Datasheet

21
SAM3S [SUMMARY]
6500ES–ATARM–11-Feb-13
5.5.3 Sleep Mode
The purpose of sleep mode is to optimize power consumption of the device versus response time. In this mode,
only the core clock is stopped. The peripheral clocks can be enabled. The current consumption in this mode is
application dependent.
This mode is entered via Wait for Interrupt (WFI) or Wait for Event (WFE) instructions with LPM = 0 in PMC_FSMR.
The processor can be woke up from an interrupt if WFI instruction of the Cortex M3 is used, or from an event if the
WFE instruction is used to enter this mode.
5.5.4 Low Power Mode Summary Table
The modes detailed above are the main low power modes. Each part can be set to on or off separately and wake
up sources can be individually configured. Table 5-1 below shows a summary of the configurations of the low
power modes.
Notes: 1. When considering wake-up time, the time required to start the PLL is not taken into account. Once started, the device
works with the 4/8/12 MHz fast RC oscillator. The user has to add the PLL start-up time if it is needed in the system.
The wake-up time is defined as the time taken for wake up until the first instruction is fetched.
2. The external loads on PIOs are not taken into account in the calculation.
3. Supply Monitor current consumption is not included.
4. Total Current consumption.
5. 5 μA on VDDCORE, 15 μA for total current consumption (using internal voltage regulator), 8 μA for total current con-
sumption (without using internal voltage regulator).
6. Depends on MCK frequency.
7. In this mode the core is supplied and not clocked but some peripherals can be clocked.
Table 5-1. Low Power Mode Configuration Summary
Mode
SUPC,
32 kHz
Oscillator
RTC RTT
Backup
Registers,
POR
(Backup
Region) Regulator
Core
Memory
Peripherals Mode Entry
Potential Wake Up
Sources
Core at
Wake Up
PIO State
while in Low
Power Mode
PIO State at
Wake Up
Consumption
(2) (3)
Wake-up
Time
(1)
Backup
Mode
ON OFF
OFF
(Not powered)
WFE
+SLEEPDEEP
bit = 1
WUP0-15 pins
SM alarm
RTC alarm
RTT alarm
Reset
Previous
state saved
PIOA &
PIOB &
PIOC
Inputs with
pull ups
3 μA typ
(4)
< 0.1 ms
Wait
Mode
ON ON
Powered
(Not clocked)
WFE
+SLEEPDEEP
bit = 0
+LPM bit = 1
Any Event from:
Fast startup through
WUP0-15 pins
RTC alarm
RTT alarm
USB wake-up
Clocked
back
Previous
state saved
Unchanged 5 μA/15 μA
(5)
< 10 μs
Sleep
Mode
ON ON
Powered
(7)
(Not clocked)
WFE or WFI
+SLEEPDEEP
bit = 0
+LPM bit = 0
Entry mode =WFI
Interrupt Only; Entry
mode =WFE Any
Enabled Interrupt
and/or Any Event
from: Fast start-up
through WUP0-15
pins
RTC alarm
RTT alarm
USB wake-up
Clocked
back
Previous
state saved
Unchanged
(6) (6)