80C186EB/80C188EB Microprocessor User's Manual - CEUNES

OVERVIEW OF THE 80C186 FAMILY ARCHITECTURE2.2.2.4 Data Types Used in the 80C186 Modular Core FamilyThe 80C186 Modular Core family supports the data types described in Table 2-12 and illustratedin Figure 2-23. In general, individual data elements must fit within defined segment limits.Table 2-12. Supported Data TypesTypeDescriptionIntegerA signed 8- or 16-bit binary numeric value (signed byte or word). All operations assumea 2’s complement representation.The 80C187 numerics processor extension, when added to an 80C186 Modular Coresystem, directly supports signed 32- and 64-bit integers (signed double-words andquad-words). The 80C188 Modular Core does not support the 80C187.OrdinalAn unsigned 8- or 16-bit binary numeric value (unsigned byte or word).BCD A byte (unpacked) representation of a single decimal digit (0-9).ASCIIA byte representation of alphanumeric and control characters using the ASCIIstandard.Packed BCD A byte (packed) representation of two decimal digits (0-9).One digit is stored in eachnibble (4 bits) of the byte.String A contiguous sequence of bytes or words. A string can contain from 1 byte to 64Kbytes.PointerA 16- or 32-bit quantity. A 16-bit pointer consists of a 16-bit offset component; a 32-bitpointer consists of the combination of a 16-bit base component (selector) plus a 16-bitoffset component.Floating Point A signed 32-, 64-, or 80-bit real number representation.The 80C187 numerics processor extension, when added to an 80C186 Modular Coresystem, directly supports floating point operands. The 80C188 Modular Core does notsupport the 80C187.2-37