Microprocessors - General approach

The field of microprocessors is evolving very fast, and the intensity of competition often leads players to make statements in which rigor plays only a very small part. The information provided is as up-to-date as possible, and avoids the "smoke and mirrors" that some manufacturers and the trade press are quick to use.

Microprocessors are approached from the angle of their architecture and use, and not from the angle of the technology and industrial processes that make them possible. In particular, the relationship with software - operating systems and compilers - is addressed.

In this dossier, the term architecture refers to the repertoire of instructions usable by programmers (the interface between hardware and software) and the underlying hardware mechanisms enabling their implementation. It also refers to the implementation of an architecture: this term designates a particular realization of an architecture. The same architecture may have several implementations, for example, to meet different performance objectives; from the software point of view, these different implementations are compatible, enabling the same programs to be run.

Given the variety of microprocessors available, and rather than deal superficially with the whole subject, the analysis focuses, after a general presentation of each aspect, more specifically on high-end microprocessors.

Wherever possible, we use French words rather than English ones. However, when there is no widely accepted and sufficiently precise equivalent, the English term –, which is often the one under which the notion appeared –, is used. The first time a concept designated by an English term appears in the text, a definition is given. Symmetrically, when a notion, designated by a French term, appears for the first time, the equivalent English term is indicated.