ATmega328P datasheet(86/448 Pages) ATMEL

86 / 448 page

8161D–AVR–10/09

ATmega48PA/88PA/168PA/328P

The alternate pin configuration is as follows:

• RESET/PCINT14 – Port C, Bit 6

RESET, Reset pin: When the RSTDISBL Fuse is programmed, this pin functions as a normal I/O

pin, and the part will have to rely on Power-on Reset and Brown-out Reset as its reset sources.

When the RSTDISBL Fuse is unprogrammed, the reset circuitry is connected to the pin, and the

pin can not be used as an I/O pin.

If PC6 is used as a reset pin, DDC6, PORTC6 and PINC6 will all read 0.

PCINT14: Pin Change Interrupt source 14. The PC6 pin can serve as an external interrupt

source.

• SCL/ADC5/PCINT13 – Port C, Bit 5

SCL, 2-wire Serial Interface Clock: When the TWEN bit in TWCR is set (one) to enable the 2-

wire Serial Interface, pin PC5 is disconnected from the port and becomes the Serial Clock I/O

pin for the 2-wire Serial Interface. In this mode, there is a spike filter on the pin to suppress

spikes shorter than 50 ns on the input signal, and the pin is driven by an open drain driver with

slew-rate limitation.

PC5 can also be used as ADC input Channel 5. Note that ADC input channel 5 uses digital

power.

PCINT13: Pin Change Interrupt source 13. The PC5 pin can serve as an external interrupt

source.

• SDA/ADC4/PCINT12 – Port C, Bit 4

SDA, 2-wire Serial Interface Data: When the TWEN bit in TWCR is set (one) to enable the 2-wire

Serial Interface, pin PC4 is disconnected from the port and becomes the Serial Data I/O pin for

the 2-wire Serial Interface. In this mode, there is a spike filter on the pin to suppress spikes

shorter than 50 ns on the input signal, and the pin is driven by an open drain driver with slew-

rate limitation.

PC4 can also be used as ADC input Channel 4. Note that ADC input channel 4 uses digital

power.

PCINT12: Pin Change Interrupt source 12. The PC4 pin can serve as an external interrupt

source.

• ADC3/PCINT11 – Port C, Bit 3

PC3 can also be used as ADC input Channel 3. Note that ADC input channel 3 uses analog

power.

PCINT11: Pin Change Interrupt source 11. The PC3 pin can serve as an external interrupt

source.

• ADC2/PCINT10 – Port C, Bit 2

PC2 can also be used as ADC input Channel 2. Note that ADC input channel 2 uses analog

power.

PCINT10: Pin Change Interrupt source 10. The PC2 pin can serve as an external interrupt

source.

ATmega328P Datenblatt(PDF) 86 Page - ATMEL Corporation