This part is a kind of semiconductor called XC3S4000.

Function of this product has Spartan-3 Generation FPGA User Guide.

Manufacturers : Xilinx

Image and pinout :

Some of the text within the PDF file :

Spartan-3 Generation FPGA User Guide Extended Spartan-3A, Spartan-3E, and Spartan-3 FPGA Families UG331 (v1.8) June 13, 2011 R R The information disclosed to you hereunder (the "Materials") is provided solely for the selection and use of Xilinx products. To the maximum extent permitted by applicable law: (1) Materials are made available "AS IS" and with all faults, Xilinx hereby DISCLAIMS ALL WARRANTIES AND CONDITIONS, EXPRESS, IMPLIED, OR STATUTORY, INCLUDING BUT NOT LIMITED TO WARRANTIES OF MERCHANTABILITY, NON-INFRINGEMENT, OR FITNESS FOR ANY PARTICULAR PURPOSE; and (2) Xilinx shall not be liable (whether in contract or tort, including negligence, or under any other theory of liability) for any loss or damage of any kind or nature related to, arising under, or in connection with, the M [ ... ]

XC3S4000 PDF Datasheet Download