Description and Comparison of Various Microprocessors That Can Process Long Words

The purpose of this essay is to provide an architectural overview and comparison of various microprocessors, featuring those having the capability of handling 32-bit words. This discussion includes 32-bit microprocessors and also some 16-bit microprocessors. The emphasis is on their commercial availability along with their suitability for general purpose usage. In addition, this essay provides some basis to choose among the various available microprocessors for a particular industrial task. Single-source micros are not included in this comparison because of the fact that industry does, not generally rely on single-source products. However, some single-source micros are described. The TMS99000, which is included in the comparison of 16-bit microprocessors, is an exception because Texas Instruments had vigorous plans to compete in the 16-bit arena at the time this essay was begun. However, Texas Instruments subsequently dropped the idea of competing and agreed to second-source the National Semiconductor\u27s 32000 series of micros instead. Almost all of the 32-bit micros are described in some detail except special-purpose and captive micros - for example, the VAX architectured VLSI micros, the NCR/ 32 and the Data General 32-bit microprocessor. This is the case not only because necessary information on these processors was unavailable prior to the completion of this essay, but also this essay focuses on general-purpose microprocessors for industrial use. The essay was updated in October 1985 to include the 32-bit microprocessors of those manufacture which dominate the 16-bit microprocessor market - companies such as Intel, Motorola, and Zilog. The essay is divided into four chapters. Chapter 1 contains a general introduction to the technology of microprocessors and discusses their features. In chapter 2, most of the 16-bit microprocessors are discussed and compared with emphasis on the iAPX 86, the iAPX 286, the MC68000, the Z8000, the TMS99000 and other 16-bit chips. Chapter 3 focuses on 32-bit microprocessors, and is divided into several sections: the general-purpose microprocessors targeted for commercial use, the general-purpose micros for in-house use, special-purpose micros, and an overall comparison of 32-bit micros. In chapter 3, an effort is made to do a comparison among the five general-purpose 32-bit microprocessors targeted towards the commercial market, and to update current microprocessor technology (October 1985). Chapter 4 is devoted to a comprehensive summary of all the considerations. It attempts to define common terms whenever they appear for the first time in the essay. It is appropriate to note that most of the information about the microprocessors is taken from their data books or from publications and articles on them