RRAM-based FPGA for \"normally off, instantly on\" applications

“Normally off, instantly on” applications are becoming common in our environment. They range from healthcare to video surveillance. As the number of applications and their associated performance requirements grow rapidly, more and more powerful, flexible and power efficient computing units are necessary. In such a context, Field Programmable Gate Arrays (FPGA) architectures present a good trade-off between performance and flexibility. However, they consume high static power and can hardly be associated with power gating techniques due to their long context restoring phase. In this paper, we propose to integrate non-volatile resistive memories in configuration cells in order to instantly restore the FPGA context. We then show that if the circuit is in `ON' state for less than 42% of time, non-volatile FPGA starts saving energy compared to classical FPGA. Finally, for a typical application with only 1% of time spent in `ON' state, the energy gain reaches 50%.