2.3.6
2.3.7
2.3.8
Port D (PD7..PD0)
Port D is an 8-bit bi-directional I/O port with internal pull-up resistors (selected for each bit). The Port D output buf-
fers have symmetrical drive characteristics with both high sink and source capability. As inputs, Port D pins that are
externally pulled low will source current if the pull-up resistors are activated. The Port D pins are tri-stated when a
reset condition becomes active, even if the clock is not running.
Port D also serves the functions of various special features of the ATmega640/1280/1281/2560/2561 as listed on
page 80.
Port E (PE7..PE0)
Port E is an 8-bit bi-directional I/O port with internal pull-up resistors (selected for each bit). The Port E output buf-
fers have symmetrical drive characteristics with both high sink and source capability. As inputs, Port E pins that are
externally pulled low will source 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.
Port E also serves the functions of various special features of the ATmega640/1280/1281/2560/2561 as listed on
page 82.
Port F (PF7..PF0)
Port F serves as 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 resistors 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.
2.3.9
Port G (PG5..PG0)
Port G is a 6-bit I/O port with internal pull-up resistors (selected for each bit). The Port G output buffers have sym-
metrical 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 con-
dition becomes active, even if the clock is not running.
Port G also serves the functions of various special features of the ATmega640/1280/1281/2560/2561 as listed on
page 86.
2.3.10
2.3.11
Port H (PH7..PH0)
Port H is a 8-bit bi-directional I/O port with internal pull-up resistors (selected for each bit). The Port H output buf-
fers 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 ATmega640/1280/2560 as listed on page 88.
Port J (PJ7..PJ0)
Port J is a 8-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 ATmega640/1280/2560 as listed on page 90.
ATmega640/V-1280/V-1281/V-2560/V-2561/V [SUMMARY]
8
2549QS–AVR–02/2014
ATMEL [ ATMEL ]
