I found an interesting "problem" with the IXP1200. When doing Type 0/1 configuration reads with the IXP, any attempt to access devices using AD26-AD31 for their IDSEL decoding will produce nasty results. With VxWorks, you'll get an exception, killing process execution. With the custom OS I'm running now, I drop into the debugger and the ARM PC is off in deep space... :-( This may be a design decision by the IXP engineers. They do support a full 10 devices, but they assume that the devices will be decoded within the config space of AD11-AD25. I'm guessing a bit here, but it seems that this is the case. There are SBCs and "passive" backplanes which hardwire device IDSELs to the higher areas of config space AD26-AD31. Something to watch out for... jk
Jon Krueger Senior Engineer Intel Corporation Network Equipment Division
13280 Evening Creek Drive San Diego, CA 92128 (858) 391-1710 jon.krueger@intel.com