A self-checking scheme to mitigate single event upset effects in SRAM-based FPAAs

In this work the problem of Single Event Upset (SEU) is considered in a recent analog technology: The Field Programmable Analog Arrays (FPAAs). Some FPAA models are based on SRAM memory cells to implement the user programmability, which makes this kind of device vulnerable to SEU when employed in applications susceptible to the incidence of radiation. In a previous work some fault injection experiments were made in order to investigate the effects of SEU in the SRAM blocks of a commercial FPAA. For this purpose, single BIT inversions were injected in the FPAA programming bitstream, when an oscillator module was programmed. Based on the obtained results, a self-checking scheme using the studied FPAA is proposed. This scheme, which is built from the FPAA programming resources, is able to restore the original programming data if an error is detected. Fault injection is also performed to investigate the reliability of the proposed scheme when the bitstream section which controls the checker blocks is corrupted due to a SEU.