4 alternate functions of port f, Atmega128rfa1 – Rainbow Electronics ATmega128RFA1 User Manual
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8266A-MCU Wireless-12/09
ATmega128RFA1
RXD0, USART0 Receive Pin. Receive Data (Data input pin for the USART0). When the
USART0 receiver is enabled this pin is configured as an input regardless of the value of
DDRE0. When the USART0 forces this pin to be an input, a logical one in PORTE0 will
turn on the internal pull-up.
PCINT8, Pin Change Interrupt source 8: The PE0 pin can serve as an external interrupt
source.
relates the alternate functions of Port E to
the overriding signals shown in
.
Table 14-10. Overriding Signals for Alternate Functions PE7:PE4
Signal
Name
PE7/INT7/ICP3
PE6/INT6/T3
PE5/INT5/OC3C
PE4/INT4/OC3B
PUOE
0
0
0
0
PUOV
0
0
0
0
DDOE
0
0
0
0
DDOV
0
0
0
0
PVOE
0
0
OC3C ENABLE
OC3B ENABLE
PVOV
0
0
OC3C
OC3B
DIEOE
INT7 ENABLE
INT6 ENABLE
INT5 ENABLE
INT4 ENABLE
DIEOV
1
1
1
1
DI
INT7 INPUT / ICP3
INPUT
INT7 INPUT / T3
INPUT
INT5 INPUT
INT4 INPUT
AIO
–
–
–
–
Table 14-11. Overriding Signals for Alternate Functions PE3:PE0
Signal
Name
PE3/AIN1/OC3A
PE2/AIN0/XCK0
PE1/TXD0
PE0 /
RXD0/PCINT8
PUOE
0
0
TXEN0
RXEN0
PUOV
0
0
0
PORTE0 & (~PUD)
DDOE
0
XCK0 OUTPUT
ENABLE
TXEN0
RXEN0
DDOV
0
1
1
0
PVOE
OC3BENABLE
XCK0 OUTPUT
ENABLE
TXEN0
0
PVOV
OC3B
XCK0 OUTPUT
TXD0
0
DIEOE
0
0
0
PCINT8 & PCIE1
DIEOV
0
0
0
1
DI
0
XCK0 INPUT
–
RXD0
PE0
0
0
0
PCINT8 INPUT
AIO
AIN1 INPUT
AIN0 INPUT
-
-
14.3.4 Alternate Functions of Port F
The Port F has an alternate function as analog input for the ADC as shown in
. If some Port F pins are configured as outputs, it is essential that
these do not switch when a conversion is in progress. This might corrupt the result of
the conversion. If the JTAG interface is enabled, the pull-up resistors on pins PF7(TDI),
PF5(TMS), and PF4(TCK) will be activated even if a Reset occurs.