Datasheet

Section 10 I/O Ports
Rev. 6.00 Mar. 18, 2010 Page 358 of 982
REJ09B0054-0600
10.13 Handling of Unused Pins
Unused input pins should be fixed high or low. Generally, the input pins of CMOS products are
high-impedance. Leaving unused pins open can cause the generation of intermediate levels due to
peripheral noise induction. This can result in shoot-through current inside the device and cause it
to malfunction. Table 10.7 lists examples of ways to handle unused pins. Pins marked NC should
be left open.
Table 10.7 Examples of Ways to Handle Unused Input Pins
Port Name Pin Handling Example
Port 1
Port 3
Connect each pin to Vcc (pull-up) or to Vss (pull-down) via a resistor.
Port 4 Connect each pin to AVcc (pull-up) or to AVss (pull-down) via a resistor.
Port 7 Connect each pin to Vcc (pull-up) or to Vss (pull-down) via a resistor.
Port 9 Connect each pin to AVcc (pull-up) or to AVss (pull-down) via a resistor.
Port A
Port B
Port C
Port D
Port E
Port F
Connect each pin to Vcc (pull-up) or to Vss (pull-down) via a resistor.
Port G