HD6432345 Datasheet, PDF (44/907 Pages) Hitachi Semiconductor – H8S/2345 F-ZTAT Hardware Manual

2.2 CPU Operating Modes
The H8S/2000 CPU has two operating modes: normal and advanced. Normal mode supports a
maximum 64-kbyte address space. Advanced mode supports a maximum 16-Mbyte total address
space (architecturally a maximum 16-Mbyte program area and a maximum of 4 Gbytes for
program and data areas combined). The mode is selected by the mode pins of the microcontroller.
CPU operating modes
Normal mode
Maximum 64 kbytes, program
and data areas combined
(Supported on ZTAT,
mask ROM, and ROMless
versions only)
Advanced mode
Maximum 16-Mbytes for
program and data areas
combined
Figure 2.1 CPU Operating Modes
(1) Normal Mode (ZTAT, Mask ROM, and ROMless Versions Only)
The exception vector table and stack have the same structure as in the H8/300 CPU.
Address Space: A maximum address space of 64 kbytes can be accessed.
Extended Registers (En): The extended registers (E0 to E7) can be used as 16-bit registers, or as
the upper 16-bit segments of 32-bit registers. When En is used as a 16-bit register it can contain
any value, even when the corresponding general register (Rn) is used as an address register. If the
general register is referenced in the register indirect addressing mode with pre-decrement (@–Rn)
or post-increment (@Rn+) and a carry or borrow occurs, however, the value in the corresponding
extended register (En) will be affected.
Instruction Set: All instructions and addressing modes can be used. Only the lower 16 bits of
effective addresses (EA) are valid.
24