Datasheet

Clock I/O pin for the two-wire Serial Interface1. 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.
– PCINT25: Pin Change Interrupt source 25. The PE1 pin can serve as an external interrupt
source.
• ACO/ICP4/SDA1/PCINT24 – Port E, Bit 0
– PE0 can also be used as Analog Comparator output.
– ICP4: Input Capture Pin. The PE0 pin can act as an Input Capture Pin for Timer/Counter4.
– SDA1: Two-wire Serial Interface1 Data. When the TWEN bit in TWCR1 is set (one) to enable
the two-wire Serial Interface, pin PE0 is disconnected from the port and becomes the Serial
Data I/O pin for the two-wire Serial Interface1. 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.
Table 17-13 relate the alternate functions of Port E to the overriding signals shown in Figure 17-5.
Table 17-13. Overriding Signals for Alternate Functions in PE3...PE0
Signal
Name
PE3/ADC7/T3/MOSI1/
PCINT27
PE2/ADC6/ICP3/SS1/
PCINT26
PE1/T4/SCL1/
PCINT25
PE0/ACO/ICP4/SDA1/
PCINT24
PUOE SPE1 • MSTR SPE1 • MSTR TWEN aco_oe + TWEN
PUOV PORTE3 • PUD PORTE2 • PUD PORTE1 • PUD PORTE0 • PUD
DDOE SPE1 • MSTR SPE1 • MSTR TWEN aco_oe + TWEN
DDOV 0 0 0 0
PVOE SPE1 • MSTR 0 SCL_OUT aco_oe + SDA_OUT
PVOV SPI1 MSTR OUTPUT 0 TWEN acompout + TWEN
DIEOE PCINT27 • PCIE3
+ADC7D
PCINT26 • PCIE3
+ADC6D
PCINT25 • PCIE3 PCINT24 • PCIE3
DIEOV PCINT27 • PCIE3 PCINT26 • PCIE3 PCINT25 • PCIE3 PCINT24 • PCIE3
DI
T0 INPUT
SPI1 SLAVE INPUT
PCINT27 INPUT
PCINT26 INPUT
ICP3 INPUT
SPI SS1
T4 INPUT
PCINT25 INPUT
PCINT24 INPUT
ICP4 INPUT
AIO ADC7 INPUT ADC6 INPUT SCL1 INPUT
AC OUTPUT
SDA1 INPUT
17.4 Register Description
ATmega328PB
I/O-Ports
© 2018 Microchip Technology Inc.
Datasheet Complete
DS40001906C-page 118