In recent years, FPGA devices have attracted a lot of attentions due to the increasing performance they provide thanks to technology scaling, besides their high flexibility through in-field reprogramming and/or partial reconfiguration capability. However, when such devices are to be deployed in safety- and mission-critical applications such as avionic and space applications, it is mandatory to verify the reliability of the device in the target environment where radiation effect is considered as one of the major sources of faults in the system. For SRAM-based FPGA devices, the SRAM cells holding the configuration data for the circuit implemented on the devices are highly susceptible against Single Event Upset (SEU) induced by charged particle striking the device and one single SEU in the configuration memory may corrupt the implemented circuit design causing system misbehavior. In this paper, we present the radiation test data on Xilinx Kintex-7 SRAM-based FPGA using Ultra High Energy heavy ion test beam for the first time available to third party radiation test in CERN.

When the result of a previous instruction is needed in the pipeline before it is available, a “data hazard” occurs. Register Forwarding and Pipeline Interlock (RF&PI) are mechanisms suitable to avoid data corruption and to limit the performance penalty caused by data hazards in pipelined microprocessors. Data hazards handling is part of the microprocessor control logic; its test can hardly be achieved with a functional approach, unless a specific test algorithm is adopted. In this paper we analyze the causes for the low functional testability of the RF&PI logic and propose some techniques able to effectively perform its test. In particular, we describe a strategy to perform Software-Based Self-Test (SBST) on the RF&PI unit. The general structure of the unit is analyzed, a suitable test algorithm is proposed and the strategy to observe the test responses is explained. The method can be exploited for test both at the end of manufacturing and in the operational phase. Feasibility and effectiveness of the proposed approach are demonstrated on both an academic MIPS-like processor and an industrial System-on-Chip based on the Power Architecture™.

Hybrid error-detection techniques combine software techniques with an external hardware module that monitors the execution of a microprocessor. The external hardware module typically observes the control flow at the input or at the output of the microprocessor and compares it with the expected one. This paper proposes a new hybrid technique that monitors the control flow at both points and compares them to detect possible errors. The proposed approach does not require any software modification to detect control-flow errors. Fault-injection campaigns have been performed on an LEON3 microprocessor. The results show full control-flow error detection with no performance degradation and small area overhead. A complete solution can be obtained by complementing the proposed approach with software fault-tolerance techniques for data errors.

Detecting the effects of transient faults is a key point in many processor-based safety-critical applications. This paper proposes to adopt the debug interface module existing today in several processors/controllers available on the market. In this way, we can achieve a good detection capability and small latency with respect to control flow errors, while the cost for adopting the proposed technique is rather limited and does not involve any change either in the processor hardware or in the application software. The method works even if the processor uses caches and we experimentally evaluated its characteristics demonstrating the advantages and showing the limitations on two pipelined processors. Experimental results performed by fault injection using different software applications demonstrate that the method is able to archieve high fault coverage (more than 95 percent in nearly all the considered cases) with a limited cost in terms of area and performance degradation.

Radiation-induced Single Event Transients (SETs) are the leading cause of mal-operations in CMOS nanometric integrated circuits. The increasing complexity of advanced CMOS digital circuits makes SET effects investigation a rising challenge. In this work, we propose a three-dimension oriented simulation approach able to model the passage of heavy ions particles through the physical structures of modern digital circuits implemented with ultra-nanometric manufacturing processes. The proposed approach is able to generate the transient voltage pulse in response to a heavy ion track and identify the effects of the sensitive volume and contact structure. We present heavy ion radiation test experiments performed on a 65 nm Flash-based CMOS technology process and, as proof-ofconcept, we successfully compared the SET cross-sections showing comparable results.