Datasheet

81
ATmega16U4/32U4 [DATASHEET]
Atmel-7766J-USB-ATmega16U4/32U4-Datasheet_04/2016
10.3.4 Alternate Functions of Port E
The Port E pins with alternate functions are shown below.
• INT6/AIN0 – Port E, Bit 6
INT6, External Interrupt source 6: The PE6 pin can serve as an external interrupt source.
AIN0 – Analog Comparator Negative input. This pin is directly connected to the negative input of the Analog
Comparator.
•HWB – Port E, Bit 2
HWB allows to execute the bootloader section after reset when tied to ground during external reset pulse. The
HWB mode of this pin is active only when the HWBE fuse is enable. During normal operation (excluded Reset),
this pin acts as a general purpose I/O.
10.3.5 Alternate Functions of Port F
The Port F has an alternate function as analog input for the ADC as shown in Table 10-13 on page 82. If some
Port F pins are configured as outputs, it is essential that these do not switch when a conversion is in progress.
Table 10-11. Port E Pins Alternate Functions
Port Pin Alternate Function
PE7 Not present on pin-out.
PE6 INT6/AIN0 (External Interrupt 6 Input or Analog Comparator Positive Input)
PE5
Not present on pin-out.PE4
PE3
PE2 HWB (Hardware bootloader activation)
PE1
Not present on pin-out.
PE0
Table 10-12. Overriding Signals for Alternate Functions PE6, PE2
Signal Name PE6/INT6/AIN0 PE2/HWB
PUOE 0 0
PUOV 0 0
DDOE 0 0
DDOV 0 1
PVOE 0 0
PVOV 0 0
DIEOE INT6 ENABLE 0
DIEOV 1 0
DI INT6 INPUT HWB
AIO AIN0 INPUT -