HD6432646 Hitachi, HD6432646 Datasheet - Page 99

• Manufacturer Part Number: HD6432646
• Description: (HD64F264x 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.
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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