r4f2426 Renesas Electronics Corporation., r4f2426 Datasheet - Page 107

• Manufacturer Part Number: r4f2426
• Description: 16-bit Single-chip Microcomputer H8s Family / H8s/2400 Series
• Manufacturer: Renesas Electronics Corporation.

3.1
The H8S/2426 Group, H8S/2426R Group, and H8S/2424 Group have five operating modes
(modes 1 to 4 and 7). The operating mode is selected by the setting of mode pins (MD2 to MD0).
Modes 1, 2, and 4 are externally expanded modes in which the CPU can access an external
memory and peripheral devices. In an externally expanded mode, the external address space can
be designated as an 8-bit or 16-bit address space for each area by the bus controller at the
beginning of program execution. If a 16-bit address space is designated for any one area, the 16-
bit bus mode is selected. If an 8-bit address space is designated for all areas, the 8-bit bus mode is
selected.
Mode 7 is a single-chip activation expanded mode in which the CPU can switch to access an
external memory and peripheral devices at the beginning of program execution.
Mode 3 is a boot mode in which the flash memory can be programmed or erased. For details on
the boot mode, refer to section 21, Flash Memory.
The settings for pins MD2 to MD0 should not be changed during LSI operation.
Table 3.1
Note:
MCU
Operating
Mode
1*
2*
3
4
7
*
Operating Mode Selection
Only modes 1 and 2 may be used in ROM-less versions.
MD2
0
0
0
1
1
MCU Operating Modes
MD1
0
1
1
0
1
Section 3 MCU Operating Modes
MD0
1
0
1
0
1
CPU
Operating
Mode
Advanced
Advanced
Advanced
Advanced
Advanced
Description
Expanded mode with
on-chip ROM disabled
Expanded mode with
on-chip ROM disabled
Boot mode
Expanded mode with
on-chip ROM enabled
Single-chip mode
Rev. 1.00 Sep. 19, 2008 Page 79 of 1270
On-Chip
ROM
Disabled
Disabled
Enabled
Enabled
Enabled
Section 3 MCU Operating Modes
Initial
Value
16 bits
8 bits

8 bits

External Data Bus
REJ09B0466-0100
Max.
Value
16 bits
16 bits
16 bits
16 bits
16 bits