HD6413008VF25 Datasheet, PDF (101/688 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

3. MCU Operating Modes
Section 3 MCU Operating Modes
3.1 Overview
3.1.1 Operating Mode Selection
The H8/3008 has four operating modes (modes 1 to 4) that are selected by the mode pins (MD₂ to
MD₀) as indicated in table 3.1. The input at these pins determines the size of the address space and
the initial bus mode.
Table 3.1 Operating Mode Selection
Description
Operating
Mode
⎯
Mode Pins
MD₂
0
MD₁
0
MD₀
0
Address
Space
Setting
prohibited
Initial Bus
Mode*¹
Setting
prohibited
On-Chip ROM On-Chip RAM
Setting
prohibited
Setting
prohibited
Mode 1 0
0
1
Expanded
mode
8 bits
Disabled
Enabled*²
Mode 2 0
1
0
Mode 3 0
1
1
Expanded
mode
Expanded
mode
16 bits
8 bits
Disabled
Disabled
Enabled*²
Enabled*²
Mode 4 1
0
0
Expanded
mode
16 bits
Disabled
Enabled*²
⎯
1
0
1
Setting
Setting
Setting
Setting
prohibited prohibited
prohibited
prohibited
⎯
1
1
0
Setting
Setting
Setting
Setting
prohibited prohibited
prohibited
prohibited
⎯
1
1
1
Setting
Setting
Setting
Setting
prohibited prohibited
prohibited
prohibited
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. 8-bit bus mode is used only if 8-bit access
is selected for all areas. For details see section 6, Bus Controller.
Rev.4.00 Aug. 20, 2007 Page 55 of 638
REJ09B0395-0400