SH7058 Datasheet, PDF (79/1130 Pages) Renesas Technology Corp – Renesas SuperHTM RISC engine

2.3.2 Addressing Modes
Table 2.8 describes addressing modes and effective address calculation.
Table 2.8 Addressing Modes and Effective Addresses
Addressing
Mode
Instruction
Format
Effective Address Calculation
Equation
Direct register Rn
addressing
The effective address is register Rn. (The operand —
is the contents of register Rn.)
Indirect register @Rn
addressing
The effective address is the contents of register Rn. Rn
Rn
Rn
Post-increment @Rn+
indirect register
addressing
The effective address is the contents of register Rn. Rn
A constant is added to the content of Rn after the
instruction is executed. 1 is added for a byte
operation, 2 for a word operation, and 4 for a
longword operation.
(After the
instruction
executes)
Byte: Rn + 1
Rn
Rn
→ Rn
Rn + 1/2/4 ₊
Word: Rn + 2
→ Rn
1/2/4
Longword:
Rn + 4 → Rn
Pre-decrement @–Rn
indirect register
addressing
The effective address is the value obtained by
subtracting a constant from Rn. 1 is subtracted for
a byte operation, 2 for a word operation, and 4 for
a longword operation.
Byte: Rn – 1
→ Rn
Word: Rn – 2
→ Rn
Rn
Rn – 1/2/4 _–
1/2/4
Rn – 1/2/4
Longword:
Rn – 4 → Rn
(Instruction
executed with
Rn after
calculation)
Indirect register
addressing with
displacement
@(disp:4, The effective address is Rn plus a 4-bit
Rn)
displacement (disp). The value of disp is zero-
extended, and remains the same for a byte
operation, is doubled for a word operation, and is
quadrupled for a longword operation.
Rn
Byte: Rn +
disp
Word: Rn +
disp × 2
Longword: Rn
+ disp × 4
disp
(zero-extended)
+
×
Rn + disp × 1/2/4
Rev. 3.0, 09/04, page 38 of 1086
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