Data Sheet

32
ATmega48A/PA/88A/PA/168A/PA/328/P [DATASHEET]
Atmel-8271H-AVR- ATmega-Datasheet_08/2014
Notes: 1. These options should only be used when not operating close to the maximum frequency of the device, and
only if frequency stability at start-up is not important for the application. These options are not suitable for
crystals.
2. These options are intended for use with ceramic resonators and will ensure frequency stability at start-up. They
can also be used with crystals when not operating close to the maximum frequency of the device, and if
frequency stability at start-up is not important for the application.
Crystal Oscillator, BOD
enabled
16K CK 14CK 1 01
Crystal Oscillator, fast
rising power
16K CK 14CK + 4.1ms 1 10
Crystal Oscillator, slowly
rising power
16K CK 14CK + 65ms 1 11
Table 9-6. Start-up Times for the Full Swing Crystal Oscillator Clock Selection (Continued)
Oscillator Source /
Power Conditions
Start-up Time from
Power-down and
Power-save
Additional Delay
from Reset
(V
CC
= 5.0V) CKSEL0 SUT1...0