HD6412340 HITACHI [Hitachi Semiconductor], HD6412340 Datasheet - Page 90

• Manufacturer Part Number: HD6412340
• Description: H8S/2345 F-ZTAT Hardware Manual
• Manufacturer: HITACHI [Hitachi Semiconductor]

Modes 4 to 6 are externally expanded modes that allow access to external memory and peripheral
devices.
The external expansion modes allow switching between 8-bit and 16-bit bus modes. After program
execution starts, an 8-bit or 16-bit address space can be set for each area, depending on the bus
controller setting. If 16-bit access is selected for any one area, 16-bit bus mode is set; if 8-bit
access is selected for all areas, 8-bit bus mode is set.
Note that the functions of each pin depend on the operating mode.
Modes 10, 11, 14, and 15 are boot modes and user program modes in which the flash memory can
be programmed and erased. For details, see section 17, ROM.
The H8S/2345 Series can only be used in modes 4 to 7, 10, 11, 14, and 15. This means that the
flash write enable pin and mode pins must be set to select one of these modes.
Do not change the inputs at the mode pins during operation.
3.1.2
Operating Mode Selection (ZTAT, Mask ROM, and ROMless Versions)
The H8S/2345 Series has seven operating modes (modes 1 to 7). These modes enable selection of
the CPU operating mode, enabling/disabling of on-chip ROM, and the initial bus width setting, by
setting the mode pins (MD
to MD
).
2
0
Table 3.2 lists the MCU operating modes.
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