(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 superscalarfunctional 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)
