RIOT -- A Simple Graphical Chip Assembly Tool

Riot is a simple interactive graphical tool designed to facilitate the assembly of cells into integrated systems. Riot supplies the user with primitive operations of connection -- abutment, routing and stretching -- in an interactive graphic environment. The designer retains full control of the design, including the assignment of positions to instances of cells and the choice of connection mechanism. The computer takes care of the tedious and exacting implementation detail, guaranteeing that connections are made correctly. The powerful connection primitives give the user of Riot the ability to quickly assemble a custom chip from a collection of low-level cells. This document provides a discussion of the motivation for Riot and a description of the Riot chip assembly system, its capabilities and its use

RIOT: a simple graphical assembly tool

Errors in the chip assembly process are harder to find than errors in cell design, since they belong to no specific part of the design, but rather to the assembly as a whole. Assembly errors are more costly than call design errors also, since they often go unnoticed until late in the design cycle. Interactive graphic tools typically require that assembly be done with primitive graphical operations, which are inappropriate far the assembly task. Language-based tools give more powerful assembly operations, but remove the two dimensional view of the chip necessary to visualize many assembly operations. Riot is a simple Interactive graphical tool designed to facilitate the assembly of cells into integrated systems. Riot supplies the user with primitive operations of connection -- abutment, routing and stretching - in an interactive graphic environment. Thus, the designer retains full control of the design, including the assignment of positions to instances of cells and the choice of connection mechanism. The computer takes care of the tedious and exacting implementation detail, guaranteeing that connections are actually made. The powerful connection primitives give the user of Riot the ability to quickly assemble a custom chip from a collection of low-level cells. This document provides a discussion of the motivation for Riot and a description of the Riot chip assembly system, its capabilities and its use

EKKO: an open-source RISC-V soft-core microcontroller

Dissertação de mestrado em Engenharia Eletrónica Industrial e Computadores (especialização em Sistemas Embebidos e Computadores)Com o surgimento da Internet das Coisas (IoT em inglês) nos últimos anos, o número de “coisas” conectadas está a crescer a um ritmo bastante rápido. Estes dispositivos tornaram-se rapidamente parte do nosso dia a dia e já podem ser encontrados nos mais diversos domínios de aplicação, tais como, telecomunicações, saúde, agricultura, e automação industrial. Devido a este crescimento exponencial, a demanda por sistemas embebidos é cada vez maior, trazendo assim diversos desafios no seu desenvolvimento. De todos os desafios, o time-to-market e os custos de desenvolvimento são de inegável importância, logo, a escolha de uma plataforma de desenvolvimento adequada é essencial no desenho destes sistemas. Devido a este novo paradigma, o grupo de investigação da Universidade do Minho onde esta dissertação se insere tem desenvolvido aplicações neste domínio. No entanto, as atuais plataformas de desenvolvimento utilizadas são complexas, têm custos associados e são de código fechado. Por estas razões, o grupo de investigação tem interesse em ter a sua própria plataforma de desenvolvimento. De modo a solucionar os problemas enumerados acima, esta dissertação tem como objetivo desenvolver uma plataforma de desenvolvimento tanto para hardware como para software. A plataforma deve ser simples de utilizar e open-source, reduzindo assim os custos e a tornando a gestão de licenças mais simples. Para além disto, o facto de o sistema ser de código aberto faz também com que este possa ser facilmente estendido e customizado de acordo com os requisitos da aplicação. Neste sentido, esta dissertação apresenta um soft-core microcontroller, o qual contem um processador RISC-V, uma RAM, uma unidade de depuração, um temporizador, um periférico I2C e um barra mento AXI. Em adição, este contem também um kit de desenvolvimento de software (SDK em inglês), o qual inclui um depurador, a opção de utilizar o sistema operativo Azure RTOS ThreadX, e outras ferramentas importantes, tornando o ciclo de desenvolvimento mais fácil, rápido e seguro.With the advent of the Internet of Things (IoT) in most recent years, the number of connected “things” is increasing quickly. These devices rapidly became part of our daily lives and can be found in the most different applications domains, such as telecommunications, health care, agriculture and industrial automation. With this exponential growth, the demand for embedded devices is increasing, bringing several challenges to the development of these systems. From these challenges, the time-to-market and development costs are undeniable extremely important. Thus, choosing a suitable development platform is essential when designing an embedded system. Due to this new paradigm, the University of Minho research group where this dissertation fits has been developing applications in this domain. However, the current development platforms are complex, have associated costs and are closed-source. For these reasons, the research group has interesting in having its development platform. To solve these problems, this dissertation aims to build a development platform for both hardware and software. The platform must be simple and open-source, reducing development costs and simplifying license management. Besides, due to its open nature, it will also be easier to extend and modify the system according to the application’s needs. In this context, this dissertation presents EKKO, an open-source soft-core microcontroller that contains a RISC-V core, an on-chip RAM, a debug unit, a timer and an I2C peripheral, and an AXI bus. In addition, it also contains a Software Development Kit (SDK), which includes a debugger, the option to use Azure RTOS ThreadX, and other crucial tools, turning the development cycle more accessible, faster and safer

Computational Methods In Flip Chip Assembly.

Flip chip technology, in the book edited by Lau (Lau, 1995) is defined as placing a chip to the substrate by flipping over the chip so that the I/O area of the chip is facing the substrate. By flipping over the chip, the interconnection between the chip and the substrate are achieved by conductive "bumps" placed directly in between the die surface and the substrate. Therefore, the whole chip surface can be utilized for active interconnections and at the same time, eliminates the need for wire bonding

Amulet: An Energy-Efficient, Multi-Application Wearable Platform

Wearable technology enables a range of exciting new applications in health, commerce, and beyond. For many important applications, wearables must have battery life measured in weeks or months, not hours and days as in most current devices. Our vision of wearable platforms aims for long battery life but with the flexibility and security to support multiple applications. To achieve long battery life with a workload comprising apps from multiple developers, these platforms must have robust mechanisms for app isolation and developer tools for optimizing resource usage.\r\n\r\nWe introduce the Amulet Platform for constrained wearable devices, which includes an ultra-low-power hardware architecture and a companion software framework, including a highly efficient event-driven programming model, low-power operating system, and developer tools for profiling ultra-low-power applications at compile time. We present the design and evaluation of our prototype Amulet hardware and software, and show how the framework enables developers to write energy-efficient applications. Our prototype has battery lifetime lasting weeks or even months, depending on the application, and our interactive resource-profiling tool predicts battery lifetime within 6-10% of the measured lifetime

Energy-aware Gossip Protocol for Wireless Sensor Networks

Dissertação de mestrado em Engenharia InformáticaIn Wireless Sensor Networks (WSNs), typically composed of nodes with resource constraints, leveraging efficient processes is crucial to enhance the network longevity and consequently the sustainability in ultra-dense and heterogeneous environments, such as smart cities. Epidemic algorithms are usually efficient in delivering packets to a sink or to all it’s peers but have poor energy efficiency due to the amount of packet redundancy. Directional algorithms, such as Minimum Cost Forward Algorithm (MCFA) or Directed Diffusion, yield high energy efficiency but fail to handle mobile environments, and have poor network coverage. This work proposes a new epidemic algorithm that uses the current energy state of the network to create a topology that is cyclically updated, fault tolerant, whilst being able to handle the challenges of a static or mobile heterogeneous network. Depending on the application, tuning in the protocol settings can be made to prioritise desired characteristics. The proposed protocol has a small computational footprint and the required memory is proportional not to the size of the network, but to the number of neighbours of a node, enabling high scalability. The proposed protocol was tested, using a ESP8266 as an energy model reference, in a simulated environment with ad-hoc wireless nodes. It was implemented at the application level with UDP sockets, and resulted in a highly energy efficient protocol, capable of leveraging extended network longevity with different static or mobile topologies, with results comparable to a static directional algorithm in delivery efficiency.Em Redes de Sensores sem Fios (RSF), tipicamente compostas por nós com recursos lim-itados, alavancar processos eficientes é crucial para aumentar o tempo de vida da rede e consequentemente a sustentabilidade em ambientes heterogéneos e ultra densos, como cidades inteligentes por exemplo. Algoritmos epidêmicos são geralmente eficientes em en-tregar pacotes para um sink ou para todos os nós da rede, no entanto têm baixa eficiência energética devido a alta taxa de duplicação de pacotes. Algoritmos direcionais, como o MCFA ou de Difusão Direta, rendem alta eficiência energética mas não conseguem lidar com ambientes móveis, e alcançam baixa cobertura da rede. Este trabalho propõe um novo protocolo epidêmico que faz uso do estado energético atual da rede para criar uma topologia que por sua vez atualizada ciclicamente, tolerante a falhas, ao mesmo tempo que é capaz de lidar com os desafios de uma rede heterogênea estática ou móvel. A depender da aplicação, ajustes podem ser feitos às configurações do protocolo para que o mesmo priorize determinadas características. O protocolo proposto tem um pequeno impacto computacional e a memória requerida é proporcional somente à quantidade de vizinhos do nó, não ao tamanho da rede inteira, permitindo assim alta escalabilidade. O algoritmo proposto foi testado fazendo uso do modelo energético de uma ESP8266, em um ambiente simulado com uma rede sem fios ad-hoc. Foi implementado à nível aplicacional com sockets UDP, e resultou em um protocol energeticamente eficiente, capaz de disponibilizar alta longevidade da rede mesmo com diferentes topologias estáticas ou móveis com resultados comparáveis à um protocolo direcional em termos de eficiência na entrega de pacotes

Index to 1981 NASA Tech Briefs, volume 6, numbers 1-4

Short announcements of new technology derived from the R&D activities of NASA are presented. These briefs emphasize information considered likely to be transferrable across industrial, regional, or disciplinary lines and are issued to encourage commercial application. This index for 1981 Tech Briefs contains abstracts and four indexes: subject, personal author, originating center, and Tech Brief Number. The following areas are covered: electronic components and circuits, electronic systems, physical sciences, materials, life sciences, mechanics, machinery, fabrication technology, and mathematics and information sciences

Wireless Sensors for Health Monitoring of Marine Structures and Machinery

Remote structural and machinery health monitoring (SMHM) of marine structures such as ships, oil and gas rigs, freight container terminals, and marine energy platforms can ensure their reliability. However, the wired sensors currently used in these applications are difficult and expensive to install and maintain. Wireless Sensor Networks (WSN) can potentially replace them but there are significant capability gaps that currently prevent their long-term deployment in the harsh marine environment and the structurally-complex, compartmentalised, all-metal scenarios with high volume occupancy of piping, ducting and operational machinery represented by marine structures. These gaps are in sensing, processing and communication hardware and firmware capabilities, reduction of power consumption, hardware assembly and packaging for reliability in the marine environment, reliability of wireless connectivity in the complex metal structures, and software for WSN deployment planning in the marine environment. Taken together, these gaps highlight the need for a systems integration methodology for marine SMHM and this is the focus of the research presented in this thesis. The research takes an applied approach by first designing the hardware and firmware for two wireless sensing modules specifically for marine SMHM, one a novel eddy-current-based 3D module for measuring multi-axis metal structural displacement, the second a fully integrated module for monitoring of structure and machinery reliability. The research then addresses module assembly and packaging methods to ensure reliability in the marine environment, the development of an efficient methodology for characterising the reliability of wireless connectivity in complex metal structures, and development of user interface software for planning WSN deployment and for managing the collection of WSN data. These are then individually and collectively characterised and tested for performance and reliability in laboratory, land-based and marine deployments. In addition to the research outcomes in each of these individual aspects, the overall research outcome represents a systems integration methodology that now allows deployment, with a high expectation of reliability of marine SMHM WSNs