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

Ruediger Dohmhardt ruediger.dohmhardt at freenet.de
Fri Sep 30 23:07:00 CEST 2005

Christoph Anton Mitterer wrote:

> Ruediger Dohmhardt wrote:
>> 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.
> Oh,.. thats bad,.. uhm is this sure? As I told my board hast 3 PCI-X 
> slots (2 with 100MHz and 1 with 133MHz) and one conventional PCI slot 
> (33MHz). I think the PCI and the PCI-X buses have each their own 
> controller.

I'm not really sure, how many busses you have. I guess 3:
 1 x PCI-33MHz
 1 x PCI-X 100MHz
 1 x PCI-X 133MHz
But again its just a guess.
I assume further that just one bus (the one you plug your card into) 
slows down to 33MHz.

> But if you're true and the wohle buse runs at the spead of the slowest 
> card, that would imply that if I'm using one of the two 100MHz slots 
> (with 100MHz PCI-X cards) than I wouldn't be able to use the 133MHz in 
> the 3rd slot.

As said above, I guess just one bus slows down.

> Is there a way to defenitely determine if a card is keyed correctly?

There are, for example, PCI-chips from companies like AMCC or PLX.
You can easily find the data sheet in the WEB, which tells you what kind 
of signalling they have.
Most PCI-interface chips are ASICS, hence you won't find a specification 
and you must rely
(which you should do, except you design/build professional systems) on 
the "keying".

Hauppauge (in Germany) is always very helpful on the phone. They might 
tell you what kind of signalling there PCI-chips use.

Ciao Ruediger

Ruediger Dohmhardt                  ruediger.dohmhardt at freenet.de
Kiefernweg 7                        Tel.:  04101 61743
25421 Pinneberg

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