ATmega128A Atmel Corporation, ATmega128A Datasheet - Page 5

• Manufacturer Part Number: ATmega128A
• Manufacturer: Atmel Corporation

Specifications of ATmega128A

• Flash (kbytes): 128 Kbytes
• Pin Count: 64
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 16
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 53
• Ext Interrupts: 8
• Usb Speed: No
• Usb Interface: No
• Spi: 1
• Twi (i2c): 1
• Uart: 2
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 15
• Analog Comparators: 1
• Resistive Touch Screen: No
• Temp. Sensor: No
• Crypto Engine: No
• Sram (kbytes): 4
• Eeprom (bytes): 4096
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 2.7 to 5.5
• Operating Voltage (vcc): 2.7 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 4
• Output Compare Channels: 8
• Input Capture Channels: 2
• Pwm Channels: 7
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

2.2.1
2.3
2.3.1
2.3.2
2.3.3
8151HS–AVR–02/11
Pin Descriptions
ATmega103 Compatibility Mode
VCC
GND
Port A (PA7:PA0)
The Atmel
ATmega103 on current Printed Circuit Boards. The application note “Replacing ATmega103 by
ATmega128A” describes what the user should be aware of replacing the ATmega103 by an
ATmega128A.
By programming the M103C fuse, the ATmega128 will be compatible with the ATmega103
regards to RAM, I/O pins and interrupt vectors as described above. However, some new fea-
tures in ATmega128 are not available in this compatibility mode, these features are listed below:
Unused I/O bits in ATmega103 should be written to 0 to ensure same operation in ATmega128.
Digital supply voltage.
Ground.
Port A is an 8-bit bi-directional I/O port with internal pull-up resistors (selected for each bit). The
Port A output buffers have symmetrical drive characteristics with both high sink and source
capability. As inputs, Port A pins that are externally pulled low will source current if the pull-up
resistors are activated. The Port A pins are tri-stated when a reset condition becomes active,
even if the clock is not running.
Port A also serves the functions of various special features of the ATmega128A as listed on
page
• One USART instead of two, Asynchronous mode only. Only the eight least significant bits of
• One 16 bits Timer/Counter with two compare registers instead of two 16-bit Timer/Counters
• Two-wire serial interface is not supported.
• Port C is output only.
• Port G serves alternate functions only (not a general I/O port).
• Port F serves as digital input only in addition to analog input to the ADC.
• Boot Loader capabilities is not supported.
• It is not possible to adjust the frequency of the internal calibrated RC Oscillator.
• The External Memory Interface can not release any Address pins for general I/O, neither
• In addition, there are some other minor differences to make it more compatible to
• Only EXTRF and PORF exists in MCUCSR.
• Timed sequence not required for Watchdog Time-out change.
• External Interrupt pins 3 - 0 serve as level interrupt only.
• USART has no FIFO buffer, so data overrun comes earlier.
the Baud Rate Register is available.
with three compare registers.
configure different wait-states to different External Memory Address sections.
ATmega103:
73.
®
AVR
®
ATmega128A is 100% pin compatible with ATmega103, and can replace the
ATmega128A
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