Proposal of an Adaptive Fault Tolerance Mechanism to Tolerate Intermittent Faults in RAM

[EN] Due to transistor shrinking, intermittent faults are a major concern in current digital systems. This work presents an adaptive fault tolerance mechanism based on error correction codes (ECC), able to modify its behavior when the error conditions change without increasing the redundancy. As a case example, we have designed a mechanism that can detect intermittent faults and swap from an initial generic ECC to a specific ECC capable of tolerating one intermittent fault. We have inserted the mechanism in the memory system of a 32-bit RISC processor and validated it by using VHDL simulation-based fault injection. We have used two (39, 32) codes: a single error correction-double error detection (SEC-DED) and a code developed by our research group, called EPB3932, capable of correcting single errors and double and triple adjacent errors that include a bit previously tagged as error-prone. The results of injecting transient, intermittent, and combinations of intermittent and transient faults show that the proposed mechanism works properly. As an example, the percentage of failures and latent errors is 0% when injecting a triple adjacent fault after an intermittent stuck-at fault. We have synthesized the adaptive fault tolerance mechanism proposed in two types of FPGAs: non-reconfigurable and partially reconfigurable. In both cases, the overhead introduced is affordable in terms of hardware, time and power consumption.This research was supported in part by the Spanish Government, project TIN2016-81,075-R, and by Primeros Proyectos de Investigacion (PAID-06-18), Vicerrectorado de Investigacion, Innovacion y Transferencia de la Universitat Politecnica de Valencia (UPV), project 20190032.Baraza Calvo, JC.; Gracia-Morán, J.; Saiz-Adalid, L.; Gil Tomás, DA.; Gil, P. (2020). Proposal of an Adaptive Fault Tolerance Mechanism to Tolerate Intermittent Faults in RAM. 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ACM SIGPLAN Notices, 47(4), 111-122. doi:10.1145/2248487.2150989Gil-Tomás, D., Gracia-Morán, J., Baraza-Calvo, J.-C., Saiz-Adalid, L.-J., & Gil-Vicente, P.-J. (2012). Studying the effects of intermittent faults on a microcontroller. Microelectronics Reliability, 52(11), 2837-2846. doi:10.1016/j.microrel.2012.06.004Plasma CPU Modelhttps://opencores.org/projects/plasmaArlat, J., Aguera, M., Amat, L., Crouzet, Y., Fabre, J.-C., Laprie, J.-C., … Powell, D. (1990). Fault injection for dependability validation: a methodology and some applications. IEEE Transactions on Software Engineering, 16(2), 166-182. doi:10.1109/32.44380Gil-Tomas, D., Gracia-Moran, J., Baraza-Calvo, J.-C., Saiz-Adalid, L.-J., & Gil-Vicente, P.-J. (2012). Analyzing the Impact of Intermittent Faults on Microprocessors Applying Fault Injection. IEEE Design & Test of Computers, 29(6), 66-73. doi:10.1109/mdt.2011.2179514Rashid, L., Pattabiraman, K., & Gopalakrishnan, S. (2010). Modeling the Propagation of Intermittent Hardware Faults in Programs. 2010 IEEE 16th Pacific Rim International Symposium on Dependable Computing. doi:10.1109/prdc.2010.52Amiri, M., Siddiqui, F. M., Kelly, C., Woods, R., Rafferty, K., & Bardak, B. (2016). FPGA-Based Soft-Core Processors for Image Processing Applications. Journal of Signal Processing Systems, 87(1), 139-156. doi:10.1007/s11265-016-1185-7Hailesellasie, M., Hasan, S. R., & Mohamed, O. A. (2019). MulMapper: Towards an Automated FPGA-Based CNN Processor Generator Based on a Dynamic Design Space Exploration. 2019 IEEE International Symposium on Circuits and Systems (ISCAS). doi:10.1109/iscas.2019.8702589Mittal, S. (2018). A survey of FPGA-based accelerators for convolutional neural networks. Neural Computing and Applications, 32(4), 1109-1139. doi:10.1007/s00521-018-3761-1Intel Completes Acquisition of Alterahttps://newsroom.intel.com/news-releases/intel-completes-acquisition-of-altera/#gs.mi6ujuAMD to Acquire Xilinx, Creating the Industry’s High Performance Computing Leaderhttps://www.amd.com/en/press-releases/2020-10-27-amd-to-acquire-xilinx-creating-the-industry-s-high-performance-computingKim, K. H., & Lawrence, T. F. (s. f.). Adaptive fault tolerance: issues and approaches. [1990] Proceedings. Second IEEE Workshop on Future Trends of Distributed Computing Systems. doi:10.1109/ftdcs.1990.138292Gonzalez, O., Shrikumar, H., Stankovic, J. A., & Ramamritham, K. (s. f.). Adaptive fault tolerance and graceful degradation under dynamic hard real-time scheduling. Proceedings Real-Time Systems Symposium. doi:10.1109/real.1997.641271Jacobs, A., George, A. D., & Cieslewski, G. (2009). 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Reliability-Based ECC System for Adaptive Protection of NAND Flash Memories. 2015 Fifth International Conference on Communication Systems and Network Technologies. doi:10.1109/csnt.2015.23Zhou, Y., Wu, F., Lu, Z., He, X., Huang, P., & Xie, C. (2019). SCORE. ACM Transactions on Architecture and Code Optimization, 15(4), 1-25. doi:10.1145/3291052Lu, S.-K., Li, H.-P., & Miyase, K. (2018). Adaptive ECC Techniques for Reliability and Yield Enhancement of Phase Change Memory. 2018 IEEE 24th International Symposium on On-Line Testing And Robust System Design (IOLTS). doi:10.1109/iolts.2018.8474118Chen, J., Andjelkovic, M., Simevski, A., Li, Y., Skoncej, P., & Krstic, M. (2019). Design of SRAM-Based Low-Cost SEU Monitor for Self-Adaptive Multiprocessing Systems. 2019 22nd Euromicro Conference on Digital System Design (DSD). doi:10.1109/dsd.2019.00080Wang, X., Jiang, L., & Chakrabarty, K. (2020). LSTM-based Analysis of Temporally- and Spatially-Correlated Signatures for Intermittent Fault Detection. 2020 IEEE 38th VLSI Test Symposium (VTS). doi:10.1109/vts48691.2020.9107600Ebrahimi, H., & G. Kerkhoff, H. (2018). Intermittent Resistance Fault Detection at Board Level. 2018 IEEE 21st International Symposium on Design and Diagnostics of Electronic Circuits & Systems (DDECS). doi:10.1109/ddecs.2018.00031Ebrahimi, H., & Kerkhoff, H. G. (2020). A New Monitor Insertion Algorithm for Intermittent Fault Detection. 2020 IEEE European Test Symposium (ETS). doi:10.1109/ets48528.2020.9131563Hsiao, M. Y. (1970). A Class of Optimal Minimum Odd-weight-column SEC-DED Codes. IBM Journal of Research and Development, 14(4), 395-401. doi:10.1147/rd.144.0395Benso, A., & Prinetto, P. (Eds.). (2004). Fault Injection Techniques and Tools for Embedded Systems Reliability Evaluation. Frontiers in Electronic Testing. doi:10.1007/b105828Gracia, J., Saiz, L. J., Baraza, J. C., Gil, D., & Gil, P. J. (2008). Analysis of the influence of intermittent faults in a microcontroller. 2008 11th IEEE Workshop on Design and Diagnostics of Electronic Circuits and Systems. doi:10.1109/ddecs.2008.4538761ZC702 Evaluation Board for the Zynq-7000 XC7Z020 SoChttps://www.xilinx.com/support/documentation/boards_and_kits/zc702_zvik/ug850-zc702-eval-bd.pd

An extensive study on iterative solver resilience : characterization, detection and prediction

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Managed access dependability for critical services in wireless inter domain environment

The Information and Communications Technology (ICT) industry has through the last decades changed and still continues to affect the way people interact with each other and how they access and share information, services and applications in a global market characterized by constant change and evolution. For a networked and highly dynamic society, with consumers and market actors providing infrastructure, networks, services and applications, the mutual dependencies of failure free operations are getting more and more complex. Service Level Agreements (SLAs) between the various actors and users may be used to describe the offerings along with price schemes and promises regarding the delivered quality. However, there is no guarantee for failure free operations whatever efforts and means deployed. A system fails for a number of reasons, but automatic fault handling mechanisms and operational procedures may be used to decrease the probability for service interruptions. The global number of mobile broadband Internet subscriptions surpassed the number of broadband subscriptions over fixed technologies in 2010. The User Equipment (UE) has become a powerful device supporting a number of wireless access technologies and the always best connected opportunities have become a reality. Some services, e.g. health care, smart power grid control, surveillance/monitoring etc. called critical services in this thesis, put high requirements on service dependability. A definition of dependability is the ability to deliver services that can justifiably be trusted. For critical services, the access networks become crucial factors for achieving high dependability. A major challenge in a multi operator, multi technology wireless environment is the mobility of the user that necessitates handovers according to the physical movement. In this thesis it is proposed an approach for how to optimize the dependability for critical services in multi operator, multi technology wireless environment. This approach allows predicting the service availability and continuity at real-time. Predictions of the optimal service availability and continuity are considered crucial for critical services. To increase the dependability for critical services dual homing is proposed where the use of combinations of access points, possibly owned by different operators and using different technologies, are optimized for the specific location and movement of the user. A central part of the thesis is how to ensure the disjointedness of physical and logical resources so important for utilizing the dependability increase potential with dual homing. To address the interdependency issues between physical and logical resources, a study of Operations, Administrations, and Maintenance (OA&M) processes related to the access network of a commercial Global System for Mobile Communications (GSM)/Universal Mobile Telecommunications System (UMTS) operator was performed. The insight obtained by the study provided valuable information of the inter woven dependencies between different actors in the delivery chain of services. Based on the insight gained from the study of OA&M processes a technological neutral information model of physical and logical resources in the access networks is proposed. The model is used for service availability and continuity prediction and to unveil interdependencies between resources for the infrastructure. The model is proposed as an extension of the Media Independent Handover (MIH) framework. A field trial in a commercial network was conducted to verify the feasibility in retrieving the model related information from the operators' Operational Support Systems (OSSs) and to emulate the extension and usage of the MIH framework. In the thesis it is proposed how measurement reports from UE and signaling in networks are used to define virtual cells as part of the proposed extension of the MIH framework. Virtual cells are limited geographical areas where the radio conditions are homogeneous. Virtual cells have radio coverage from a number of access points. A Markovian model is proposed for prediction of the service continuity of a dual homed critical service, where both the infrastructure and radio links are considered. A dependability gain is obtained by choosing a global optimal sequence of access points. Great emphasizes have been on developing computational e cient techniques and near-optimal solutions considered important for being able to predict service continuity at real-time for critical services. The proposed techniques to obtain the global optimal sequence of access points may be used by handover and multi homing mechanisms/protocols for timely handover decisions and access point selections. With the proposed extension of the MIH framework a global optimal sequence of access points providing the highest reliability may be predicted at real-time

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