The NuMicro® M251/M252 series is a low-power microcontroller platform based on Arm® Cortex®. It runs up to 48 MHz with 32 ~ 256 Kbytes embedded Flash memory and 8 ~ 32 Kbytes embedded SRAM, 4 Kbytes Flash loader memory (LDROM) for InSystem Programming (ISP). The 32-bit low-power microcontrollers supports wide supply voltage from 1.75V ~ 5.5V and operating temperature range from -40C ~ +105C.