92
8025I–AVR–02/09
ATmega48P/88P/168P/328P
11.4
Register Description
11.4.1
MCUCR – MCU Control Register
• 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
for more details about this feature.
11.4.2
PORTB – The Port B Data Register
11.4.3
DDRB – The Port B Data Direction Register
11.4.4
PINB – The Port B Input Pins Address
11.4.5
PORTC – The Port C Data Register
11.4.6
DDRC – The Port C Data Direction Register
11.4.7
PINC – The Port C Input Pins Address
Bit
7
6
5
4
3
2
1
0
–
BODS
BODSE
PUD
–
–
IVSEL
IVCE
MCUCR
Read/Write
R
R
R
R/W
R
R
R/W
R/W
Initial Value
0
0
0
0
0
0
0
0
Bit
7
6
5
4
3
2
1
0
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
7
6
5
4
3
2
1
0
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
7
6
5
4
3
2
1
0
PINB7
PINB6
PINB5
PINB4
PINB3
PINB2
PINB1
PINB0
PINB
Read/Write
R
R
R
R
R
R
R
R
Initial Value
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
Bit
7
6
5
4
3
2
1
0
–
PORTC6
PORTC5
PORTC4
PORTC3
PORTC2
PORTC1
PORTC0
PORTC
Read/Write
R
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
7
6
5
4
3
2
1
0
–
DDC6
DDC5
DDC4
DDC3
DDC2
DDC1
DDC0
DDRC
Read/Write
R
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
7
6
5
4
3
2
1
0
–
PINC6
PINC5
PINC4
PINC3
PINC2
PINC1
PINC0
PINC
Read/Write
R
R
R
R
R
R
R
R
Initial Value
0
N/A
N/A
N/A
N/A
N/A
N/A
N/A