Configuration Basics
2-8
Am186™CC/CH/CU Microcontrollers User’s Manual
2.7
DATA TYPES
The Am186CC/CH/CU microcontrollers directly support the following data types:
■
Integer: A signed binary numeric value contained in an 8-bit byte or a 16-bit word. All
operations assume a two’s complement representation.
■
Ordinal: An unsigned binary numeric value contained in an 8-bit byte or a 16-bit word.
■
Double Word: A signed binary numeric value contained in two sequential 16-bit
addresses, or in a DX::AX register pair.
■
Quad Word: A signed binary numeric value contained in four sequential 16-bit
addresses.
■
BCD: An unpacked byte representation of the decimal digits 0–9.
■
ASCII: A byte representation of alphanumeric and control characters using the ASCII
standard of character representation.
■
Packed BCD: A packed byte representation of two decimal digits (0–9). Each nibble
(four bits) of the byte contains one digit.
■
Pointer: A 16-bit or 32-bit quantity, composed of a 16-bit offset component or a 16-bit
segment base component in addition to a 16-bit offset component.
■
String: A contiguous sequence of bytes or words. A string can contain from 1 byte up
to 64 Kbytes.
In general, individual data elements must fit within defined segment limits. Figure 2-5
graphically represents the data types supported by the Am186CC/CH/CU microcontrollers.
Table 2-4
Segment Register Selection Rules
Memory Reference
Needed
Segment Register
Used
Implicit Segment Selection Rule
Local Data
Data (DS)
All data references
Instructions
Code (CS)
Instructions (including immediate data)
Stack
Stack (SS)
All stack pushes and pops
Any memory references that use the BP register
External Data (Global)
Extra (ES)
All string instruction references that use the DI
register as an index
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...