Datasheet

Section 8 I/O Ports
Rev. 8.00 Mar. 09, 2010 Page 245 of 658
REJ09B0042-0800
8.13 Application Note
8.13.1 The Management of the Un-Use Terminal
If an I/O pin not used by the user system is floating, pull it up or down.
• If an unused pin is an input pin, handle it in one of the following ways:
⎯ Pull it up to V
CC
with an on-chip pull-up MOS.
⎯ Pull it up to V
CC
with an external resistor of approximately 100 kΩ.
⎯ Pull it down to V
SS
with an external resistor of approximately 100 kΩ.
⎯ For a pin also used by the A/D converter, pull it up to AV
CC
.
• If an unused pin is an output pin, handle it in one of the following ways:
⎯ Set the output of the unused pin to high and pull it up to V
CC
with an on-chip pull-up MOS.
⎯ Set the output of the unused pin to high and pull it up to V
CC
with an external resistor of
approximately 100 kΩ.
⎯ Set the output of the unused pin to low and pull it down to GND with an external resistor of
approximately 100 kΩ.