grounding unused inputs
Dan Michaels email (remove spam text)
Olin Lathrop wrote:
>Do unused inputs really need to be connected to ground?
>What is the effect if they are not grounded?
>Does it affect operation of the PIC?
>This has been beaten to death several times. Check the archive.
>I leave unused pins open and set them as outputs. I usually tie unused
>input-only pins to ground.
To be "safe", it is best to tie unused input pins to ground [or Vcc,
doesn't much matter which] *ONLY* through a resistor, rather than
directly with a short. This is not superstition, as during code
development it is all too easy to accidentally configure a pin
intended as input to output. You then run the risk of
short-circuiting an output.
Furthermore, having a resistor on the pin, rather than a short,
makes it much easier to utilize that pin later on for some useful
function, as the need may arise.
http://www.piclist.com hint: The PICList is archived three different
ways. See http://www.piclist.com/#archives for details.
See also: www.piclist.com/techref/microchip/ios.htm?key=input
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