Low Power WAIT Mode

Currently, CodeWarrior supports two low power modes: normal WAIT and normal STOP. The Microcontrollers Software Analysis Tools component provides support for the normal WAIT state. This state allows peripherals to function, while allowing CPU to go to sleep reducing power.

The Wait For Interrupt (WFI) instruction is used to enter the low power WAIT state. When an interrupt request occurs, the CPU exits the WAIT mode and resumes processing, beginning with the stacking operations leading to the interrupt service routine.

Note: When a processor issues a WFI instruction, it can suspend execution and enter a low power state. The processor can remain in that state until it detects a reset or one of the following WFI wake-up events:

an asynchronous exception at a priority that preempts any currently active exceptions.
a debug event with debug enabled.

When the hardware detects a WFI wake-up event, or earlier if the implementation chooses, the WFI instruction completes.

To activate low power mode monitoring and view results, you need to:

Configure Low Power WAIT State
Debug the project and collect trace data.
View Low Power WAIT Results

These steps are described in the following topics.