Rainbow Electronics ATmega128L - Manual (Page 77)

77
ATmega128(L)
2467B–09/01
OC3A, Output Compare matchA output: The PE3 pin can serve as an external output
for the Timer/Counter3 output compareA. The pin has to be configured as an output
(DDE3 set “one”) to serve this function. The OC3A pin is also the output pin for the PWM
mode timer function.
• AIN0/XCK0 - Port E, Bit 2
AIN0 - Analog Comparator Positive Input. This pin is directly connected to the positive
input of the analog comparator.
XCK0, USART0 external clock. The Data Direction Register (DDE2) controls whether
the clock is output (DDE2 set) or input (DDE2 cleared). The XCK0 pin is active only
when the USART0 operates in synchronous mode.
• PDO/TXD0 - Port E, Bit 1
PDO, Serial Programming Data Output. During Serial Program Downloading, this pin is
used as data output line for the ATmega128.
TXD0, UART0 Transmit Pin.
• PDI/RXD0 - Port E, Bit 0
PDI, Serial Programming Data Input. During Serial Program Downloading, this pin is
used as data input line for the ATmega128.
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.
Table 40 and Table 41 relates the alternate functions of Port E to the overriding signals
shown in
Figure 32 on page 66.
Table 40. Overriding Signals for Alternate Functions PE7..PE4
Signal
Name
PE7/INT7/IC3 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/IC3
INPUT INT7 INPUT/T3
INPUT INT5 INPUT INT4 INPUT
AIO – – – –