hd66100 Renesas Electronics Corporation., hd66100 Datasheet - Page 60

• Manufacturer Part Number: hd66100
• Description: H8/3867 Series
• Manufacturer: Renesas Electronics Corporation.

2.7
2.7.1
There are four CPU states: the reset state, program execution state, program halt state, and
exception-handling state. The program execution state includes active (high-speed or medium-
speed) mode and subactive mode. In the program halt state there are a sleep (high-speed or
medium-speed) mode, standby mode, watch mode, and sub-sleep mode. These states are shown in
figure 2.14. Figure 2.15 shows the state transitions.
CPU States
Overview
CPU state
Note: See section 5, Power-Down Modes, for details on the modes and their transitions.
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
Figure 2.14 CPU Operation States
Program halt state
execution state
handling state
Reset state
Exception-
Program
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 system clock
The CPU executes
successive program
instructions at reduced
speed, synchronized
by the subclock
Sleep (medium-speed)
(medium speed) mode
Sleep (high-speed)
(high speed) mode
Subactive mode
Subsleep mode
Standby mode
Watch mode
Active
Active
mode
mode
Low-power
modes
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