Found 4 alternatives for XC3S1600E-4FGG400I by Xilinx Inc.. Embedded Fpgas Field Programmable Gate Array — 400-BGA.
IC FPGA 301 I/O 400FBGA
IC FPGA TRION T20 230 IO 400FBGA
IC FPGA TRION T35 230 IO 400FBGA
IC FPGA 304 I/O 400FBGA