2.1.2
Address Space
The H8/300 CPU supports an address space with a maximum size of 64 kbytes for program code
and data combined. The memory map differs depending on the mode (mode 1, 2, or 3). For details,
see section 3.4, Address Space Map in Each Operating Mode.
2.1.3
Register Configuration
Figure 2.1 shows the internal register structure of the H8/300 CPU. There are two groups of
registers: the general registers and control registers.
General registers (Rn)
7
0 7
0
R0H
R1H
R2H
R3H
R4H
R5H
R6H
R7H
R0L
R1L
R2L
R3L
R4L
R5L
R6L
R7L
SP: Stack pointer
(SP)
PC
Control registers
15
0
PC: Program counter
7 6 5 4 3 2 1 0
CCR I U H U N Z V C
CCR: Condition code register
Carry flag
Overflow flag
Zero flag
Negative flag
Half-carry flag
Interrupt mask bit
User bit
User bit
Figure 2.1 CPU Registers
20