
34
8024A–AVR–04/08
ATmega8HVA/16HVA
10. Power Management and Sleep Modes
Sleep modes enable the application to shut down unused modules in the MCU, thereby saving
power. The AVR provides various sleep modes allowing the user to tailor the power consump-
tion to the application’s requirements.
10.1
Sleep Modes
their distribution. The figure is helpful in selecting an appropriate sleep mode. The different sleep
shows a sleep mode state diagram.
Notes:
1. Discharge FET must be switched off for Charger Detect to be active.
2. Instantaneous and Accumulate Conversion Complete wake-up only.
ter” on page 39, must be written to logic one and a SLEEP instruction must be executed. The
SM2..0 bits in the SMCR Register select which sleep mode will be activated by the SLEEP
If an enabled interrupt occurs while the MCU is in a sleep mode, the MCU wakes up. The MCU
is then halted for four cycles in addition to the start-up time, executes the interrupt routine, and
resumes execution from the instruction following SLEEP. The contents of the register file and
SRAM are unaltered when the device wakes up from any sleep mode except Power-off. If a
reset occurs during sleep mode, the MCU wakes up and executes from the Reset Vector.
Table 10-1.
Wake-up Sources for Sleep Modes
Mode
Wake-up sources
W
a
ke-up
on
Regular
C
u
rr
ent
Battery
Pr
otectio
n
Interrupts
External
Interrupts
WD
T
EEPR
OM
Read
y
VREGM
O
N
CC-AD
C
V
-ADC
Ot
her
I/
O
Char
g
e
rDe
tect
Idle
X
XX
XX
ADC Noise Reduction
X
XX
X
X
Power-save
XX
X
Power-off
X