Design techniques for low-power systems

Portable products are being used increasingly. Because these systems are battery powered, reducing power consumption is vital. In this report we give the properties of low-power design and techniques to exploit them on the architecture of the system. We focus on: minimizing capacitance, avoiding unnecessary and wasteful activity, and reducing voltage and frequency. We review energy reduction techniques in the architecture and design of a hand-held computer and the wireless communication system including error control, system decomposition, communication and MAC protocols, and low-power short range networks

Engineering study for a mass memory system for advanced spacecrafts Final report, 1 Dec. 1969 - 1 Jul. 1970

Mass memory system for advanced spacecraf

COHERENT/INCOHERENT MAGNETIZATION DYNAMICS OF NANOMAGNETIC DEVICES FOR ULTRA-LOW ENERGY COMPUTING

Nanomagnetic computing devices are inherently nonvolatile and show unique transfer characteristics while their switching energy requirements are on par, if not better than state of the art CMOS based devices. These characteristics make them very attractive for both Boolean and non-Boolean computing applications. Among different strategies employed to switch nanomagnetic computing devices e.g. magnetic field, spin transfer torque, spin orbit torque etc., strain induced switching has been shown to be among the most energy efficient. Strain switched nanomagnetic devices are also amenable for non-Boolean computing applications. Such strain mediated magnetization switching, termed here as “Straintronics”, is implemented by switching the magnetization of the magnetic layer of a magnetostrictive-piezoelectric nanoscale heterostructure by applying an electric field in the underlying piezoelectric layer. The modes of “straintronic” switching: coherent vs. incoherent switching of spins can affect device performance such as speed, energy dissipation and switching error in such devices. There was relatively little research performed on understanding the switching mechanism (coherent vs. incoherent) in xiv straintronic devices and their adaptation for non-Boolean computing, both of which have been studied in this thesis. Detailed studies of the effects of nanomagnet geometry and size on the coherence of the switching process and ultimately device performance of such strain switched nanomagnetic devices have been performed. These studies also contributed in optimizing designs for low energy, low dynamic error operation of straintronic logic devices and identified avenues for further research. A Novel non-Boolean “straintronic” computing device (Ternary Content Addressable Memory, abbreviated as TCAM) has been proposed and evaluated through numerical simulations. This device showed significant improvement over existing CMOS device based TCAM implementation in terms of scaling, energy-delay product, operational simplicity etc. The experimental part of this thesis answered a very fundamental question in strain induced magnetization rotation. Specifically, this experiment studied the variation in magnetization orientation for strain induced magnetization rotation along the thickness of a magnetostrictive thin film using polarized neutron reflectometry and demonstrated non-uniform magnetization rotation along the thickness of the sample. Additional experimental work was performed to lay the groundwork for ultra-low voltage straintronic switching demonstration. Preliminary sample fabrication and characterization that can potentially lead to low voltage (~10-100 mV) operation and local clocking of such devices has been performed