Datasheet

Table Of Contents
Section 9 I/O Ports
REJ09B0140-0900 Rev. 9.00 Page 281 of 846
Sep 16, 2010
H8S/2215 Group
9.13 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 9.76 lists examples of ways to handle unused pins.
For the handling of dedicated boundary scan pins that are unused, see section 14.2, Pin
Configuration, and section 14.5, Usage Notes. For the handling of dedicated USB pins that are
unused, see section 15.9.14, Pin Processing when USB Not Used.
Table 9.76 Examples of Ways to Handle Unused Input Pins
Pin Name Pin Handling Example
Port 1 Connect each pin to Vcc (pull-up) or to Vss (pull-down) via a resistor.
Port 3
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 Connect each pin to Vcc (pull-up) or to Vss (pull-down) via a resistor.
Port B
Port C
Port D
Port E
Port F
Port G