Instruction Set

An instruction set, or instruction set architecture (ISA), is the part of the computer architecture related to programming, including the native data types, instructions, registers, addressing modes, memory architecture, interrupt and exception handling, and external I/O. An ISA includes a specification of the set of opcodes (machine language), and the native commands implemented by a particular processor.

Instruction set architecture is distinguished from the microarchitecture, which is the set of processor design techniques used to implement the instruction set. Computers with different microarchitectures can share a common instruction set. For example, the Intel Pentium and the AMD Athlon implement nearly identical versions of the x86 instruction set, but have radically different internal designs.

Some virtual machinesthat support bytecode for Smalltalk, the Java virtual machine, and Microsoft's Common Language Runtime virtual machine as their ISA implement it by translating the bytecode for commonly used code paths into native machine code, and executing less-frequently-used code paths by interpretation; Transmeta implemented the x86 instruction set atop VLIW processors in the same fashion.

Read more about Instruction Set:  Classification of Instruction Sets, Machine Language, Instruction Set Implementation

Famous quotes containing the words instruction and/or set:

    One year, I’d completely lost my bearings trying to follow potty training instruction from a psychiatric expert. I was stuck on step on, which stated without an atom of irony: “Before you begin, remove all stubbornness from the child.” . . . I knew it only could have been written by someone whose suit coat was still spotless at the end of the day, not someone who had any hands-on experience with an actual two-year-old.
    Mary Kay Blakely (20th century)

    Colleges, in like manner, have their indispensable office,—to teach elements. But they can only highly serve us, when they aim not to drill, but to create; when they gather from far every ray of various genius to their hospitable halls, and, by the concentrated fires, set the hearts of their youth on flame.
    Ralph Waldo Emerson (1803–1882)