The AT90USB1287-MU is a low-power 8-bit CMOS Microcontroller based on the AVR enhanced RISC architecture. By executing powerful instructions in a single clock cycle, the AT90USB128 achieves throughputs approaching 1MIPS 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. The AT90USB128 provides 128kB ISP flash memory with read-while-write capabilities, 4kB EEPROM, 8kB SRAM and 48 programmable I/O lines. The device is manufactured using the high-density non-volatile memory technology.