The Atmel SAM D20 family uses the ARM Cortex-M0+ core. Peripherals include general purpose serial comms, timer/counters, PWMs, ADCs, a DAC, and capacitive touch channels. Go to their website for more information.
There are a number of different programming protocols you can use with the Atmel SAMD family. This includes the ARM SWD protocol. The pinout used by the Atmel-ICE programming is shown below: