– 28-pin PDIP, 32-lead TQFP, 28-pad QFN/MLF and 32-pad QFN/MLF – Six Sleep Modes: Idle, ADC Noise Reduction, Power-save, Power-down, Standby, and Extended Standby – External and Internal Interrupt Sources – Power-on Reset and Programmable Brown-out Detection – Programmable Watchdog Timer with Separate On-chip Oscillator

– Byte-oriented 2-wire Serial Interface (Philips I2C compatible) – 6-channel 10-bit ADC in PDIP Package Temperature Measurement – 8-channel 10-bit ADC in TQFP and QFN/MLF package Temperature Measurement – Real Time Counter withSeparate Oscillator – One 16-bit Timer/Counter with Separate Prescaler, Compare Mode, and Capture Mode – Two 8-bit Timer/Counters with Separate Prescaler and Compare Mode – Capacitive touch buttons, sliders and wheels In-System Programming by On-chip Boot Program – Optional Boot Code Section with Independent Lock Bits – 4/8/16/32KBytes of In-System Self-Programmable Flash program memory High Endurance Non-volatile Memory Segments.– 32 x 8 General Purpose Working Registers – 131 Powerful Instructions – Most Single Clock Cycle Execution High Performance, Low Power Atmel® AVR® 8-Bit Microcontroller.By executing powerful instructions in a single clock cycle, the ATmega48A/PA/88A/PA/168A/PA/328/P achieves throughputs approaching 1 MIPS per MHz allowing the system designer to optimizepower consumption versus processing speed. The ATmega48A/PA/88A/PA/168A/PA/328/P is a low-power CMOS 8-bit microcontroller based on the AVR enhanced RISC architecture.

Atmel arduino uno datasheet