Overview
The ATmega128 is a low-power CMOS 8-bit microcontroller based on the AVR enhanced RISC architecture. By executing powerful instructions in a single clock cycle, the ATmega128 achieves throughputs approaching 1 MIPS per MHz allowing the system designer to optimize power consumption versus processing speed.
The AVR core combines a rich instruction set with 32 general purpose working registers. All the 32 registers are directly connected to the Arithmetic Logic Unit (ALU), allowing two independent registers to be accessed in one single instruction executed in one clock cycle. The resulting architecture is more code efficient while achieving throughputs up to ten times faster than conventional CISC microcontrollers.

Features
• High-performance, Low-power AVR® 8-bit Microcontroller
• Advanced RISC Architecture
   – 133 Powerful Instructions – Most Single Clock Cycle Execution
   – 32 x 8 General Purpose Working Registers + Peripheral Control Registers
   – Fully Static Operation
   – Up to 16 MIPS Throughput at 16 MHz
   – On-chip 2-cycle Multiplier
• Nonvolatile Program and Data Memories
   – 128K Bytes of In-System Reprogrammable Flash
      Endurance: 10,000 Write/Erase Cycles
   – Optional Boot Code Section with Independent Lock Bits
      In-System Programming by On-chip Boot Program
      True Read-While-Write Operation
   – 4K Bytes EEPROM
      Endurance: 100,000 Write/Erase Cycles
   – 4K Bytes Internal SRAM
   – Up to 64K Bytes Optional External Memory Space
   – Programming Lock for Software Security
   – SPI Interface for In-System Programming
• JTAG (IEEE std. 1149.1 Compliant) Interface
   – Boundary-scan Capabilities According to the JTAG Standard
   – Extensive On-chip Debug Support
   – Programming of Flash, EEPROM, Fuses and Lock Bits through the JTAG Interface
• Peripheral Features
   – Two 8-bit Timer/Counters with Separate Prescalers and Compare Modes
   – Two Expanded 16-bit Timer/Counters with Separate Prescaler, Compare Mode and
      Capture Mode
   – Real Time Counter with Separate Oscillator
   – Two 8-bit PWM Channels
   – 6 PWM Channels with Programmable Resolution from 2 to 16 Bits
   – Output Compare Modulator
   – 8-channel, 10-bit ADC
      8 Single-ended Channels
      7 Differential Channels
      2 Differential Channels with Programmable Gain at 1x, 10x, or 200x
   – Byte-oriented Two-wire Serial Interface
   – Dual Programmable Serial USARTs
   – Master/Slave SPI Serial Interface
   – Programmable Watchdog Timer with On-chip Oscillator
   – On-chip Analog Comparator
• Special Microcontroller Features
   – Power-on Reset and Programmable Brown-out Detection
   – Internal Calibrated RC Oscillator
   – External and Internal Interrupt Sources
   – Six Sleep Modes: Idle, ADC Noise Reduction, Power-save, Power-down, Standby,
      and Extended Standby
   – Software Selectable Clock Frequency
   – ATmega103 Compatibility Mode Selected by a Fuse
   – Global Pull-up Disable
• I/O and Packages
   – 53 Programmable I/O Lines
   – 64-lead TQFP and 64-pad QFN/MLF
• Operating Voltages
   – 2.7 - 5.5V for ATmega128L
   – 4.5 - 5.5V for ATmega128
• Speed Grades
   – 0 - 8 MHz for ATmega128L
   – 0 - 16 MHz for ATmega128