ATA6612C View Datasheet(PDF) - Atmel Corporation
Part Name
Description
MFG CO.
ATA6612C
Atmel Corporation
'ATA6612C' PDF : 312 Pages View PDF
5.7.4
Power-down Mode
When the SM2..0 bits are written to 010, the SLEEP instruction makes the MCU enter power-down mode. In this mode, the
external oscillator is stopped, while the external interrupts, the 2-wire serial interface address watch, and the watchdog
continue operating (if enabled). Only an external reset, a watchdog system reset, a watchdog interrupt, a brown-out reset, a
2-wire serial interface address match, an external level interrupt on INT0 or INT1, or a pin change interrupt can wake up the
MCU. This sleep mode basically halts all generated clocks, allowing operation of asynchronous modules only.
Note that if a level triggered interrupt is used for wake-up from power-down mode, the changed level must be held for some
time to wake up the MCU. Refer to Section 5.11 “External Interrupts” on page 92 for details.
When waking up from power-down mode, there is a delay from the wake-up condition occurs until the wake-up becomes
effective. This allows the clock to restart and become stable after having been stopped. The wake-up period is defined by the
same CKSEL fuses that define the reset time-out period, as described in Section 5.6.2 “Clock Sources” on page 47.
5.7.5
Power-save Mode
When the SM2..0 bits are written to 011, the SLEEP instruction makes the MCU enter power-save mode. This mode is
identical to power-down, with one exception.
If Timer/Counter2 is enabled, it will keep running during sleep. The device can wake up from either timer overflow or output
compare event from Timer/Counter2 if the corresponding Timer/Counter2 interrupt enable bits are set in TIMSK2, and the
global interrupt enable bit in SREG is set.
If Timer/Counter2 is not running, power-down mode is recommended instead of power-save mode.
The Timer/Counter2 can be clocked both synchronously and asynchronously in power-save mode. If Timer/Counter2 is not
using the asynchronous clock, the Timer/Counter oscillator is stopped during sleep. If Timer/Counter2 is not using the
synchronous clock, the clock source is stopped during sleep. Note that even if the synchronous clock is running in
power-save, this clock is only available for Timer/Counter2.
5.7.6
Standby Mode
When the SM2..0 bits are 110 and an external crystal/resonator clock option is selected, the SLEEP instruction makes the
MCU enter standby mode. This mode is identical to power-down with the exception that the oscillator is kept running. From
standby mode, the device wakes up in six clock cycles.
Table 5-19. Active Clock Domains and Wake-up Sources in the Different Sleep Modes
Active Clock Domains
Oscillators
Wake-up Sources
Sleep Mode
Idle
XXX
X
X(2)
X
X
X
ADC noise
Reduction
XX
X
X(2)
X(3)
X
X
Power-down
X(3)
X
Power-save
X
X
X(3)
X
X
Standby(1)
X
X(3)
X
Notes: 1. Only recommended with external crystal or resonator selected as clock source.
2. If timer/Ccunter2 is running in asynchronous mode.
3. For INT1 and INT0, only level interrupt.
X
XXX
X
XX
X
X
X
ATA6612C/ATA6613C [DATASHEET]
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9111L–AUTO–11/14
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