Datasheet

Section 2 CPU
Rev. 3.00 Mar. 15, 2006 Page 35 of 526
REJ09B0060-0300
2.7 CPU States
There are four CPU states: the reset state, program execution state, program halt state, and
exception-handling state. The program execution state includes active mode and subactive mode.
For the program halt state, there are a sleep mode, standby mode, and sub-sleep mode. These
states are shown in figure 2.11. Figure 2.12 shows the state transitions. For details on program
execution state and program halt state, refer to section 6, Power-Down Modes. For details on
exception processing, refer to section 3, Exception Handling.
CPU state Reset state
Program
execution state
Program halt state
Exception-
handling state
Active
(high speed) mode
Subactive mode
Sleep mode
Subsleep mode
Power-down
modes
The CPU executes successive program
instructions at high speed,
synchronized by the system clock
The CPU executes
successive program
instructions at reduced
speed, synchronized
by the subclock
A state in which some
or all of the chip
functions are stopped
to conserve power
A transient state in which the CPU changes
the processing flow due to a reset or an interrupt
The CPU is initialized
Standby mode
Figure 2.11 CPU Operation States