MC68030 Datasheet, PDF (41/602 Pages) Motorola, Inc – ENHANCED 32-BIT MICROPROCESSOR

Data Organization and Addressing Capabilities
Bit ≤ (0 Modulo (Offset)<31, Offset of 0 = MSB)
31 30 29
MSB
•••
1
0
LSB
Byte
31
24
High-Order Byte
23
16
Middle-High Byte
15
8
Middle-Low Byte
7
0
Low-Order Byte
16-Bit Word
31
16 15
0
High-Order Word
Low-Order Word
Long Word
31
0
Long Word
Quad Word
63 62
32
MSB
Any Dx
31
0
Offset
MSB
•••
LSB
Bit Field (0 ≤ Offset<32, 0<Width ≤ 32)
31
0
Long Word
Note: If width + offset < 32, bit filed wraps around within the register.
Unpacked BCD (a = MSB)
31
8
7
6
5
4
3
2
1
0
x
x
x
x
a
b
c
d
Packed BCD (a = MSB First Digit, e = MSB Second Digit)
31
8
7
6
5
4
3
2
1
0
a
b
c
d
e
f
g
h
Data Organization in Data Registers
MOTOROLA
MC68030 USER’S MANUAL
2-3