High-performance, low-power Atmel AVR 8-bit microcontroller series n Advanced RISC architecture – 131 powerful instructions – Most executed in a single clock cycle – 32 x 8 general-purpose working registers – Fully static operation – Up to 20 MIPS throughput at 20MHz – On-chip 2-cycle multiplier n High-endurance non-volatile memory segments – 4/8/16/32KBytes of on-chip in-system programmable Flash program memory – 256/512/512/1KBytes EEPROM – 512/1K/1K/2KBytes internal SRAM – Write/erase cycles: 10,000 Flash/100,000 EEPROM – Data retention: 20 years at 85°C/100 years at 25°C – Optional boot code segment with independent lock bits n On-chip in-system programming implemented by on-chip bootloader for true read/write operations n Software-secure programming lock n Atmel QTouch library support – Capacitive touch buttons, sliders and wheels – QTouch and QMatrix sensing – Up to 64 sensing channels n Peripheral features – Two 8-bit timers/counters with independent prescalers and compare modes – One 16-bit timer/counter with independent prescaler, compare mode and capture mode – Real-time clock with separate oscillator – Six PWM channels – 8-channel 10-bit ADC (TQFP and QFN/MLF packages) temperature measurement – 6-channel 10-bit ADC (PDIP package) temperature measurement – Programmable serial USART – Master/slave SPI serial interface – Byte-oriented 2-wire serial interface (Philips I2C compatible) – Programmable watchdog timer with separate on-chip oscillator – On-chip analog comparator – Pin change interrupt and wake-up n Special microcontroller features – Power-on reset and programmable undervoltage detection – Internal calibrated oscillator – External and internal interrupt sources – Six sleep modes: Idle, ADC Noise Reduction, Power-down, Standby and Extended Standby n I/O and packages – 23 programmable I/O lines – 28-pin PDIP, 32-pin TQFP, 28-pad QFN/MLF and 32-pad QFN/MLF