SAM D20 Arm® Cortex®-M0+ Microcontroller Microchip's SAM D20 Arm® Cortex®-M0+ Microcontroller (MCU) series builds on decades of innovation and experience in embedded Flash microcontroller technology. It not only sets a new benchmark for flexibility and ease-of-use but also combines the performance and energy efficiency of an Arm Cortex-M0+ based MCU with an optimized architecture and peripheral set.