R01UH0823EJ0100 Rev.1.00
Page 191 of 1823
Jul 31, 2019
RX23W Group
9. Clock Generation Circuit
9.2.18
Main Clock Oscillator Forced Oscillation Control Register (MOFCR)
Note:
Set the PRCR.PRC1 bit to 1 (write enabled) before rewriting this register.
The EXTAL/XTAL pin is also used as a port. In the initial setting state, the pin is set as a port.
MODRV21 Bit (Main Clock Oscillator Drive Capability Switch)
These bits select the drive capability of the main clock oscillator.
MOSEL Bit (Main Clock Oscillator Switch)
This bit selects the oscillation source of the main clock oscillator.
Address(es): 0008 C293h
b7
b6
b5
b4
b3
b2
b1
b0
—
MOSEL MODR
V21
—
—
—
—
—
Value after reset:
0
0
0
0
0
0
0
0
Bit
Symbol
Bit Name
Description
R/W
b4 to b0
—
Reserved
These bits are read as 0. The write value should be 0.
R/W
b5
Main Clock Oscillator Drive
Capability Switch
VCC
2.4 V
0: 1 MHz or higher and lower than 10 MHz
1: 10 MHz to 20 MHz
VCC < 2.4 V
0: 1 MHz to 8 MHz
1: Setting prohibited
R/W
b6
Main Clock Oscillator Switch
0: Resonator
1: External oscillator input
R/W
b7
—
Reserved
This bit is read as 0. The write value should be 0.
R/W