I'm in the beginning of designing some custom IP that I want to put on a PCI
card. I want the IP to modify a few bits in the downstream and upstream
communications path, and then pass this modified data either downstream to a
standard Ethernet controller which has a PCI backend or upstream to the PC.
I figure for this application I would need to implement a PCI bridge
function that would essentially appear transparent to the Ethernet chip, and
look just like another Ethernet device on main PC PCI bus.

Will the opencores core work as a PCI bridge? If not what should be
modified? Are there any special caveats that I'm missing in my top level
analysis?

Thanks for any help,

-db