
Data Organization and Addressing Capabilities
2-24
MC68030 USER’S MANUAL
MOTOROLA
Table 2–2 shows the categories to which each of the effective addressing modes belong.
These categories are sometimes combined, forming new categories that are more
restrictive. Two combined classifications are alterable memory or data alterable. The former
refers to those addressing modes that are both alterable and memory addresses, and the
latter refers to addressing modes that are both data and alterable.
2.6 PROGRAMMER`S VIEW OF ADDRESSING MODES
Extensions to the indexed addressing modes, indirection, and full 32-bit displacements
provide additional programming capabilities for both the MC68020 and the MC68030. This
section describes addressing techniques that exploit these capabilities and summarizes the
addressing modes from a programming point of view.
Addressing Modes
Mode
Register
Data
Memory
Control
Alterable
Assembler
Syntax
Dn
An
(An)
Data Register Direct
Address Register Direct
Address Register Indirect
Address Register Indirect
with Postincrement
Address Register Indirect
with Predecrement
Address Register Indirect
with Displacement
Address Register Indirect with
Index (8-Bit Displacement)
Address Register Indirect with
Index (Base Displacement)
Memory Indirect Postindexed
Memory Indirect Preindexed
Absolute Short
Absolute Long
Program Counter Indirect
with Displacement
Program Counter Indirect
with Index (8-Bit) Displacement
Program Counter Indirect
with Index (Base Displacement)
PC Memory Indirect
Postindexed
PC Memory Indirect
Preindexed
Immediate
000
001
010
reg. no.
reg. no.
reg. no
X
—
X
—
—
X
—
—
X
X
X
X
011
100
101
reg. no.
reg. no.
reg. no.
X
X
X
X
X
X
—
—
X
X
X
X
(An)+
-(An)
(d
16
,An)
110
110
110
110
111
111
reg. no.
reg. no.
reg. no
reg. no.
000
001
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
(d
8
,An,Xn)
(bd,An,Xn)
([bd,An],Xn,od)
([bd,An,Xn],od)
(xxx).W
(xxx).L
111
111
111
111
111
010
011
011
011
011
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
—
—
—
—
—
(d
16
,PC)
(d
8
,PC,Xn)
(bd,PC,Xn)
([bd,PC],Xn,od)
([bd,PC,Xn],od)
#
data
111
100
X
X
—
—