instruction set architecture
<architecture> (ISA) The parts of a {processor}'s design that
need to be understood in order to write {assembly language},
such as the {machine language} instructions and {registers}.
Parts of the architecture that are left to the implementation,
such as number of {superscalar} {functional units}, {cache}
size and {cycle} speed, are not part of the ISA.
The definition of {SPARC}, for example, carefully
distinguishes between an implementation and a specification.
(1999-01-16)