< 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)