Xilinx Answer #4071 : Can an FPGA be used in combination with an external crystal oscillator as an amplifier?
Xilinx Answer #3826 : Spartan: Are Spartan devices footprint compatible with 4000E/XL devices?
Xilinx Answer #3592 : Spartan: What library components in the 4000E library are not supported by spartan devices
Xilinx Answer #3569 : SPARTAN: Pinouts for XCS20 and XCS30 in PQ208 package are incorrect in 1998 Databook
Xilinx Answer #3561 : Spartan: What is the comparison between Spartan and 4000E families?
Xilinx Answer #3473 : Spartan: Pinouts on the Version 0.6 of the data sheet are incorrect.