On Sun, Nov 2, 2008 at 3:05 PM, Rodent of Unusual Size
<RoUS@sourcery.org> wrote:
> Does setting an output port low or high again -- whatever it's
> current value is -- introduce any sort of tranient?  Will there
> be a blip on the output port from this?  (example)
>
>        BSF     PORTB, 2
>        NOP
>        NOP
>        NOP
>        NOP
>        NOP
>        BSF     PORTB, 2


In theory, no, it doesn't.

HOWEVER, the oft disregarded RMW problem can rear its ugly head. See
here for more info: http://www.piclist.org/techref/readmodwrite.htm

The gist of it is that when you perform a pin specific operation, the
PIC will read the port into a buffer, do the operation, then write it
back to the port. Normally not a problem. But if something is pulling
that pin in a direction you aren't expecting, that unexpected value
might actually get written back to the port as a proper value. The
link above gives a much better explanation with examples!

Josh
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