A self-scrubbing scheme for embedded systems in radiation environments

As one of the most important components in the embedded systems, the SRAM are sensitive to radiation effects. When the embedded systems working in the extreme radiation environments, the bit flips could occur frequently and decrease the reliability of the systems significantly. In this paper, the self-scrubbing RAM scheme is proposed for light wight embedded systems in the extreme radiation environments. In the scheme, both scrubbing and ECC are used to mitigate the large number of the errors in the RAMs. The separately scrubber is designed to scrub the RAM separately. Therefore it is can be able to operating the scrubbing, when the CPUs are busy. In addition, the scrubber is a portable modules and the hardware costs do not grow with the size of the available RAM. The results of the real world radiation experiments show that it can correct most errors in the RAM under neutron radiation where the errors rates in unhardened RAMs is approximately 1.2bit/(KB·h). The results of the 6 hours radiation experiments show that the error rates of in the conventional ECC RAM is approximately 4.3×10 -4 bit/(KB·h), while the self-scrubbing RAMs is less than 8.7×10 -5 bit/(KB·h)