3.9.1
Reset Levels
The reset operations of the MB91350A are classified into two levels, each of which has
different causes and initialization operations.
This section describes these reset levels.
■ Settings Initialization Reset (INIT)
The highest-level reset, which initializes all settings, is called a settings initialization reset (INIT).
A settings initialization reset (INIT) mainly performs the following initialization:
[Items initialized in a settings initialization reset (INIT)]
•
Device operation mode (bus mode and external bus width settings)
•
All internal clock settings (clock source selection, PLL control, and divide ratio setting)
•
All settings on external bus CS0 area
•
All settings on pin statuses other than the above settings
•
All sections initialized by an operation initialization reset (RST)
For more information, see the description of each for these functions.
After power-on, be sure to apply a settings initialization reset (INIT) at the INIT pin.
■ Operation Initialization Reset (RST)
A normal-level reset that initializes the operation of a program is called an operation initialization reset
(RST).
If a settings initialization reset (INIT) occurs, an operation initialization reset (RST) also occurs.
An operation initialization reset (RST) mainly initializes the following items:
[Items initialized by an operation initialization reset (RST)]
•
Program operation
•
CPU and internal buses
•
Register settings of peripheral circuits
•
I/O port settings
•
All CS0 area settings of external buses
For more information, see the description of each for these functions.
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