Xilinx FPGA XC3S400A-4FTG256C, Spartan-3A 8064 Cells, 400000 Gates, 57344bit, 8064 Blocks, 256-Pin FTBGA

An FPGA is a semiconductor device consisting of a matrix of Configurable Logic Blocks (CLBs) connected through programmable interconnects. The user determines these interconnections by programming SRAM. A CLB can be simple (AND, OR gates, etc) or complex (a block of RAM). The FPGA allows changes to be made to a design even after the device is soldered into a PCB.