Proton-induced SEU, dose effects, and LEO performance predictions for R3000 microprocessors

Abstruct-This paper presents low energy ( I 60 MeV) proton exposure test results for commercial unhardened versions of the MIPS Computer Systems MOO0 and R3OOOA microprocessors from four different vendors, and compares these results with previously obtained data at 256 MeV. Proton SEU cross sections and total dose hardness values are presented. Two of the processors functioned to about 1 Mrad. All processors, with one exception, remained functional above 40 krad. SEU cross sections were obtained with the use of specially designed software tests which were executed dynamically during radiation exposure of the chips. Radiation hardness and SEU are investigated for LEO. Results indicate that commercial WOO0 and R3OOOA microprocessors are suitable for multi-year operation at LEO altitudes in space.