The ATmega128 is a high-end 8-bit AVR Microcontroller featuring 128-Kbyte self-programming Flash Program Memory, 4-Kbyte SRAM, 4-Kbyte EEPROM and 8 Channel 10-bit A/D-converter. In-system Debugging and programming is supported through a JTAG interface. ISP Programming is also possible via an SPI Interface.

There are 2 versions of the chip:

• ATmega128-16Ax  - runs at 0 - 16MHz @4.5 - 5.5V
• ATmega128L-8Ax - runs at 0 - 8MHz @2.7 - 5.5V 
  where x = Temperature range (I=Industrial)

Both versions of the chip come in a TQFP-64 package giving 53 programmable I/O pins.