What are the interpretations of the theory of computer architecture?

It can interpret the theory of computer architecture at several levels of rising abstraction. At each level, the architecture will be represented by declaring the underlying computational model, the functional specification, and the actual implementation. Therefore, the interpretation covers three elements including the underlying computational model, the level of consideration, and the scope of interest, as displayed in the figure.

First, it can overview the underlying computational model. Several years in the past, the term ‘computer architecture’ was inherently interpreted as a von Neumann architecture.

Subsequently, when novel architectures that depend on a model of computation other than the von Neumann model have been introduced, these architectures were correctly labelled, for example, dataflow architecture, reduction architecture, etc.

There are generally three levels of interest (in increasing degree of abstraction) including

  • the micromachine level (in microprogrammed processors)
  • the processor level
  • the computer-system level

The phrase ‘architecture’ can be used at each level of consideration with two specific scopes of interest. In the functional specification of a computer, it can be dealing with its abstract architecture. In its implementation, it can be concerned with its concrete architecture.

The abstract architecture reverses the black-box view whereas the concrete architecture covers the representation of the internal structure and operation. The abstract architecture is also defined as an exo-architecture, an external or logical architecture, a black-box description, or in specific contexts as a programming model and behavioral description.

The abstract architecture is a black-box specification

  • either from the programmer’s point of view
  • from the hardware designer’s point of view.

In the first case, dealing with the programming model, in the second with the hardware model.

While the programming model is a black-box specification from the programmer’s point of view, the hardware model is viewed as a black-box description for a hardware designer.

Concrete architecture is designed by various authors as an endo-architecture, or frequently as an internal or physical architecture or a structural description. It determines how a computer is executed at a specific level of abstraction, whereby a specific computational model is taken for allowed. Concrete architecture can also be viewed from two various points of view: logic design or physical design.

The logic design is an abstraction of the physical design and anticipates it. Its specification needed −

  • the declaration of the logical components used, including registers, execution units, etc.

  • the specification of their interconnections

  • the specification of the sequence of data transfers, which are proposed by each of the declared functions.

The physical design depends on concrete circuit elements. The specification of a physical design covers −

  • the declaration of the circuit elements used, which also includes the specification of signals

  • the specification of their interconnections

  • the declaration of the initiated signal sequences.