ATTINY20-EK1 Datasheet, PDF (57/220 Pages) ATMEL Corporation – 8-bit AVR Microcontroller with 2K Bytes In-System Programmable Flash

10.4.2 PUEA – Port A Pull-up Enable Control Register
Bit
0x03
Read/Write
Initial Value
7
PUEA7
R/W
0
6
PUEA6
R/W
0
10.4.3 PORTA – Port A Data Register
5
PUEA5
R/W
0
4
PUEA4
R/W
0
3
PUEA3
R/W
0
2
PUEA2
R/W
0
1
PUEA1
R/W
0
0
PUEA0
R/W
0
PUEA
Bit
0x02
Read/Write
Initial Value
7
PORTA7
R/W
0
6
PORTA6
R/W
0
5
PORTA5
R/W
0
4
PORTA4
R/W
0
3
PORTA3
R/W
0
2
PORTA2
R/W
0
1
PORTA1
R/W
0
0
PORTA0
R/W
0
10.4.4 DDRA – Port A Data Direction Register
PORTA
Bit
0x01
Read/Write
Initial Value
7
DDA7
R/W
0
6
DDA6
R/W
0
10.4.5 PINA – Port A Input Pins
5
DDA5
R/W
0
4
DDA4
R/W
0
3
DDA3
R/W
0
2
DDA2
R/W
0
1
DDA1
R/W
0
0
DDA0
R/W
0
DDRA
Bit
0x00
Read/Write
Initial Value
7
PINA7
R/W
N/A
6
PINA6
R/W
N/A
5
PINA5
R/W
N/A
4
PINA4
R/W
N/A
10.4.6 PUEB – Port B Pull-up Enable Control Register
3
PINA3
R/W
N/A
2
PINA2
R/W
N/A
1
PINA1
R/W
N/A
0
PINA0
R/W
N/A
PINA
Bit
7
6
5
0x07
–
–
–
Read/Write
R
R
R
Initial Value
0
0
0
10.4.7 PORTB – Port B Data Register
4
3
2
1
0
–
PUEB3
PUEB2
PUEB1
PUEB0
PUEB
R
R/W
R/W
R/W
R/W
0
0
0
0
0
Bit
7
6
5
0x06
–
–
–
Read/Write
R
R
R
Initial Value
0
0
0
10.4.8 DDRB – Port B Data Direction Register
4
3
2
1
0
–
PORTB3
PORTB2
PORTB1
PORTB0
PORTB
R
R/W
R/W
R/W
R/W
0
0
0
0
0
Bit
7
6
5
4
3
2
1
0
0x05
–
–
–
–
DDB3
DDB2
DDB1
DDB0
DDRB
Read/Write
R
R
R
R
R/W
R/W
R/W
R/W
Initial Value
0
0
0
0
0
0
0
0
ATtiny20 [DATASHEET] 57
8235E–AVR–03/2013