ATMEGA128A-AN Atmel, ATMEGA128A-AN Datasheet - Page 85

• Manufacturer Part Number: ATMEGA128A-AN
• Description: IC MCU AVR 128K FLASH 64TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA128A-AN

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: EBI/EMI, I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 53
• Program Memory Size: 128KB (64K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 4K x 8
• Ram Size: 4K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-TQFP
• Core: AVR8
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

12.3.7
8151H–AVR–02/11
Alternate Functions of Port G
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 configuration is as follows:
Table 12-20. Port G Pins Alternate Functions
• TOSC1 – Port G, Bit 4
TOSC1, Timer Oscillator pin 1: When the AS0 bit in ASSR is set (one) to enable asynchronous
clocking of Timer/Counter0, pin PG4 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 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 asynchronous
clocking of Timer/Counter0, pin PG3 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.
• 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.
• WR – Port G, Bit 0
WR is the external data memory write control strobe.
Port Pin
PG4
PG3
PG2
PG1
PG0
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)
ATmega128A
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