Radiation-Hardened Cortex-R4F System-on-Chip Prototype With Total Ionizing Dose Dynamic Compensation in 28-nm FD-SOI

Abstract

This article presents a radiation-hardened Cortex-R4F system-on-chip prototype with integrated total ionizing dose (TID) dynamic compensation capabilities, designed and fabricated in 28-nm fully depleted silicon-on-insulator (FD-SOI) technology. The processor was made robust to single-event effects, thanks to several design techniques: error correcting code (ECC) protected and bit-interleaved memories, optimized radiation-hardened sequential cells, and sensitive logic cells filtering. To counter the TID effects on the processor functionality and performances, the system embeds an integrated digital dosimeter. The dosimeter is capable of computing the TID in real time and providing the information to the system. Using a software lookup table (LUT), coupled with 28-nm FD-SOI technology support of asymmetric and wide-body-biasing, the reported TID can be converted to a request made to an external body-bias generator and be fully compensated. The system, operating at 0.9 V and 500 MHz, was tested under space grade radiations and has shown no failure in the 0 krad(Si) to 50 krad(Si) TID range.