A Fully Functional 64 Mb DDR3 ST-MRAM Built on 90 nm CMOS Technology

DRAM consumes a significant amount of energy in mobile computing devices today. Emerging non-volatile memory such as magnetoresistive memory (MRAM) offers a DRAM alternative and can potentially lead to a more energy-efficient memory system. The MRAM technology is already mature, but considering the memory industry is highly standardized, we are still unable to see any MRAM used in mainstream products. To tackle this problem, we design an LPDDRx-compatible MRAM interface by considering both MRAM pros and cons. Our design solves the pincompatibility and the performance issues caused by MRAM small page size, and it optimizes the interface protocol by leveraging the MRAM unique feature of non-destructive reads. Combining our techniques, we boost the MRAM performance by 14% and provide a DRAM-swappable MRAM solution with 20% less energy.

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“…Compared to DRAM, MRAM is non-volatile and consumes zero standby power [6,13,22,27]. Figure 1 illustrates the basic concept of MRAM.…”

Section: Mram Technologymentioning

confidence: 99%

“…This compatibility is not only highly required for a successful MRAM early adoption, but also critical for enabling a tiered memory system using refresh-free MRAM and high-performance DRAM [10,20]. Everspin's effort [22] to produce a DDR3-compatible MRAM is another example of this.…”

Section: Introductionmentioning

confidence: 99%

Enabling high-performance LPDDRx-compatible MRAM

Wang

Dong

Xie

2014

Proceedings of the 2014 International Symposium on Low Power Electronics and Design

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“…The fundamental physics behind STT is that when applying a current through a magnetic layer, the spins of electrons that constitute the current will be aligned to the magnetization orientation, which is known as spin-polarization, and these spins can be repolarized if such a spin-polarized current is directed into another magnet. During the repolarization process, the magnetic layer is subjected to a torque that can stimulate spin-wave excitations or flip the magnetization direction of the magnetic layer at sufficiently high current density [59]. According to this mechanism, the STT based magnetic tunnelling junction (MTJ) can be switched between a LRS and a HRS using the spin-polarized current induced between two ferromagnetic layers.…”

Section: Spintronic Memristormentioning

confidence: 99%

Overview of emerging memristor families from resistive memristor to spintronic memristor

Wang

Yang

Wen

et al. 2015

J Mater Sci: Mater Electron

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Memristor is a fundamental circuit element in addition to resistor, capacitor, and inductor. As it can remember its resistance state even encountering a power off, memristor has recently received widespread applications from non-volatile memory to neural networks. The current memristor family mainly comprises resistive memristor, polymeric memristor, ferroelectric memristor, manganite memristor, resonant-tunneling diode memristor, and spintronic memristor in terms of the materials the device is made of. In order to help researcher better understand the physical principles of the memristor, and thus to provide a promising prospect for memristor devices, this paper presents an overview of memristor materials properties, switching mechanisms, and potential applications. The performance comparison among different memristor members is also given.

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“…Since their discovery by Jullière, 1 magnetic tunnel junctions (MTJ) have attracted considerable interest due to the multitude of applications as sensors, 2 read heads in hard disc drives, [3][4][5][6][7] and, in particular, their use in magnetoresistive random-access memory (MRAM). 4,[8][9][10] MRAM has the potential to become the preferred memory technology of the future, due to the outstanding technical performance, such as high speed, high density, non-volatility, reliability, and very low power consumption. 4,9,11 Traditionally, a MTJ consists of two ferromagnetic layers separated by a thin tunnel barrier layer; often one ferromagnetic layer is pinned while the other is "free," i.e., has a much lower switching magnetic field.…”

mentioning

confidence: 99%

Characterization of magnetic tunnel junction test pads

Østerberg

Kjær

Nielsen³

et al. 2015

Journal of Applied Physics

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We show experimentally as well as theoretically that patterned magnetic tunnel junctions can be characterized using the current-in-plane tunneling (CIPT) method, and the key parameters, the resistance-area product (RA) and the tunnel magnetoresistance (TMR), can be determined. The CIPT method relies on four-point probe measurements performed with a range of different probe pitches and was originally developed for infinite samples. Using the method of images, we derive a modified CIPT model, which compensates for the insulating boundaries of a finite rectangular sample geometry. We measure on square tunnel junction pads with varying sizes and analyze the measured data using both the original and the modified CIPT model. Thus, we determine in which sample size range the modified CIPT model is needed to ensure validity of the extracted sample parameters, RA and TMR. In addition, measurements as a function of position on a square tunnel junction pad are used to investigate the sensitivity of the measurement results to probe misalignment.

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A Fully Functional 64 Mb DDR3 ST-MRAM Built on 90 nm CMOS Technology

Cited by 128 publications

References 15 publications

Enabling high-performance LPDDRx-compatible MRAM

Enabling high-performance LPDDRx-compatible MRAM

Overview of emerging memristor families from resistive memristor to spintronic memristor

Characterization of magnetic tunnel junction test pads

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