ATMEGA325-16AJ ATMEL [ATMEL Corporation], ATMEGA325-16AJ Datasheet - Page 7

• Manufacturer Part Number: ATMEGA325-16AJ
• Description: 8-bit Microcontroller with In-System Programmable Flash
• Manufacturer: ATMEL [ATMEL Corporation]

Port F (PF7..PF0)
Port G (PG4..PG0)
Port H (PH7..PH0)
Port J (PJ6..PJ0)
RESET
XTAL1
XTAL2
AVCC
2570A–AVR–09/04
current if the pull-up resistors are activated. The Port E pins are tri-stated when a reset
condition becomes active, even if the clock is not running.
P o r t E a l s o s e r v e s t h e f u n c t i o n s o f v a r i o u s s p e c i a l f e a t u r e s o f t h e
ATmega325/3250/645/6450 as listed on page 63.
Port F serves as the analog inputs to the A/D Converter.
Port F also serves as an 8-bit bi-directional I/O port, if the A/D Converter is not used.
Port pins can provide internal pull-up resistors (selected for each bit). The Port F output
buffers have symmetrical drive characteristics with both high sink and source capability.
As inputs, Port F pins that are externally pulled low will source current if the pull-up
resistors are activated. The Port F pins are tri-stated when a reset condition becomes
active, even if the clock is not running. If the JTAG interface is enabled, the pull-up resis-
tors on pins PF7(TDI), PF5(TMS), and PF4(TCK) will be activated even if a reset
occurs.
Port F also serves the functions of the JTAG interface.
Port G is a 5-bit bi-directional I/O port with internal pull-up resistors (selected for each
bit). The Port G output buffers have symmetrical drive characteristics with both high sink
and source capability. As inputs, Port G pins that are externally pulled low will source
current if the pull-up resistors are activated. The Port G pins are tri-stated when a reset
condition becomes active, even if the clock is not running.
P o r t G a l s o s e r v e s t h e f u n c t i o n s o f v a r i o u s s p e c i a l f e a t u r e s o f t h e
ATmega325/3250/645/6450 as listed on page 63.
Port H is a 8-bit bi-directional I/O port with internal pull-up resistors (selected for each
bit). The Port H output buffers have symmetrical drive characteristics with both high sink
and source capability. As inputs, Port H pins that are externally pulled low will source
current if the pull-up resistors are activated. The Port H pins are tri-stated when a reset
condition becomes active, even if the clock is not running.
Port H also serves the functions of various special features of the ATmega3250/6450 as
listed on page 63.
Port J is a 7-bit bi-directional I/O port with internal pull-up resistors (selected for each
bit). The Port J output buffers have symmetrical drive characteristics with both high sink
and source capability. As inputs, Port J pins that are externally pulled low will source
current if the pull-up resistors are activated. The Port J pins are tri-stated when a reset
condition becomes active, even if the clock is not running.
Port J also serves the functions of various special features of the ATmega3250/6450 as
listed on page 63.
Reset input. A low level on this pin for longer than the minimum pulse length will gener-
ate a reset, even if the clock is not running. The minimum pulse length is given in Table
16 on page 39. Shorter pulses are not guaranteed to generate a reset.
Input to the inverting Oscillator amplifier and input to the internal clock operating circuit.
Output from the inverting Oscillator amplifier.
AVCC is the supply voltage pin for Port F and the A/D Converter. It should be externally
connected to V
nected to V
CC
through a low-pass filter.
CC
, even if the ADC is not used. If the ADC is used, it should be con-
ATmega325/3250/645/6450
7