SH7708 Datasheet, PDF (36/625 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 Instructio
Mode
n Format Effective Address Calculation MethodCalculation Formula
Register direct Rn
Effective address is register Rn. (Operand is —
register Rn contents.)
Register
indirect
@Rn
Effective address is register Rn contents. Rn
Rn
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, Byte: Rn – 1 → Rn
decremented by a constant beforehand: 1 for _{Word: Rn – 2 → Rn}
a byte operand, 2 for a word operand, 4 for a
longword operand.
Longword: Rn – 4 → Rn
(Instruction executed
Rn
with Rn after
Rn – 1/2/4 _–
calculation)
Rn – 1/2/4
1/2/4
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