Cpu Operating Modes; Normal Mode; Figure 2.1 Cpu Operating Modes - Renesas H8SX/1500 Series Hardware Manual

2.2

CPU Operating Modes

The H8SX CPU has four operating modes: normal, middle, advanced and maximum modes. For
details on mode settings, see section 3.1, Operating Mode Selection.
CPU operating modes
2.2.1

Normal Mode

The exception vector table and stack have the same structure as in the H8/300 CPU.
Note: Normal mode is not supported in this LSI.
• Address Space
The 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 the extended register 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 Rn is referenced in the register indirect addressing mode with
pre-/post-increment or pre-/post-decrement 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.
Normal mode
Middle mode
Advanced mode
Maximum mode

Figure 2.1 CPU Operating Modes

Maximum 64 kbytes for program
and data areas combined
Maximum 16-Mbyte program
area and 64-kbyte data area,
maximum 16 Mbytes for program
and data areas combined
Maximum 16-Mbyte program
area and 4-Gbyte data area,
maximum 4 Gbytes for program
and data areas combined
Maximum 4 Gbytes for program
and data areas combined
Rev. 3.00 Mar. 14, 2006 Page 21 of 804
REJ09B0104-0300
Section 2 CPU