Re: Thunder HEsl S2567 / PCI 64 - 66MHz

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

Hi,
Sorry for my this morning's response. It's wrong.

1. Latency Timer is only used by PCI Masters, not by PCI Targets.
When host bridge gave STOP# signals, it means host bridge is playing Target
role, not Master role.

Even though Host bridge has a Latency Timer, its value change has nothing to
to do with improving your situation.

2. You may try another thing, maybe still a bad idea: change Cacheline Size
in HOST BRIDGE:
The PCI-to-PCI Bridge Architecture Specification page 35 says:
"The Cacheline Size register is used when terminating a transaction that
uses the Memory Write and Invalidate command and when prefetchng(Memory
ReadLine and Memory ReadMultiple commands)."

Try doubling HOST BRIDGE Cacheline Size value and see what's happening.

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
>
>
>
>
>
>