D12320VF25IV Datasheet, PDF (110/1304 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

Section 3 MCU Operating Modes
The CPU's architecture allows for 4 Gbytes of address space, but the H8S/2328B F-ZTAT and
H8S/2326 F-ZTAT actually accesses a maximum of 16 Mbytes.
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 19, ROM.
The H8S/2328B F-ZTAT and H8S/2326 F-ZTAT 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 (Mask ROM and ROMless Versions, H8S/2329B
F-ZTAT)
The ROMless and mask ROM versions have four operating modes (modes 4 to 7). H8S/2329B
F-ZTAT has six operating modes (modes 2 to 7). The operating mode is determined by the mode
pins (MD₂ to MD₀). The CPU operating mode, enabling or disabling of on-chip ROM, and the
initial bus width setting can be selected as shown in table 3.2.
Table 3.2 lists the MCU operating modes.
Rev.6.00 Sep. 27, 2007 Page 78 of 1268
REJ09B0220-0600