High-performance flash version of the 80C51 single-chip 8-bit microcontroller with full speed USB functions. It features a full-speed USB module compatible with the USB specifications Version 1.1 and 2.0. The module integrates the USB transceivers with a 3.3V voltage regulator. The serial interface engine integrates digital phase locked loop and 48-MHz clock recovery. The module also contains USB event detection logic and FIFO buffers which support the mandatory control endpoint and up to six versatile endpoints with minimum software overhead.

This device retains the features of the Atmel 80C52 and adds 1024 bytes of on-chip ERAM, dual- data pointer, 16-bit up/down timer, programmable counter array, up to four programmable LED current sources, programmable hardware watchdog, and power-on reset.

Two software-selectable modes of reduced activity further reduce power consumption. In the idle mode the CPU is frozen while the timers, serial ports and interrupt system operate. In the power-down mode, the RAM is saved and the peripheral clock is frozen, but the device has full wake-up capability through USB events or external interrupts.