57
8126F–AVR–05/12
ATtiny13A
10.4
Register Description
10.4.1
MCUCR – MCU Control Register
• Bits 7, 2 – Res: Reserved Bits
These bits are reserved bits in the ATtiny13A and will always read as zero.
• Bit 6 – 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.
10.4.2
PORTB – Port B Data Register
10.4.3
DDRB – Port B Data Direction Register
Table 10-5.
Overriding Signals for Alternate Functions in PB[2
:
0]
Signal
Name
PB2/SCK/ADC1/
T0/PCINT2
PB1/MISO/AIN1/
OC0B/INT0/PCINT1
PB0/MOSI/AIN0/
AREF/OC0A/PCINT0
PUOE
0
0
0
PUOV
0
0
0
DDOE
0
0
0
DDOV
0
0
0
PVOE
0
OC0B Enable
OC0A Enable
PVOV
0
OC0B
OC0A
PTOE
0
0
0
DIEOE
PCINT2 • PCIE + ADC1D
PCINT1 • PCIE + AIN1D
PCINT0 • PCIE + AIN0D
DIEOV
ADC1D
AIN1D
AIN0D
DI
T0/PCINT2 Input
INT0/PCINT1 Input
PCINT0 Input
AIO
ADC1 Input
Analog Comparator
Negative Input
Analog Comparator Positive
Input
Bit
7
6
5
4
3
2
1
0
–
PUD
SE
SM1
SM0
–
ISC01
ISC00
MCUCR
Read/Write
R
R/W
R/W
R/W
R/W
R
R/W
R/W
Initial Value
0
0
0
0
0
0
0
0
Bit
7
6
5
4
3
2
1
0
–
–
PORTB5
PORTB4
PORTB3
PORTB2
PORTB1
PORTB0
PORTB
Read/Write
R
R
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
–
–
DDB5
DDB4
DDB3
DDB2
DDB1
DDB0
DDRB
Read/Write
R
R
R/W
R/W
R/W
R/W
R/W
R/W
Initial Value
0
0
0
0
0
0
0
0