Design and analysis of SRAMs for energy harvesting systems

PhD ThesisAt present, the battery is employed as a power source for wide varieties of microelectronic systems ranging from biomedical implants and sensor net-works to portable devices. However, the battery has several limitations and incurs many challenges for the majority of these systems. For instance, the design considerations of implantable devices concern about the battery from two aspects, the toxic materials it contains and its lifetime since replacing the battery means a surgical operation. Another challenge appears in wire-less sensor networks, where hundreds or thousands of nodes are scattered around the monitored environment and the battery of each node should be maintained and replaced regularly, nonetheless, the batteries in these nodes do not all run out at the same time. Since the introduction of portable systems, the area of low power designs has witnessed extensive research, driven by the industrial needs, towards the aim of extending the lives of batteries. Coincidentally, the continuing innovations in the field of micro-generators made their outputs in the same range of several portable applications. This overlap creates a clear oppor-tunity to develop new generations of electronic systems that can be powered, or at least augmented, by energy harvesters. Such self-powered systems benefit applications where maintaining and replacing batteries are impossi-ble, inconvenient, costly, or hazardous, in addition to decreasing the adverse effects the battery has on the environment. The main goal of this research study is to investigate energy harvesting aware design techniques for computational logic in order to enable the capa- II bility of working under non-deterministic energy sources. As a case study, the research concentrates on a vital part of all computational loads, SRAM, which occupies more than 90% of the chip area according to the ITRS re-ports. Essentially, this research conducted experiments to find out the design met-ric of an SRAM that is the most vulnerable to unpredictable energy sources, which has been confirmed to be the timing. Accordingly, the study proposed a truly self-timed SRAM that is realized based on complete handshaking protocols in the 6T bit-cell regulated by a fully Speed Independent (SI) tim-ing circuitry. The study proved the functionality of the proposed design in real silicon. Finally, the project enhanced other performance metrics of the self-timed SRAM concentrating on the bit-line length and the minimum operational voltage by employing several additional design techniques.Umm Al-Qura University, the Ministry of Higher Education in the Kingdom of Saudi Arabia, and the Saudi Cultural Burea

D2.1 - Report on Selected TRNG and PUF Principles

This report represents the final version of Deliverable 2.1 of the HECTOR work package WP2. It is a result of discussions and work on Task 2.1 of all HECTOR partners involved in WP2. The aim of the Deliverable 2.1 is to select principles of random number generators (RNGs) and physical unclonable functions (PUFs) that fulfill strict technology, design and security criteria. For example, the selected RNGs must be suitable for implementation in logic devices according to the German AIS20/31 standard. Correspondingly, the selected PUFs must be suitable for applying similar security approach. A standard PUF evaluation approach does not exist, yet, but it should be proposed in the framework of the project. Selected RNGs and PUFs should be then thoroughly evaluated from the point of view of security and the most suitable principles should be implemented in logic devices, such as Field Programmable Logic Arrays (FPGAs) and Application Specific Integrated Circuits (ASICs) during the next phases of the project

Power delivery mechanisms for asynchronous loads in energy harvesting systems

PhD ThesisFor systems depending on methods, a fundamental contradiction in the power delivery chain has existed between conventional to supply it. DC/DC conversion (e.g.) has therefore been an integral part of such systems to resolve this contradiction. be made tolerant to a much wider range of Vdd variance. This may open up opportunities for much more energy efficient methods of power delivery. performance of different power delivery mechanisms driving both asynchronous and synchronous loads directly from a harvester source bypassing bulky energy method, which employs a energy from a EH circuit depending on load and source conditions, is developed. through comprehensive comparative analysis. Based on the novel CBB power delivery method, an asynchronous controller is circuits to work with tasks. The successful asynchronous control design drives a case study that is meant to explore relations between power path and task path. To deal with different tasks with variable harvested power, systems may have a range of operation conditions and thus dynamically call for CBB or SCC type power set of capacitors to form CBB or SCC is implemented with economic system size. This work presents an unconventional way of designing a compact-size, quick- circuit overcome large voltage variation in EH systems and implement smart power management for harsh EH environment. The power delivery mechanisms (SCC, employed to help asynchronous- logic-based chip testing and micro-scale EH system demonstrations

A 3.4pJ FeRAM-enabled D flip-flop in 0.13µm CMOS for nonvolatile processing in digital systems

Nonvolatile processing-continuously operating a digital circuit and retaining state through frequent power interruptions-creates new applications for portable electronics operating from harvested energy and high-performance systems managing power by operating “normally off”. To enable these scenarios, energy processing must happen in parallel with information processing. This work makes the following contributions: 1) the design of a nonvolatile D flip-flop (NVDFF) with embedded ferroelectric capacitors (fecaps) that senses data robustly and avoids race conditions; 2) the integration of the NVDFF into the ASIC design flow with a power management unit (PMU) and a simple one-bit interface to brown-out detection circuitry; and 3) a characterization of the NVDFF statistical signal margin and the energy cost of retaining data.Focus Center Research Program. Focus Center for Circuit & System Solution

A 3.4pJ FeRAM-enabled D flip-flop in 0.13µm CMOS for nonvolatile processing in digital systems

Nonvolatile processing-continuously operating a digital circuit and retaining state through frequent power interruptions-creates new applications for portable electronics operating from harvested energy and high-performance systems managing power by operating “normally off”. To enable these scenarios, energy processing must happen in parallel with information processing. This work makes the following contributions: 1) the design of a nonvolatile D flip-flop (NVDFF) with embedded ferroelectric capacitors (fecaps) that senses data robustly and avoids race conditions; 2) the integration of the NVDFF into the ASIC design flow with a power management unit (PMU) and a simple one-bit interface to brown-out detection circuitry; and 3) a characterization of the NVDFF statistical signal margin and the energy cost of retaining data.Focus Center Research Program. Focus Center for Circuit & System Solution

AMANDA : an autonomous self-powered miniaturized smart sensing embedded system

​© 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.This paper introduces an Autonomous Smart Sensing Card (ASSC), an embedded system that will be powered indoors and outdoors by harvested energy, have miniaturized dimensions and serve multi-sensorial IoT applications for smart living and working environments. It will consist of a combination of newly developed and optimized off-the-shelf or close-tocommercialization technologies such as PV harvesters, energy storage and power management units, MCUs and sensors, all packed with a form factor under 3mm in thickness. The system will introduce technical breakthroughs that will boost further miniaturization, a small footprint, ultra-low power consumption as well as short- and long-range communications

Voltage, throughput, power, reliability, and multicore scaling

This article studies the interplay between the performance, energy, and reliability (PER) of parallel-computing systems. It describes methods supporting the meaningful cross-platform analysis of this interplay. These methods lead to the PER software tool, which helps designers analyze, compare, and explore these properties

Interconnect and Memory Design for Intelligent Mobile System

Technology scaling has driven the transistor to a smaller area, higher performance and lower power consuming which leads us into the mobile and edge computing era. However, the benefits of technology scaling are diminishing today, as the wire delay and energy scales far behind that of the logics, which makes communication more expensive than computation. Moreover, emerging data centric algorithms like deep learning have a growing demand on SRAM capacity and bandwidth. High access energy and huge leakage of the large on-chip SRAM have become the main limiter of realizing an energy efficient low power smart sensor platform. This thesis presents several architecture and circuit solutions to enable intelligent mobile systems, including voltage scalable interconnect scheme, Compute-In-Memory (CIM), low power memory system from edge deep learning processor and an ultra-low leakage stacked voltage domain SRAM for low power smart image signal processor (ISP). Four prototypes are implemented for demonstration and verification. The first two seek the solutions to the slow and high energy global on-chip interconnect: the first prototype proposes a reconfigurable self-timed regenerator based global interconnect scheme to achieve higher performance and energy-efficiency in wide voltage range, while the second one presents a non Von Neumann architecture, a hybrid in-/near-memory Compute SRAM (CRAM), to address the locality issue. The next two works focus on low-power low-leakage SRAM design for Intelligent sensors. The third prototype is a low power memory design for a deep learning processor with 270KB custom SRAM and Non-Uniform Memory Access architecture. The fourth prototype is an ultra-low leakage SRAM for motion-triggered low power smart imager sensor system with voltage domain stacking and a novel array swapping mechanism. The work presented in this dissertation exploits various optimizations in both architecture level (exploiting temporal and spatial locality) and circuit customization to overcome the main challenges in making extremely energy-efficient battery-powered intelligent mobile devices. The impact of the work is significant in the era of Internet-of-Things (IoT) and the age of AI when the mobile computing systems get ubiquitous, intelligent and longer battery life, powered by these proposed solutions.PHDElectrical and Computer EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttps://deepblue.lib.umich.edu/bitstream/2027.42/155232/1/jiwang_1.pd

ULTRALOW-POWER, LOW-VOLTAGE DIGITAL CIRCUITS FOR BIOMEDICAL SENSOR NODES

Ph.DDOCTOR OF PHILOSOPH

Wireless Sensor Network Based Monitoring System For Forest

Wildlife prevention has become an important practice due to negative effects of human activities such as cutting of trees on large scale and unregulated hunting which causes major threat to wildlife. So we are going to introduce the project on prevention of trees and wildlife in forest. This article presents the design of a system for detection of vibration for prevention of cutting of trees, detection of temperature for prevention of forest fires also detection of pulses of animal for prevention wildlife using wireless sensor networks to prevent a disaster (forest) that could lead to loss of a significant number of natural resources. In this project, The sensing device can sense the vibration, pulse, and temperature, and then sent them over zig-bee networks to forest office. To save the transmission cost, we also sent the GPS location information simultaneously. Here we use Wireless Sensor Networks (WSNs).In this network numerous sensors are usually deployed on remote places, the deployment and maintenance must be easy and scalable. Wireless sensor network is the network which consists of large number of small nodes. Sensor nodes are great for deployment in hostile environments or over large geographical areas. DOI: 10.17762/ijritcc2321-8169.150318