Chaining of PCMCIA Cardbus controllers

[Braun_Josef#Tel3805 <bj3805@denbgm31m.scnn1.msmgate.m30x.nbg.scn.de>]

Hello everybody,

for our current system we have to design a PCI add-in-card with 3 PCMCIA 
Cardbus
sockets. The PCI Local Bus Specification 2.1 (Chapter 4.4.3.4) says, you 
must not
attach two or more PCI devices on an expansion board, unless they are placed
behind a PCI-to-PCI bridge. Even if we would offend against this rule, we 
must not
use more than one controller for the PCI-bus interface to get no additional 
loads on the PCI-bus. As the PCMCIA Cardbus controllers on the market only 
support two
PCMCIA-sockets, that would mean, we have to use a PCI-to-PCI bridge with two
PCMCIA controllers behind it. Because this is very expensive, we?re thinking 
about
another solution. PCI bus protocol is very similar to the PCMCIA Cardbus 
signaling
environment. Might there be a chance to build a chain by using one
PCMCIA-controller for the interface to the PCI-bus and attach the second to 
one
PCMCIA-socket of the first controller? Although some vendors of 
PCMCIA-Cardbus
controllers suggest a solution like that, they don?t guarantee the proper 
functionality.

So the question is:

Is there anybody out there having a similar problem or better has already 
done a design like that?


Thanks a lot for any help!


Regards,
Braun Josef
bj3805@nbg.scn.de


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