Rainbow Electronics ATmega162V - Manual (Page 35)

35
ATmega162/V
2513E–AVR–09/03
Figure 19. Crystal Oscillator Connections
The Oscillator can operate in four different modes, each optimized for a specific fre-
quency range. The operating mode is selected by the fuses CKSEL3:1 as shown in
Table 7.
Note: 1. This option should not be used with crystals, only with ceramic resonators.
The CKSEL0 Fuse together with the SUT1..0 Fuses select the start-up times as shown
in Table 8.
Table 7. Crystal Oscillator Operating Modes
CKSEL3:1
Frequency Range
(MHz)
Recommended Range for Capacitors C1 and
C2 for Use with Crystals (pF)
100 (1) 0.4 - 0.9 –
101 0.9 - 3.0 12 - 22
110 3.0 - 8.0 12 - 22
111 8.0 - 12 - 22
Table 8. 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) 4.1 ms Ceramic resonator,
fast rising power
0 01 258 CK (1) 65 ms Ceramic resonator,
slowly rising power
0 10 1K CK (2) – Ceramic resonator,
BOD enabled
0 11 1K CK (2) 4.1 ms Ceramic resonator,
fast rising power
1 00 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
XTAL2
XTAL1
GND
C2
C1