Intel 80C188XL, 80C186XL user manual Chapter Math Coprocessing, Overview Of Math Coprocessing

Models: 80C186XL 80C188XL

1 405
Download 405 pages 42.62 Kb
Page 286
Image 286
CHAPTER 11

CHAPTER 11

MATH COPROCESSING

The 80C186 Modular Core Family meets the need for a general-purpose embedded microproces- sor. In most data control applications, efficient data movement and control instructions are fore- most and arithmetic performed on the data is simple. However, some applications do require more powerful arithmetic instructions and more complex data types than those provided by the 80C186 Modular Core.

11.1 OVERVIEW OF MATH COPROCESSING

Applications needing advanced mathematics capabilities have the following characteristics.

Numeric data values are non-integral or vary over a wide range

Algorithms produce very large or very small intermediate results

Computations must be precise (i.e., calculations must retain several significant digits)

Computations must be reliable without dependence on programmed algorithms

Overall math performance exceeds that afforded by a general-purpose processor and software alone

For the 80C186 Modular Core family, the 80C187 math coprocessor satisfies the need for pow- erful mathematics. The 80C187 can increase the math performance of the microprocessor system by 50 to 100 times.

11.2 AVAILABILITY OF MATH COPROCESSING

The 80C186 Modular Core supports the 80C187 with a hardware interface under microcode con- trol. However, not all proliferations support the 80C187. Some package types have insufficient leads to support the required external handshaking requirements. The 3-volt versions of the pro- cessor do not specify math coprocessing because the 80C187 has only a 5-volt rating. Please refer to the current data sheets for details.

To execute numerics instructions, the 80C186XL must exit reset in Enhanced Mode. The pro- cessor checks its TEST pin at reset and automatically enters Enhanced Mode if the math copro- cessor is present.

11-1

Page 286
Image 286
Intel 80C188XL, 80C186XL Chapter Math Coprocessing, Overview Of Math Coprocessing, Availability Of Math Coprocessing