ATMEGA2561V ATMEL [ATMEL Corporation], ATMEGA2561V Datasheet - Page 115

• Manufacturer Part Number: ATMEGA2561V
• Description: 8-bit Microcontroller with 64K/128K/256K Bytes In-System Programmable Flash
• Manufacturer: ATMEL [ATMEL Corporation]

Register Description for I/O-Ports
MCUCR – MCU Control
Register
PORTA – Port A Data Register
DDRA – Port A Data Direction
Register
PINA – Port A Input Pins
Address
PORTB – Port B Data Register
DDRB – Port B Data Direction
Register
PINB – Port B Input Pins
Address
2549K–AVR–01/07
• Bit 4 – PUD: Pull-up Disable
When this bit is written to one, the I/O ports pull-up resistors are disabled even if the
DDxn and PORTxn Registers are configured to enable the pull-up resistor ({DDxn,
PORTxn} = 0b01). See “Configuring the Pin” on page 84 for more details about this
feature.
Bit
0x35 (0x55)
Read/Write
Initial Value
Bit
0x02 (0x22)
Read/Write
Initial Value
Bit
0x01 (0x21)
Read/Write
Initial Value
Bit
0x00 (0x20)
Read/Write
Initial Value
Bit
0x05 (0x25)
Read/Write
Initial Value
Bit
0x04 (0x24)
Read/Write
Initial Value
Bit
0x03 (0x23)
Read/Write
Initial Value
PORTB7
PORTA7
PINA7
PINB7
DDB7
DDA7
R/W
R/W
R/W
R/W
R/W
R/W
N/A
N/A
7
0
7
0
7
7
0
7
0
7
R/W
JTD
7
0
PORTA6
PORTB6
PINA6
PINB6
DDB6
DDA6
R/W
R/W
R/W
R/W
R/W
R/W
N/A
N/A
6
0
6
0
6
6
0
6
0
6
ATmega640/1280/1281/2560/2561
R
6
–
0
PORTA5
PORTB5
PINA5
PINB5
DDA5
DDB5
R/W
R/W
R/W
R/W
R/W
R/W
N/A
N/A
5
0
5
0
5
5
0
5
0
5
R
5
–
0
PORTA4
PORTB4
PINA4
PINB4
DDA4
DDB4
R/W
R/W
R/W
R/W
R/W
R/W
N/A
N/A
4
0
4
0
4
4
0
4
0
4
PUD
R/W
4
0
PORTA3
PORTB3
PINA3
PINB3
DDA3
DDB3
R/W
R/W
R/W
R/W
R/W
R/W
N/A
N/A
3
0
3
0
3
3
0
3
0
3
R
3
–
0
PORTA2
PORTB2
PINA2
PINB2
DDA2
DDB2
R/W
R/W
R/W
R/W
R/W
R/W
N/A
N/A
2
0
2
0
2
2
0
2
0
2
R
2
–
0
PORTA1
PORTB1
PINA1
PINB1
DDA1
DDB1
R/W
R/W
R/W
R/W
R/W
R/W
IVSEL
N/A
N/A
R/W
1
0
1
0
1
1
0
1
0
1
1
0
PORTA0
PORTB0
PINA0
PINB0
DDA0
DDB0
R/W
R/W
R/W
R/W
R/W
R/W
IVCE
N/A
N/A
R/W
0
0
0
0
0
0
0
0
0
0
0
0
MCUCR
PORTA
PORTB
DDRA
DDRB
PINA
PINB
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