R01UH0823EJ0100 Rev.1.00
Page 232 of 1823
Jul 31, 2019
RX23W Group
11. Low Power Consumption
11.2.7
Sub Operating Power Control Register (SOPCCR)
Note:
Set the PRCR.PRC1 bit to 1 (write enabled) before rewriting this register.
Note 1. Depends on the setting of OPCCR.OPCM[2:0].
The SOPCCR register is used to reduce power consumption in normal operating mode, sleep mode, and deep sleep mode
by controlling a transition to low-speed operating mode.
Setting this register initiates entry to/exit from low-speed operating mode.
Low-speed operating mode is used for the sub-clock oscillator only.
The OPCCR register cannot be rewritten when the SOPCM bit is 1 (low-speed operating mode).
The SOPCCR register cannot be rewritten under the following conditions:
When the SOPCCR.SOPCMTSF flag is 1 (during transition)
Time period from WAIT instruction execution for a sleep mode transition, until exit from sleep mode to normal
operation
Time period from WAIT instruction execution for a deep sleep mode transition, until exit from deep sleep mode to
normal operation
This register cannot be rewritten while the flash memory is being programmed or erased (P/E).
For the procedures for changing operating power control modes, refer to Function in
section 11.5, Function for Lower
During sleep mode or mode transitions, do not write to the registers related to system control (indicated by ‘SYSTEM’ in
the Module Symbol column in
Table 5.1, List of I/O Registers (Address Order)
).
SOPCM Bit (Sub Operating Power Control Mode Select)
The SOPCM bit selects operating power control in normal operating mode and sleep mode.
Setting this bit to 1 allows a transition to low-speed operating mode. Setting this bit to 0 allows a return to the operating
mode (operating mode set by OPCCR.OPCM[2:0]) before the transition to low-speed operating mode.
shows the relationship between operating power control modes, the OPCM[2:0] and SOPCM bit settings,
and the operating frequency and voltage ranges.
Address(es): 0008 00AAh
b7
b6
b5
b4
b3
b2
b1
b0
—
—
—
SOPC
MTSF
—
—
—
SOPC
M
Value after reset:
0
0
0
0
0
0
0
0
Bit
Symbol
Bit Name
Description
R/W
b0
Sub Operating Power
Control Mode Select
0: High-speed operating mode or middle-speed operating mode*
1: Low-speed operating mode
R/W
b3 to b1
—
Reserved
These bits are read as 0. The write value should be 0.
R/W
b4
Sub Operating Power
Control Mode Transition
Status Flag
0: Transition completed
1: During transition
R
b7 to b5
—
Reserved
These bits are read as 0. The write value should be 0.
R/W