h8s-2628 Renesas Electronics Corporation., h8s-2628 Datasheet - Page 60

• Manufacturer Part Number: h8s-2628
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2600 Series
• Manufacturer: Renesas Electronics Corporation.

Section 2 CPU
2.4.1
The H8S/2600 CPU has eight 32-bit general registers. These general registers are all functionally
identical and can be used as both address registers and data registers. When a general register is
used as a data register, it can be accessed as a 32-bit, 16-bit, or 8-bit register. Figure 2.7 illustrates
the usage of the general registers. When the general registers are used as 32-bit registers or address
registers, they are designated by the letters ER (ER7 to ER0).
The ER registers divide into 16-bit general registers designated by the letters E (E7 to E0) and R
(R7 to R0). These registers are functionally equivalent, providing a maximum of sixteen 16-bit
registers. The E registers (E7 to E0) are also referred to as extended registers.
The R registers divide into 8-bit general registers designated by the letters RH (R7H to R0H) and
RL (R7L to R0L). These registers are functionally equivalent, providing a maximum of sixteen 8-
bit registers.
The usage of each register can be selected independently.
General register ER7 has the function of stack pointer (SP) in addition to its general-register
function, and is used implicitly in exception handling and subroutine calls. Figure 2.8 shows the
stack.
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REJ09B0155-0300
General Registers
• Address registers
• 32-bit registers
(ER7 to ER0)
ER registers
Figure 2.7 Usage of General Registers
E registers (extended registers)
• 16-bit registers
R registers
(R7 to R0)
(E7 to E0)
• 8-bit registers
(R7H to R0H)
(R7L to R0L)
RH registers
RL registers