The Atmel SAMD51 or ATSAMD51 is an Arduino-compatible microcontroller chip with a 120MHz 32-bit ARM® Cortex®-M4 processor. It runs off 3.3V power.

Here are a couple models:

• ATSAMD51G18A (128KB RAM/256KB storage)
• ATSAMD51N19A (192KB RAM/512KB storage)
• ATSAMD51J20A (256KB RAM/1MB storage)
• Find more

It can be programmed with:

• C++
• MicroPython
• CircuitPython

Some boards that feature the SAMD51 include:

• Adafruit Neotrellis M4
• Adafruit PyPortal
• Adafruit Grand Central M4 Express without headers
• Adafruit Grand Central M4 Express with headers
• Adafruit TensorFlow Lite for Microcontrollers Kit
• Sparkfun Thing Plus
• SparkFun MicroMod SAMD51 Processor

Read more at https://en.wikipedia.org/wiki/Atmel_ARM-based_processors