Power Supply and Power Distribution System (PDS)

With a noisy or under-rated power supply, a circuit board is an expensive piece of garbage.

Family Primary Reference
Virtex®- 5 FPGA Virtex-5 PCB Designer's Guide
Virtex-4 FPGA Virtex-4 PCB Designer's Guide,
Virtex-4 User Guide
Virtex-II, Virtex-II Pro XAPP623