Amigabill Projects

It seems that rev 2 of Expresscard assigns the PCI-Express SERDES and USB3 superspeed SERDES to the same pins, and some muxing is required to support everything. Pericom has such a mux, and TI has one or two coming soon. Interesting.

For other people that are curious about how the PCI-Express Gen2 lanes and the USB3 lanes are muxed together for ExpressCard 2 slots, check out the ExpressCard2 Specification, and search for "PCI-Express signal switch" or "USB3 signal switch". Most of what I found are suitable for PCI-Express Gen1 (2.5Gbps) speed, but are not fast enough for USB3 or PCI-Express Gen2 (5Gbps) speed. One available is, and one or two coming soon from another vendor are as well. Check the speeds supported by your search results.

There's also a power controller involved, so it knows which power to provide, when, and when not to.

I think that this, with a PCI-Express lane and a USB3 port, should give a workable ExpressCard2 slot. There may be a little more, but I'll trip over that bridge when I get there. Probably firmware/software stuff to deal with too. The ComExpress spec talks about having some PCI-Express lanes being ExpressCard capable, and I haven't yet figured out exactly what they mean by that, if there's something special about the lane in the root controller for that, or what.