Adafruit Feather M4 Express - Featuring ATSAMD51 - ATSAMD51 Cortex M4
About this product
*ATSAMD51 32-bit Cortex M4 core running at 120 MHz, 32-bit, 3.3V logic and power
*512 KB flash, 192 KB RAM
*2 MB SPI FLASH chip for storing files and CircuitPython code storage.
*USB native support, comes with USB bootloader and serial port debugging
*Built in crypto engines with AES (256 bit), true RNG, Pubkey controller