80
8210C–AVR–09/11
Atmel AVR XMEGA D
shows the different sleep modes and the active clock domains, oscillators,
and wake-up sources.
The wake-up time for the device is dependent on the sleep mode and the main clock source.
The startup time for the system clock source must be added to the wake-up time for sleep
modes where the system clock source is not kept running. For details on the startup time for the
different oscillator options, refer to
”System Clock and Clock Options” on page 58
The content of the register file, SRAM and registers are kept during sleep. If a reset occurs dur-
ing sleep, the device will reset, start up, and execute from the reset vector.
7.3.1
Idle Mode
In idle mode the CPU and nonvolatile memory are stopped (note that any ongoing programming
will be completed), but all peripherals, including the interrupt controller, and event system are
kept running. Any enabled interrupt will wake the device.
7.3.2
Power-down Mode
In power-down mode, all clocks, including the real-time counter clock source, are stopped. This
allows operation only of asynchronous modules that do not require a running clock. The only
interrupts that can wake up the MCU are the two-wire interface address match interrupt, and
asynchronous port interrupts.
7.3.3
Power-save Mode
Power-save mode is identical to power down, with one exception. If the real-time counter (RTC)
is enabled, it will keep running during sleep, and the device can also wake up from either an
RTC overflow or compare match interrupt.
Table 7-1.
Active clock domains and wake-up sources in the different sleep modes.
Active Clock
Domain
Oscillators
Wake-up Sources
Sleep Modes
CPU Cloc
k
RT
C
C
lo
c
k
System
Cloc
k
Sour
ce
R
T
C Cloc
k
So
ur
ce
Async
h
ro
no
us P
o
rt
In
terru
p
ts
TW
I
Ad
dres
s Ma
tc
h Inte
rrupts
Real Time Cloc
k Interrupts
Al
l In
terr
up
ts
Idle
X
X
X
X
X
X
X
Power down
X
X
Power save
X
X
X
X
X
Standby
X
X
X
Extended standby
X
X
X
X
X
X