Atmel SAM4S Series, Preliminary Data Sheet

Page: 179 / 1163

179
11100B–ATARM–31-Jul-12
SAM4S Series [Preliminary]
11.6.11.11 WFE
Wait For Event.
Syntax
WFE{cond}
where:
cond is an optional condition code, see
“Conditional Execution”
.
Operation
WFE is a hint instruction.
If the event register is 0, WFE suspends execution until one of the following events occurs:
• an exception, unless masked by the exception mask registers or the current priority level
• an exception enters the Pending state, if SEVONPEND in the System Control Register is set
• a Debug Entry request, if Debug is enabled
• an event signaled by a peripheral or another processor in a multiprocessor system using the
SEV instruction.
If the event register is 1, WFE clears it to 0 and returns immediately.
For more information, see
“Power Management”
.
Condition Flags
This instruction does not change the flags.
Examples
WFE ; Wait for event
11.6.11.12 WFI
Wait for Interrupt.
Syntax
WFI{cond}
where:
cond is an optional condition code, see
“Conditional Execution”
.
Operation
WFI is a hint instruction that suspends execution until one of the following events occurs:
• an exception
• a Debug Entry request, regardless of whether Debug is enabled.
Condition Flags
This instruction does not change the flags.
Examples
WFI ; Wait for interrupt