Some ploblems about PCI core

1. I don't see why you should have to enable the clamping diodes if you've got a level shifter in between the FPGA and PCI bus.

2. I haven't used a recent version of the PCI core but by the sounds of it you don't need to set constraints manually. Does the script assign exactly the same timing constraints to each pin? - if so then moving the pins shouldn't matter from this point of view.

However it could be a board problem - timing, signal integrity etc.

Much more fundamentally how does the QS3861 handle the bi-directional signals - do you have to pass it some sort of control signal to do this?does the PCI compiler handle this?