ABSTRACT
A microprocessor (mP) is a semiconductor die containing the component‘s of a computer’s central processor, complete with instruction processing unit, arithmetic, interrupt electronics and basic communication
facilities. Such devices have been available since the early 1970s and have benefited from continuing
improvements in electronics. As microelectronics technology allowed feature sizes of components to decrease,
more powerful systems were put on single dies. Those developments have changed the functions of
microprocessors, markedly among commercial electronic components. Enhanced electronics capabilities led to
two major trends: an increase in circuit speed and a widening of the datapath. Data acquisition components,
memory blocks and output ports now are commonly added to a basic mP to build a complete microcontroller (mC) on a single chip. This allows the mC to be used for a wide range of applications, whose function is merely a matter of programming. Current clock speeds can be set in the low GHz for personal computer chips but are
usually found in the low MHz range for simple control applications. mP systems commonly have either 8, 16 or 32 bits, although original 4-bit and high-end 64-bit processors are available. mC systems form the heart of embedded devices performing specific control tasks in all applications. These devices are universal and highly
adaptable for control applications. One of the early mPs, the Intel 8080, still is widely used. Similarly, the Motorola 6800 and its family, the HC11 and related units, are widely used in dedicated control applications.
The original 4-bit mP, intended for calculators and containing a few thousand transistors, has been largely supplanted by 8-bit and 16-bit units, even when their increased capabilities are not utilized. This is due largely
to economies of scale and design simplifications. High-end mP chips can contain several billion transistors. The chips are built with CMOS technology, minimizing power consumption.
