SLAU723A October 2017 – October 2018 MSP432E401Y , MSP432E411Y
The wait for event instruction, WFE, causes entry to sleep mode conditional on the value of a 1-bit event register. When the processor executes a WFE instruction, it checks the event register. If the register is 0, the processor stops executing instructions and enters sleep mode. If the register is 1, the processor clears the register and continues executing instructions without entering sleep mode.
If the event register is 1, the processor must not enter sleep mode when a WFE instruction is executed. Typically, this situation occurs if an SEV instruction has been executed. Software cannot access this register directly.
See the Cortex-M4 instruction set chapter in the Arm Cortex-M4 Devices Generic User Guide for more information.