Re: PCI board not working in some mother boards?

["Kevin Brace" <kevinbraceusenet@hotmail.com>]

        Interesting . . .
The PCI card works fine with Intel and VIA chipsets, but doesn't work with 
SiS or AMD chipsets . . .
I personally doubt that this problem has anything to do with the card being 
a universal PCI card, considering that almost all desktop motherboards have 
only 5V PCI slots.
        Although it might have nothing to do with your problem, one thing I 
can say about some older SiS chipsets (Socket 7 generation) is that they 
have a tendency to insert wait states (FRAME# = 'L' and IRDY# = 'H') for a 
few cycles during the first data transfer (FRAME# and IRDY# will remain 'L' 
and 'H' respectively for a few cycles after an address phase.), whether or 
not the transaction is a single or a burst transfer.
If the designer of the chip you are talking about didn't pay attention to 
this phenomenon (PCI Local Bus Specification 2.2 3.5.2 Master Data Latency), 
and assumed that IRDY# will always be asserted right after an address phase, 
then it is possible that such a PCI device might somehow get confused, and 
may ultimately cause the computer to lock up.
You may want to hook up a logic analyze to the motherboard, and see what 
causes the problem.
If whatever I said occurred, likely the lock up is occurring within the BIOS 
code when the BIOS tries to search the PCI bus to see what is connected.


Kevin Brace (In general, don't respond to me directly, and respond within 
the mailing list.)



>From: "William Benner" <William_Benner@email.msn.com>
>To: "PCI-SIG, Mail List" <pci-sig@znyx.com>
>Subject: PCI board not working in some mother boards?
>Date: Thu, 10 Oct 2002 18:57:12 -0400
>
>Hi all,
>
>I am wondering if anyone can help. We have been distributing a PCI board
>that uses the Cypress CY7C09449PV-AC chip (Formerly the AnchorChips AN3042Q
>"Comem LITE") since 1999 with great results. Recently we have a client who
>informs us that when he places our PCI board into some mother boards, the
>system will not boot.
>
>For this client, the list of working mother boards are:
>
>DFI        CB61             Intel Chips (old)
>Elitegroup K7VTA3           VIA KT333(VT8367),(VT8233A) Chips(new)
>Gigabyte   GA-7VRXP         VIA KT333 AGPset(new)
>Gigabyte   GA-7VR           VIA KT333 AGPset(new)
>Gigabyte   GA-71XEH         VIA KT133/KT133E AGPset(old)
>Gigabyte   GA-7ZXE          VIA KT133A AGPset(old)
>
>
>For this client, the list of non-working mother boards are:
>Gigabyte   GA-7DX+          AMD 761/VIA 686B
>ASUS       A7S333/PA/UAY    SIS745
>MSI        MS-6561          SIS745
>
>Does anyone have any ideas as to what might be going on here? Could there 
>be
>some 3V/5V issues here?
>
>Best regards,
>
>William Benner
>Pangolin Laser Systems



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