Note On Modification Of Serial Port Control Register; Application Note; The Management Of The Un-Use Terminal - Renesas H8/3847R Series Hardware Manual

Section 8 I/O Ports
8.14.3

Note on Modification of Serial Port Control Register

When a serial port control register is modified, the data being input or output up to that point is
inverted immediately after the modification, and an invalid data change is input or output. When
modifying a serial port control register, do so in a state in which data changes are invalidated.
8.15

Application Note

8.15.1

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
 Pull it up to V
 Pull it down to V
 For a pin also used by the A/D converter, pull it up to AV
• 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
approximately 100 kΩ.
 Set the output of the unused pin to low and pull it down to V
approximately 100 kΩ.
Rev. 6.00 Aug 04, 2006 page 256 of 680
REJ09B0145-0600
with an on-chip pull-up MOS.
CC
with an external resistor of approximately 100 kΩ.
CC
with an external resistor of approximately 100 kΩ.
SS
.
CC
with an external resistor of
CC
with an external resistor of
SS