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14.3.2 80C187 Data Types
The microprocessor/math coprocessor combination supports seven data types:
•
Word Integer — A signed 16-bit numeric value. All operations assume a 2's complement
representation.
•
Short Integer — A signed 32-bit numeric value (double word). All operations assume a 2's
complement representation.
•
Long Integer — A signed 64-bit numeric value (quad word). All operations assume a 2's
complement representation.
•
Packed Decimal — A signed numeric value contained in an 80-bit BCD format.
•
Short Real — A signed 32-bit floating point numeric value.
•
Long Real — A signed 64-bit floating point numeric value.
•
Temporary Real — A signed 80-bit floating point numeric value. Temporary real is the
native 80C187 format.
Figure 14-1 graphically represents these data types.
14.4 MICROPROCESSOR AND COPROCESSOR OPERATION
The 80C187 interfaces directly to the microprocessor (as shown in Figure 14-2) and operates as
an I/O-mapped slave peripheral device. Hardware handshaking requires connections between the
80C187 and four special pins on the processor: NCS, BUSY, PEREQ and ERROR.
MATH COPROCESSING
14-7
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