ATA5771 ATMEL Corporation, ATA5771 Datasheet - Page 84

• Manufacturer Part Number: ATA5771
• Manufacturer: ATMEL Corporation

7. Power Management and Sleep Modes
7.1
7.1.1
32
Sleep Modes
ATtiny24/44/84
Idle Mode
The high performance and industry leading code efficiency makes the AVR microcontrollers an
ideal choise for low power applications. In addition, 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 consumption to the application’s requirements.
Figure 6-1 on page 23
ATtiny24/44/84. The figure is helpful in selecting an appropriate sleep mode.
the different sleep modes and their wake up sources.
Table 7-1.
Note:
To enter any of the three sleep modes, the SE bit in MCUCR must be written to logic one and a
SLEEP instruction must be executed. The SM1..0 bits in the MCUCR Register select which
sleep mode (Idle, ADC Noise Reduction, Standby or Power-down) will be activated by the
SLEEP instruction. See
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 sleep. If a reset occurs during sleep mode,
the MCU wakes up and executes from the Reset Vector.
Note that if a level triggered interrupt is used for wake-up the changed level must be held for
some time to wake up the MCU (and for the MCU to enter the interrupt service routine). See
“External Interrupts” on page 48
When the SM1..0 bits are written to 00, the SLEEP instruction makes the MCU enter Idle mode,
stopping the CPU but allowing Analog Comparator, ADC, Timer/Counter, Watchdog, and the
interrupt system to continue operating. This sleep mode basically halts clk
allowing the other clocks to run.
Sleep Mode
Idle
ADC Noise Reduction
Power-down
Stand-by
1. For INT0, only level interrupt.
2. Only recommended with external crystal or resonator selected as clock source
Active Clock Domains and Wake-up Sources in the Different Sleep Modes
Table 7-2 on page 36
Active Clock Domains
presents the different clock systems and their distribution in
for details.
X
X
X
for a summary.
Oscillators
X
X
X
X
X
X
(1)
(1)
Wake-up Sources
X
X
X
(2)
CPU
and clk
Table 7-1
X
X
8006G–AVR–01/08
FLASH
X
shows
, while
X
X
X