RE01 32-Bit Microcontroller Group Renesas Electronics RE01 32-Bit Microcontroller Group is a family of Arm® Cortex®-M0+ ultra-low power MCUs based on SOTB™ (Silicon on Thin Buried Oxide) process technology, enabling ultra-low current consumption in both active and standby mode and high-speed operation at low voltage. The RE01 MCUs can significantly extend battery life and deliver high performance even for applications with small batteries that can supply only a small amount of current. In addition, these devices integrate an on-chip energy harvesting controller can extend the battery life further, or completely eliminate a battery to achieve a maintenance-free system.