Datasheet

Section 6 Power-Down Modes
Rev. 3.00 Mar. 15, 2006 Page 75 of 526
REJ09B0060-0300
Section 6 Power-Down Modes
This LSI has five modes of operation after a reset. These include a normal active mode and four
power-down modes, in which power consumption is significantly reduced. The module standby
function reduces power consumption by selectively halting on-chip module functions.
• Active mode
The CPU and all on-chip peripheral modules are operable on the system clock. The system
clock frequency can be selected from φosc, φosc/8, φosc/16, φosc/32, and φosc/64.
• Subactive mode
The CPU and all on-chip peripheral modules are operable on the subclock. The subclock
frequency can be selected from φw/2, φw/4, and φw/8.
• Sleep mode
The CPU halts. On-chip peripheral modules are operable on the system clock.
• Subsleep mode
The CPU halts. On-chip peripheral modules are operable on the subclock.
• Standby mode
The CPU and all on-chip peripheral modules halt. When the clock time-base function is
selected, the RTC is operable.
• Module standby function
Independent of the above modes, power consumption can be reduced by halting on-chip
peripheral modules that are not used in module units.
6.1 Register Descriptions
The registers related to power-down modes are listed below. For details on the serial mode control
register (SCI3_3 module standby), see section 17, Serial Communication Interface 3 (SCI3).
• System control register 1 (SYSCR1)
• System control register 2 (SYSCR2)
• Module standby control register 1 (MSTCR1)
• Module standby control register 2 (MSTCR2)
• Serial Mode Control Register (SMCR)