Datasheet

84
ATmega16U4/32U4 [DATASHEET]
Atmel-7766J-USB-ATmega16U4/32U4-Datasheet_04/2016
10.4 Register Description for I/O-Ports
10.4.1 MCU Control Register – MCUCR
• Bit 4 – PUD: Pull-up Disable
When this bit is written to one, the pull-ups in the I/O ports are disabled even if the DDxn and PORTxn Registers
are configured to enable the pull-ups ({DDxn, PORTxn} = 0b01). See “Configuring the Pin” on page 68 for more
details about this feature.
10.4.2 Port B Data Register – PORTB
10.4.3 Port B Data Direction Register – DDRB
10.4.4 Port B Input Pins Address – PINB
10.4.5 Port C Data Register – PORTC
10.4.6 Port C Data Direction Register – DDRC
Bit7654 3210
JTD – –PUD– – IVSEL IVCE MCUCR
Read/Writ
e
R/W R R R/W R R R/W R/W
Initial Val-
ue
0000 0000
Bit 76543210
PORTB7 PORTB6 PORTB5 PORTB4 PORTB3 PORTB2 PORTB1 PORTB0 PORTB
Read/Write R/W R/W R/W R/W R/W R/W R/W R/W
Initial Value 0 0 0 0 0 0 0 0
Bit 76543210
DDB7 DDB6 DDB5 DDB4 DDB3 DDB2 DDB1 DDB0 DDRB
Read/Write R/W R/W R/W R/W R/W R/W R/W R/W
Initial Value 0 0 0 0 0 0 0 0
Bit 76543210
PINB7 PINB6 PINB5 PINB4 PINB3 PINB2 PINB1 PINB0 PINB
Read/Write R/W R/W R/W R/W R/W R/W R/W R/W
Initial Value N/A N/A N/A N/A N/A N/A N/A N/A
Bit 76543210
PORTC7PORTC6------PORTC
Read/Write R/W R/W R/W R/W R/W R/W R/W R/W
Initial Value00000000
Bit 76543210
DDC7 DDC6 - - ----DDRC
Read/Write R/W R/W R/W R/W R/W R/W R/W R/W
Initial Value00000000