129 research outputs found
Area-driven partial reconfiguration for SEU mitigation on SRAM-based FPGAs
This paper presents an area-driven Field-Programmable Gate Array (FPGA) scrubbing technique based on partial reconfiguration for Single Event Upset (SEU) mitigation. The proposed method is compared with existing techniques such as blind and on-demand scrubbing on a novel SEU mitigation framework implemented on the ZYNQ platform, supporting various SEU and scrubbing rates. A design space exploration on the availability versus data transfers from a Double Data Rate Type 3 (DDR3) memory, shows that our approach outperforms blind scrubbing for a range of availability values when a second order polynomial IP is targeted. A comparison to an existing on-demand scrubbing technique based on Dual Modular Redundancy (DMR) shows that our approach saves up to 46% area for the same case study
Optimizing Scrubbing by Netlist Analysis for FPGA Configuration Bit Classification and Floorplanning
Existing scrubbing techniques for SEU mitigation on FPGAs do not guarantee an
error-free operation after SEU recovering if the affected configuration bits do
belong to feedback loops of the implemented circuits. In this paper, we a)
provide a netlist-based circuit analysis technique to distinguish so-called
critical configuration bits from essential bits in order to identify
configuration bits which will need also state-restoring actions after a
recovered SEU and which not. Furthermore, b) an alternative classification
approach using fault injection is developed in order to compare both
classification techniques. Moreover, c) we will propose a floorplanning
approach for reducing the effective number of scrubbed frames and d),
experimental results will give evidence that our optimization methodology not
only allows to detect errors earlier but also to minimize the
Mean-Time-To-Repair (MTTR) of a circuit considerably. In particular, we show
that by using our approach, the MTTR for datapath-intensive circuits can be
reduced by up to 48.5% in comparison to standard approaches
A Framework for implementing radiation-tolerant circuits on reconfigurable FPGAs
The outstanding versatility of SRAM-based FPGAs make them the preferred choice for implementing complex customizable circuits. To increase the amount of logic available, manufacturers are using nanometric technologies to boost logic density and reduce prices. However, the use of nanometric scales also makes FPGAs particularly vulnerable to radiation-induced faults, especially because of the increasing amount of configuration memory cells that are necessary to define their functionality. This paper describes a framework for implementing circuits immune to radiation-induced faults, based on a customized Triple Modular Redundancy (TMR) infrastructure and on a detection-and-fix controller. This controller is responsible for the detection of data incoherencies, location of the faulty module and restoration of the original configuration, without affecting the normal operation of the mission logic. A short survey of the most recent data published concerning the impact of radiation-induced faults in FPGAs is presented to support the assumptions underlying our proposed framework. A detailed explanation of the controller functionality is also provided, followed by an experimental case study
Self-reference Scrubber for TMR Systems Based on Xilinx Virtex FPGAs
SRAM-based FPGAs are sensitive to radiation effects. Soft errors can appear and accumulate, potentially defeating mitigation strategies deployed at the Application Layer. Therefore, Configuration Memory scrubbing is required to improve radiation tolerance of such FPGAs in space applications. Virtex FPGAs allow runtime scrubbing by means of dynamic partial reconfiguration. Even with scrubbing, intra-FPGA TMR systems are subjected to common-mode errors affecting more than one design domain. This is solved in inter-FPGA TMR systems at the expense of a higher cost, power and mass. In this context, a self-reference scrubber for device-level TMR system based on Xilinx Virtex FPGAs is presented. This scrubber allows for a fast SEU/MBU detection and correction by peer frame comparison without needing to access a golden configuration memor
Design techniques for xilinx virtex FPGA configuration memory scrubbers
SRAM-based FPGAs are in-field reconfigurable an unlimited number of times. This characteristic, together with their high performance and high logic density, proves to be very convenient for a number of ground and space level applications. One drawback of this technology is that it is susceptible to ionizing radiation, and this sensitivity increases with technology scaling. This is a first order concern for applications in harsh radiation environments, and starts to be a concern for high reliability ground applications. Several techniques exist for coping with radiation effects at user application. In order to be effective they need to be complemented with configuration memory scrubbing, which allows error mitigation and prevents failures due to error accumulation. Depending on the radiation environment and on the system dependability requirements, the configuration scrubber design can become more or less complex. This paper classifies and presents current and novel design methodologies and architectures for SRAM-based FPGAs, and in particular for Xilinx Virtex-4QV/5QV, configuration memory scrubbers
An adaptive method to tolerate soft errors in SRAM-based FPGAs
AbstractIn this paper, we present an adaptive method that is a combination of SEU-avoidance in CAD flow and adaptive redundancy to tolerate soft error effects in SRAM-based FPGAs. This method is based on the modification of T-VPack and VPR tools. Three different steps of these tools are modified for SEU-awareness: (1) clustering, (2) placement and (3) routing. Then we use the unused resources as redundancy. We have investigated the effect of this method on several MCNC benchmarks. This investigation has been performed using three experiments: (1) SEU-awareness in clustering with redundancy, (2) SEU-awareness in clustering and placement with redundancy and (3) SEU-awareness in clustering, placement and routing with redundancy. With a confidence level of 95%, the results show that, using each of these three experiments, the system failure rate of ten MCNC circuits has been decreased between 4.52% and 10.42%, between 10.25% and 21.63%, and between 10.48% and 24.39%, respectively
Analyse und Erweiterung eines fehler-toleranten NoC für SRAM-basierte FPGAs in Weltraumapplikationen
Data Processing Units for scientific space mission need to process ever higher volumes of data and perform ever complex calculations. But the performance of available space-qualified general purpose processors is just in the lower three digit megahertz range, which is already insufficient for some applications. As an alternative, suitable processing steps can be implemented in hardware on a space-qualified SRAM-based FPGA. However, suitable devices are susceptible against space radiation.
At the Institute for Communication and Network Engineering a fault-tolerant, network-based communication architecture was developed, which enables the construction of processing chains on the basis of different processing modules within suitable SRAM-based FPGAs and allows the exchange of single processing modules during runtime, too. The communication architecture and its protocol shall isolate non SEU mitigated or just partial SEU mitigated modules affected by radiation-induced faults to prohibit the propagation of errors within the remaining System-on-Chip. In the context of an ESA study, this communication architecture was extended with further components and implemented in a representative hardware platform.
Based on the acquired experiences during the study, this work analyses the actual fault-tolerance characteristics as well as weak points of this initial implementation. At appropriate locations, the communication architecture was extended with mechanisms for fault-detection and fault-differentiation as well as with a hardware-based monitoring solution. Both, the former measures and the extension of the employed hardware-platform with selective fault-injection capabilities for the emulation of radiation-induced faults within critical areas of a non SEU mitigated processing module, are used to evaluate the effects of radiation-induced faults within the communication architecture. By means of the gathered results, further measures to increase fast detection and isolation of faulty nodes are developed, selectively implemented and verified. In particular, the ability of the communication architecture to isolate network nodes without SEU mitigation could be significantly improved.Instrumentenrechner für wissenschaftliche Weltraummissionen müssen ein immer höheres Datenvolumen verarbeiten und immer komplexere Berechnungen ausführen. Die Performanz von verfügbaren qualifizierten Universalprozessoren liegt aber lediglich im unteren dreistelligen Megahertz-Bereich, was für einige Anwendungen bereits nicht mehr ausreicht. Als Alternative bietet sich die Implementierung von entsprechend geeigneten Datenverarbeitungsschritten in Hardware auf einem qualifizierten SRAM-basierten FPGA an. Geeignete Bausteine sind jedoch empfindlich gegenüber der Strahlungsumgebung im Weltraum.
Am Institut für Datentechnik und Kommunikationsnetze wurde eine fehlertolerante netzwerk-basierte Kommunikationsarchitektur entwickelt, die innerhalb eines geeigneten SRAM-basierten FPGAs Datenverarbeitungsmodule miteinander nach Bedarf zu Verarbeitungsketten verbindet, sowie den Austausch von einzelnen Modulen im Betrieb ermöglicht. Nicht oder nur partiell SEU mitigierte Module sollen bei strahlungsbedingten Fehlern im Modul durch das Protokoll und die Fehlererkennungsmechanismen der Kommunikationsarchitektur isoliert werden, um ein Ausbreiten des Fehlers im restlichen System-on-Chip zu verhindern. Im Kontext einer ESA Studie wurde diese Kommunikationsarchitektur um Komponenten erweitert und auf einer repräsentativen Hardwareplattform umgesetzt.
Basierend auf den gesammelten Erfahrungen aus der Studie, wird in dieser Arbeit eine Analyse der tatsächlichen Fehlertoleranz-Eigenschaften sowie der Schwachstellen dieser ursprünglichen Implementierung durchgeführt. Die Kommunikationsarchitektur wurde an geeigneten Stellen um Fehlerdetektierungs- und Fehlerunterscheidungsmöglichkeiten erweitert, sowie um eine hardwarebasierte Überwachung ergänzt. Sowohl diese Maßnahmen, als auch die Erweiterung der Hardwareplattform um gezielte Fehlerinjektions-Möglichkeiten zum Emulieren von strahlungsinduzierten Fehlern in kritischen Komponenten eines nicht SEU mitigierten Prozessierungsmoduls werden genutzt, um die tatsächlichen auftretenden Effekte in der Kommunikationsarchitektur zu evaluieren. Anhand der Ergebnisse werden weitere Verbesserungsmaßnahmen speziell zur schnellen Detektierung und Isolation von fehlerhaften Knoten erarbeitet, selektiv implementiert und verifiziert. Insbesondere die Fähigkeit, fehlerhafte, nicht SEU mitigierte Netzwerkknoten innerhalb der Kommunikationsarchitektur zu isolieren, konnte dabei deutlich verbessert werden
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