This part is a kind of semiconductor called AT89C4051.

Function of this product has 8-Bit Microcontroller.

Manufacturers : ATMEL Corporation

Image and pinout :

Some of the text within the PDF file :

Features • Compatible with MCS®51 Products • 4K Bytes of Reprogrammable Flash Memory – Endurance: 10,000 Write/Erase Cycles • 2.7V to 6V Operating Range • Fully Static Operation: 0 Hz to 24 MHz • Two-level Program Memory Lock • 128 x 8-bit Internal RAM • 15 Programmable I/O Lines • Two 16-bit Timer/Counters • Six Interrupt Sources • Programmable Serial UART Channel • Direct LED Drive Outputs • On-chip Analog Comparator • Low-power Idle and Power-down Modes • Brown-out Detection • Power-On Reset (POR) • Green (Pb/Halide-free/RoHS Compliant) Packaging 1. Description The AT89C4051 is a low-voltage, high-performance CMOS 8-bit microcontroller with 4K bytes of Flash programmable and erasable read-only memory. The device is manufactured using Atmel’s high-den [ ... ]

AT89C4051 PDF Datasheet Download