Microarchitecture - Relation To Instruction Set Architecture

Relation To Instruction Set Architecture

The ISA is roughly the same as the programming model of a processor as seen by an assembly language programmer or compiler writer. The ISA includes the execution model, processor registers, address and data formats among other things. The microarchitecture includes the constituent parts of the processor and how these interconnect and interoperate to implement the ISA.

The microarchitecture of a machine is usually represented as (more or less detailed) diagrams that describe the interconnections of the various microarchitectural elements of the machine, which may be everything from single gates and registers, to complete arithmetic logic units (ALUs) and even larger elements. These diagrams generally separate the datapath (where data is placed) and the control path (which can be said to steer the data).

Each microarchitectural element is in turn represented by a schematic describing the interconnections of logic gates used to implement it. Each logic gate is in turn represented by a circuit diagram describing the connections of the transistors used to implement it in some particular logic family. Machines with different microarchitectures may have the same instruction set architecture, and thus be capable of executing the same programs. New microarchitectures and/or circuitry solutions, along with advances in semiconductor manufacturing, are what allows newer generations of processors to achieve higher performance while using the same ISA.

In principle, a single microarchitecture could execute several different ISAs with only minor changes to the microcode.

Read more about this topic:  Microarchitecture

Famous quotes containing the words relation to, relation, instruction, set and/or architecture:

    It would be disingenuous, however, not to point out that some things are considered as morally certain, that is, as having sufficient certainty for application to ordinary life, even though they may be uncertain in relation to the absolute power of God.
    René Descartes (1596–1650)

    Much poetry seems to be aware of its situation in time and of its relation to the metronome, the clock, and the calendar. ... The season or month is there to be felt; the day is there to be seized. Poems beginning “When” are much more numerous than those beginning “Where” of “If.” As the meter is running, the recurrent message tapped out by the passing of measured time is mortality.
    William Harmon (b. 1938)

    Much of the pressure contemporary parents feel with respect to dressing children in designer clothes, teaching young children academics, and giving them instruction in sports derives directly from our need to use our children to impress others with our economic surplus. We find “good” rather than real reasons for letting our children go along with the crowd.
    David Elkind (20th century)

    There is no intrinsic worth in money but what is alterable with the times, and whether a guinea goes for twenty pounds or for a shilling, it is ... the labour of the poor and not the high and low value that is set on gold or silver, which all the comforts of life must arise from.
    Bernard Mandeville (1670–1733)

    All architecture is great architecture after sunset; perhaps architecture is really a nocturnal art, like the art of fireworks.
    Gilbert Keith Chesterton (1874–1936)