OPENCORES.ORG

Hi Stefan,

The solution is to use the MTRR register that it's available in the
Pentium III and up.

This register tolds the CPU that some region of the PCI address space is
type "write-back" and will make burst reads.

more information in this
thread:http://www.pcisig.com/reflector/msg04112.html

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Sebastián Fernández
_____________________________
Instituto de Ing. Eléctrica
Facultad de Ingenieria
Tel: 7110974 int.107
On Wed, 10 Dec 2003, adalbert.mueller wrote:

> Hi Stefan,
>
> on PCI you can influent the kind of transfer by setting the command
> bit's on the bus. These bit's are laying during addressing phase on the
> bus and indicate the desired busmode.
> Beneath the single cycle read/write modes there exist two modes for
> initiating a burst. They are called 'read cache line' and 'read
> multiple'. For writing, no such modes are defined!!
> Of course, write bursts occour, but you can't take control over them.
> They are assembled by the (intelligent) PCI-bridge into a burst.
>
> If you want to know, how to initiate 'read cache line' or 'read
> multiple' transfers (I recomend read multiple) you have to look into
> you're description/driver how to influent the C/BE# of your device.
>
> I hope this was helpful for you,
>
> Adalbert
>
>
> Stefan Bergström wrote:
>
> >I'm just using write bursts. I do not know if my board can use burst read.
> >The PCI standard and the Altera PCI core can handle it but I do not know if
> >there are limitations in the motherboard hardware that prevent read bursts.
> >I have no clue whether the Opencore PCI can handle read bursts.
> >
> >It should be technically possible to use read busts (in a slave PCI-core) at
> >a PC since Altera has made code for it but I don't know for sure.
> >
> >Sincerely
> >STB
> >
> >-----Ursprungligt meddelande-----
> >Från: tomko81@h... [mailto:tomko81@h...]
> >Skickat: den 10 december 2003 02:08
> >Till: stb@v...; pci@o...
> >Ämne: Re: [pci] how to handle burst mode read/write of PCI in device driver
> >
> >Thank you for your reply.
> >
> >But my point is that in slave PCI, the write/read process is initiated by
> >others like CPU, i try to read in a string of DWORD in the PCI device
> >driver but it just read in the data one by one and so the speed is slow. I
> >would like to know is there any solution can call out the burst read/write
> >in slave PCI?
> >
> >You say you are using slave PCI but can still perform burst read, how
> >can you do that ?
> >
> >
> >Regards,
> >TOM
> >
> >
> >
> >
> >_______________________________________________
> >http://www.opencores.org/mailman/listinfo/pci
> >
> >
>
>
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