SAM4S_14 Datasheet, PDF (87/1231 Pages) ATMEL Corporation – ARM-based Flash MCU

In addition, if the SEVONPEND bit in the SCR is set to 1, any new pending interrupt triggers an event and wakes
up the processor, even if the interrupt is disabled or has insufficient priority to cause an exception entry. For more
information about the SCR, see “System Control Register” .
12.5.2.3 External Event Input
The processor provides an external event input signal. Peripherals can drive this signal, either to wake the
processor from WFE, or to set the internal WFE event register to 1 to indicate that the processor must not enter
sleep mode on a later WFE instruction. See “Wait for Event” for more information.
12.5.3 Power Management Programming Hints
ISO/IEC C cannot directly generate the WFI and WFE instructions. The CMSIS provides the following functions for
these instructions:
void __WFE(void) // Wait for Event
void __WFI(void) // Wait for Interrupt
SAM4S Series [DATASHEET]
87
Atmel-11100G-ATARM-SAM4S-Datasheet_27-May-14