Usage Notes; Notes On Input Buffer Control Register (Icr) Setting; Notes On Port Function Control Register (Pfcr) Settings - Renesas H8SX/1500 Series Hardware Manual

8.4

Usage Notes

8.4.1

Notes on Input Buffer Control Register (ICR) Setting

•
When the ICR setting is changed, the LSI may malfunction due to an edge occurred internally
according to the pin states. To change the ICR setting, fix the pin high or disable the input
function corresponding to the pin by setting the on-chip module registers.
•
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 of individual modules. Care must be taken for the
settings of unused input function on each module side.
•
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 function corresponding to the pin 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 PFC controls I/O ports. To specify the function of each pin, specify the input/output
destination before enabling the input/output function.
•
When the input/output destination is changed by the corresponding selection bit, an edge may
occur if the previous pin level differs from the pin level after the change. To change the pin
direction correctly, follow the procedure shown below.
1. Disable the input function corresponding to the pin by the on-chip module registers.
2. Select the input function by setting PFCR.
3. Enable the input function.
•
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. 3.00 Mar. 14, 2006 Page 249 of 804
REJ09B0104-0300