3.1.2 Full Swing Crystal Oscillator

A clarification has been made to Table 9-6 Start-Up Times for the Full Swing Crystal Oscillator Clock Selection, where 14 CK in the column Additional Delay from Reset (VCC = 5.0V) has been replaced by 19 CK. Functional changes are shown in bold.

Table 9-6. Start-Up Times for the Full Swing Crystal Oscillator Clock Selection

Oscillator Source/Power ConditionsStart-Up Time from Power-Down and Power-SaveAdditional Delay from Reset 
(VCC = 5.0V)CKSEL0SUT[1:0]
Ceramic resonator, fast rising power258 CK19 CK + 4.1 ms(1)000
Ceramic resonator, slowly rising power258 CK19 CK + 65 ms(1)001
Ceramic resonator, BOD enabled1K CK19 CK(2)010
Ceramic resonator, fast rising power1K CK19 CK + 4.1 ms(2)011
Ceramic resonator, slowly rising power1K CK19 CK + 65 ms(2)100
Crystal Oscillator, BOD enabled16K CK19 CK101
Crystal Oscillator, fast rising power16K CK19 CK + 4.1 ms110
Crystal Oscillator, slowly rising power16K CK19 CK + 65 ms111
Note:
  1. These options should only be used when not operating close to the maximum device frequency 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 device frequency and if frequency stability at start-up is unimportant for the application.