AT90USB646-AU [Microchip]

The high-performance, low-power Microchip 8-bit AVR RISC-based microcontroller combines 64KB ISP flash memory with read-while-write capabilities, 2KB EEPROM, 4KB SRAM, 48 general purpose I/O lines, 32 general purpose working registers, real time counter, 4 flexible timer/counters with compare modes and PWM, USART, byte oriented 2-wire serial interface, USB 2.0 low-speed and full-speed device an 8-channel 10-bit A/D converter with optional differential input stage with programmable gain, programmable watchdog timer with internal oscillator, SPI serial port, JTAG (IEEE 1149.1 compliant) interface for on-chip debugging, and six software selectable power saving modes.

By executing powerful instructions in a single clock cycle, the device achieves throughputs approaching 1 MIPS per MHz, balancing power consumption and processor speed.