High-Density 1 Mbit SPI F-RAM with Industrial Qualification The FM25V10-GTR is a 1-Mbit (128K × 8) nonvolatile F-RAM with a high-speed SPI interface supporting up to 40 MHz operation. It delivers virtually unlimited endurance of 100 trillion (1014) read/write cycles, 151-year data retention at 65°C, and operates from 2.0 V to 3.6 V across -40°C to +85°C.