SH7708 Datasheet, PDF (40/633 Pages) Renesas Technology Corp – SuperH™ RISC engine

2.3.2 Addressing Modes
Addressing modes and effective address calculation methods are shown in table 2.2.
Table 2.2 Addressing Modes and Effective Addresses
Addressing Instruction
Mode
Format Effective Address Calculation Method
Register direct Rn
Effective address is register Rn. (Operand is
register Rn contents.)
Register
indirect
@Rn
Effective address is register Rn contents.
Rn
Rn
Calculation Formula
—
Rn
Register
@Rn+
indirect with
post-increment
Effective address is register Rn contents. A
constant is added to Rn after instruction
execution: 1 for a byte operand, 2 for a word
operand, 4 for a longword operand.
Rn
Rn
Rn + 1/2/4 ₊
Rn
After instruction
execution
Byte: Rn + 1 → Rn
Word: Rn + 2 → Rn
Longword: Rn + 4 → Rn
Register
@–Rn
indirect with
pre-decrement
1/2/4
Effective address is register Rn contents,
decremented by a constant beforehand: 1 for
a byte operand, 2 for a word operand, 4 for a
longword operand.
Rn
Rn – 1/2/4 _–
Rn – 1/2/4
Byte: Rn – 1 → Rn
Word: Rn – 2 → Rn
Longword: Rn – 4 → Rn
(Instruction executed
with Rn after
calculation)
1/2/4
22