The main function of the supply voltage supervisor is to oversee DVcc. By default, the Supply Voltage Supervision (SVS) is turned ON for all power modes. It is possible to disable the SVS to save power in some modes such as LPM3, 4, 3.5 and 4.5. As mentioned in the previous slide the PMM module provides a means for DVcc and the internal core voltage to be supervised. When the device is powering up, the SVS ensures that a power stable power supply is available before releasing the device from reset. The SVS is on by default at power up ensuring that the device only starts to execute code when a clean rail is present. After power up, during operation, the SVS function detects when the supply voltage falls below a specified threshold and alerts the application accordingly. In the FR59xx device there is an additional option to set the device in LPM4.5 when an SVS event due to power fail occurs. In this case, the device fires a system non-maskable interrupt instead of issuing a reset. This allows the application to safely turn off critical tasks, lock I/Os and disable the SVS to further save power before entering LPM4.5 ensuring optimized usage of the remaining battery power.