Starting from Power-Down Mode

When waking up from Power-Down sleep mode, the supply voltage is assumed to be at a sufficient level and only the oscillator start-up time is counted to ensure the stable operation of the oscillator. The oscillator start-up time is counted on the selected main clock, and the start-up time depends on the clock selected.

Table 1. Start-up Time from Power-Down Sleep Mode.
Oscillator start-up time	Total start-up time
6 cycles	6 oscillator cycles ⁽¹⁾

Note: 1. The start-up time is measured in main clock oscillator cycles.

8-bit AVR Microcontroller

Starting from Power-Down Mode