 User Interface | Human interface on SAM L21 Xplained Pro: |
| FatFS file system service | Service of FatFS file system |
| Port of low level driver for FatFS | Low level driver for FatFS |
| Memory Control Access | Common abstraction layer for memory interfaces |
| SAM RTC Calendar (RTC CAL) 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 Calendar operating mode, for the configuration and retrieval of the current time and date as maintained by the RTC module |
 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 (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 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 Universal Serial Bus (USB) | The Universal Serial Bus (USB) module complies with the USB 2.1 specification |
| SAM External Interrupt (EXTINT) Driver | This driver for Atmel® | SMART ARM®-based microcontrollers provides an interface for the configuration and management of external interrupts generated by the physical device pins, including edge detection |
| 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 |
| Sleep manager | The sleep manager is a service for ensuring that the device is not put to sleep in deeper sleep modes than the system (e.g., peripheral drivers, services or the application) allows at any given time |
| USB Stack | This stack includes the USB Device Stack, USB Host Stack and common definitions |
| USB Stack Host | This module includes USB Stack Host implementation |
| USB Host Driver Implement (UHD) | USB low-level driver for USB Host mode |
| USB host Controller (UHC) | The UHC provides a high-level abstraction of the usb host |
| Implementation of UHC | Internal implementation |
| USB Host Controller (UHC) - Prerequisites | Common prerequisites for all USB hosts |
| USB Host Controller (UHC) - Example code | Common example code for all USB hosts |
| USB Device Controller (UHC) - Workflow | Common workflow for all USB devices |
| USB Host Driver (UHD) | The UHD driver provides a low-level abstraction of the host controller hardware |
 USB Host Interface (UHI) | The UHI provides a common API for all classes, and this is used by UHC for the main control of USB host interface |
 UHI for Human Interface Device Mouse Class | Common APIs used by high level application to use this USB host class |
| Implementation of UHI HID Mouse | Class internal implementation |
| Interface with USB Host Core (UHC) | Define and functions required by UHC |
| UHI for Mass Storage Class | Common APIs used by high level application to use this USB host class |
| Implementation of UHI Mass Storage Class | Class internal implementation |
| USB host Mass Storage interface for control access module | Layer added on UHI MSC interface to allow the usage of control access module |
| Implementation of USB host Mass Storage | Interface for control access module |
| Interface with USB Host Core (UHC) | Define and functions required by UHC |
| USB dual role driver | USB low-level driver for dual role features |
| Atmel USB Identifiers | This module defines Atmel PID and VIDs constants |
| USB Protocol Definitions | This module defines constants and data structures provided by the USB 2.0 specification |
| USB Human Interface Device (HID) | Protocol definitions |
| USB Mass Storage Class (MSC) protocol definitions | |
| SCSI Block Commands protocol definitions | |
| SCSI Primary Commands protocol definitions | |
| Generic board support | The generic board support module includes board-specific definitions and function prototypes, such as the board initialization function |
| SAM L21 Xplained Pro board | |
| Features | Symbols that describe features and capabilities of the board |
1.8.5