Introduction
The Atmel® 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 throughputs 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
    – On-chip 2-cycle Multiplier
• 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
    – Programming of Flash, EEPROM, Fuses and Lock Bits through the JTAG Interface
• Atmel QTouch® library support
    – Capacitive touch buttons, sliders and wheels
    – Atmel QTouch and QMatrix 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