unit to perform inference in adder attention Vision Transformer networks, AM5 consumes about one-tenth of the energy required by a processor-centric unit.