Datasheet

75
ATmega16U4/32U4 [DATASHEET]
Atmel-7766J-USB-ATmega16U4/32U4-Datasheet_04/2016
• OC1A/PCINT5/OC.4B/ADC12, Bit 5
OC1A, Output Compare Match A output: The PB5 pin can serve as an external output for the Timer/Counter1
Output Compare A. The pin has to be configured as an output (DDB5 set (one)) to serve this function. The
OC1A pin is also the output pin for the PWM mode timer function.
PCINT5, Pin Change Interrupt source 5: The PB7 pin can serve as an external interrupt source.
OC.4B
: Timer 4 Output Compare B. This pin can be used to generate a high-speed PWM signal from Timer 4
module, complementary to OC.4B (PB5) signal. The pin has to be configured as an output (DDB5 set (one)) to
serve this function.
ADC12: Analog to Digital Converter, channel 12.
• PCINT4/ADC11, Bit 4
PCINT4, Pin Change Interrupt source 4: The PB7 pin can serve as an external interrupt source.
ADC11, Analog to Digital Converter channel 11.
• PDO/MISO/PCINT3 – Port B, Bit 3
PDO, SPI Serial Programming Data Output. During Serial Program Downloading, this pin is used as data output
line for the ATmega16U4/ATmega32U4.
MISO: Master Data input, Slave Data output pin for SPI channel. When the SPI is enabled as a master, this pin
is configured as an input regardless of the setting of DDB3. When the SPI is enabled as a slave, the data
direction of this pin is controlled by DDB3. When the pin is forced to be an input, the pull-up can still be
controlled by the PORTB3 bit.
PCINT3, Pin Change Interrupt source 3: The PB7 pin can serve as an external interrupt source.
• PDI/MOSI/PCINT2 – Port B, Bit 2
PDI, SPI Serial Programming Data Input. During Serial Program Downloading, this pin is used as data input line
for the ATmega16U4/ATmega32U4.
MOSI: SPI Master Data output, Slave Data input for SPI channel. When the SPI is enabled as a slave, this pin is
configured as an input regardless of the setting of DDB2. When the SPI is enabled as a master, the data
direction of this pin is controlled by DDB2. When the pin is forced to be an input, the pull-up can still be
controlled by the PORTB2 bit.
PCINT2, Pin Change Interrupt source 2: The PB7 pin can serve as an external interrupt source.
• SCK/PCINT1 – Port B, Bit 1
SCK: Master Clock output, Slave Clock input pin for SPI channel. When the SPI is enabled as a slave, this pin is
configured as an input regardless of the setting of DDB1. When the SPI0 is enabled as a master, the data
direction of this pin is controlled by DDB1. When the pin is forced to be an input, the pull-up can still be
controlled by the PORTB1 bit.
PCINT1, Pin Change Interrupt source 1: The PB7 pin can serve as an external interrupt source.
•SS/PCINT0 – Port B, Bit 0
SS: Slave Port Select input. When the SPI is enabled as a slave, this pin is configured as an input regardless of
the setting of DDB0. As a slave, the SPI is activated when this pin is driven low. When the SPI is enabled as a
master, the data direction of this pin is controlled by DDB0. When the pin is forced to be an input, the pull-up can
still be controlled by the PORTB0 bit.
Table 10-4 and Table 10-5 on page 76 relate the alternate functions of Port B to the overriding signals shown in
Figure 10-5 on page 72. SPI MSTR INPUT and SPI SLAVE OUTPUT constitute the MISO signal, while MOSI is
divided into SPI MSTR OUTPUT and SPI SLAVE INPUT.