IPF: In-Place X-Filling to Mitigate Soft Errors in SRAM-Based FPGAs

SRAM-based Field Programmable Gate Arrays (FPGAs) are vulnerable to Single Event Upsets (SEUs). We show that a large portion (40%-60% for the circuits in our experiments) of the total used LUT configuration bits are don´t care bits, and propose to decide the logic values of don´t care bits such that soft errors are reduced. Our approaches are efficient and do not change LUT level placement and routing. Therefore, they are suitable for design closure. For the ten largest combinational MCNC benchmark circuits mapped for 6-LUTs, our approaches obtain 20% chip level Mean Time To Failure (MTTF) improvements, compared to the baseline mapped by Berkeley ABC mapper. They obtain 3× more chip level MTTF improvements and are 128× faster when compared to the existing best in-place IPD algorithm.