Datasheet

Chapter 2. ColdFire Core 2-15
Addressing Mode Summary
2.5 Addressing Mode Summary
Addressing modes are categorized by how they are used. Data addressing modes refer to
data operands. Memory addressing modes refer to memory operands. Alterable addressing
modes refer to alterable (writable) data operands. Control addressing modes refer to
memory operands without an associated size.
These categories sometimes combine to form more restrictive categories. Two combined
classifications are alterable memory (both alterable and memory) and data alterable (both
alterable and data). Twelve of the most commonly used effective addressing modes from
the M68000 Family are available on ColdFire microprocessors. Table 2-5 summarizes
these modes and their categories.
2.6 Instruction Set Summary
The ColdFire instruction set is a simplified version of the M68000 instruction set. The
removed instructions include BCD, bit field, logical rotate, decrement and branch, and
integer multiply with a 64-bit result. Nine new MAC instructions have been added.
Table 2-6 lists notational conventions used throughout this manual.
Table 2-5. ColdFire Effective Addressing Modes
Addressing Modes Syntax
Mode
Field
Reg.
Field
Category
Data Memory Control Alterable
Register direct
Data
Address
Dn
An
000
001
reg. no.
reg. no.
X
—
—
—
—
—
X
X
Register indirect
Address
Address with
Postincrement
Address with
Predecrement
Address with
Displacement
(An)
(An)+
–(An)
(d
16
, An)
010
011
100
101
reg. no.
reg. no.
reg. no.
reg. no.
X
X
X
X
X
X
X
X
X
—
—
X
X
X
X
X
Address register indirect with
scaled index
8-bit displacement
(d
8
, An,
Xi*SF)
110 reg. no. X X X X
Program counter indirect
with displacement (d
16
, PC) 111 010 X X X —
Program counter indirect
with scaled index
8-bit displacement
(d
8
, PC,
Xi*SF)
111 011 X X X —
Absolute data addressing
Short
Long
(xxx).W
(xxx).L
111
111
000
001
X
X
X
X
X
X
—
—
Immediate #<xxx> 111 100 X X — —