ATmega640/1280/1281/2560/2561
Table 13-5. Overriding Signals for Alternate Functions in PA3:PA0
Signal
Name
PA3/AD3
PA2/AD2
PA1/AD1
PA0/AD0
PUOE
PUOV
SRE
SRE
SRE
SRE
~(WR | ADA) •
PORTA3 • PUD
~(WR | ADA) •
PORTA2 • PUD
~(WR | ADA) •
PORTA1 • PUD
~(WR | ADA) •
PORTA0 • PUD
DDOE
DDOV
PVOE
SRE
WR | ADA
SRE
SRE
WR | ADA
SRE
SRE
WR | ADA
SRE
SRE
WR | ADA
SRE
A3 • ADA | D3
OUTPUT • WR
A2• ADA | D2
OUTPUT • WR
A1 • ADA | D1
OUTPUT • WR
A0 • ADA | D0
OUTPUT • WR
PVOV
DIEOE
DIEOV
DI
0
0
0
0
0
D3 INPUT
–
0
D2 INPUT
–
0
D1 INPUT
–
0
D0 INPUT
–
AIO
13.3.2
Alternate Functions of Port B
The Port B pins with alternate functions are shown in Table 13-6.
Table 13-6. Port B Pins Alternate Functions
Port Pin
Alternate Functions
OC0A/OC1C/PCINT7 (Output Compare and PWM Output A for Timer/Counter0, Output
Compare and PWM Output C for Timer/Counter1 or Pin Change Interrupt 7)
PB7
OC1B/PCINT6 (Output Compare and PWM Output B for Timer/Counter1 or Pin Change
PB6
PB5
PB4
Interrupt 6)
OC1A/PCINT5 (Output Compare and PWM Output A for Timer/Counter1 or Pin Change
Interrupt 5)
OC2A/PCINT4 (Output Compare and PWM Output A for Timer/Counter2 or Pin Change
Interrupt 4)
PB3
PB2
PB1
PB0
MISO/PCINT3 (SPI Bus Master Input/Slave Output or Pin Change Interrupt 3)
MOSI/PCINT2 (SPI Bus Master Output/Slave Input or Pin Change Interrupt 2)
SCK/PCINT1 (SPI Bus Serial Clock or Pin Change Interrupt 1)
SS/PCINT0 (SPI Slave Select input or Pin Change Interrupt 0)
The alternate pin configuration is as follows:
• OC0A/OC1C/PCINT7, Bit 7
OC0A, Output Compare Match A output: The PB7 pin can serve as an external output for the
Timer/Counter0 Output Compare. The pin has to be configured as an output (DDB7 set “one”) to
serve this function. The OC0A pin is also the output pin for the PWM mode timer function.
OC1C, Output Compare Match C output: The PB7 pin can serve as an external output for the
Timer/Counter1 Output Compare C. The pin has to be configured as an output (DDB7 set (one))
to serve this function. The OC1C pin is also the output pin for the PWM mode timer function.
79
2549L–AVR–08/07
ATMEL [ ATMEL ]
