Renesas R8C/18 Series Hardware Manual page 74

R8C/18 Group, R8C/19 Group
High-Speed On-Chip Oscillator Control Register 1
b7 b6 b5 b4 b3 b2 b1 b0
NOTE:
1. Set the PRC0 bit in the PRCR register to 1 (w rite enable) before rew riting the HRA1 register.
High-Speed On-Chip Oscillator Control Register 2
b7 b6 b5 b4 b3 b2 b1 b0
0 0 0
NOTES:
1. Set the PRC0 bit in the PRCR register to 1 (w rite enable) before rew riting the HRA2 register.
2. High-speed on-chip oscillator frequency = 8 MHz (HRA1 register = value w hen shipping)
3. If fRING-fast mode 0 is sw itched to fRING-fast mode 1, the frequency is multiplied by 1.5.
4. If fRING-fast mode 0 is sw itched to fRING-fast mode 2, the frequency is multiplied by 0.5.
Figure 10.6 Registers HRA1 and HRA2
Rev.1.30 Apr 14, 2006
REJ09B0222-0130
Symbol Address
HRA1
The frequency of the high-speed on-chip oscillator is adjusted w ith bits 0 to 7.
High-speed on-chip oscillator frequency = 8 MHz
(HRA1 register = value w hen shipping ; fRING-fast mode 0)
Setting the HRA1 register to a low er value (minimum value: 00h), results in a higher
frequency.
Setting the HRA1 register to a higher value (maximum value: FFh), results in a low er
frequency.
Symbol Address
HRA2
Bit Symbol Bit Name
High-speed on-chip oscillator mode
select bits
HRA20
HRA21
— Reserved bits
(b4-b2)
— Nothing is assigned. If necessary, set to 0.
(b7-b5) When read, the content is 0.
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(1)
0021h
Function
(1)
0022h
b1 b0
0 0 : fRING-fast mode 0
0 1 : fRING-fast mode 1
1 0 : fRING-fast mode 2
1 1 : Do not set.
Set to 0.
10. Clock Generation Circuit
After Reset
When Shipping
After Reset
00h
Function
(2)
(3)
(4)
RW
RW
RW
RW
RW
RW
—