Datasheet

27
ATmega8535(L)
2502K–AVR–10/06
The CKSEL0 fuse together with the SUT1..0 Fuses select the start-up times as shown in
Table 5.
Notes: 1. These options should only be used when not operating close to the maximum fre-
quency 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 fre-
quency 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.
Table 5. Start-up Times for the Crystal Oscillator Clock Selection
CKSEL0 SUT1..0
Start-up Time from
Power-down and
Power-save
Additional Delay
from Reset
(V
CC
= 5.0V) Recommended Usage
000 258 CK
(1)
4.1 ms Ceramic resonator, fast
rising power
001 258 CK
(1)
65 ms Ceramic resonator,
slowly rising power
010 1K CK
(2)
– Ceramic resonator, BOD
enabled
011 1K CK
(2)
4.1 ms Ceramic resonator, fast
rising power
100 1K CK
(2)
65 ms Ceramic resonator,
slowly rising power
1 01 16K CK – Crystal Oscillator, BOD
enabled
1 10 16K CK 4.1 ms Crystal Oscillator, fast
rising power
1 11 16K CK 65 ms Crystal Oscillator, slowly
rising power