High-performance ROM version of the 80C51 single-chip, 8-bit microcontroller with full-speed USB functions. It is pin-compatible with AT89C5130A 16-KB and AT89C5131A 32-KB ISP flash microcontrollers, allowing those devices be used for development and pre-production while this device can be used in mass production to reduce costs.

It features a full-speed USB module that is compatible with the USB specification version 2.0. This module integrates the USB transceivers and the serial interface engine with digital phase locked loop and 48-MHz clock recovery. It also includes USB event detection logic and FIFO buffers supporting the mandatory control endpoint and five versatile endpoints with minimum software overhead.

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