SAM3SD8C Atmel Corporation, SAM3SD8C Datasheet - Page 18

• Manufacturer Part Number: SAM3SD8C
• Manufacturer: Atmel Corporation

5.4
5.5
5.5.1
18
Active Mode
Low-power Modes
SAM3S8/SD8
Backup Mode
Figure 5-3.
Active mode is the normal running mode with the core clock running from the fast RC oscillator,
the main crystal oscillator or the PLLA. The power management controller can be used to adapt
the frequency and to disable the peripheral clocks.
The various low-power modes of the SAM3S8/SD8 are described below:
The purpose of backup mode is to achieve the lowest power consumption possible in a system
which is performing periodic wake-ups to perform tasks but not requiring fast startup time
(<0.1ms). Total current consumption is 1.5 µA typical.
The Supply Controller, zero-power power-on reset, RTT, RTC, Backup registers and 32 kHz
oscillator (RC or crystal oscillator selected by software in the Supply Controller) are running. The
regulator and the core supply are off.
Backup mode is based on the Cortex-M3 deep sleep mode with the voltage regulator disabled.
The SAM3S8/SD8 can be awakened from this mode through WUP0-15 pins, the supply monitor
(SM), the RTT or RTC wake-up event.
Backup mode is entered by using WFE instructions with the SLEEPDEEP bit in the Cortex-M3
System Control Register set to 1. (See the Power management description in The ARM Cortex-
M3 Processor section of the product datasheet).
Exit from Backup mode happens if one of the following enable wake up events occurs:
• WKUPEN0-15 pins (level transition, configurable debouncing)
Main Supply
Backup Battery
Backup
Battery
IN
ON/OFF
3.3V
LDO
Note: The two diodes provide a “switchover circuit” (for illustration purpose)
between the backup battery and the main supply when the system is put in
backup mode.
+
-
OUT
External wakeup signal
ADC, DAC, Analog
Comparator Supply
(2.0V-3.6V)
VDDCORE
VDDIO
VDDPLL
VDDOUT
VDDIN
PIOx (Output)
WAKEUPx
Analog Comp.
Transceivers.
Regulator
ADC, DAC
Voltage
USB
11090A–ATARM–10-Feb-12