 Cyclic Redundancy Check Calculation Unit (CRCCU) | Driver for the Cyclic Redundancy Check Calculation Unit |
| Embedded Flash Service | The Embedded Flash service provides functions for internal flash operations |
| Power Management Controller (PMC) | |
| Enhanced Embedded Flash Controller (EEFC) | The Enhanced Embedded Flash Controller ensures the interface of the Flash block with the 32-bit internal bus |
| Universal Asynchronous Receiver Transceiver (UART) | The Universal Asynchronous Receiver Transmitter features a two-pin UART that can be used for communication and trace purposes and offers an ideal medium for in-situ programming solutions |
| Universal Synchronous Asynchronous | Receiver Transmitter (USART) |
 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 |
| Peripheral Parallel Input/Output (PIO) Controller | |
| Compiler abstraction layer and code utilities | Compiler abstraction layer and code utilities for AT91SAM |
| 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 | |
| Clock Management | |
| Generic Clock Management | Generic clocks are configurable clocks which run outside the system clock domain |
| Oscillator Management | This group contains functions and definitions related to configuring and enabling/disabling on-chip oscillators |
| PLL Management | This group contains functions and definitions related to configuring and enabling/disabling on-chip PLLs |
| System Clock Management | See Quick Start Guide for the System Clock Management service (SAM4S) |
| Power Manager (PM) | This is a stub on the SAM Power Manager Control (PMC) for the sleepmgr service |
| Serial Interface (Serial) | See Quick start guide for Serial Interface service |
| Universal Synchronous Asynchronous Receiver | Transmitter (USART) |
| Generic board support | The generic board support module includes board-specific definitions and function prototypes, such as the board initialization function |
| Common IOPORT API | See Quick start guide for the common IOPORT service |
| General Purpose Input/Output | This is the common API for GPIO |
1.8.5