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MCF5272 User’s Manual
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.
31
24 23
16 15
8
7
0
Longword 0x0000_0000
Word 0x0000_0000
Word 0x0000_0002
Byte 0x0000_0000
Byte 0x0000_0001
Byte 0x0000_0002
Byte 0x0000_0003
Longword 0x0000_0004
Word 0x0000_0004
Word 0x0000_0006
Byte 0x0000_0004
Byte 0x0000_0005
Byte 0x0000_0006
Byte 0x0000_0007
.
.
.
Longword 0xFFFF_FFFC
Word 0xFFFF_FFFC
Word 0xFFFF_FFFE
Byte 0xFFFF_FFFC
Byte 0xFFFF_FFFD
Byte 0xFFFF_FFFE
Byte 0xFFFF_FFFF
Figure 2-9. Memory Operand Addressing
Содержание DigitalDNA ColdFire MCF5272
Страница 1: ...MCF5272UM D Rev 0 02 2001 MCF5272 ColdFire Integrated Microprocessor User s Manual ...
Страница 38: ...xxxviii MCF5272 User s Manual TABLES Table Number Title Page Number ...
Страница 58: ...1 10 MCF5272 User s Manual MCF5272 Specific Features ...
Страница 90: ...2 42 MCF5272 User s Manual Exception Processing Overview ...
Страница 96: ...3 6 MCF5272 User s Manual MAC Instruction Execution Timings ...
Страница 158: ...5 46 MCF5272 User s Manual Motorola Recommended BDM Pinout ...
Страница 184: ...7 12 MCF5272 User s Manual Interrupt Controller Registers ...
Страница 338: ...13 44 MCF5272 User s Manual Application Examples ...
Страница 414: ...18 6 MCF5272 User s Manual PWM Programming Model ...
Страница 452: ...19 38 MCF5272 User s Manual Power Supply Pins ...
Страница 482: ...20 30 MCF5272 User s Manual Reset Operation ...
Страница 492: ...21 10 MCF5272 User s Manual Non IEEE 1149 1 Operation ...
Страница 548: ...INDEX Index 12 MCF5272 User s Manual ...