[linux-dvb] DVB-T card for PCI-X

Ruediger Dohmhardt ruediger.dohmhardt at freenet.de
Fri Sep 30 22:34:17 CEST 2005

Christoph Anton Mitterer wrote:

> Ruediger Dohmhardt wrote:
>> Jon Burgess wrote:
>>> Many of the PCI cards currently on the market have the keys for 
>>> operation in both 5V and 3.3V slots
>> Because those PCI cards have a "3.3V signalling" which is "5V tolerant".
> Does this mean that the PCI-X slots in my board
> (http://tyan.com/products/html/thunderk8we_spec.html) can use
> conventional PCI cards with 3,3V or cards that work with both (3,3V and
> 5V) in each case, too? 

As said before PCI-X is "3.3V signalling",
whereas a PCI motherboard has either 3.3V or 5V signalling.

There are (1) 5V PCI-cards,
               (2) 3.3V PCI-cards and
               (3) 3.3V PCI cards that are "5V tolerant"

To answer your question: You can plug (2) and (3) into a PCI-X slot.
Disadvantage: The whole PCI-X bus slows down to 33MHz, whenever it 
recognizes a single PCI-card.

When the card "keying" is correct, only (2) and (3) can be plugged at all.
Sometimes "keying" is incorrect. You can plug a 5V PCI-card into a 
motherboard with
a 3.3V signalling environment and it may work,
but it is neither reliable nor is it specified.

Ciao Ruediger

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