 Standard I/O (stdio) | Common standard I/O driver that implements the stdio read and write functions on AVR and SAM devices |
  Standard serial I/O (stdio) | Common standard serial I/O management driver that implements a stdio serial interface on AVR and SAM devices |
| Compiler abstraction layer and code utilities | Compiler abstraction layer and code utilities for Cortex-M0+ based Atmel SAM devices |
 Status Codes | |
| Preprocessor - Macro Recursion | |
| Preprocessor - Macro Repeat | |
| Preprocessor - Stringize | |
| Preprocessor - Token Paste | |
| Global interrupt management | This is a driver for global enabling and disabling of interrupts |
| Deprecated interrupt definitions | |
| Atmel part identification macros | This collection of macros identify which series and families that the various Atmel parts belong to |
| AVR UC3 parts | |
| AVR XMEGA parts | |
| megaAVR parts | |
| SAM parts | |
| Generic board support | The generic board support module includes board-specific definitions and function prototypes, such as the board initialization function |
 SAM C21 Xplained Pro board | |
 Features | Symbols that describe features and capabilities of the board |
| SAM Port (PORT) Driver | This driver for Atmel® | SMART ARM®-based microcontrollers provides an interface for the configuration and management of the device's General Purpose Input/Output (GPIO) pin functionality, for manual pin state reading and writing |
| SAM System Pin Multiplexer (SYSTEM PINMUX) Driver | This driver for Atmel® | SMART ARM®-based microcontrollers provides an interface for the configuration and management of the device's physical I/O Pins, to alter the direction and input/drive characteristics as well as to configure the pin peripheral multiplexer selection |
| SAM RTC Count (RTC COUNT) Driver | This driver for Atmel® | SMART ARM®-based microcontrollers provides an interface for the configuration and management of the device's Real Time Clock functionality in Count operating mode, for the configuration and retrieval of the current RTC counter value |
| SAM System (SYSTEM) Driver | This driver for Atmel® | SMART ARM®-based microcontrollers provides an interface for the configuration and management of the device's system relation functionality, necessary for the basic device operation |
| SAM System Clock Management (SYSTEM CLOCK) Driver | This driver for Atmel® | SMART ARM®-based microcontrollers provides an interface for the configuration and management of the device's clocking related functions |
| SAM System Interrupt (SYSTEM INTERRUPT) Driver | This driver for Atmel® | SMART ARM®-based microcontrollers provides an interface for the configuration and management of internal software and hardware interrupts/exceptions |
| Busy-Wait Delay Routines | This module provides simple loop-based delay routines for those applications requiring a brief wait during execution |
| Test Suite Framework | This module is the test suite framework, which provides a set of standard functions and macros for defining and running test suites |
| Serial Interface (Serial) | See Quick start guide for Serial Interface service |
| SAM Serial USART (SERCOM USART) Driver | This driver for Atmel® | SMART ARM®-based microcontrollers provides an interface for the configuration and management of the SERCOM module in its USART mode to transfer or receive USART data frames |
1.8.5