Xilinx Foundation: Tips and Techniques
General
Solution 1518 - Foundation: Changing title block information on schematics
Simulation
Solution 1286 - Foundation Simulator: simulating bidirectional signals
VHDL
Solution 1372 - Foundation XVHDL: How to lock down I/O pins
Solution 1485 - Foundation XVHDL: Using RAM and ROM in XC4000 devices