atmega323l ATMEL Corporation, atmega323l Datasheet - Page 7

• Manufacturer Part Number: atmega323l
• Description: Atmega323 8-bit Avr Microcontroller With 32k Bytes Of In-system Programmable Flash
• Manufacturer: ATMEL Corporation

External Clock
External RC Oscillator
Timer Oscillator
1457G–AVR–09/03
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 73 on page 215.
Figure 4. External RC Configuration
For the Timer Oscillator pins, PC6(TOSC1) and PC7(TOSC2), the crystal is connected
directly between the pins. No external capacitors are needed. The Oscillator is opti-
mized for use with a 32.768 kHz watch crystal. Applying an external clock source to
PC6(TOSC1) is not recommended.
R
C
V
CC
NC
XTAL2
XTAL1
GND
ATmega323(L)
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