On prior PIC® microcontrollers, Sleep mode was provided to allow low-power use by shutting down the processor core. However, SRAM remained powered-on to retain data. To completely stop power consumption, an external switch circuit would be required to cut power to the microcontroller. On new PIC microcontrollers with Deep Sleep capability, both the processor core and SRAM are powered-off to drop power consumption to virtually zero, eliminating the need for an external switch. Certain key peripherals can be configured to remain powered-on, allowing greater flexibility for applications.