ATMEga64L ATMEL Corporation, ATMEga64L Datasheet - Page 83

• Manufacturer Part Number: ATMEga64L
• Description: 8-bit AVR Microcontroller with 64K Bytes In-System Programmable Flash
• Manufacturer: ATMEL Corporation

Alternate Functions of Port G
2490G–AVR–03/04
Table 44. Overriding Signals for Alternate Functions in PF3..PF0
In ATmega103 compatibility mode, only the alternate functions are the defaults for Port
G, and Port G cannot be used as General Digital Port Pins. The alternate pin configura-
tion is as follows:
Table 45. Port G Pins Alternate Functions
• TOSC1 – Port G, Bit 4
TOSC2, Timer Oscillator pin 1: When the AS0 bit in ASSR is set (one) to enable asyn-
chronous clocking of Timer/Counter0, pin PG4 is disconnected from the port, and
becomes the inverting output of the Oscillator amplifier. In this mode, a crystal Oscillator
is connected to this pin, and the pin can not be used as an I/O pin.
• TOSC2 – Port G, Bit 3
TOSC2, Timer Oscillator pin 2: When the AS0 bit in ASSR is set (one) to enable asyn-
chronous clocking of Timer/Counter0, pin PG3 is disconnected from the port, and
becomes the input of the inverting Oscillator amplifier. In this mode, a crystal Oscillator
is connected to this pin, and the pin cannot be used as an I/O pin.
• ALE – Port G, Bit 2
ALE is the external data memory Address Latch Enable signal.
• RD – Port G, Bit 1
RD is the external data memory read control strobe.
Signal
Name
PUOE
PUOV
DDOE
DDOV
PVOE
PVOV
DIEOE
DIEOV
DI
AIO
Port Pin
PG4
PG3
PG2
PG1
PG0
PF3/ADC3
0
0
0
0
0
0
0
0
–
ADC3 INPUT
Alternate Function
TOSC1 (RTC Oscillator Timer/Counter0)
TOSC2 (RTC Oscillator Timer/Counter0)
ALE (Address Latch Enable to external memory)
RD (Read strobe to external memory)
WR (Write strobe to external memory)
PF2/ADC2
0
0
0
0
0
0
0
0
–
ADC2 INPUT
PF1/ADC1
0
0
0
0
0
0
0
0
–
ADC1 INPUT
ATmega64(L)
PF0/ADC0
0
0
0
0
0
0
0
0
–
ADC0 INPUT
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