This part is a kind of semiconductor called 89C51RD2.

Function of this product has 80C51 8-bit Flash microcontroller family 16KB/32KB/64KB ISP/IAP Flash with 512B/512B/1KB RAM.

Manufacturers : NXP

Image and pinout :

Some of the text within the PDF file :

INTEGRATED CIRCUITS 89C51RB2/89C51RC2/89C51RD2 80C51 8-bit Flash microcontroller family 16KB/32KB/64KB ISP/IAP Flash with 512B/512B/1KB RAM Preliminary specification IC28 Data Handbook 1999 Sep 23 Philips Semiconductors Philips Semiconductors Preliminary specification 80C51 8-bit Flash microcontroller family 16KB/32KB/64KB ISP/IAP Flash with 512B/512B/1KB RAM 89C51RB2/89C51RC2/ 89C51RD2 DESCRIPTION The 89C51RB2/RC2/RD2 device contains a non-volatile 16kB/32kB/64kB Flash program memory that is both parallel programmable and serial In-System and In-Application Programmable. In-System Programming (ISP) allows the user to download new code while the microcontroller sits in the application. In-Application Programming (IAP) means that the microcontroller fetches new program code and repro [ ... ]

89C51RD2 PDF Datasheet Download