In-memory processing can dramatically improve the latency and energy consumption of computing systems by minimizing the data transfer between the memory and the processor. Efficient execution of processing operations within the memory is therefore a highly motivated objective in modern computer architecture. This paper presents a novel automatic framework for efficient implementation of arbitrary combinational logic functions within a memristive memory. Using tools from logic design, graph theory and compiler register allocation technology, we developed SIMPLER (Synthesis and In-memory MaPping of Logic Execution in a single Row), a tool that optimizes the execution of in-memory logic operations in terms of throughput and area. Given a logical function, SIMPLER automatically generates a sequence of atomic Memristor-Aided loGIC (MAGIC) NOR operations and efficiently locates them within a single size-limited memory row, reusing cells to save area when needed. This approach fully exploits the parallelism offered by the MAGIC NOR gates. It allows multiple instances of the logic function to be performed concurrently, each compressed into a single row of the memory. This virtue makes SIMPLER an attractive candidate for designing in-memory Single Instruction, Multiple Data (SIMD) operations. Compared to previous work (that optimizes latency rather than throughput for a single function), SIMPLER achieves an average throughput improvement of 435×. When previous tools are parallelized similarly to SIMPLER, SIMPLER achieves higher throughput of at least 5×, with 23× improvement in area and 20× improvement in area efficiency. These improvements more than fully compensate for the increase (up to 17% on average) in latency.

Memristor-aided logic (MAGIC) is a technique for performing in-memory computing using memristive devices. The design of a MAGIC NOR gate has been described in detail, and it serves as the basic building block for several processing-in-memory architectures. However, the input stability of the MAGIC NOR gate forces a limitation on the threshold voltages: the magnitude of the set voltage must be higher than the magnitude of the reset voltage. Unfortunately, many of the current leading resistive switching technologies, particularly, valence change memory (VCM), have the opposite ratio between the threshold voltages. In this article, we experimentally demonstrate the undesirable effects of input instability. Furthermore, we introduce three new MAGIC gates for devices with low set-to-reset voltage ratios and experimentally demonstrate their robust operation using Pt/Ta ₂ O ₅ /W/Pt devices. The three gates, combined with constant values, are functionally complete and are demonstrated as building blocks for in-memory logic on VCM devices.

High-performance radio frequency (RF) switches play a critical role in allowing radio transceivers to provide access to shared resources such as antennas. They are important, especially in reconfigurable radios, where the connections within and between the different blocks (e.g., filters, amplifiers, and mixers) can be changed to customize and compose RF functions for distinct frequency bands. To realize this potential, new concepts for RF switch devices that can be integrated with standard transistor process, while providing better transmission performance, lower power consumption, smaller area, and lower actuation voltage than current RF switch technologies [e.g., field-effect transistors (FETs) and microelectromechanical systems (MEMSs)] are needed. Recently, RF switches based on emerging memory technologies, such as conductive-bridge RAM (CBRAM), resistive RAM (ReRAM), and phase-change memory (PCM), have been proposed. These nanoscale switches present major advantages, for example, high cutoff frequency, nonvolatility, fast and low-energy switching, small footprint, and compatibility with back-end-of-line (BEOL) of the standard CMOS process, thus placing them as possible contenders for high-performance RF switches. This article surveys high-performance RF switches based on resistive memories, comparing them with mature RF switching technologies like RF MEMS, p-i-n diodes, and FETs. We discuss the physical mechanisms, device structure, performance characteristics, and applications of these novel RF switches. Furthermore, we examine the prospects and future research directions of these technologies that could lead to their adoption at the industrial level.