ATMEGA163 ATMEL [ATMEL Corporation], ATMEGA163 Datasheet - Page 6

• Manufacturer Part Number: ATMEGA163
• Description: 8-bit Microcontroller with 16K Bytes In-System Programmable Flash
• Manufacturer: ATMEL [ATMEL Corporation]

Crystal Oscillator
External Clock
External RC Oscillator
Timer Oscillator
6
ATmega163(L)
XTAL1 and XTAL2 are input and output, respectively, of an inverting amplifier which can
be configured for use as an On-chip Oscillator, as shown in Figure 2. Either a quartz
crystal or a ceramic resonator may be used.
Figure 2. Oscillator Connections
To drive the device from an external clock source, XTAL1 should be driven as shown in
Figure 3.
Figure 3. External Clock Drive Configuration
For timing insensitive applications, the external RC configuration shown in Figure 4 can
be used. For details on how to choose R and C, see Table 64 on page 162.
Figure 4. External RC Configuration
For the Timer Oscillator pins, TOSC1 and TOSC2, the crystal is connected directly
between the pins. No external capacitors are needed. The Oscillator is optimized for use
with a 32,768 Hz watch crystal. Applying an external clock source to the TOSC1 pin is
not recommended.
C
R
V
CC
NC
XTAL2
XTAL1
GND
1142E–AVR–02/03