77
4317I–AVR–01/08
AT90PWM2/3/2B/3B
11.3.5
Alternate Functions of Port E
The Port E pins with alternate functions are shown in
The alternate pin configuration is as follows:
• XTAL2/ADC0 – Bit 2
XTAL2: Chip clock Oscillator pin 2. Used as clock pin for crystal Oscillator or Low-frequency
crystal Oscillator. When used as a clock pin, the pin can not be used as an I/O pin.
ADC0, Analog to Digital Converter, input channel 0.
• XTAL1/OC0B – Bit 1
Table 11-11.
Overriding Signals for Alternate Functions in PD3..PD0
Signal Name
PD3/TXD/OC0A/
SS/MOSI_A
PD2/PSCIN2/
OC1A/MISO_A
PD1/PSCIN0/
CLKO
PD0/PSCOUT00/X
CK/SS_A
PUOE
TXEN + SPE •
MSTR • SPIPS
–
0
SPE •
MSTR • SPIPS
PUOV
TXEN • SPE • MSTR
• SPIPS • PD3 • PUD
–
0
PD0 • PUD
DDOE
TXEN + SPE •
MSTR • SPIPS
–
0
P SPE •
MSTR • SPIPS
DDOV
TXEN
0
0
PSCen00
PVOE
TXEN + OC0en +
SPE •
MSTR • SPIPS
–
0
P UMSEL
PVOV
TXEN • TXD + TXEN
• (OC0en • OC0 +
OC0en • SPIPS •
MOSI)
–
0
–
DIEOE
0
0
0
0
DIEOV
0
0
0
0
DI
SS
MOSI_Ain
SS_A
AIO
Table 11-12. Port E Pins Alternate Functions
Port Pin
Alternate Function
PE2
XTAL2: XTAL Output
ADC0 (Analog Input Channel 0)
PE1
XTAL1: XTAL Input
OC0B (Timer 0 Output Compare B)
PE0
RESET# (Reset Input)
OCD (On Chip Debug I/O)