The Port E pins with alternate functions
are shown in this table:
Table 1. Port E Pins Alternate Functions
Port Pin |
Alternate Function |
PE3 |
ADC7 (ADC Input Channel 7)
MOSI1 (SPI1 Master Data output)
T3 (Timer/Counter 3 External Counter Input)
PCINT27
|
PE2 |
ADC6 (ADC Input Channel 6)
ICP3 (Timer/Counter3 Input Capture Input)
SS1 (SPI1 Bus Master Slave select)
PCINT26
|
PE1 |
T4 (Timer/Counter 4 External Counter Input)
SCL1 (two-wire Serial1 Bus Clock Line)
PCINT25
|
PE0 |
ACO (AC Output Channel 0)
ICP4 (Timer/Counter4 Input Capture Input)
SDA1 (two-wire Serial1 Bus Data Input/Output Line)
PCINT24
|
The alternate pin configuration is as follows:
- ADC7/T3/MOSI1/PCINT27– Port E, Bit 3
- PE3 can also be used as ADC input
Channel 7.
- T3: Timer/Counter3 counter
source.
- MOSI1: SPI1 Master Data output, Slave Data input for SPI1 channel. When the SPI1
is enabled as a Slave, this pin is configured as an input regardless of the
setting of DDE3. When the SPI1 is enabled as a Master, the data direction of this
pin is controlled by DDE3. When the pin is forced by the SPI1 to be an input, the
pull-up can still be controlled by the PORTE3 bit.
- PCINT27: Pin Change Interrupt
source 27. The PE3 pin can serve as an external interrupt source.
- ADC6/ICP3/SS1/PCINT26 – Port E, Bit 2
- PE2 can also be used as ADC input Channel 6.
- ICP3: Input Capture Pin. The PE2 pin can act as an Input Capture Pin for
Timer/Counter3.
- PCINT26: Pin Change Interrupt source 26. The PE2 pin can serve as an external
interrupt source.
- T4/SCL1/PCINT25 – Port E, Bit 1
- T4: Timer/Counter4 counter source.
- SCL1: Two-wire Serial Interface1
Clock. When the TWEN bit in TWCR1 is set (one) to enable the two-wire Serial
Interface, pin PE1 is disconnected from the port and becomes the Serial 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 2 relate the alternate functions of Port E to the overriding
signals shown in Figure 1.
Table 2. 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
|