Re: Determine if card is in 32 or 64 bit PCI slot?

[Johannes Erdfelt <johannes@erdfelt.com>]

On Tue, Aug 14, 2001, Jes Sorensen <jes@sunsite.dk> wrote:
> >>>>> "Johannes" == Johannes Erdfelt <johannes@erdfelt.com> writes:
> 
> Johannes> On Wed, Aug 08, 2001, Alan Cox <alan@lxorguk.ukuu.org.uk>
> Johannes> wrote:
> >> Are you sure the card actually needs this. Most such cards support
> >> dual address cycle, so when placed in a 32bit slot will still do
> >> 64bit DMA
> 
> Johannes> No I don't know if it's needed. I had no idea that PCI could
> Johannes> do that.
> 
> Johannes> Is dual address cycle mandated by the PCI specs?
> 
> According to the PCI spec "The master is required in all cases to use
> two clocks to communicate a 64-bit address, since the width of a
> target's bus is not known during the address phase."
> 
> Aka, the answer to your question is yes.

Ahh, excellent. Thank you very much.

JE