HD6417021 Hitachi Semiconductor, HD6417021 Datasheet - Page 41

• Manufacturer Part Number: HD6417021
• Description: SuperH RISC engine
• Manufacturer: Hitachi Semiconductor

2.3.2
Addressing modes and effective address calculation are described in table 2.8.
Table 2.8
Addressing
Mode
Direct
register
addressing
Indirect
register
addressing
Post-incre-
ment
indirect
register
addressing
Pre-decre-
ment
indirect
register
addressing
22 HITACHI
Addressing Modes
Addressing Modes and Effective Addresses
Mnemonic
Expression
Rn
@Rn
@Rn +
@–Rn
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 long
word 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
long word operation.
1/2/4
1/2/4
Rn
Rn
Rn
Rn + 1/2/4
Rn – 1/2/4
+
–
Rn – 1/2/4
Rn
Rn
Equation
—
Rn
Rn
(After the
instruction is
executed)
Byte: Rn + 1
Word: Rn + 2
Long word:
Rn + 4
Byte: Rn – 1
Word: Rn – 2
Long word:
Rn – 4
(Instruction
executed with
Rn after
calculation)
Rn
Rn
Rn
Rn
Rn
Rn