HD6433044 Hitachi Semiconductor, HD6433044 Datasheet - Page 61

• Manufacturer Part Number: HD6433044
• Description: (HD64 Series) Hitachi Single-Chip Microcomputer
• Manufacturer: Hitachi Semiconductor

2.8 Processing States
2.8.1 Overview
The H8/300H CPU has five processing states: the program execution state, exception-handling
state, power-down state, reset state, and bus-released state. The power-down state includes sleep
mode, software standby mode, and hardware standby mode. Figure 2-11 classifies the processing
states. Figure 2-13 indicates the state transitions.
Processing states
Exception-handling state
Program execution state
The CPU executes program instructions in sequence
A transient state in which the CPU executes a hardware sequence
(saving PC and CCR, fetching a vector, etc.) in response to a reset,
interrupt, or other exception
The external bus has been released in response to a bus request
signal from a bus master other than the CPU
The CPU and all on-chip supporting modules are initialized and halted
The CPU is halted to conserve power
Bus-released state
Power-down state
Figure 2-11 Processing States
Reset state
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Hardware standby mode
Software standby mode
Sleep mode