Power-Down mode does everything that Deep Sleep mode does, but also turns off the flash memory. This saves more power, but requires waiting for resumption of flash operation before execution of code or data access in the flash memory can be accomplished. Wake up from Power-Down mode can be brought about by a Non-Maskable Interrupt (NMI), External Interrupts EINT0 through EINT3, GPIO interrupts, the Ethernet Wake-on-LAN interrupt, Brownout Detect, an RTC Alarm interrupt, a USB input pin transition, or a CAN input pin transition, when the related interrupt is enabled. In Deep Power-Down mode, power is shut off to the entire chip with the exception of the Real-Time Clock, the RESET pin, the WIC, and the RTC backup registers. To optimize power conservation, the user has the additional option of turning off or retaining power to the 32 kHz oscillator. Wake up from Deep Power-down mode will occur when an external reset signal is applied, or the RTC interrupt is enabled and an RTC interrupt is generated.