I understand you need information about your Intel chipset with ICH7M.
I am currently researching on this issue. As soon as I can, I will send you a message with my findings. Thank you for your patience and understanding.
Allan, thanks for looking into this.
Intel doc i-o-controller-hub-7-datasheet.pdf lists the configuration registers, and it would be great to get some help whether the latency of a single-byte read or write to the external PCI bus is in any way influenced by these.
It seems weird that the Atom/ICH7 combination spends 0.7us more on a bus access than the older 852GM. The read/write seems pretty much an MMU mapped, low level bus access - or is this too naive ?