Andrea Portaluri

Field Programmable Gate Arrays (FPGAs) have witnessed an increase in space applications in the last years, mainly due to their cost-effective high-performances and flexibility. However, the susceptibility of these devices to radiation-induced effects when working in such an environment is well known. When common mitigation techniques are not sufficient to ensure the correct completion of a task, radiation-hardened FPGAs represent one of the most effective solutions. NanoXplore, in this context, is the first European developer of rad-hard FPGAs, which embed intrinsic high complexity in their architectures preventing the user from using or developing custom placement and routing algorithms. In this paper, we overcame these issues by proposing the first tool tailored to NanoXplore devices which allows the exploration of NanoXplore device architectures and routing of points through a Python interface. We developed a model that reflects the one used by the vendor, allowing the user to extract info about routes, nets and additional logic, otherwise unavailable. The tool also performs routing of points in the programmable logic, computing the optimal path. An implementation of the router on Graphic Processing Unit (GPU) is proposed to exploit the highly parallelizable nature of the problem. Finally, routing timing analyses on different benchmarks have been performed, improving the routing routine time.

The continuous scaling of electronic components has led to the development of high-performance microprocessors that are suitable even for safety-critical applications where radiation-induced errors such as Single Event Effects (SEEs) can have a significant impact on the performance and reliability of the system. This work is dedicated to investigating the reliability of systems based on programmable hardware and Real-time operating Systems (RTOS) in the presence of architectural faults induced by soft errors in the configuration memory of the programmable hardware. We performed a proton radiation test campaigned at PSI radiation facility to identify the fault model affecting the configuration memory of Xilinx Zynq-7020 reconfigurable AP-Soc Device. The identified fault model in terms of SEU and MBU clusters has been used to evaluate the impact of proton-induced faults on applications running within FreeRTOS on a Microblaze soft processor. A Single Event Multiple Upset fault model resulting from a proton test is presented, focusing on characteristics such as shape, size, and frequency of observed cluster of errors. We conduct two fault injection campaigns and analyze the results to assess the effect of cluster size on system reliability. Moreover, we discuss software exceptions caused by faults that can affect the hardware structure of the soft processor.