Configuration Basics
Am186™CC/CH/CU Microcontrollers User’s Manual
2-9
Figure 2-5
Supported Data Types
2.8
ADDRESSING MODES
The Am186CC/CH/CU microcontrollers use eight categories of addressing modes to
specify operands: two addressing modes for instructions that operate on register or
immediate operands, and six modes that specify the location of an operand in a memory
segment.
2.8.1
Register and Immediate Operands
■
Register Operand Mode: The operand is in one of the 8-bit or 16-bit registers.
■
Immediate Operand Mode: The operand is constant data included in the instruction.
2.8.2
Memory Operands
A memory-operand address consists of two 16-bit components: a segment value and an
offset. The segment value is supplied by a 16-bit segment register either implicitly chosen
by the addressing mode or explicitly chosen by a segment override prefix. The offset, also
called the
effective address, is calculated by summing any combination of the following
three address elements:
■
Displacement: An 8-bit or 16-bit immediate value contained in the instruction.
■
Base: The contents of either the BX or BP base register.
■
Index: The contents of either the SI or DI index register.
Any carry from the 16-bit addition is ignored. Eight-bit displacements are sign-extended to
16-bit values.
7 0
Signed
Byte
Magnitude
Magnitude
7 0
MSB
Unsigned
Byte
Signed
Word
Magnitude
MSB
+1
0
Magnitude
MSB
+3
+2
+1
0
Signed
Quad
Word
Magnitude
MSB
63 48 47 32 31 16 15 0
Unsigned
Word
Magnitude
MSB
+1
0
7 0
7 0
7 0
+N
+1
0
. . .
7 0
7 0
7 0
+N
+1
0
. . .
7 0
7 0
7 0
+N
+1
0
. . .
Binary
Coded
Decimal
(BCD)
BCD
Digit N
BCD
Digit 1
BCD
Digit 0
ASCII
Character
N
ASCII
Character
1
ASCII
Character
0
ASCII
Most Significant
Digit
Least
Significant Digit
Packed
BCD
7 0 7 0
+N
+1
0
. . .
Byte/WordN
Byte/Word1 Byte/Word0
String
+3
+2
+1
0
Segment Base
Offset
Pointer
31 1615 0
0
15
+3
+2
+1
+6
+5
+4
+0
+7
15 14
8 7
0
7
0
Signed
Double
Word
Sign Bit
Sign Bit
Sign Bit
Sign Bit
Содержание Am186 CC
Страница 1: ...Am186 CC CH CU Microcontrollers User s Manual Order 21914B...
Страница 4: ...iv Am186 CC CH CU Microcontrollers User s Manual...
Страница 18: ...Table of Contents xviii Am186 CC CH CU Microcontrollers User s Manual...
Страница 24: ...Introduction xxiv Am186 CC CH CU Microcontrollers User s Manual...
Страница 39: ...Architectural Overview Am186 CC CH CU Microcontrollers User s Manual 1 15 Figure 1 6 32 Channel Linecard CH CC...
Страница 40: ...Architectural Overview 1 16 Am186 CC CH CU Microcontrollers User s Manual...
Страница 86: ...System Overview 3 36 Am186 CC CH CU Microcontrollers User s Manual...
Страница 92: ...Emulator Support 4 6 Am186 CC CH CU Microcontrollers User s Manual...
Страница 112: ...DRAM Controller 6 8 Am186 CC CH CU Microcontrollers User s Manual...
Страница 134: ...Interrupts 7 22 Am186 CC CH CU Microcontrollers User s Manual...
Страница 186: ...Programmable I O Signals 9 8 Am186 CC CH CU Microcontrollers User s Manual...
Страница 200: ...Watchdog Timer 11 6 Am186 CC CH CU Microcontrollers User s Manual...
Страница 232: ...Asynchronous Serial Ports UARTs 13 24 Am186 CC CH CU Microcontrollers User s Manual...
Страница 242: ...Synchronous Serial Port SSI 14 10 Am186 CC CH CU Microcontrollers User s Manual...
Страница 264: ...High Level Data Link Control HDLC 15 22 Am186 CC CH CU Microcontrollers User s Manual...
Страница 332: ...Universal Serial Bus USB 18 34 Am186 CC CH CU Microcontrollers User s Manual...
Страница 348: ...Register Summary A 16 Am186 CC CH CU Microcontrollers User s Manual...
Страница 376: ...Index Index 18 Am186 CC CH CU Microcontrollers User s Manual...