Usage Notes; Notes On Input Buffer Control Register (Icr) Setting; Notes On Port Function Control Register (Pfcr) Settings - Renesas H8SX/1650 Hardware Manual

8.4

Usage Notes

8.4.1

Notes on Input Buffer Control Register (ICR) Setting

• When changing the ICR setting, the LSI may malfunction due to an edge that is internally
generated according to the pin states. To change the ICR setting, fix the pin high or disable the
input function by setting the peripheral module allocated to the corresponding pin.
• If an input is enabled by setting ICR while multiple input functions are assigned to the pin, the
pin state is reflected in all the inputs. Care must be taken for each module settings for unused
input functions.
• When a pin is used as an output, data to be output from the pin will be latched as the pin state
if the input by the ICR setting is enabled. To use the pin as an output, disable the input
function for the pin by setting ICR.
8.4.2

Notes on Port Function Control Register (PFCR) Settings

• The port function controller controls the I/O ports. To set the input/output to each pin, select
the input/output destination and then enable input/output.
• When changing the input pin, an edge may be generated if the previous pin level differs from
the pin level after the change, causing an unintended malfunction. To change the input pin,
follow the procedure below.
(1) Disable the input function by the setting of the peripheral module corresponding to the pin
to be changed.
(2) Select the input pin by the setting of PFCR.
(3) Enable the input function by the setting of the peripheral module corresponding to the pin
to be changed.
• If a pin function has both a selection bit that modifies the input/output destination and an
enable bit that enables the pin function, first specify the input/output destination by the
selection bit and then enable the pin function by the enable bit.
Section 8 I/O Ports
Rev.2.00 Jun. 28, 2007 Page 303 of 666
REJ09B0311-0200