Datasheet

Section 3 MCU Operating Modes
Rev.6.00 Mar. 18, 2009 Page 57 of 980
REJ09B0050-0600
Section 3 MCU Operating Modes
3.1 Operating Mode Selection
This LSI has six operating modes (modes 1 to 5 and 7). Modes 1 to 5 and 7 are available in the
H8S/2368 0.18 μm F-ZTAT Group flash memory version. Modes 1 to 4 and 7 are available in the
H8S/2367F. Modes 1, 2, 4, and 7 are available in the masked ROM version. Modes 1 and 2 are
available in the ROMless version. 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 the externally expanded mode, each area can be switched to 8-
bit or 16-bit address space by the bus controller. If any one of the areas is set to 16-bit address
space, the bus mode is 16 bits. If all areas are set to 8-bit address space, the bus mode is 8 bits.
Mode 7 is a single-chip activation externally expanded mode in which the CPU can switch to
access an external memory and peripheral devices at the beginning of a program execution.
Modes 3 and 5 are a boot mode/user boot mode in which the flash memory can be programmed or
erased. For details on the boot mode/user boot mode, refer to section 19, Flash Memory (0.35-μm
F-ZTAT Version), or section 20, Flash Memory (0.18-μm F-ZTAT Version).
Do not change the MD2 to MD0 pin settings during operation.
Table 3.1 MCU Operating Mode Selection
External Data Bus
MCU
Operating
Mode
MD2 MD1 MD0
CPU
Operating
Mode
Description On-Chip ROM
Initial
Width
Max.
Value
1 0 0 1 Advanced Expanded mode with on-
chip ROM disabled
Disabled 16 bits 16 bits
2 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 1 0 0 Advanced Expanded mode with on-
chip ROM enabled
Enabled 8 bits 16 bits
5
*
1 0 1 Advanced User boot mode Enabled — 16 bits
7 1 1 1 Advanced Single-chip mode Enabled — 16 bits
Note: * Supported only by the H8S/2368 0.18 μm F-ZTAT Group.