NXP Semiconductors Lite5200B, Руководство пользователя, Страница: 117 / 138

LITE5200B User’s Manual, Rev. 0
Freescale Semiconductor B-1
Appendix B
PCI Compatibility
The Lite5200B board ONLY supports PCI cards which use 3.3 volt I/O pins. Pins A16, A59, B19 and B59 on the Lite5200B PCI connectors
are used as the power supply pins for the I/O. These pins are wired directly to 3.3 volts on the Lite5200B board.
In general, PCI cards that support 5 volt I/O pins are keyed in such a way that they will not plug into the PCI connectors on the Lite5200B
board.
However, there are Universal PCI cards that will plug into the Lite5200B board that support both 3.3 volt and 5 volt I/O. These cards work
by detecting the voltage on pins A16, A59, B19 and B59 and then configuring the I/O power supply accordingly on the card. A problem arises
in that some PCI cards use the Universal PCI card form factor when in fact, these cards only support 5 volt I/O. That is, pins A16, A59, B19
and B59 are connected directly to the 5 volt supply pin on the card, itself. (This is a violation of the specification for Universal PCI cards.)
If a Universal PCI card (or any PCI card) is plugged into the Lite5200B board where pins A16, A59, B19 and B59 are connected directly to
5 volts on the card, itself, damage will result on the Lite5200B board.
It is the responsibility of the user of the Lite5200B board to insure that pins A16, A59, B19 and B59 on any PCI cards used with the board
are driven by 3.3 volts and NOT 5 volts.
THE Lite5200B BOARD WILL BE DAMAGED IF A PCI CARD IS PLUGGED INTO THE PCI CONNECTORS IF PINS A16, A59, B19
and B59 ON THE CARD ARE DRIVEN BY THE 5 VOLT SUPPLY.