Renesas SuperH SH-4A - Page 46

Rev. 1.50, 10/04, page 26 of 448
Addressing
Mode
Instruction
Format Effective Address Calculation Method
Calculation
Formula
Register
indirect with
displacement
@(disp:4, Rn) Effective address is register Rn contents with
4-bit displacement disp added. After disp is
zero-extended, it is multiplied by 1 (byte), 2
(word), or 4 (longword), according to the operand
size.
Rn
Rn + disp × 1/2/4
+
×
1/2/4
disp
(zero-extended)
Byte: Rn + disp
→ EA
Word: Rn +
disp × 2 → EA
Longword:
Rn + disp × 4
→ EA
Indexed
register
indirect
@(R0, Rn) Effective address is sum of register Rn and R0
contents.
Rn
R0
Rn + R0
+
Rn + R0 → EA
GBR indirect
with displace-
ment
@(disp:8, GBR) Effective address is register GBR contents with
8-bit displacement disp added. After disp is
zero-extended, it is multiplied by 1 (byte), 2
(word), or 4 (longword), according to the operand
size.
GBR
1/2/4
GBR
+ disp × 1/2/4
+
×
disp
(zero-extended)
Byte: GBR +
disp → EA
Word: GBR +
disp × 2 → EA
Longword:
GBR + disp × 4
→ EA
Indexed GBR
indirect
@(R0, GBR) Effective address is sum of register GBR and R0
contents.
GBR
R0
GBR + R0
+
GBR + R0 →
EA