R01UH0823EJ0100 Rev.1.00
Page 197 of 1823
Jul 31, 2019
RX23W Group
9. Clock Generation Circuit
9.3.2
External Clock Input
shows connection of an external clock. If operation is to be driven by an external clock, set the
MOFCR.MOSEL bit to 1 and leave the XTAL pin open-circuit.
Figure 9.6
Connection Example of External Clock
9.3.3
Handling of Pins When the Main Clock is Not Used
For details on pin handling when the main clock is not used, refer to
section 21.5, Handling of Unused Pins
9.3.4
Notes on the External Clock Input
The frequency of the external clock input can only be changed while the main clock oscillator is stopped. Do not change
the frequency of the external clock input while the setting of the main clock oscillator stop bit (MOSCCR.MOSTP) is 0
(main clock oscillator is operating).
XTAL
EXTAL
Open
External clock input