atmega161-4pi ATMEL Corporation, atmega161-4pi Datasheet - Page 6

• Manufacturer Part Number: atmega161-4pi
• Description: 8-bit Microcontroller With 16k Bytes Of In-system Programmable Flash
• Manufacturer: ATMEL Corporation

Crystal Oscillator
6
ATmega161(L)
XTAL1 and XTAL2 are input and output, respectively, of an inverting amplifier that 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. To drive the device from an external clock
source, XTAL2 should be left unconnected while XTAL1 is driven as shown in Figure 3.
Figure 2. Oscillator Connections
Figure 3. External Clock Drive Configuration
OSCILLATOR
EXTERNAL
SIGNAL
NC
C2
C1
XTAL2
XTAL1
GND
XTAL2
XTAL1
GND
1228D–AVR–02/07