Datasheet

Section 6 Power-Down Modes
LPW3003A_010020030600 Rev. 2.00 Sep. 23, 2005 Page 69 of 444
REJ09B0068-0200
Section 6 Power-Down Modes
This LSI has five modes of operation after a reset. These include a normal active mode and three
power-down modes, in which power consumption is significantly reduced. Module standby mode
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.
• Sleep mode
The CPU halts. On-chip peripheral modules are operable on the system clock.
• Standby mode
The CPU and all on-chip peripheral modules halt.
• Subsleep mode
The CPU and all on-chip peripheral modules halt. I/O ports keep the same states as before the
transition.
• Module standby mode
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.
• System control register 1 (SYSCR1)
• System control register 2 (SYSCR2)
• Module standby control register 1 (MSTCR1)
• Module standby control register 2 (MSTCR2)