ATTIny2313-16MI ATMEL Corporation, ATTIny2313-16MI Datasheet - Page 53

• Manufacturer Part Number: ATTIny2313-16MI
• Description: 8-bit AVR Microcontroller with 2K Bytes In-System Programmable Flash
• Manufacturer: ATMEL Corporation

MCU Control Register –
MCUCR
Alternate Functions of Port A
Alternate Functions of Port B
2543C–AVR–12/03
• Bit 7 – 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 47 for more details about this feature.
The Port A pins with alternate functions are as shown in Table 5.
Table 25. Port A Pins Alternate Functions
The Port B pins with alternate functions are shown in Table 26.
Table 26. Port B Pins Alternate Functions
The alternate pin configuration is as follows:
• USCK/SCL/PCINT7 - Port B, Bit 7
USCK: Three-wire mode Universal Serial Interface Clock.
SCL: Two-wire mode Serial Clock for USI Two-wire mode.
PCINT7: Pin Change Interrupt source 7. The PB7 pin can serve as an external interrupt
source.
• DO/PCINT6 - Port B, Bit 6
DO: Three-wire mode Universal Serial Interface Data output. Three-wire mode Data out-
put overrides PORTB6 value and it is driven to the port when data direction bit DDB6 is
set (one). However the PORTB6 bit still controls the pull-up enabling pull-up, if direction
is input and PORTB6 is set (one).
Bit
Read/Write
Initial Value
Port Pin
PB7
PB6
PB5
PB4
PB3
PB2
PB1
PB0
Port Pin
PA2
PA1
PA0
Alternate Functions
USCK/SCL/PCINT7
DO/PCINT6
DI/SDA/PCINT5
OC1B/PCINT4
OC1A/PCINT3
OC0A/PCINT2
AIN1/PCINT1
AIN0/PCINT0
PUD
R/W
7
0
SM1
R/W
6
0
Alternate Function
RESET, dW
XTAL2
XTAL1
R/W
SE
5
0
SM0
R/W
4
0
ISC11
R/W
3
0
ISC10
R/W
2
0
ATtiny2313/V
ISC01
R/W
1
0
ISC00
R/W
0
0
MCUCR
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