mcf5272 Freescale Semiconductor, Inc, mcf5272 Datasheet - Page 80

• Manufacturer Part Number: mcf5272
• Description: Mcf5272 Coldfire Integrated Microprocessor User
• Manufacturer: Freescale Semiconductor, Inc

Addressing Mode Summary
2.4.2 Organization of Integer Data Formats in Memory
All ColdFire processors use a big-endian addressing scheme. The byte-addressable
organization of memory allows lower addresses to correspond to higher order bytes. The
address N of a longword data item corresponds to the address of the high-order word. The
lower order word is located at address N + 2. The address N of a word data item corresponds
to the address of the high-order byte. The lower order byte is located at address N + 1. This
organization is shown in Figure 2-9.
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.
2-12
31
Byte 0xFFFF_FFFC
Byte 0x0000_0000
Byte 0x0000_0004
Word 0xFFFF_FFFC
Word 0x0000_0000
Word 0x0000_0004
24 23
Figure 2-9. Memory Operand Addressing
Byte 0xFFFF_FFFD
Byte 0x0000_0001
Byte 0x0000_0005
MCF5272 User’s Manual
Longword 0xFFFF_FFFC
Longword 0x0000_0000
Longword 0x0000_0004
16 15
.
.
.
Byte 0xFFFF_FFFE
Byte 0x0000_0002
Byte 0x0000_0006
Word 0xFFFF_FFFE
Word 0x0000_0002
Word 0x0000_0006
8
7
Byte 0xFFFF_FFFF
Byte 0x0000_0003
Byte 0x0000_0007
MOTOROLA
0