Hitachi SH7095 Hardware User Manual page 31

Table 2.8 Addressing Modes and Effective Addresses
Addressing Instruction
Mode Format
Direct register Rn
addressing
Indirect register @Rn
addressing
Post-increment @Rn+
indirect register
addressing
Pre-decrement @–Rn
indirect register
addressing
Hitachi 20
Effective Addresses Calculation
The effective address is register Rn. (The operand is
the contents of register Rn.)
The effective address is the content of register Rn.
The effective address is the content of register 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.
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.
Equation
—
Rn
Rn
(After the
instruction
executes)
Byte: Rn + 1
→ Rn
Word: Rn + 2
→ Rn
Longword:
Rn + 4 → Rn
Byte: Rn – 1
→
Rn
Word: Rn – 2
→
Rn
Longword:
→
Rn – 4 Rn
(Instruction
executed
with Rn after
calculation)