Mcu Operating Modes; Overview; Operating Mode Selection - Hitachi H8/3022 Hardware Manual

3.1 Overview

3.1.1 Operating Mode Selection

The H8/3022 Series has five operating modes (modes 1, 3, 5 to7) that are selected by the mode
pins (MD and MD
2
or single-chip mode.
Table 3-1 Operating Mode Selection
Mode Pins
Operating
Mode MD
2
— 0
Mode 1 0
Mode 2 0
Mode 3 0
Mode 4 1
Mode 5 1
Mode 6 1
Mode 7 1
Notes: 1. If the RAM enable bit (RAME) in the system control register (SYSCR) is cleared to 0,
these addresses become external addresses.
2. In mode 7, clearing bit RAME in SYSCR to 0 and reading the on-chip RAM always
return H'FF, and write access is ignored. For details, see section 14.3, Operation.
For the address space size there are two choices: 1 Mbyte, or 16 Mbytes.
Modes 1 and 3 are on-chip ROM disable expanded modes capable of accessing external memory
and peripheral devices.
Mode 1 supports a maximum address space of 1 Mbyte. Mode 3 supports a maximum address
space of 16 Mbytes.
Modes 5 and 6 are externally expanded mode that enables access to external memory and
peripheral devices and also enables access to the on-chip ROM. Mode 5 supports a maximum
address space of 1 Mbyte.
Mode 6 supports a maximum address space of 16 Mbyte.
Section 3 MCU Operating Modes
) as indicated in table 3-1. The input at these pins determines expanded mode
0
MD MD Address Space
1 0
0 0 —
0 1 Expanded mode
1 0 —
1 1 Expanded mode
0 0 —
0 1 Expanded mode
1 0 Expanded mode
1 1 Single-chip advanced mode
Description
Initial Bus On-Chip
1
Mode* ROM
— —
8 bits Disabled
— —
8 bits Disabled
— —
8 bits Enabled
8 bits Enabled
— Enabled
On-Chip
RAM
—
1
Enabled*
—
1
Enabled*
—
1
Enabled*
1
Enabled*
2
Enabled*
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