HD6473847RHV Datasheet, PDF (66/546 Pages) Renesas Technology Corp – Renesas 8-Bit Single-Chip Microcomputer H8 Family / H8/300L Super Low Power Series

Section 2 CPU
2.3.1 General Registers
All the general registers can be used as both data registers and address registers.
When used as data registers, they can be accessed as 16-bit registers (R0 to R7), or the upper bytes
(R0H to R7H) and low bytes (R0L to R7L) can be accessed separately as 8-bit registers.
When used as address registers, the general registers are accessed as 16-bit registers (R0 to R7).
R7 also functions as the stack pointer (SP), used implicitly by hardware in exception handling and
subroutine calls. When it functions as the stack pointer, as indicated in figure 2.3, SP (R7) points
to the top of the stack.
Lower address side [H'0000]
SP (R7)
Unused area
Stack area
Upper address side [H'FFFF]
Figure 2.3 Stack Pointer
2.3.2 Program Counter (PC)
This 16-bit counter indicates the address of the next instruction the CPU will execute. All
instructions are fetched 16 bits (1 word) at a time, so the least significant bit of the PC is ignored
(always regarded as 0).
Rev. 7.00 Mar. 08, 2010 Page 34 of 510
REJ09B0024-0700