23
Table 2.2
Effective Address Calculation
No.
Addressing Mode and
Instruction Format
Effective Address
Calculation Method
Effective Address (EA)
1
Register direct, Rn
Operand is contents of
registers indicated by rm/rn
op
rm
rn
8 7
3
4
0
15
rm
3
0
rn
3
0
2
op
rm
7 6
3
4
0
15
Register indirect, @Rn
Contents (16 bits) of
register indicated by rm
0
15
0
15
3
Register indirect with
displacement, @(d:16, Rn)
op
rm
7 6
3
4
0
15
disp
0
15
disp
0
15
Contents (16 bits) of
register indicated by rm
4
op
rm
7 6
3
4
0
15
Register indirect with
post-increment, @Rn+
op
rm
7 6
3
4
0
15
Register indirect with
pre-decrement, @–Rn
Incremented or
decremented by 1 if
operand is byte size,
and by 2 if word size
0
15
1 or 2
0
15
0
15
1 or 2
0
15
Contents (16 bits) of
register indicated by rm
Contents (16 bits) of
register indicated by rm