SH7262/SH7264 Group
Hardware Design Guide
REJ06B0999-0100 Rev. 1.00
Page 28 of 36
Jun. 30, 2010
9. Power-down
Modes
The SH7264 has the following power-down modes and function.
(1) Sleep mode
(2) Software standby mode
(3) Deep standby mode
(4) Module standby function
As power-down modes stop CPU, clock, internal memory, and some peripherals or turns off the power supply, it will
reduce power consumption. The SH7264 wakes up from these modes by reset or interrupt.
Table 12 lists transition conditions, module states, and how to wake up the MCU. For more information on the register
states, refer to 36.3 Register State in Each Operating Mode in the Sh7262 Group, SH7264 Group Hardware Manual.
Table 12 State of Power-Down Modes
State
(1)
Power-
Down
Modes
Transition Conditions
CPG
CPU
CPU
Register
High-
speed
RAM
Cache
Memory
Large-
capacity RAM
(Data-
retention RAM
included)
OPM
RTC
PS
External
Memory
How to Wake Up the
MCU
Sleep
mode
Execute SLEEP
instruction when the
STBY bit in the
STBCR1 is 0
ON OFF
States
held ON
ON
ON ON
(2)
ON
Auto-refresh • Interrupt
• Manual reset
• Power-on reset
• DMA address error
Software
standby
mode
Execute SLEEP
instruction when the
STBY bit in the
STBCR1 is 1 and
DEEP bit in the
STBCR1 is 0
OFF
OFF
States held OFF (Data is
retained)
(5) (6)
OFF (Data is
retained)
(5) (7)
OFF
ON
(2)
ON
Self-refresh • NMI interrupt
• IRQ interrupt
• Power-on reset
Deep
standby
mode
Execute SLEEP
instruction when bits
STBY and DEEP in
the STBCR1 are 1
OFF
OFF OFF
OFF
(Data
is
not retained)
OFF (Data in the
Data-retention
RAM
is retained)
(3)
OFF
ON
(2)
OFF Self-refresh • NMI interrupt
(4)
• Power-on reset
(4)
• Realtime Clock alarm
interrupt
(4)
• Change pins to wake up the
MCU
(4)
Module
standby
mode
Set the MSTP bits in
the STBCR2,
STBCR3, STBCR4,
STBCR5, STBCR6,
STBCR7, STBCR8
ON
ON
States held
ON
ON
Specified
module
is OFF
OFF
ON
Auto-refresh • Clear the MSTP bit to 0
• Power-on reset (Only for
H-UDI and DMAC)
Notes
1. Pin state is either "states held" or "high impedance".
2. The Realtime Clock is ON when the START bit in the RCR2 register is 1. When waking up the MCU from deep standby mode by
power-on reset, the operating state cannot be retained. Configure the Realtime Clock again.
3. Set bits RRAMKP3 to RRAMKP0 in the RRAMKP register to 1, and the data stored in the data-retention RAM target area can be
retained when the MCU transitions to deep standby mode. Note that the data is initialized when waking up the MCU from deep
standby mode by power-on reset. Bits RRAMKP3 and RRAMKP2 can be used only on the MCU with 640-KB RAM.
4. The MCU is woke up from deep standby mode by interrupts (NMI, or real-time clock alarm interrupt), reset (power-on reset), or
change pins to wake up the MCU (PC8 to PC5, PG11, PG10, PJ3, and PJ1). When waking up the MCU from deep standby mode
not by the reset, the power-on reset exception handling is executed instead of interrupt exception handling. Pins PG11 and PG10
can be used to wake up the MCU only on the MCU with 640-KB RAM.
5. When waking up the MCU from software standby mode by power-on reset, the retained data is initialized.
6. Disable the RAME bit in the SYSCR1 register or RAMWE bit in the SYSCR2 register to retain the data in the high-speed internal
RAM when waking up the MCU from software standby mode by power-on reset.
7. Disable the VRAME bit in the SYSCR3 register or VRAMWE bit in the SYSCR4 register to retain the data in the large-capacity
internal RAM (data-retention RAM included) when waking up the MCU from software standby mode by power-on reset.