UBB and USB (was Re: Statistics: November 2012)

Werner Almesberger werner at almesberger.net
Wed Dec 5 15:05:35 EST 2012

Paul Boddie wrote:
> It's a shame that the UBB doesn't provide some kind of edge connector so that 
> it could plug into a suitable socket,

With the cable you can connect to a large number of connectors:

The leftmost takes about a second to assemble (insert cable,
push, done) and connects to the ubiquitous 100 mil headers.

And you normally want a bit of cable between UBB and your
circuit, to avoid putting too much mechanical stress on the

And if you make a really tiny circuit that doesn't need a cable,
then you're likely to have your own PCB anyway and can just
construct your own half-UBB with the PCB connector footprint
(8_10-card.fpd) we have in kicad-libs.

> Perhaps we should have a link on the "Ben NanoNote" page for hardware 
> projects.

Yeah, I find the Wiki somehow difficult to navigate, too. I
usually cherry-pick with Google instead of trying to worm my
way through the hierarchy/thicket. 

> Such a wasted opportunity! Given that USB ports are frequently used in this 
> way, you'd think that the SoC designers would have considered such 
> applications.

I don't know how exactly such multifunction ports are implemented.
Maybe they route several pins to one signal, either inside our
outside the SoC, and tri-state all but one of the systems at any
given time.

But besides that, the choice of diagnostic options is indeed
unusually small.

- Werner

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