4 register description, 1 mcucr – mcu control register, 2 portb – port b data register – Rainbow Electronics ATmega8HVD User Manual
Page 70: 3 ddrb – port b data direction register, 4 pinb – port b input pins address, Atmega4hvd/8hvd
70
8052B–AVR–09/08
ATmega4HVD/8HVD
14.4
Register Description
14.4.1
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
”Configuring the Pin” on page 62
for more details about this feature.
14.4.2
PORTB – Port B Data Register
14.4.3
DDRB – Port B Data Direction Register
14.4.4
PINB – Port B Input Pins Address
Bit
7
6
5
4
3
2
1
0
–
–
CKOE
PUD
–
–
–
–
MCUCR
Read/Write
R
R
R/W
R/W
R
R
R
R
Initial Value
0
0
0
0
0
0
0
0
Bit
7
6
5
4
3
2
1
0
-
-
-
-
-
PORTB2
PORTB1
PORTB0
PORTB
Read/Write
R
R
R
R
R
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
-
-
-
-
-
DDB2
DDB1
DDB0
DDRB
Read/Write
R
R
R
R
R
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
-
-
-
-
-
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