HD64336900G Datasheet, PDF (95/408 Pages) Renesas Technology Corp – 16-Bit Single-Chip Microcomputer H8 Family/H8/300H Tiny Series

5.2 Register Descriptions
Clock oscillators are controlled by the following registers.
• RC control register (RCCR)
• RC trimming data protect register (RCTRMDPR)
• RC trimming data register (RCTRMDR)
• Clock control/status register (CKCSR)
5.2.1 RC Control Register (RCCR)
RCCR controls the internal RC oscillator.
Bit
7
6
5
4 to 2
1
0
Initial
Bit Name Value R/W
RCSTP 0
R/W
FSEL
0
R/W
VCLSEL 0
R/W

All 0 
RCPSC1 0
R/W
RCPSC0 0
R/W
Description
Internal RC Oscillator Standby
The internal RC oscillator standby state is entered by
setting this bit to 1.
Frequency Select for Internal RC Oscillator
0: 8MHz
1: 10MHz
Power Supply Select for Internal RC Oscillator
0: Selects VBGR
1: Selects VCL
When VCL is selected, the accuracy of the internal RC
oscillator frequency cannot be guaranteed.
Reserved
These bits are always read as 0
Division Ratio Select for Internal RC Oscillator
The division ratio of φRC changes right after rewriting this
bit.
These bits can be written to only when the CKSTA bit in
CKCSR is 0.
0X: φRC (not divided)
10: φRC/2
11: φRC/4
Rev. 1.00, 11/03, page 67 of 376