Using a resistor makes in-field changes (such as adding
an extra output pin) easier then if the pin was hard
wired to Vdd or Vss on the PCB. The resistor can be
de-soldered and make the pin available for other uses.

Jan-Erik.

David Meiklejohn wrote:
>> If you are developing real application and not demo boards, you should
>> add a pull-up or pull down to set the input to a defined state.
> 
> Is it considered ok to connect inputs directly to Vdd or Vss, or should a
> pull up/down resistor always be used?  I can see that using a resistor is
> a good idea in case the PIC somehow ends up with what is supposed to be an
> input, set to output, in which case the resistor protects against e.g.
> grounding a high output, but is there any other reason to use them?  E.g.
> I note that MCLR is often held high through a resistor, instead of
> directly to Vdd.  What's the danger in connecting it (an input-only pin)
> to Vdd?
> 
> 
> David Meiklejohn
> www.gooligum.com.au
> 
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