The most common wake-up sources available for Deep Sleep include Interrupt 0, the DSWDT, an RTCC alarm, and the ULPWU. MCLR Reset can also be used as a wake-up source. However, I/O pin states will be lost upon wake-up, instead of waiting for application firmware to clear the Deep Sleep “RELEASE” bit. A power off/power on sequence will also “wake” a device from Deep Sleep, but this will behave exactly like a traditional Power-On Reset. Data stored in special Deep Sleep registers will not be retained over a full power off/on cycle, since VDD voltage is required to maintain these Deep Sleep registers. Like MCLR Reset, power off/power on cycling will not retain I/O pin states.