Overview
The ATmega325P/3250P 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 ATmega325P/3250P achieves throughputs approaching 1 MIPS per MHz allowing the system designer to optimize power consumption versus processing speed.
   
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 20 MIPS Throughput at 20 MHz
    – On-Chip 2-cycle Multiplier
• High Endurance Non-volatile Memory segments
    – 32K Bytes of In-System Self-programmable Flash program memory
    – 1K Bytes EEPROM
    – 2K Bytes Internal SRAM
    – Write/Erase cyles: 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
    – Programming Lock for Software Security
• 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 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
    – Programmable Serial USART
    – Master/Slave SPI Serial Interface
    – Universal Serial Interface with Start Condition Detector
    – Programmable Watchdog Timer with Separate On-chip Oscillator
    – On-chip Analog Comparator
    – Interrupt and Wake-up on Pin Change
• Special Microcontroller Features
    – Power-on Reset and Programmable Brown-out Detection
    – Internal Calibrated Oscillator
    – External and Internal Interrupt Sources
    – Five Sleep Modes: Idle, ADC Noise Reduction, Power-save,
        Power-down, and Standby
• I/O and Packages
    – 54/69 Programmable I/O Lines
    – 64-lead TQFP, 64-pad QFN/MLF, and 100-lead TQFP
• Speed Grade:
    – ATmega325PV/ATmega3250PV:
        0 - 4 MHz @ 1.8 - 5.5V, 0 - 10 MHz @ 2.7 - 5.5V
    – ATmega325P/3250P:
        0 - 10 MHz @ 2.7 - 5.5V, 0 - 20 MHz @ 4.5 - 5.5V
• Temperature range:
    – -40°C to 85°C Industrial
• Ultra-Low Power Consumption
    – Active Mode:
        420 µA at 1 MHz, 1.8V
    – Power-down Mode:
        40 nA at 1.8V
    – Power-save Mode:
        750 nA at 1.8V