The ATMEGA128A 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 ATMEGA128A achieves through puts close to 1MIPS per MHz .This empowers system designer to optimize the device for power consumption versus processing speed. 

Features:-

• High-performance, Low-power Atmel AVR 8-bit Microcontroller 

• Advanced RISC Architecture 

    - 133 Powerful Instructions 

    - Most Single-clock Cycle Execution 

    -  32 × 8 General Purpose Working Registers + Peripheral Control Registers 

    -  Fully Static Operation 

    -  Up to 16MIPS Throughput at 16MHz 

• High Endurance Non-volatile Memory segments 

    - 128Kbytes of In-System Self-programmable Flash program memory 

    - 4Kbytes EEPROM 

    - 4Kbytes Internal SRAM

    -  Write/Erase cycles: 10,000 Flash/100,000 EEPROM 

    -  Data retention: 20 years at 85°C/100 years at 25°C(1) 

    - Optional Boot Code Section with Independent Lock Bits 

          • In-System Programming by On-chip Boot Program 

          • True Read-While-Write Operation 

    -  Up to 64 Kbytes 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 Atmel-8151

     - Programming of Flash, EEPROM, Fuses and Lock Bits through the JTAG Interface

• Atmel QTouch® library support 

     – Capacitive touch buttons, sliders and wheels 

     – Atmel Q-Touch and Q-Matrix acquisition 

     – Up to 64 sense channels 

• 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 

• Speed Grades

   – 0 - 16MHz

    - On-chip 2-cycle Multiplier