Restoring Reliability in Fault Tolerant Reconfigurable Systems

The new generations of SRAM-based FPGAdevices, built on nanometer technology, are thepreferred choice for the implementation ofreconfigurable computing platforms. However,smaller technological scales increase theirvulnerability to manufacturing imperfections andhence to the occurrence of electromigration.Moreover, the large internal RAM (for configurationpurposes or as embedded memory blocks) makesthem more prone to soft errors.The incorporation of self-reconfigurationcapabilities in recent FPGAs, allied to the use of softand hard microprocessor cores, facilitates the offsetof these vulnerabilities by enabling the developmentof self-restoring fault tolerant reconfigurablesystems. In the methodology presented in this paper,the embedded microprocessor is also responsible forthe implementation of online self-test-and-repairstrategies, based on modular redundancy and onself-reconfiguration. The detection of faults, causedby soft or hard errors, may be followed by repairingactions, depending on the fault type. This approachleads to smoother system degradation, extending itslifetime and improving its reliability

Robust configurable system design with built-in self-healing

The new generations of SRAM-based FPGA (Field Programmable Gate Array) devices, built on nanometre technology, are the preferred choice for the implementation of reconfigurable computing platforms. However, their vulnerability to hard and soft errors is a major weakness to robust system design based on FPGAs. In this paper, a novel Built-In Self-Healing (BISH) methodology, based on modular redundancy and on selfreconfiguration, is proposed. A soft microprocessor core implemented in the FPGA is responsible for the management and execution of all the BISH procedures. Fault detection and diagnosis is followed by repairing actions, taking advantage of the self-configuration features. Meanwhile, modular redundancy assures that the system still works correctly. This approach leads to a robust system design able to assure high reliability, availability and data integrity

EOLES Course – Five Years of Remote Learning and Experimenting

The EOLES (Electronics and Optics e-Learning for Embedded Systems) course consists of a 3rd year Bachelor degree that relies exclusively on e-learning and remote laboratories, developed as the result of an EU funded ERASMUS+ project, involving 15 institutions from four European and three North African countries and concluded in 2015. This paper presents an overview and overall results for this initial period and a more detailed analysis of the Digital Systems Teaching Unit contents, pedagogical approach, grading methodology and results. The focus is on the unit specific characteristics and features, student and teacher experiences and the methodologies that were applied to enhance learning success. The Teaching Unit expositive material is provided as the student progresses, with progressive unlocking of content depending timeline and automatic quizzes results. Grading is divided between weekly assignments, an online exam at the end of each TU and a final exam at the end of the academic year. In short, students are allowed and encouraged to adjust their learning rhythm within the limits allowed by time restraints and evaluation criteria. The developed course was accredited as a specialization year in most partner institutions and has been running non-stop since then, mainly with students from North African institutions. Although no longer supported by an EU project, the course is a good example of sustainability as it already had 4 effective editions with successful approval rates and always with many more candidates than available vacancies.ERASMUS+info:eu-repo/semantics/publishedVersio

An integrated reusable remote laboratory to complement electronics teaching

The great majority of the courses on science and technology areas where lab work is a fundamental part of the apprenticeship was not until recently available to be taught at distance. This reality is changing with the dissemination of remote laboratories. Supported by resources based on new information and communication technologies, it is now possible to remotely control a wide variety of real laboratories. However, most of them are designed specifically to this purpose, are inflexible and only on its functionality they resemble the real ones. In this paper, an alternative remote lab infrastructure devoted to the study of electronics is presented. Its main characteristics are, from a teacher's perspective, reusability and simplicity of use, and from a students' point of view, an exact replication of the real lab, enabling them to complement or finish at home the work started at class. The remote laboratory is integrated in the Learning Management System in use at the school, and therefore, may be combined with other web experiments and e-learning strategies, while safeguarding security access issues

AR2T : implementing a truly SRAM-based FPGA on-line concurrent testing

The new partial and dynamic reconfigurable features offered by new generations of SRAM-based FPGAs may be used to improve the dependability of reconfigurable hardware platforms through the implementation of on-line concurrent testing / fault tolerance mechanisms. However, such mechanisms imply the existence of new test strategies that do not interfere with the current system functionality.The AR2T (Active Replication and Release for Testing) technique is a set of procedures that enables the implementation of a truly non-intrusive structural on-line concurrent testing approach, detecting and avoiding permanent faults and correcting errors due to transient faults. Experimental results prove the effectiveness of these solutions. In relation to a previous technique proposed by the authors as part of the DRAFT FPGA concurrent test methodology, AR2T extends the range of circuits that can be replicated, by introducing a small replication aid block

An integrated framework to support remote IEEE 1149.1 /1149.4 design for test experiments

Remote experiments for academic purposes can only achieve their educational goals if an appropriate framework is able to provide a basic set of features, namely remote laboratory management, collaborative learning tools and content management and delivery. This paper presents a framework developed to support remote experiments in a design for test class offered to final year students at the Electrical and Computer Engineering degree at the University of Porto. The proposed solution combines a test language command interpreter and various virtual instruments (VIs), with a demonstration board that comprises a boundary-scan IEEE 1149.1 / 1149.4 test infrastructure. The experiments are presented as embedded learning objects, with no distinction from other e-learning contents (e.g. lessons, lecture notes, etc.)

Techniques to improve the reliability of fault-tolerant systems based on self-reconfigurable FPGAs

In this paper it is proposed a new technique toimprove the reliability of fault-tolerant systemsbased on self-reconfigurable FPGAs. The aim is tocreate a self-tolerant system based on selfreconfiguration.To achieve this objective the workwas divided in five main tasks: the analysis of faultinducement mechanisms in FPGAs, its correlationand its matching with existent fault models, or,eventually, if necessary, the proposal of a newmodel; the design and evaluation of a fault tolerancemechanism for FPGAs; the design andimplementation of a methodology able to detect,diagnose and repair the emerging faults; thedevelopment and validation of the proposedmethodology. This study will be the base for a PhDthesis

Run-time management of logic resources on reconfigurable systems

Dynamically reconfigurable systems based on partialand dynamically reconfigurable FPGAs may have theirfunctionality partially modified at run-time withoutstopping the operation of the whole system.The efficient management of the logic space availableis one of the biggest problems faced by these systems.When the sequence of reconfigurations to be performed isnot predictable, resource allocation decisions have to bemade on-line. A rearrangement may be necessary to getenough contiguous space to implement incomingfunctions, avoiding the spreading of their components andthe resulting degradation of system performance.A new software tool that helps to handle the problemsposed by the consecutive reconfiguration of the same logicspace is presented in this paper. This tool uses a novel on--line rearrangement procedure to solve fragmentationproblems and to rearrange the logic space in a waycompletely transparent to the applications currentlyrunnin

EOLES Course, 4 years and going…results and experiences

The EOLES (Electronics and Optics e-Learning for Embedded Systems) course consists of a 3rd year Bachelor degree that relies exclusively on e-learning and remote laboratories, developed as the result of an EU funded ERASMUS+ project, involving 15 institutions from four European and three North African countries and concluded in 2015. The developed course was accredited as a specialization year in most partner institutions and has been running non-stop since then, mainly with students from North African institutions. Although no longer supported by an EU project, the course is a good example of sustainability as it already had 4 effective editions with successful approval rates and always with many more candidates than available vacancies. This paper presents an overview and overall results for this initial period and a more detailed analysis of the Digital Systems Teaching Unit. The focus is on the course specific characteristics and features, student and teacher experiences and the methodologies that were applied to enhance learning results. Although being a fully online course, several synchronous activities and communication tools are included in the methodology to enhance student and teacher iteration and also to provide an impartial grading process, as required for accreditation. The course expositive material is provided as the student progresses, with progressive unlocking of content depending on each teaching unit timeline, and automatic quizzes results. In short, students are allowed and encouraged to adjust their learning rhythm within the limits allowed by time restraints and evaluation criteria.info:eu-repo/semantics/publishedVersio

E-Engineering: from concept to reality

Even before the digital era, the implementation of distance learning in higher education was a reality in many areas. Notwithstanding, the offer of distance higher education courses was not equal in all knowledge areas due to different teaching and learning requirements. The experimental work developed during the learning process in engineering areas is widely recognized as essential for engineering students. However, the remote availableness of this experimental, hands-on, works, typically done in University laboratories designed according to the different teaching subject requirements, was nonexistent. With the advent of remote laboratories, real-time remotely controlled laboratory facilities made possible by the advancements on the Internet network, this limitation disappeared. The concept of e-engineering, a merge between the e-learning concept and the remote laboratories, emerged as a solution to offer distance learning engineering courses without abdicating of the indispensable practical component of any engineering course. Two European projects – the Tempus EOLES project and the ERASMUS+ e-LIVES project – try to bridge the gap between concept and reality by first implementing an accredited higher education engineering course in Electronics and Optics e-Learning for Embedded Systems and then by producing a set of guidelines to help others to be autonomous in the creation of their own eengineering courses.info:eu-repo/semantics/publishedVersio