This part is a kind of semiconductor called AT89C51.

Function of this product has 8-Bit Microcontroller with 4K Bytes Flash.

Manufacturers : ATMEL Corporation

Image and pinout :

Some of the text within the PDF file :

Features • Compatible with MCS-51™ Products • 4K Bytes of In-System Reprogrammable Flash Memory • • • • • • • • – Endurance: 1,000 Write/Erase Cycles Fully Static Operation: 0 Hz to 24 MHz Three-Level Program Memory Lock 128 x 8-Bit Internal RAM 32 Programmable I/O Lines Two 16-Bit Timer/Counters Six Interrupt Sources Programmable Serial Channel Low Power Idle and Power Down Modes Description The AT89C51 is a low-power, high-performance CMOS 8-bit microcomputer with 4K bytes of Flash Programmable and Erasable Read Only Memory (PEROM). The device is manufactured using Atmel’s high density nonvolatile memory technology and is compatible with the industry standard MCS-51™ instruction set and pinout. The on-chip Flash allows the program memory to be reprogrammed in [ ... ]

AT89C51 PDF Datasheet Download