Effective Address Calculation - Hitachi H8/500 Series Hardware Manual

3.4.3 Effective Address Calculation

Table 3-8 explains how the effective address is calculated in each addressing mode.
Table 3-8 Effective Address Calculation
No. Addressing Mode Effective Address Calculation
1 Register direct
Rn
1010Sz
2 Register indirect
@Rn
1101Sz
3 Register indirect
with displacement
@(d:8,Rn)
1110Sz
@(d:16,Rn)
1111Sz
4 Register indirect
with pre-decrement
@–Rn
1011Sz
Register indirect
with post-increment
@Rn+
1100Sz
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—
rrr
—
rrr
8 Bits
15
Rn
15
rrr Displacement with
sign extension
16 Bits
rrr 15
Rn
15
Displacement
15
Rn
1 or 2
Rn is decremented by –1 or –2
rrr
before instruction execution.
—
Rn is incremented by +1 or +2
rrr after instruction execution.
Effective Address
Operand is contents of
Rn
23
DP
Or TP or EP
0 23
DP
0 Or TP or EP
+
0 23
DP
0 Or TP or EP
+
0 23
DP
Or TP or EP
–
*3*4*5
23
DP
*3*4*5
Or TP or EP
47
15 0
*1
Rn
*2
15 0
*1
Result
*2
15 0
*1
Result
*2
15 0
*1
Result
*2
15 0
*1
Rn
*2