Datasheet

27
2503Q–AVR–02/11
ATmega32(L)
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 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 fre-
quency 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
0 00 258 CK
(1)
4.1ms
Ceramic resonator, fast
rising power
0 01 258 CK
(1)
65ms
Ceramic resonator, slowly
rising power
010 1K CK
(2)
–
Ceramic resonator, BOD
enabled
011 1K CK
(2)
4.1ms
Ceramic resonator, fast
rising power
100 1K CK
(2)
65ms
Ceramic resonator, slowly
rising power
101 16K CK –
Crystal Oscillator, BOD
enabled
1 10 16K CK 4.1ms
Crystal Oscillator, fast
rising power
1 11 16K CK 65ms
Crystal Oscillator, slowly
rising power