R8C/38T-A Group
10. Power Control
Under development Preliminary document
Specifications in this document are tentative and subject to change.
R01UH0241EJ0010 Rev.0.10
Page 112 of 730
Aug 05, 2011
10.2.5
High-Speed On-Chip Oscillator Control Register 0 (FRA0)
Notes:
1. Set the FRA01 bit under the following conditions:
FRA00 bit = 1 (high-speed on-chip oscillator on)
CM14 bit in the CM1 register = 0 (low-speed on-chip oscillator on)
Bits FRA22 to FRA20 in the FRA2 register:
All division modes can be set when VCC = 2.7 to 5.5 V: 000b to 111b
Division ratio of 8 or more when VCC = 1.8 to 5.5 V: 110b (divide-by-8 mode), 111b (divide-by-9 mode)
2. When writing 0 (low-speed on-chip oscillator selected) to the FRA01 bit, do not write 0 (high-speed on-chip
oscillator off) to the FRA00 bit at the same time. After the FRA01 bit is set to 0, set the FRA00 bit to 0.
Set the PRC0 bit in the PRCR register to 1 (write enabled) before rewriting the FRA0 register.
10.2.6
STBY VDC Power Control Register STBY VDC Power Control Register
(SVDC)
Note:
1. Do not set the SVC0 bit to 1 (transition to low-power-consumption mode enabled) when using a DTC transfer
during wait mode.
Set the PRC3 bit in the PRCR register to 1 (write enabled) before rewriting the SVDC register.
Address 00012h
Bit
b7b6
b5b4b3
b2b1b0
Symbol
————
FRA03
—
FRA01
FRA00
After Reset
0
000
0000
Bit
Symbol
Bit Name
Function
R/W
b0
FRA00
High-speed on-chip oscillator enable
bit
0: High-speed on-chip oscillator off
1: HIgh-speed on-chip oscillator on
R/W
b1
FRA01
fOCO clock source select bit (1)
0: Low-speed on-chip oscillator selected (2)
1: High-speed on-chip oscillator selected
R/W
b2
—
Reserved
Set to 0.
R/W
b3
FRA03
fOCO128 clock select bit
0: fLOCO divided by 128 selected
1: fHOCO-F divided by 128 selected
R/W
b4
—
Nothing is assigned. The write value must be 0. The read value is 0.
—
b5
—
b6
—
b7
—
Address 0002Ch
Bit
b7b6
b5b4b3
b2b1b0
Symbol
After Reset
0
000
0000
Bit
Symbol
Bit Name
Function
R/W
b0
SVC0
Low-power-consumption mode
transition enabled bit
(1)0: Transition to low-power-consumption mode
disabled
1: Transition to low-power-consumption mode
enabled
R/W
b1
—
Reserved
Set to 0.
R/W
b2
—
b3
—
b4
—
b5
—
b6
—
b7
—