 SSD1306 OLED Controller Low-level driver | This is a low level driver for the SSD1306 OLED controller through 4-wire SPI |
| 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 |
 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 | |
| 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 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 |
| SAM Serial Peripheral Interface (SERCOM SPI) Driver | This driver for Atmel® | SMART ARM®-based microcontrollers provides an interface for the configuration and management of the SERCOM module in its SPI mode to transfer SPI data frames |
| Busy-Wait Delay Routines | This module provides simple loop-based delay routines for those applications requiring a brief wait during execution |
 Generic board support | The generic board support module includes board-specific definitions and function prototypes, such as the board initialization function |
 SAM D21 Xplained Pro board | |
| Features | Symbols that describe features and capabilities of the board |
1.8.5