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From: npd@a...<npd@a...>
Date: Thu Mar 24 15:11:31 CET 2005
Subject: [pci] TARGET_ONLY definition (correction)
Sorry, reposting to correct for single and double quotes.

Hi,
I'm new to the PCI bus. I have been working with your core now for a
couple of weeks now and have some questions. I have been using your
tool to configure the PCI Bridge (PCIBridgeConfig.exe) for my project.
I'm trying to create a simple PCI target device so I select "Guest-Bridge"
and then "Target only". This creates a definition in the
pci_user_contrants.v file called TARGET_ONLY. My problem is that I
don't understand how this definition is being used. I did a search though
all the files and could not see how it was being implemented. Also, I
could not find it mentioned in the documents supplied with this core.

A similar problem was noticed with the definition ADDR_TRAN_IMPL.
While this could be found in the documents, I was unable to find any
verlog file that used it other than being defined in the
pci_user_contrants.v file.

So what am I missing?

An observation. I think the configuration tool is great for people like me
that are new to PCI, but it looks like it needs to be updated a little. The
changes made last July defining SubsystemVendorID, SubsystemID,
MAXLatency, MinGnt need to be added to this tool. Also, I noticed that
when the tool creates the pci_user_contrants.v file, PCI_AT_EN# and
WB_AT_EN# are defined with a value of 20'hN_ or 20'hY_ instead of
1'b0 or 1'b1 and WB_BA# is defined with a nothing. WB_BA# should be
defined with something like 20'h0000_0 as a default.

Anyhow, I’ve been pouring though this IP core before asking for help in
understanding this core. This is also my first time using Wishbone and I
prefer it over the Avalon bus from Altera. Good choice on this. So if I
could get some advice on a simple PCI target, I would greatly
appreciate it.

Thanks,
Nick