Unused Pins of a Microcontroller

[M_A A. (muashr)]

Hi,

What should be done with the unused pins of a microcontroller? Can they 
be left just soldered (unconnected) or something additional has to be 
done?
For example, in case of this microcontroller what needs to be done with 
pins with a status:
''I(pull-up)''
or
''O(Hi-Z)''
or
''-''?


Datasheet: 
http://www.epsondevice.com/webapp/docs_ic/DownloadServlet?id=ID002599

[Rufus Τ. F. (rufus)]

Check the datasheet.


The language used in this board is german. Please use the english 
counterpart https://embdev.net/forum/, if you're unable to communicate 
in german.

[Alex R. (itaxel)]

Yes, the pins you don't need can left free, just soldered.
Also the pins with I/O can be free.

The "-" means that they haven't an input or output and no status. In 
your case its always for the  power supply. They should be connected.

[Jan H. (jan_m_h)]

You should on most devices either configure them as an output or, if 
they are configured as input, enable build in pull-up/-down resistors. 
This reduces unnecessary currents caused by the undefined state of the 
input gates.