OVERVIEW OF THE 80C186 FAMILY ARCHITECTURE

2.2.2.4Data 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.

 

Table 2-12. Supported Data Types

 

 

Type

Description

 

 

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.

 

 

2-37

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Intel 80C188XL Data Types Used in the 80C186 Modular Core Family, Supported Data Types, Type Description, Bcd, Ascii