Olin, I never spoke about price, size, etc. I just refered to protection. So
maybe, I see now, my "always" could create a confussion to you, or others.
So I asume I missused the word "always". I referred to electrical protection
not pice, size, etc.
You prefer to leave them unconnected, stacked to Vcc or to Gnd, is all up to
you. I prefer to not. But, of course, I do not complain about more size and
the extra components. Usually you (me, somebody) would chosse a
microcontroller that best fits the project, not only peripherals, speed,
memory, also pin count is taken in consideration. So, the number of
unconnected pins is not going to be very large, and so tradeoff. But that's
my opinion with my very personal conditions, and yours should be different.

You bring again the death fish and mix with real engineering... May be I do
not know sufficient english to really understand it, but it seems to me
offensive, correct me if it's not. So I'm not going to respond that way.

2009/9/17 Olin Lathrop <olin_piclist@embedinc.com>

> Vicent Colomar Prats wrote:
> > It's "always" better to have a protection on each non-used pin than
> > having nothing? True.
>
> It's absolute statements like this that are voodoo electronics.  They are
> certainly not real engineering.  In real engineering there is most often a
> tradeoff, as in this case.
>
> Protection on pins can sometimes be the right tradeoff.  But saying it is
> *always* the right tradeoff is just silly since that ignores the costs.  In
> this case the costs include components, board space for the components, and
> board space for routing the lines.  These costs have to be weighed against
> the benefits, which are miniscule at best compared to not even routing
> traces to the pins.  Adding the tracks and extra parts may actually make
> things worse due to high susceptibility to static discharge or RF pickup.
>
> So if you want absolute certainty, go wave a dead fish over your project.
> That always works, although you have to use the right species of fish
> during
> the right phase of the monne and your thoughts have to be pure.  Meanwhile
> for the rest of us there are real engineering tradeoffs to consider.
>
> > No need to be sarcastic about your customers boards. I never spoke about
> > them nor told you to change them.
>
> Actually you did since they fall into your "always" case.
>
>
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