As the ATECC508A is just an I2C peripheral you still have a broad choice for microcontrollers (as you still need a U2F program and U2F). I choose to use a EFMU

As the ATECC508A is just an I2C peripheral you still have a broad choice for microcontrollers (as you still need a U2F program and U2F). I choose to use a EFMUB1 from silicon labs.