Datasheet

28
11057BS–ATARM–13-Jul-12
SAM3X/A
28
11057BS–ATARM–13-Jul-12
SAM3X/A
5.7 Fast Start-Up
The SAM3X/A series allows the processor to restart in a few microseconds while the processor
is in wait mode. A fast start up can occur upon detection of a low level on one of the 19 wake-up
inputs.
The fast restart circuitry, as shown in Figure 5-4, is fully asynchronous and provides a fast start-
up signal to the Power Management Controller. As soon as the fast start-up signal is asserted,
the PMC automatically restarts the embedded 4/8/12 MHz fast RC oscillator, switches the mas-
ter clock on this 4/8/12 MHz clock and reenables the processor clock.
Figure 5-4. Fast Start-Up Sources
RTCEN
rtc_alarm
RTTEN
rtt_alarm
USBEN
usb_wakeup
fast_restart
WKUP15
FSTT15
WKUP1
WKUP0
FSTT0
FSTT1
High/Low
Level
Detector
High/Low
Level
Detector
High/Low
Level
Detector