HD6432621 Hitachi, HD6432621 Datasheet - Page 105

• Manufacturer Part Number: HD6432621
• Description: (HD64F262x Series) 16-Bit Microcomputer
• Manufacturer: Hitachi

2.8
2.8.1
The CPU has five main processing states: the reset state, exception handling state, program
execution state, bus-released state, and power-down state. Figure 2-14 shows a diagram of the
processing states. Figure 2-15 indicates the state transitions.
Note: * The power-down state also includes a medium-speed mode, module stop mode,
Processing
states
Processing States
Overview
subactive mode, subsleep mode, and watch mode. Subclock functions (subactive
mode, subsleep mode, and watch mode) are not available in the H8S/2623 Series,
but are available in the H8S/2626 Series.
Exception-handling
Program execution
Bus-released state
Power-down state
Figure 2-14 Processing States
The CPU and all on-chip supporting modules have been
initialized and are stopped.
A transient state in which the CPU changes the normal
processing flow in response to a reset, interrupt, or trap
instruction.
The CPU executes program instructions in sequence.
The external bus has been released in response to a bus
request signal from a bus master other than the CPU.
CPU operation is stopped
to conserve power.*
Reset state
state
state
Hardware standby
Software standby
Sleep mode
mode
mode
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