Datasheet

Section 5 Clock Pulse Generators
Rev. 3.00 Sep. 14, 2006 Page 71 of 408
REJ09B0105-0300
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 on-chip oscillator.
Bit Bit Name
Initial
Value R/W Description
7 RCSTP 0 R/W On-chip Oscillator Standby
The internal on-chip oscillator standby state is entered by
setting this bit to 1.
6 FSEL 0 R/W Frequency Select for On-chip Oscillator
0: 8MHz
1: 10MHz
5 VCLSEL 0 R/W Power Supply Select for On-chip Oscillator
0: Selects VBGR
1: Selects VCL
When VCL is selected, the accuracy of the on-chip
oscillator frequency cannot be guaranteed.
4 to 2  All 0  Reserved
These bits are always read as 0.
1
0
RCPSC1
RCPSC0
0
0
R/W
R/W
Division Ratio Select for On-chip Oscillator
The division ratio of R
OSC
changes right after rewriting this
bit.
These bits can be written to only when the CKSTA bit in
CKCSR is 0.
0X: R
OSC
(not divided)
10: R
OSC
/2
11: R
OSC
/4