RE: Is is possible to receive a cheep SubVendorID?

[Dave New <NewD@esi.com>]

Yeah, that's what I was complaining about earlier.
Frankly, I haven't seen anyone get bit by that
'requirement'.  It certainly wasn't a requirement
of the PCI spec, so Microsoft hasn't much sway in
this matter.

The truth of the matter is that Microsoft, like
so many other companies, *must* support their
legacy operating systems and applications.  If
they broke compatibility with earlier PCI-aware
systems by refusing to work with boards that
did not implement the sub-fields, their user
base would fry them.  I could think of some
*large* corporate customers that would simply
refuse to upgrade to the latest and greatest
because of this.  So, Microsoft may rattle
their sabres, but they must support all the
old ways of doing things, as well.

So, if you have the opportunity to support
and use the sub-fields, then do so for any
new designs.  But, it doesn't make much
sense to simply duplicate the VID and DID
into the sub-fields.  That's just redundant.
And don't use them for adapter revision
information. There's another field for that,
already.

Cheers,

-- DaveN

-----Original Message-----
From: Marco Brambilla [mailto:marco-tpa.brambilla@st.com]
Sent: Thursday, October 26, 2000 11:28 AM
To: NewD@esi.com
Cc: pci-sig@znyx.com
Subject: Re: Is is possible to receive a cheep SubVendorID?


Hi Dave,

> Actually, I see four common situations, because some
> chipsets allow you to modify the Vendor ID (VID) and
> Device ID (DID) fields yourself at powerup.  I'll copy
> your two and add to them below:

Agree.

I was not considering 1a and 2a because Microsoft claims that in order
to get compliance to PC99 and newer you have to populate SVID and SDID.

> 1a) The Vendor of the final product has a valid Vendor ID
> The Vendor ID (VID), and Device ID (DID) are chosen by the oem
> The SubVID, SubDID are unused

> 2a) The vendor of the final product IS NOT registered to the pci sig
> VID is from the chip vendor
> DID is allocated from the chip vendor to the customer
> SVID and SDID are unused

Ciao, Marco.
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