Datasheet

23
SAM3S [SUMMARY]
6500ES–ATARM–11-Feb-13
5.7 Fast Startup
The device 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 (WKUP0 to 15 + SM + RTC + RTT).
The fast restart circuitry, as shown in Figure 5-5, 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 master clock on this 4MHz clock and reenables the processor clock.
Figure 5-5. Fast Start-Up Circuitry
fast_restart
WKUP15
FSTT15
FSTP15
WKUP1
FSTT1
FSTP1
WKUP0
FSTT0
FSTP0
RTTAL
RTCAL
USBAL
RTT Alarm
RTC Alarm
USB Alarm