User's Manual

Table Of Contents
R01UH0823EJ0110 Rev.1.10 Page 240 of 1852
Nov 30, 2020
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
Operating Power Consumption.
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.
Table 11.4 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:
00000000
Bit Symbol Bit Name Description R/W
b0 SOPCM Sub Operating Power
Control Mode Select
0: High-speed operating mode or middle-speed operating mode*
1
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 SOPCMTSF 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