Datasheet

6.1.11. XTAL1
Input to the inverting Oscillator amplifier and input to the internal clock operating circuit.
6.1.12. XTAL2
Output from the inverting Oscillator amplifier.
6.1.13. AV
CC
AV
CC
is the supply voltage pin for Port F and the A/D Converter. It should be externally connected to V
CC
,
even if the ADC is not used. If the ADC is used, it should be connected to V
CC
through a low-pass filter.
6.1.14. AREF
AREF is the analog reference pin for the A/D Converter.
6.1.15. PEN
PEN is a programming enable pin for the SPI Serial Programming mode, and is internally pulled high. By
holding this pin low during a Power-on Reset, the device will enter the SPI Serial Programming mode.
PEN has no function during normal operation.
Atmel ATmega64A [DATASHEET]
Atmel-8160E-ATmega64A_Datasheet_Complete-09/2015
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