atmega323l ATMEL Corporation, atmega323l Datasheet - Page 153

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

Port D Schematics
1457G–AVR–09/03
• INT0 – Port D, Bit 2
INT0, External Interrupt Source 0: The PD2 pin can serve as an external interrupt
source to the MCU. See the interrupt description for further details, and how to enable
the source.
• TXD – Port D, Bit 1
TXD, Transmit Data (Data output pin for the USART). When the USART Transmitter is
enabled, this pin is configured as an output regardless of the value of DDD1.
• RXD – Port D, Bit 0
RXD, Receive Data (Data input pin for the USART). When the USART Receiver is
enabled this pin is configured as an input regardless of the value of DDD0. When the
USART forces this pin to be an input, a logical one in PORTD0 will turn on the internal
pull-up.
Note that all port pins are synchronized. The synchronization latches are not shown in
the figures.
Figure 79. Port D Schematic Diagram (Pin PD0)
PD0
WP:
WD:
RL:
RP:
RD:
RXD:
RXEN:
PUD:
MOS
PULL-
UP
WRITE PORTD
WRITE DDRD
READ PORTD LATCH
READ PORTD PIN
READ DDRD
UART RECEIVE DATA
UART RECEIVE ENABLE
PULL-UP DISABLE
PUD
RL
RP
ATmega323(L)
Q
Q
PORTD0
RESET
RESET
DDD0
WD
WP
RD
C
C
D
D
RXEN
RXD
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