Description; Programming Interface - IBM AT 5170 Technical Reference

Description
The IBM Personal Computer AT Math Coprocessor enables the
IBM Personal Computer AT to perform high-speed arithmetic,
,,-........ logarithmic functions, and trigonometric operations.
The coprocessor works in parallel with the microprocessor. The
parallel operation decreases operating time by allowing the
coprocessor to do mathematical calculations while the
microprocessor continues to do other functions.
The coprocessor works with seven numeric data types, which are
divided into the following three classes:
• Binary integers (3 types)
• Decimal integers (1 type)
• Real numbers (3 types)
Programming Interface
The coprocessor offers extended data types, registers, and
instructions to the microprocessor.
The coprocessor has eight 80-bit registers, which provides the
equivalent capacity of forty 16-bit registers. This register space
allows constants and temporary results to be held
in
registers
during calculations, thus reducing memory access and improving
speed as well as bus availability. The register space can be used as
a stack or as a fixed register set. When used as a stack, only the
top two stack elements are operated on.
Coprocessor 2-3