Modes of OperationThe ARM CPU has t

Modes of OperationThe ARM CPU has three primary modes of operation: run, sleep, and deep sleep. The WFI instruction is used to invoke sleep and deep sleep modes. For Freescale microcontrollers, run, wait and stop are the common terminology used for the primary operating modes. The following table shows the translation between the ARM CPU and the MCU power modes.ARM CPU mode MCU modeSleep WaitDeep sleep StopAccordingly, the ARM CPU documentation refers to sleep and deep sleep, while the Freescale MCU documentation normally uses wait and stop.This device augments stop, wait, and run in a number of ways. The power management controller (PMC) contains a run and a stop mode regulator. Run regulation is used in normal run, wait and stop modes. Stop mode regulation is used during all very low power and low leakage modes. During stop mode regulation the bus frequencies are limited for the very low power modes.The PMC provides the user with multiple power options. The low power operating modes can drastically reduce run time power when maximum bus frequency is not required tohandle the application needs. From normal run mode, the run mode (RUNM) bit field can be modified to change the the MCU into the very lower power run (VLPR) mode whenlimited frequency is required during the application. For the low power run mode, a corresponding wait and stop mode can be entered.Depending on the needs of the user application, a variety of stop modes are available that allow the state retention, partial power down or full power down of certain logic and/ormemory. I/O states are held in all modes of operation. Several registers are used to configure the various modes of operation for the device.The following table describes the power modes available for the device.