Here is a list of all related documentation pages:

Clock configuration
Fuse configuration
MCUConfig.h
Definitions model
Getting started
Macros
ADC.h
ATmega328P.h
AnalogComparator.h
Architecture.h
Bootloader.h
Clock.h
Config.h
CPU.h
DebugWire.h
Device.h
EEPROM.h
Electrical.h
Errata.h
ExternalInterrupts.h
Fuse.h
GPIO.h
Interrupts.h
LockBits.h
Memory.h
PackagePins.h
Package.h
PinFunctions.h
Pin.h
Power.h
Programming.h
PWM.h
QTouch.h
RegisterBits.h
RegisterMap.h
Reset.h
RTC.h
SPI.h
Timer.h
TWI.h
USART.h
Watchdog.h
Namespace map
No runtime implementation
Technical references