Table of Contents
Advertisement
3.1
Overview
3.1.1
Operating Mode Selection
The H8/3006 and H8/3007 have four operating modes (modes 1 to 4) that are selected by the
mode pins (MD
to MD
2
the address space and the initial bus mode.
Table 3-1
Operating Mode Selection
Mode Pins
Operating
Mode
MD
MD
2
—
0
0
Mode 1
0
0
Mode 2
0
1
Mode 3
0
1
Mode 4
1
0
—
1
0
—
1
1
—
1
1
Notes: 1. In modes 1 to 4, an 8-bit or 16-bit data bus can be selected on a per-area basis by
settings made in the area bus width control register (ABWCR). For details see
section 6, Bus Controller.
2. If the RAME bit in SYSCR is cleared to 0, these addresses become external addresses.
For the address space size there are two choices: 1 Mbyte, or 16 Mbyte.The external data bus is
either 8 or 16 bits wide depending on ABWCR settings. If 8-bit access is selected for all areas, 8-
bit bus mode is used. For details see section 6, Bus Controller.
Modes 1 and 2 support a maximum address space of 1 Mbyte. Modes 3 and 4 support a maximum
address space of 16 Mbytes.
The H8/3006 and H8/3007 can be used only in modes 1 to 4. The inputs at the mode pins must
select one of these four modes. The inputs at the mode pins must not be changed during operation.
When changing the mode, the chip must be placed in the reset state before the mode pin inputs are
changed.
Section 3 MCU Operating Modes
) as indicated in table 3-1. The input at these pins determines the size of
0
MD
Address Space
1
0
0
Setting prohibited
1
1 Mbyte
0
1 Mbyte
1
16 Mbytes
0
16 Mbytes
1
—
0
—
1
—
Description
Initial Bus
On-Chip
1
Mode*
RAM
Setting prohibited
Setting prohibited
8 bits
Enabled*
16 bits
Enabled*
8 bits
Enabled*
16 bits
Enabled*
—
—
—
—
—
—
2
2
2
2
57
Advertisement
Table of Contents
