AT90USB64/128
Note:
1. ADA is short for ADdress Active and represents the time when address is output. See “Exter-
nal Memory Interface” on page 29 for details.
Table 10-5. Overriding Signals for Alternate Functions in PA3..PA0
Signal
Name
PA3/AD3
PA2/AD2
PA1/AD1
PA0/AD0
PUOE
SRE
SRE
SRE
SRE
~(WR | ADA) •
PORTA3 • PUD
~(WR | ADA) •
PORTA2 • PUD
~(WR | ADA) •
PORTA1 • PUD
~(WR | ADA) •
PORTA0 • PUD
PUOV
DDOE
DDOV
PVOE
SRE
SRE
SRE
SRE
WR | ADA
SRE
WR | ADA
SRE
WR | ADA
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
0
0
0
D3 INPUT
–
D2 INPUT
–
D1 INPUT
–
D0 INPUT
–
AIO
10.3.3
Alternate Functions of Port B
The Port B pins with alternate functions are shown in Table 10-6.
Table 10-6. 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
PB6
PB5
PB4
PB3
PB2
OC1B/PCINT6 (Output Compare and PWM Output B for Timer/Counter1 or Pin
Change 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)
PDO/MISO/PCINT3 (Programming Data Output or SPI Bus Master Input/Slave
Output or Pin Change Interrupt 3)
PDI/MOSI/PCINT2 (Programming Data Input orSPI Bus Master Output/Slave Input
or Pin Change Interrupt 2)
PB1
PB0
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.
81
7593A–AVR–02/06
ATMEL [ ATMEL ]
