RX610 Group
8. Low Power Consumption
R01UH0032EJ0120 Rev.1.20
Page 189 of 1006
Feb 20, 2013
8.5
Low Power Consumption Modes
8.5.1
Sleep Mode
8.5.1.1
Transition to Sleep Mode
When the WAIT instruction is executed while the SSBY bit in SBYCR is 0, the CPU enters sleep mode.
In sleep mode, the CPU stops operating but the contents of its internal registers are retained. Other peripheral functions
do not stop.
To use sleep mode, make the following settings and then execute a WAIT instruction.
1. Clear the PSW.I bit
*1
of the CPU to 0.
2. Set the interrupt destination to be used for recovery from sleep mode to the CPU.
3. Set the priority
*2
of the interrupt to be used for recovery from sleep mode to a level higher than the setting of the
PSW.IPL[2:0] bits
*1
of the CPU.
4. Set the IERm.IENj bit
*2
for the interrupt to be used for recovery from sleep mode to 1.
5. For the last I/O register to which writing proceeded, read the register to confirm that the value written has been
reflected.
6. Execute the WAIT instruction (this automatically sets the PSW.I bit
*1
of the CPU to 1).
Notes: 1. For details, see section 2, CPU.
2. For details, see section 10, Interrupt Control Unit (ICU).
8.5.1.2
Canceling Sleep Mode
Sleep mode is canceled by any interrupt, reset signal from the RES# pin, or a reset caused by a watchdog timer overflow.
•
Canceling by an interrupt
When an interrupt occurs, sleep mode is canceled and the interrupt exception handling starts. If a maskable interrupt
has been masked by the CPU (the priority level*
1
of the interrupt has been set to a value lower than that of the
IPL[2:0] bits*
2
in PSW of the CPU), sleep mode is not canceled.
Notes: 1. For details, see section 10, Interrupt Control Unit (ICU).
2. For details, see section 2, CPU.
•
Canceling by the RES# pin
When the RES# pin is driven low, the LSI enters the reset state. When the RES# pin is driven high after the reset
signal is input for a predetermined time period, the CPU starts the reset exception handling.
•
Canceling by a watchdog timer overflow reset
Sleep mode is canceled by an internal reset generated by a watchdog timer overflow.
Summary of Contents for RX600 Series
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