Datasheet

Section 3 MCU Operating Modes
Rev. 3.00 Mar 17, 2006 page 58 of 926
REJ09B0283-0300
Table 3.1 MCU Operating Mode Selection
External Data
Bus
MCU
Operating
Mode
*
1
FWE
*
2
MD2 MD1 MD0
CPU
Operating
Mode Description
On-Chip
ROM
Initial
Width
Max.
Value
1 0 0 0 1 Advanced Expanded mode with
on-chip ROM disabled
Disabled 16 bits 16 bits
2 0 0 1 0 Advanced Expanded mode with
on-chip ROM disabled
Disabled 8 bits 16 bits
3 — 0 1 1 Advanced Boot mode Enabled — 16 bits
4 0 1 0 0 Advanced Expanded mode with
on-chip ROM enabled
Enabled 8 bits 16 bits
5 0 1 0 1 Advanced Expanded mode with
on-chip ROM enabled
Enabled 16 bits 16 bits
6 0 1 1 0 Advanced Expanded mode with
on-chip ROM enabled
Enabled 8 bits 16 bits
7 0 1 1 1 Advanced Single-chip mode Enabled — 16 bits
10 1 0 1 0 Advanced Boot mode Enabled 8 bits 16 bits
11 1 0 1 1 Advanced Boot mode Enabled — 16 bits
12 1 1 0 0 Advanced User program mode Enabled 8 bits 16 bits
13 1 1 0 1 Advanced User program mode Enabled 16 bits 16 bits
14 1 1 1 0 Advanced User program mode Enabled 8 bits 16 bits
15 1 1 1 1 Advanced User program mode Enabled — 16 bits
Notes: 1. Modes 1, 2, 4 to 7, and 10 to 15 are supported in the H8S/2678 Group.
Modes 1 to 7 are supported in the H8S/2678R Group.
2. The FWE pin setting is available only in the H8S/2678 Group. The FWE pin is not
available in the H8S/2678R Group.
3.2 Register Descriptions
The following registers are related to the operating mode.
• Mode control register (MDCR)
• System control register (SYSCR)