Re: Thunder HEsl S2567 / PCI 64 - 66MHz

["Weng" <wtx@umem.com>]

Hi,
Your questions are raised then and again. It is a ubiquitous problem. I will
meet it when I am debugging my board design.

My suggestion: Please check PCI-TO-PCI bridge specs 1.1. In PCI bridge there
is another Latency Timer. If the latency timer in the HOST BRIDGE has a
small value, your latency timer has no control like your situation.

How to modify the latency timer in the host bridge is a different issue. If
someone knows it, please let everyone who are interested in know.

Weng Tianxiang

wtx@umem.com
wengtianxiang@yahoo.com

Micro Memory Inc.
9540 Vassar Avenue
Chartsworth, CA 91311
Tel: 818-998-0070
Fax: 818-998-4459





----- Original Message -----
From: Naert, Hans <hans.naert@barco.com>
To: <pci-sig@znyx.com>
Sent: Wednesday, May 02, 2001 7:58 AM
Subject: Thunder HEsl S2567 / PCI 64 - 66MHz


>
> Dear,
>
> We are using the Thunder HEsl S2567,
> We use the PCI 64bit 66Mhz slot.
>
> When we put our card into the slot (32 bit 66MHz), the maximum bandwith is
> 1/4 of the theoretical,
> our card (initiator who reads out of memory with the pci "read memory"
> command) get a STOP from the motherboard after a read transfer of 4 words.
> With the pci  "memory read multiple" command the bandwith is 1/2 of the
> theoretical, but we get a stop after 16 words.
>
> We tried with a 64bit 66Mhz card but the result are the same.
>
> What must we do to get a greather bandwith.(to make that we don't get a
STOP
> and that we can transfer data until our latency timer expires)
> We have also the latenscy timer of the bridges changed in F8 (the latency
> timer value of our card is also F8).
>
> Can you help me?
>
> Greetings,
>
> Hans Naert
> R&D Engineer
> Barco Graphics, Industrial Printing
>
> -----Original Message-----
> From: Naert, Hans
> Sent: Wednesday, May 02, 2001 9:58 AM
> To: 'mattv@tyan.com'; 'techsupport@tyan.com'
> Subject: Thunder HEsl S2567 / PCI 64 - 66MHz
>
>
> Dear,
>
> We are using the Thunder HEsl S2567,
> We use the PCI 64bit 66Mhz slot.
>
> When we put our card into the slot (32 bit 66MHz), the maximum bandwith is
> 1/4 of the theoretical,
> our card (initiator who reads out of memory with the pci "read memory"
> command) get a STOP from the motherboard after a read transfer of 4 words.
> With the pci  "memory read multiple" command the bandwith is 1/2 of the
> theoretical, but we get a stop after 16 words.
>
> We tried with a 64bit 66Mhz card but the result are the same.
>
> What must we do to get a greather bandwith.(to make that we don't get a
STOP
> and that we can transfer data until our latency timer expires)
> We have also the latenscy timer of the bridges changed in F8 (the latency
> timer value of our card is also F8).
>
> Can you help me?
>
> Greetings,
>
> Hans Naert
> R&D Engineer
> Barco Graphics, Industrial Printing
>
>
>
>
>
>