Overview
The ATmega323 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 ATmega323 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
   – 130 Powerful Instructions – Most Single-clock Cycle Execution
   – 32 x 8 General Purpose Working Registers
   – Fully Static Operation
   – Up to 8 MIPS Throughput at 8 MHz
   – On-chip 2-cycle Multiplier
• Non-volatile Program and Data Memories
   – 32K Bytes of In-System Self-programmable Flash Endurance: 1,000 Write/Erase Cycles
   – Optional Boot Code Section with Independent Lock Bits In-System Programming by On-chip Boot Program
   – 1K Byte EEPROM Endurance: 100,000 Write/Erase Cycles
   – 2K Bytes Internal SRAM
   – Programming Lock for Software Security
• JTAG (IEEE Std. 1149.1 Compliant) Interface
   – Extensive On-chip Debug Support
   – Programming of Flash, EEPROM, Fuses, and Lock Bits through the JTAG Interface
   – Boundary-Scan Capabilities According to the JTAG Standard
• Peripheral Features
   – Two 8-bit Timer/Counters with Separate Prescaler and Compare Mode
   – One 16-bit Timer/Counter with Separate Prescaler, Compare Mode, and Capture Mode
   – Real Time Counter with Separate Oscillator
   – Four PWM Channels
   – 8-channel, 10-bit ADC
   – Byte-oriented Two-wire Serial Interface
   – Programmable Serial USART
   – Master/Slave SPI Serial Interface
   – Programmable Watchdog Timer with Separate 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
• I/O and Packages
   – 32 Programmable I/O Lines
   – 40-pin PDIP and 44-lead TQFP
• Operating Voltages
   – 2.7 - 5.5V (ATmega323L)
   – 4.0 - 5.5V (ATmega323)
• Speed Grades
   – 0 - 4 MHz (ATmega323L)
   – 0 - 8 MHz (ATmega323)