179
SAM4CP [DATASHEET]
43051E–ATPL–08/14
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
12.6.12.12 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
12.7
Cortex-M4 Core Peripherals
12.7.1 Peripherals
Nested Vectored Interrupt Controller (NVIC)
The Nested Vectored Interrupt Controller (NVIC) is an embedded interrupt controller that supports low latency
interrupt processing. See
Section 12.8 ”Nested Vectored Interrupt Controller (NVIC)”
System Control Block (SCB)
The System Control Block (SCB) is the programmers model interface to the processor. It provides system
implementation information and system control, including configuration, control, and reporting of system
exceptions. See
Section 12.9 ”System Control Block (SCB)”
System Timer (SysTick)
The System Timer, SysTick, is a 24-bit count-down timer. Use this as a Real Time Operating System (RTOS) tick
timer or as a simple counter. See
Section 12.10 ”System Timer (SysTick)”
Memory Protection Unit (MPU)
The Memory Protection Unit (MPU) improves system reliability by defining the memory attributes for different
memory regions. It provides up to eight different regions, and an optional predefined background region. See
Section 12.11 ”Memory Protection Unit (MPU)”
Floating-point Unit (FPU)
The Floating-point Unit (FPU) provides IEEE754-compliant operations on single-precision, 32-bit, floating-point
values. See
Section 12.12 ”Floating Point Unit (FPU)”