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2.2.2.4
Data Types Used in the 80C186 Modular Core Family
The 80C186 Modular Core family supports the data types described in Table 2-12 and illustrated
in Figure 2-23. In general, individual data elements must fit within defined segment limits.
Type
Integer
A signed 8- or 16-bit binary numeric value (signed byte or word). All operations assume
a 2's complement representation.
The 80C187 numerics processor extension, when added to an 80C186 Modular Core
system, directly supports signed 32- and 64-bit integers (signed double-words and
quad-words). The 80C188 Modular Core does not support the 80C187.
Ordinal
An unsigned 8- or 16-bit binary numeric value (unsigned byte or word).
BCD
A byte (unpacked) representation of a single decimal digit (0-9).
ASCII
A byte representation of alphanumeric and control characters using the ASCII
standard.
Packed BCD
A byte (packed) representation of two decimal digits (0-9).One digit is stored in each
nibble (4 bits) of the byte.
String
A contiguous sequence of bytes or words. A string can contain from 1 byte to 64
Kbytes.
Pointer
A 16- or 32-bit quantity. A 16-bit pointer consists of a 16-bit offset component; a 32-bit
pointer consists of the combination of a 16-bit base component (selector) plus a 16-bit
offset component.
Floating Point
A signed 32-, 64-, or 80-bit real number representation.
The 80C187 numerics processor extension, when added to an 80C186 Modular Core
system, directly supports floating point operands. The 80C188 Modular Core does not
support the 80C187.
OVERVIEW OF THE 80C186 FAMILY ARCHITECTURE
Table 2-12. Supported Data Types
Description
2-37
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