A Self-Adaptive SEU Mitigation Scheme for Embedded Systems in Extreme Radiation Environments

When electronic systems are working in radiation environments, transient errors, and permanent errors may occur. Static random-access memory (SRAM) has been the one of most significant parts in various semiconductor chips for its high performance and high logic density features. However, because of their dedicated electronic circuits, SRAMs are sensitive to radiation effects. In this article, a portable scheme combined with error correcting code (ECC) and refreshing techniques is proposed to correct errors and mitigate error accumulation in extreme radiation environments. Since the proposed scheme is small and transparent to other modules and no additional latency is introduced, it therefore can be easily applied to the system where the hardware modules are designed with fixed reading and writing latency. We evaluated this design by simulation in a hardware fault injection platform and radiation experiments in the neutron radiation facility. The results obtained in the neutron experiment, where the flux of neutron particles is
$5 \times {\rm 10^6\text{ cm}^2. \ s^{-1}}$
, show that the number of bit-flips in 32 kB self-refresh ECC RAM on the Xilinx Artix-7 FPGA remains zero, while the number of bit-flips in unhardened RAM rose to 32 in 1.5 h.