Mini PCI-Express is also USB2 is also mSATA
I didn't realize that the mini PCI-Express card format has USB2 data signals as well. Or that some cards to fit these sockets are purely USB2. (WLAN is PCIe, WWAN is USB2 from the sounds of it) Interesting. I do not at this time find anything about USB3 SuperSpeed support in any standard use of this connection/form factor.
I also did not realize that SATA drives also come in this PCB form factor, termed mSATA. It seems that the SATA signals are muxed with the PCI-Express signals (or replace them completely for an mSATA specific slot without PCIe) similar to how ExpressCard2 muxes USB3 SuperSpeed signals with PCI_Express.
The Mini PCI-Express connector defines pins for a SIM card for cellular based wireless data such as 3G. The SIM card is not on the module itself, perhaps on the motherboard or possibly on an adapter card if the motherboard lacks this and you need it.
It seems the Mini PCI-Express module is useful for more than just WiFI+Bluetooth, which is all I was aware of previously. Such as a hardware video decoder.
Labels: msata, pci-express, pcie, sata, usb
ExpressCard2 SERDES mux
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.
Labels: expresscard
That's so tacky!
I've been trying to read up on doing BGA rework with the hot air gun. Articles and youtube videos suggest making use of gel flux. Googling for gel flux was frustrating at first. At some point I can to the realization that gel is one word for a thing with a variety of words. When you're ordering from Digikey, Amazon, etc. you'll probably want to search for the term tacky flux to find what you want. Some people call it paste flux. All the same thing I guess, in terms of viscosity and why you use it over liquid. The only thing left is to figure out if you want no-clean (you probably do), water soluble, halide-free, lead-free or tin-lead compatiblecharacteristics in tacky/paste/gel form.
It sounds like this tacky/paste/gel flux is what you want to use while reballing a BGA. The tackiness helps hold a loose ball on each pad until you get it under heat for reflow to really attach the solder balls. And some people use it with solder wick/braid in cleaning old solder off the BGA pads before reball or reflow on the PCB board.
Preparing for a lot of hot air
I'm (very) gradually tooling up to be able to rework SMT and BGA devices on circuit boards. I've got a hot air station now, and some BGA type liquid flux, and have a preheater, hot air gun holder, and board holder on the long-range radar. Maybe someday I'll save up for them... Until then, I've got a toaster oven for preheating and making out humidity and such things.
My hot air station is the Aoyue 968A+. Relatively inexpensive for that sort of thing, and has a vacuum pen tool for moving around little SMT devices. Also has a soldering iron, but I'd rather that was a tweezer iron, and I do hope to order a tweezer to put in its place at some point. I already have a soldering iron that I'm pretty happy with, and would rather have a tweezer that would make some things like the AmigaOneXE DMA fix easier to do than holding my iron in one hand and my desoldering iron in the other hand and try to maneuver things that way without hurting myself. A holder would also be nice for the air gun so I can have hands free to drive pickup tweezers and vacuum pickup tools.
For my first projects, I intend to play with a couple old broken cell phones to get a feel for things, and then move on to removing parts from Mac G4 processor modules, and a similar AmigaOneXE module, for the purpose of mapping the Megarray connectors and perhaps work out an adapter between them. This project can be seen here.
