Spartan-3/-3E devices are not 5V-tolerant, however, can these devices be used in a 5V PCI system?
It is not possible to use a Spartan-3/-3E device in a 5V PCI environment and still maintain strict PCI compliance.
However, if you do not need to maintain PCI compliance, you might be able to use a bus switch to interface the Spartan-3/-3E device to the 5V PCI bus. The resulting design is not PCI-compliant. Consequently, Xilinx cannot guarantee that this solution will work, especially in an open system that requires add-in cards to be fully compliant.