SS_A: Slave Port Select input. When the SPI is enabled as a slave, this pin is configured as an
input regardless of the setting of DDD0. As a slave, the SPI is activated when this pin is driven
low. When the SPI is enabled as a master, the data direction of this pin is controlled by DDD0.
When the pin is forced to be an input, the pull-up can still be controlled by the PORTD0 bit.
PCINT9, Pin Change Interrupt 9.
• PCINT8/PSCOUT1A/INT3 – Bit 0
PSCOUT1A, Output 1A of PSC.
INT3, External Interrupt source 3: This pin can serve as an external interrupt source to the MCU.
PCINT8, Pin Change Interrupt 8.
Table 9-7 and Table 9-8 relate the alternate functions of Port C to the overriding signals shown
in Figure 9-5 on page 67.
Table 9-7.
Overriding Signals for Alternate Functions in PC7..PC4
PC6/ADC10/
ACMP1/
PC5/ADC9/
AMP1+/ACMP3/
PCINT13
PC4/ADC8/
PC7/D2A/AMP2+/
PCINT15
AMP1-/ACMPN3/
PCINT12
Signal Name
PUOE
PUOV
DDOE
DDOV
PVOE
PVOV
PCINT14
0
0
0
0
0
0
DAEN
0
0
0
0
0
0
0
0
0
0
–
0
0
0
–
DIEOE
DIEOV
DI
DAEN
0
ADC10D
0
ADC9D
0
ADC8D
0
ADC8 Amp1-
ACMPN3
AIO
–
ADC10 Amp1
ADC9 Amp1+
Table 9-8.
Overriding Signals for Alternate Functions in PC3..PC0
PC1/PSCIN1/
PC0/INT3/
PSCOUT1A/
PCINT8
PC3/T1/RXCAN/
ICP1B/PCINT11
PC2/T0/TXCAN/
PCINT10
OC1B/SS_A/
PCINT9
Signal Name
PUOE
0
0
0
0
0
0
PUOV
0
0
DDOE
0
PSCen10
1
DDOV
1
1
0
PVOE
OC1Ben
OC1B
PSCen10
PSCout10
In3en
In3en
PVOV
DIEOE
DIEOV
PSCin1
SS_A
DI
T1
T0
INT3
AIO
74
ATmega16/32/64/M1/C1
7647F–AVR–04/09
ATMEL [ ATMEL ]
