Nonvolatile Magnetic Flip-Flop for standby-power-free SoCs

Abstract

A nonvolatile Magnetic Flip-Flop (MFF) primitive cell for SoC design libraries has been developed using a unique MRAM process. It has high design compatibility with conventional CMOS LSI designs. MFF maximum frequency was estimated to be 3.5 GHz, which is comparable to that of a normal CMOS DFF. An MFF test chip was fabricated with the process. The chip's functional performance was sufficiently high to demonstrate the potential of MFFs, which helps to reduce the power dissipation of SoCs dramatically.

Energy/Reliability Trade-Offs in Low-Voltage ReRAM-Based Non-Volatile Flip-Flop Design

“…3(a). A similar circuit topology has been used in [17], which, however, used magnetic memory devices. In this baseline NVFF, the two ReRAM devices are always used in a complementary fashion, i.e., one device is programmed to the HRS, while the other one is programmed to the LRS.…”

A ReRAM-based non-volatile flip-flop with sub-V<inf>T</inf> read and CMOS voltage-compatible write

“…2 in blue color. In order to add non-volatility to this basic CMOS flipflop, two ReRAM devices are inserted in the current sink of the cross-coupled inverter pair in the slave latch [13]. These ReRAM devices are used in a complementary way, i.e., one device is programmed to the HRS, while the other one is programmed to the LRS.…”

High Performance SoC Design Using Magnetic Logic and Memory

“…A non-volatile configuration point of MLUTs consists of an SRAM based Sense Amplifier (SA) associated with a couple of complementary MTJs [29]. FPGA circuits can be configured instantaneously and the high-speed SA ensures nearly the same speed as SRAM-LUT [19][20][21][22][23][24]. Thanks to the small cell area and 3D integration of MRAM, multi-context can be easily implemented, allowing dynamical and run-time reconfiguration methods [26,29,37].…”

“…In 2008, NEC presented the first prototype based on 0.15μm hybrid process and high performance up to 3.5 GHz was shown. MFF is expected to make low standby power for electrical appliances like LCD TV, PC and portable devices in the next years [23]. MFF is the key element to build non-volatile logic circuits and allows true instant on/off and zero standby power [29].…”

“…(a) 2D structure of CMOS logic (b) 3D structure of MRAM logic, the distance between logic and memory can be greatly reduced and then accelerate the computing speed MRAM based logic circuits (magnetic logic) were initiated in 2000 [18] and considered as a potential computing paradigm featuring high performances in terms of power, speed and area. Numerous academic and industry research groups joined this field since 2006 [19][20][21][22] and some Magnetic logic circuits have been presented and successfully prototyped, such as Magnetic Look-Up- Table (MLUT), Magnetic Flip-Flop (MFF) and embedded MRAM (eMRAM) as different levels of cache memory [15,23,24]. In this chapter, we describe an overview of the magnetic logic circuits and discuss their potential applications from both the physics and architecture points of view.…”