atmega32u4-16mu ATMEL Corporation, atmega32u4-16mu Datasheet - Page 76

• Manufacturer Part Number: atmega32u4-16mu
• Description: Atmega32u4 8-bit Avr Microcontroller With 32k Bytes Of Isp Flash And Usb Controller
• Manufacturer: ATMEL Corporation

ADC8: Analog to Digital Converter, Channel 8
.
• INT3/TXD1 – Port D, Bit 3
INT3, External Interrupt source 3: The PD3 pin can serve as an external interrupt source to the
MCU.
TXD1, Transmit Data (Data output pin for the USART1). When the USART1 Transmitter is
enabled, this pin is configured as an output regardless of the value of DDD3.
• INT2/RXD1 – Port D, Bit 2
INT2, External Interrupt source 2. The PD2 pin can serve as an External Interrupt source to the
MCU.
RXD1, Receive Data (Data input pin for the USART1). When the USART1 receiver is enabled
this pin is configured as an input regardless of the value of DDD2. When the USART forces this
pin to be an input, the pull-up can still be controlled by the PORTD2 bit.
• INT1/SDA/OC2B – Port D, Bit 1
INT1, External Interrupt source 1. The PD1 pin can serve as an external interrupt source to the
MCU.
SDA, 2-wire Serial Interface Data: When the TWEN bit in TWCR is set (one) to enable the 2-wire
Serial Interface, pin PD1 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.
OC.2B: Timer 2 Output Compare B. This pin can be used to generate a PWM signal from the
Timer 2 module.
• INT0/SCL/OC0B – Port D, Bit 0
INT0, External Interrupt source 0. The PD0 pin can serve as an external interrupt source to the
MCU.
SCL, 2-wire Serial Interface Clock: When the TWEN bit in TWCR is set (one) to enable the 2-
wire Serial Interface, pin PD0 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.
OC.0B: Timer 0 Output Compare B. This pin can be used to generate a PWM signal from the
Timer 0 module.
Table 10-9
and
Table 10-10
relates the alternate functions of Port D to the overriding signals
shown in
Figure 10-5 on page
68.
ATmega32U4
76
7766A–AVR–03/08