Addressing Modes And Effective Address Calculation; Register DirectRn; Register Indirect@Ern; Register Indirect With Displacement@(D:16, Ern) Or @(D:32, Ern) - Hitachi H8S/2628 Hardware Manual

2.7

Addressing Modes and Effective Address Calculation

The H8S/2600 CPU supports the eight addressing modes listed in table 2.11. Each instruction uses
a subset of these addressing modes. Arithmetic and logic instructions can use the register direct
and immediate modes. Data transfer instructions can use all addressing modes except program-
counter relative and memory indirect. Bit manipulation instructions use register direct, register
indirect, or the absolute addressing mode to specify an operand, and register direct (BSET, BCLR,
BNOT, and BTST instructions) or immediate (3-bit) addressing mode to specify a bit number in
the operand.

Table 2.11 Addressing Modes

No. Addressing Mode
1 Register direct
2 Register indirect
3 Register indirect with displacement
4 Register indirect with post-increment
Register indirect with pre-decrement
5 Absolute address
6 Immediate
7 Program-counter relative
8 Memory indirect
Register Direct    Rn
2.7.1
The register field of the instruction specifies an 8-, 16-, or 32-bit general register containing the
operand. R0H to R7H and R0L to R7L can be specified as 8-bit registers. R0 to R7 and E0 to E7
can be specified as 16-bit registers. ER0 to ER7 can be specified as 32-bit registers.
Register Indirect    @ERn
2.7.2
The register field of the instruction code specifies an address register (ERn) which contains the
address of the operand on memory. If the address is a program instruction address, the lower 24
bits are valid and the upper 8 bits are all assumed to be 0 (H'00).
Register Indirect with Displacement    @(d:16, ERn) or @(d:32, ERn)
2.7.3
A 16-bit or 32-bit displacement contained in the instruction is added to an address register (ERn)
specified by the register field of the instruction, and the sum gives the address of a memory
operand. A 16-bit displacement is sign-extended when added.
Rev. 1.0, 09/02, page 38 of 568
Symbol
Rn
@ERn
@(d:16,ERn)/@(d:32,ERn)
@ERn+
@–ERn
@aa:8/@aa:16/@aa:24/@aa:32
#xx:8/#xx:16/#xx:32
@(d:8,PC)/@(d:16,PC)
@@aa:8