ATMEGA325-16AJ ATMEL [ATMEL Corporation], ATMEGA325-16AJ Datasheet - Page 64

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

64
ATmega325/3250/645/6450
• XCK/AIN0/PCINT2 – Port E, Bit 2
XCK, USART External Clock. The Data Direction Register (DDE2) controls whether the
clock is output (DDE2 set) or input (DDE2 cleared). The XCK pin is active only when the
USART operates in synchronous mode.
AIN0 – Analog Comparator Positive input. This pin is directly connected to the positive
input of the Analog Comparator.
PCINT2, Pin Change Interrupt Source 2: The PE2 pin can serve as an external interrupt
source.
• TXD/PCINT1 – Port E, Bit 1
TXD0, UART0 Transmit pin.
PCINT1, Pin Change Interrupt Source 1: The PE1 pin can serve as an external interrupt
source.
• RXD/PCINT0 – Port E, Bit 0
RXD, USART Receive pin. 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
DDE0. When the USART forces this pin to be an input, a logical one in PORTE0 will turn
on the internal pull-up.
PCINT0, Pin Change Interrupt Source 0: The PE0 pin can serve as an external interrupt
source.
Table 32 and Table 33 relates the alternate functions of Port E to the overriding signals
shown in Figure 26 on page 57.
Table 32. Overriding Signals for Alternate Functions PE7..PE4
Note:
Signal
Name
PUOE
PUOV
DDOE
DDOV
PVOE
PVOV
PTOE
DIEOE
DIEOV
DI
AIO
1. CKOUT is one if the CKOUT Fuse is programmed
PE7/PCINT7
0
0
CKOUT
1
CKOUT
clk
–
PCINT7 • PCIE0
1
PCINT7 INPUT
–
I/O
(1)
(1)
PE6/DO/
PCINT6
0
0
0
0
USI_THREE-
WIRE
DO
–
PCINT6 • PCIE0
1
PCINT6 INPUT
–
PE5/DI/SDA/
PCINT5
USI_TWO-WIRE
0
USI_TWO-WIRE
(SDA +
PORTE5) •
DDE5
USI_TWO-WIRE
• DDE5
0
–
(PCINT5 •
PCIE0) + USISIE
1
DI/SDA INPUT
PCINT5 INPUT
–
PE4/USCK/SCL/
PCINT4
0
0
USI_TWO-WIRE
(USI_SCL_HOL
D + PORTE4) +
DDE4
USI_TWO-WIRE
• DDE4
0
USITC
(PCINT4 •
PCIE0) + USISIE
1
USCKL/SCL
INPUT
PCINT4 INPUT
–
2570A–AVR–09/04