ARITHMETIC PROCESSORS

General purpose microprocessors such as 8086,8088,80286,80386 etc.are not optimized to perform complex numerical calculations,CRT graphics manipulations or word processing.For these purposes specialized co processors have been developed.For example,the 8087 is a numeric data co processors operate in parallel with CPUs.

There are two ways to interface an arithmetic processor  to a CPU.In one approach it is treated as a peripheral device.such units are called peripheral processor.The CPU sends data and instructions for processing to such an unit and receives results from it.Examples of peripheral arithmetic processors are AMD 9511/12,Intel 8231 A,etc.In another approach the arithmetic processor is connected as an extension of the CPU.The instructions and registers of arithmetic processor are extension to those of the CPU.The instruction set of the CPU includes a special subset of opcodes reserved for arithmetic processor. Arithmetic processor of this type is called co processor. Unlike a peripheral processor,a co processor,and special instruction for co processor. Example of numeric data coprocessors Intel 8087,80287,80387 etc.