Partial TMR in FPGAs Using Approximate Logic Circuits

TMR is a very effective technique to mitigate SEU effects in FPGAs, but it is often expensive in terms of FPGA resource utilization and power consumption. For certain applications, Partial TMR can be used to trade off the reliability with the cost of mitigation. In this work we propose a new approach to build Partial TMR circuits for FPGAs using approximate logic circuits. This approach is scalable, with a fine granularity, and can provide a flexible balance between reliability and overheads. The proposed approach has been validated by the results of fault injection experiments and proton irradiation campaigns.This work was supported in part by the Spanish Ministry of Economy and Competitiveness under contract ESP2015-68245-C4-1-P

AN EXHAUSTIVE ANALYSIS OF SEU EFFECTS IN THE SRAM MEMORY OF SOFT PROCESSOR

The Embedded system design is characterized by its daily complexity. It integrates a hardware and software parts together on a common platform. These parts may be defective by a spurious signal, subsequently found to be two types of errors. The software and hardware errors can attack the embedded system. In this paper an exhaustive analysis of the effects of Single Event Upset into the Static Random Access Memory occupied area of Aeroflex Gaisler LEON3 processor is presented. It is a soft core pipeline processor that is part of the GRLIB IP library based on Scalable Processor Architecture, SPARC V8,implemented in Virtex-5 FPGA. A new software methodology allowing fault injection is explored and illustrated in order to classify the defective behaviours while executing several benchmarks. This investigation is done by an exhaustive fault injection campaign (More than 200000 transient faults) into SRAM memory of LEON3 considered as a processor. The proposed method makes error rate predictions more accurate compared to other techniques

A Hybrid Fault-Tolerant LEON3 Soft Core Processor Implemented in Low-End SRAM FPGA

In this work we implemented a hybrid fault-tolerant LEON3 soft-core processor in a low-end FPGA (Artix-7) and evaluated its error detection capabilities through neutron irradiation and fault injection in an incremental manner. The error mitigation approach combines the use of SEC/DED codes for memories, a hardware monitor to detect control-flow errors, software-based techniques to detect data errors and configuration memory scrubbing with repair to avoid error accumulation. The proposed solution can significantly improve fault tolerance and can be fully embedded in a low-end FPGA, with reduced overhead and low intrusiveness