Basic Computer Architecture
What is the difference between computer organization and computer architecture?
Computer organization deals more with the interface between software and hardware while computer architecture deals more with
higher level issues.
- Computer architecture is the design of a computer, including the instruction set, hardware components, and
machine organization.
- Instruction-set architecture (ISA) versus hardware system architecture (HSA):
- ISA
The design of instruction set, ISA determines the semantic characteristics of
the instruction set of a computer.
HSA
The subsystems and their interconnections, including CPU, storage and I/O systems
that implement the semantics.
Machine Organization
The structure of the data path that implements the ISA using the
implementation technology of the HSA
A further distinction between computer architecture and computer design could be made with the hardware attributes aligning with design and instruction set, formatting, and memory addressing techniques aligning with architecture. The defining line between the two is muddled as ISA and HSA each can be used to replace portions of the other.
Basic features of a John Von Neumann style computer:
- has three basic hardware subsystems: a CPU, a main-memory system and an I/O system;
- is a stored-program computer;
- carries out instructions sequentially.
The following are the main components of a typical von Neumann style
computer:
- CPU which consists of
- a control unit (CU),
- an arithmetic and logic unit (ALU), and
- a set of registers including a program counter (PC), which hold various values during the computer's operation.
- Memory
- I/O subsystem
Begin work on Program 0 (P0) "Fetch".
