XMEGAA datasheet(95/445 Pages) ATMEL

95 / 445 page

8077H–AVR–12/09

XMEGA A

Power Management and Sleep

8.1

Features

• 5 sleep modes

–Idle

– Power-down

–Power-save

–Standby

– Extended standby

• Power Reduction register to disable clock to unused peripherals

8.2

Overview

XMEGA provides various sleep modes and software controlled clock gating in order to tailor

power consumption to the application's requirement. Sleep modes enables the microcontroller to

shut down unused modules to save power. When the device enters sleep mode, program exe-

cution is stopped and interrupts or reset is used to wake the device again. The individual clock to

unused peripherals can be stopped during normal operation or in sleep, enabling a much more

fine tuned power management than sleep modes alone.

8.3

Sleep Modes

Sleep modes are used to shut down modules and clock domains in the microcontroller in order

to save power. XMEGA has five different sleep modes. A dedicated Sleep instruction (SLEEP) is

available to enter sleep. Before executing SLEEP, the selected sleep mode to enter must be

configured. The available interrupt wake-up sources is dependent on the selected sleep mode.

When an enabled interrupt occurs the device will wake up and execute the interrupt service rou-

tine before continuing normal program execution from the first instruction after the SLEEP

instruction. If other higher priority interrupts are pending when the wake-up occurs, their interrupt

service routines will be executed according to their priority before the interrupt service routine for

the wake-up interrupt is executed. After wake-up the CPU is halted for four cycles before execu-

tion starts.

XMEGAA Datasheet(PDF) 95 Page - ATMEL Corporation